Clearway Energy (CWEN.A) 10-K/A 1 May 18 2017 FY Annual report (amended) Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Jan. 31, 2018	Jun. 30, 2016
Class of Stock [Line Items]
Entity Registrant Name	NRG Yield LLC
Entity Central Index Key	1,637,757
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Document Fiscal Year Focus	2,017
Entity Public Float			$ 0
Document Fiscal Period Focus	FY
Common Class A [Member]
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		34,586,250
Common Class B [Member]
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		42,738,750
Common Class C [Member]
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		64,730,519
Common Class D [Member]
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		42,738,750

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015
Operating Revenues
Total operating revenues	$ 231	$ 269	$ 288	$ 221	$ 235	$ 276	$ 287	$ 237	$ 1,009	$ 1,035	[1]	$ 968	[1]
Operating Costs and Expenses [Abstract]
Cost of operations									326	308	[1]	323	[1]
Depreciation and amortization									334	303	[1]	303	[1]
Impairment losses									44	185	[1],[2]	1	[1],[2]
General and administrative									19	14	[1]	10	[1]
Acquisition-related transaction and integration costs									3	1	[1]	3	[1]
Total operating costs and expenses									726	811	[1]	640	[1]
Operating Income	19	85	124	55	(100)	120	130	74	283	224	[1]	328	[1]
Costs and Expenses [Abstract]
Equity in earnings of unconsolidated affiliates									71	60	[1],[2]	31	[1],[2]
Other income, net									4	3	[1]	3	[1]
Loss on debt extinguishment									(3)	0	[1],[2]	(9)	[1],[2]
Interest expense									(293)	(272)	[1]	(258)	[1]
Total other income (expense), net									(221)	(209)	[1]	(233)	[1]
Net Income	$ (38)	$ 41	$ 59	$ 0	$ (138)	$ 68	$ 80	$ 5	62	15	[1],[3],[4]	95	[1],[3],[4]
Net (Loss) Income Attributable to Noncontrolling Interest									(75)	(111)	[1]	(62)	[1]
Net Income Attributable to NRG Yield LLC									137	126	[1]	157	[1]
Noncontrolling Interest [Member]
Costs and Expenses [Abstract]
Net Income									$ (75)	$ (111)	[4]	$ (62)	[4]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	[2]	Dec. 31, 2015	[2]
Statement of Comprehensive Income [Abstract]
Net Income (Loss)	$ (38)	$ 41	$ 59	$ 0	$ (138)	$ 68	$ 80	$ 5	$ 62	$ 15	[1],[3]	$ 95	[1],[3]
Other Comprehensive Loss, net of tax
Unrealized (loss) gain on derivatives									17	13		(17)
Other comprehensive (loss) income									17	13		(17)
Comprehensive Income									79	28		78
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest									75	111		63
Comprehensive Income Attributable to NRG Yield LLC									$ 154	$ 139		$ 141
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Current Assets
Cash and cash equivalents	$ 146	$ 321	[1]
Restricted cash	168	176	[1]
Accounts receivable — trade	96	96	[1]
Inventory	39	39	[1]
Notes receivable	13	16	[1]
Prepayments and other current assets	19	22	[1]
Total current assets	481	670	[1]
Property, plant and equipment
Property, Plant and Equipment, Net	5,204	5,554	[1]
Other Assets
Equity investments in affiliates	1,178	1,152	[1]
Intangible assets, net	1,228	1,303	[1]
Other non-current assets	63	67	[1]
Total other assets	2,469	2,522	[1]
Total Assets	8,154	8,746	[1]
Current Liabilities
Current portion of long-term debt — external	306	323	[1]
Accounts payable — trade	27	23	[1]
Accounts payable — affiliate	48	40	[1]
Derivative instruments	17	33	[1]
Accrued expenses and other current liabilities	87	85	[1]
Total current liabilities	485	504	[1]
Other Liabilities
Long-term debt — external	4,921	5,128	[1]
Long-term debt — affiliate	618	618	[1]
Due to Related Parties, Noncurrent	0	9	[1]
Derivative instruments	31	46	[1]
Other non-current liabilities	91	77
Total non-current liabilities	5,661	5,878	[1]
Total Liabilities	6,146	6,382	[1]
Members' Equity
Contributed capital	1,897	2,179	[1]
Retained earnings	17	44	[1]
Accumulated other comprehensive loss	(68)	(85)	[1]
Members' Equity Attributable to Noncontrolling Interest	162	226	[1]
Total Members' Equity	2,008	2,364	[1]
Total Liabilities and Members’ Equity	$ 8,154	$ 8,746	[1]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Intangible assets, accumulated amortization	$ 237	$ 168

Consolidated Statements Of Cas

Consolidated Statements Of Cash Flows $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)		Dec. 31, 2015USD ($)
Cash Flows from Operating Activities
Net Income (Loss)	$ 62	$ 15	[1],[2],[3]	$ 95	[1],[2],[3]
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Equity in earnings of unconsolidated affiliates	(71)	(60)	[1],[4]	(31)	[1],[4]
Distributions from unconsolidated affiliates	72	58	[4]	60	[4]
Depreciation and amortization	334	303	[4]	303	[4]
Amortization of financing costs	13	8	[4]	7	[4]
Amortization of intangibles and out-of-market contracts	70	76	[4]	55	[4]
Loss on debt extinguishment	3	0	[1],[4]	9	[1],[4]
Impairment losses	44	185	[1],[4]	1	[1],[4]
Changes in derivative instruments	(16)	(15)	[4]	(44)	[4]
Loss on disposal of asset components	16	6	[4]	3	[4]
Changes in prepaid and accrued capacity payments	(4)	(8)	[4]	(12)	[4]
Changes in other working capital	(7)	9	[4]	(22)	[4]
Net Cash Provided by Operating Activities	516	577	[4]	424	[4]
Cash Flows from Investing Activities
Acquisition of businesses, net of cash acquired	0	0	[4]	37	[4]
Acquisition of Drop Down Assets, net of cash acquired	250	77	[4]	698	[4]
Capital expenditures	(31)	(20)	[4]	(29)	[4]
Cash receipts from notes receivable	17	17	[4]	17	[4]
Return of investment from unconsolidated affiliates	47	28	[4]	42	[4]
Investments in unconsolidated affiliates	(73)	(83)	[4]	(402)	[4]
Other	7	4	[4]	9	[4]
Net Cash Used in Investing Activities	(283)	(131)	[4]	(1,098)	[4]
Cash Flows from Financing Activities
Net contributions from noncontrolling interests	13	5	[4]	122	[4]
Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets	(20)	(184)	[4]	(79)	[4]
Proceeds from the issuance of class C units	33	0	[4]	599	[4]
Payments of distributions	(202)	(173)	[4]	(139)	[4]
Proceeds from the revolving credit facility	55	60	[4]	551	[4]
Payments for the revolving credit facility	0	366	[4]	245	[4]
Proceeds from issuance of long-term debt — external	41	740	[4]	6	[4]
Proceeds from issuance of long-term debt — affiliate	0	0	[4]	281	[4]
Payments of debt issuance costs	(4)	(15)	[4]	(7)	[4]
Payments for long-term debt — external	(332)	(269)	[4]	(735)	[4]
Net Cash (Used in) Provided by Financing Activities	(416)	(202)	[4]	354	[4]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	(183)	244		(320)
Cash and Cash Equivalents at End of Period	146	321	[5]	110
Interest paid, net of amount capitalized	(297)	(271)	[4]	(279)	[4]
Additions to fixed assets for accrued capital expenditures	4	3	[4]	3	[4]
Non-cash return of capital and distributions to NRG, net of contributions	(2)	65	[4]	(9)	[4]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	314	497	[4]	253	[4]
Additional Paid-in Capital [Member]
Cash Flows from Operating Activities
Net Income (Loss)	0	0	[3]	0	[3]
Cash Flows from Investing Activities
Acquisition of Drop Down Assets, net of cash acquired	250	77
Cash Flows from Financing Activities
Net contributions from noncontrolling interests	0	0		0
Proceeds from the issuance of class C units	34			599
Noncontrolling Interest [Member]
Cash Flows from Operating Activities
Net Income (Loss)	(75)	(111)	[3]	(62)	[3]
Cash Flows from Investing Activities
Acquisition of Drop Down Assets, net of cash acquired	0	0
Cash Flows from Financing Activities
Net contributions from noncontrolling interests		$ 5		122
Proceeds from the issuance of class C units	$ 0			$ 0
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[5]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Consolidated Statements of Memb

Consolidated Statements of Members' Equity Statement - USD ($) $ in Millions		Total		Retained Earnings, Unappropriated [Member]	AOCI Attributable to Parent [Member]	Noncontrolling Interest [Member]	Additional Paid-in Capital [Member]	NRG [Member]		NRG [Member]Retained Earnings, Unappropriated [Member]		NRG [Member]AOCI Attributable to Parent [Member]		NRG [Member]Noncontrolling Interest [Member]		NRG [Member]Additional Paid-in Capital [Member]		NRG Yield, Inc. [Member]	NRG Yield, Inc. [Member]Retained Earnings, Unappropriated [Member]	NRG Yield, Inc. [Member]AOCI Attributable to Parent [Member]	NRG Yield, Inc. [Member]Noncontrolling Interest [Member]	NRG Yield, Inc. [Member]Additional Paid-in Capital [Member]	NRG Yield, Inc. [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest | Scenario, Previously Reported [Member]	[1]	$ 2,695		$ 133	$ (80)	$ 334	$ 2,308
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		2,757		124	(82)	199	2,516
Net Assets Acquired, Drop Down Assets		62		(9)	(2)	(135)	208
Net Income (Loss) | Scenario, Previously Reported [Member]	[2]	93
Net Income (Loss)	[5]	95	[3],[4]	157	0	(62)	0
Unrealized Gain (Loss) on Derivatives		(17)		0	(16)	(1)	0
Gross Payment to Acquire Business under Common Control		(698)		0	0	0	(698)
Acquisition of Drop Down Assets, net of cash acquired	[6]	(698)
Non-cash return of capital and distributions to NRG, net of contributions		(9)	[6]					$ 9	[5]	$ (6)	[5]	$ 0	[5]	$ 0	[5]	$ 15	[5]
Noncontrolling Interest, Increase from Business Combination		74		0	0	74	0
Proceeds from the issuance of class C units		599	[6]	0	0	0	599
Payment of capital distributions and returns of capital, net of capital contributions	[5]							(79)		(41)		0		0		(38)
Net contributions from noncontrolling interests		122	[6]	0	0	122	0
Proceeds from Noncontrolling Interests		122
Payments of Ordinary Dividends, Common Stock								(70)		(70)		0		0		0		$ (69)	$ (69)	$ 0	$ 0	$ 0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		2,705		107	(98)	332	2,364
Net Income (Loss) | Scenario, Previously Reported [Member]	[2]	15
Net Income (Loss)	[5]	15	[3],[4]	126	0	(111)	0
Unrealized Gain (Loss) on Derivatives		13		0	13	0	0
Acquisition of Drop Down Assets, net of cash acquired		(77)	[6]	0	0	0	(77)
Non-cash return of capital and distributions to NRG, net of contributions		65	[6]					65	[5]	(9)	[5]	0	[5]	0	[5]	74	[5]	5	5	0	0	0
Proceeds from the issuance of class C units	[6]	0
Payment of capital distributions and returns of capital, net of capital contributions	[5]							(184)		(2)		0		0		(182)
Net contributions from noncontrolling interests		5	[6]	0	0	5	0
Proceeds from Noncontrolling Interests		5
Payments of Ordinary Dividends, Common Stock								(81)		(81)		0		0		0		(92)	(92)	0	0	0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest | Scenario, Previously Reported [Member]	[7]	2,304
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		2,364		44	(85)	226	2,179
Net Income (Loss)		62		137	0	(75)	0
Unrealized Gain (Loss) on Derivatives		17		0	17	0	0
Acquisition of Drop Down Assets, net of cash acquired		(250)		0	0	0	(250)
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability		(8)		0	0	0	8
Non-cash return of capital and distributions to NRG, net of contributions		(2)						(2)		(6)		0		0		(8)
Proceeds from the issuance of class C units		33		0	0	0	34																$ 34
Payment of capital distributions and returns of capital, net of capital contributions								(18)		0		0		0		(18)
Net contributions from noncontrolling interests		13		0	0		0
Proceeds from Noncontrolling Interests		11				11
Payments of Ordinary Dividends, Common Stock								$ (94)		$ (88)		$ 0		$ 0		$ 6		$ (108)	$ (82)	$ 0	$ 0	$ 26
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest		$ 2,008		$ 17	$ (68)	$ 162	$ 1,897
[1]	(a) As previously reported in the Company's consolidated financial statements for the year ended December 31, 2016, included in the Company's May 9, 2017 Form 8-K.
[2]	(a) As previously reported in the May 9, 2017 Form 8-K filed in connection with the March 2017 Drop Down completed on March 27, 2017
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[5]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[6]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[7]	(a) As previously reported in the May 9, 2017 Form 8-K filed in connection with the March 2017 Drop Down completed on March 27, 2017.

Nature of Business

Nature of Business	12 Months Ended
	Dec. 31, 2017
Nature of Business Disclosure [Abstract]
Business Description and Basis of Presentation [Text Block]	NRG Yield LLC, together with its consolidated subsidiaries, or the Company, is the primary vehicle through which NRG owns, operates and acquires contracted renewable and conventional generation and thermal infrastructure assets. NRG owns 100% of the Company's Class B units and Class D units and receives distributions through its ownership of these units. NRG Yield, Inc., or Yield, Inc., owns 100% of the Company's Class A units and Class C units. NRG Yield LLC, through its wholly owned subsidiary, NRG Yield Operating LLC, or Yield Operating LLC, holds a portfolio of renewable and conventional generation and thermal infrastructure assets, primarily located in the Northeast, Southwest, Midwest and California regions of the U.S. Yield, Inc. closed its initial public offering of Class A common stock in July 2013, which was then followed by a Class A common stock offering in July 2014, a Recapitalization in May 2015, as described below, and a Class C common stock offering in June 2015. Effective May 14, 2015, Yield, Inc. amended its certificate of incorporation to create two new classes of capital stock, Class C common stock and Class D common stock, and distributed shares of the Class C common stock and Class D common stock to holders of Yield, Inc.'s outstanding Class A common stock and Class B common stock, respectively, through a stock split. The stock split is referred to as the Recapitalization. The Company also amended its operating agreement to reflect the Recapitalization. Effective May 14, 2015, each Class A unit of the Company was automatically reclassified into one Class A unit and one Class C unit and each Class B unit of the Company was automatically reclassified into one Class B unit and one Class D unit. The following table represents the structure of the Company as of December 31, 2017 : On July 12, 2017, NRG announced that it had adopted and initiated a three-year, three-part improvement plan, or the NRG Transformation Plan. As part of the NRG Transformation Plan, NRG announced that it is exploring strategic alternatives for its renewables platform and its interest in the Company. NRG, through its holdings of Class B common stock and Class D common stock, has a 55.1% voting interest in the Company and receives distributions from NRG Yield LLC through its ownership of Class B units and Class D units. On February 6, 2018, Global Infrastructure Partners, or GIP, entered into a purchase and sale agreement with NRG, or the NRG Transaction, for the acquisition of NRG's full ownership interests in the Company and NRG's renewable development and operations platform. The NRG Transaction is subject to certain closing conditions, including customary legal and regulatory approvals. The Company expects the NRG Transaction to close in the second half of 2018. NRG is the Company's controlling stockholder and the Company has been highly dependent on NRG for, among other things, growth opportunities and management and administration services. See Part I, Item 1A, Risk Factors for risks related to the Strategic Sponsorship with GIP and the Company's relationship with NRG. As of December 31, 2017 , the Company's operating assets are comprised of the following projects: Projects Percentage Ownership Net Capacity (MW) (a) Offtake Counterparty Expiration Conventional El Segundo 100 % 550 Southern California Edison 2023 GenConn Devon 50 % 95 Connecticut Light & Power 2040 GenConn Middletown 50 % 95 Connecticut Light & Power 2041 Marsh Landing 100 % 720 Pacific Gas and Electric 2023 Walnut Creek 100 % 485 Southern California Edison 2023 1,945 Utility Scale Solar Agua Caliente 16 % 46 Pacific Gas and Electric 2039 Alpine 100 % 66 Pacific Gas and Electric 2033 Avenal 50 % 23 Pacific Gas and Electric 2031 Avra Valley 100 % 26 Tucson Electric Power 2032 Blythe 100 % 21 Southern California Edison 2029 Borrego 100 % 26 San Diego Gas and Electric 2038 CVSR 100 % 250 Pacific Gas and Electric 2038 Desert Sunlight 250 25 % 63 Southern California Edison 2034 Desert Sunlight 300 25 % 75 Pacific Gas and Electric 2039 Kansas South 100 % 20 Pacific Gas and Electric 2033 Roadrunner 100 % 20 El Paso Electric 2031 TA High Desert 100 % 20 Southern California Edison 2033 Utah Solar Portfolio (b)(e) 50 % 265 PacifiCorp 2036 921 Distributed Solar Apple I LLC Projects 100 % 9 Various 2032 AZ DG Solar Projects 100 % 5 Various 2025-2033 SPP Projects 100 % 25 Various 2026-2037 Other DG Projects 100 % 13 Various 2023-2039 52 Wind Alta I 100 % 150 Southern California Edison 2035 Alta II 100 % 150 Southern California Edison 2035 Alta III 100 % 150 Southern California Edison 2035 Alta IV 100 % 102 Southern California Edison 2035 Alta V 100 % 168 Southern California Edison 2035 Alta X (b) 100 % 137 Southern California Edison 2038 Alta XI (b) 100 % 90 Southern California Edison 2038 Buffalo Bear 100 % 19 Western Farmers Electric Co-operative 2033 Projects Percentage Ownership Net Capacity (MW) (a) Offtake Counterparty Expiration Crosswinds (b)(f) 99 % 21 Corn Belt Power Cooperative 2027 Elbow Creek (b)(f) 100 % 122 NRG Power Marketing LLC 2022 Elkhorn Ridge (b)(f) 66.7 % 54 Nebraska Public Power District 2029 Forward (b)(f) 100 % 29 Constellation NewEnergy, Inc. 2022 Goat Wind (b)(f) 100 % 150 Dow Pipeline Company 2025 Hardin (b)(f) 99 % 15 Interstate Power and Light Company 2027 Laredo Ridge 100 % 80 Nebraska Public Power District 2031 Lookout (b)(f) 100 % 38 Southern Maryland Electric Cooperative 2030 Odin (b)(f) 99.9 % 20 Missouri River Energy Services 2028 Pinnacle 100 % 55 Maryland Department of General Services and University System of Maryland 2031 San Juan Mesa (b)(f) 75 % 90 Southwestern Public Service Company 2025 Sleeping Bear (b)(f) 100 % 95 Public Service Company of Oklahoma 2032 South Trent 100 % 101 AEP Energy Partners 2029 Spanish Fork (b)(f) 100 % 19 PacifiCorp 2028 Spring Canyon II (b) 90.1 % 29 Platte River Power Authority 2039 Spring Canyon III (b) 90.1 % 25 Platte River Power Authority 2039 Taloga 100 % 130 Oklahoma Gas & Electric 2031 Wildorado (b)(f) 100 % 161 Southwestern Public Service Company 2027 2,200 Thermal NRG Energy Center Dover LLC 100 % 103 NRG Power Marketing LLC 2018 Thermal generation 100 % 20 Various Various 123 Total net generation capacity (c) 5,241 Thermal equivalent MWt (d) 100 % 1,319 Various Various (a) Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of December 31, 2017 . (b) Projects are part of tax equity arrangements. (c) The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247 . (d) For thermal energy, net capacity represents MWt for steam or chilled water and excludes 134 MWt available under the right-to-use provisions contained in agreements between two of the Company's thermal facilities and certain of its customers. (e) Represents interests in Four Brothers Solar, LLC, Granite Mountain Holdings, LLC, and Iron Springs Holdings, LLC, all acquired as part of the March 2017 Drop Down Assets acquisition (ownership percentage is based upon cash to be distributed). (f) Projects are part of NRG Wind TE Holdco portfolio. In addition to the facilities owned or leased in the table above, the Company entered into partnerships to own or purchase solar power generation projects, as well as other ancillary related assets from a related party via intermediate funds. The Company does not consolidate these partnerships and accounts for them as equity method investments. The Company's net interest in these projects is 247 MW based on cash to be distributed as of December 31, 2017 . For further discussions, refer to Note 5 , Investments Accounted for by the Equity Method and Variable Interest Entities to the Consolidated Financial Statements. Substantially all of the Company's generation assets are under long-term contractual arrangements for the output or capacity from these assets. The thermal assets are comprised of district energy systems and combined heat and power plants that produce steam, hot water and/or chilled water and, in some instances, electricity at a central plant. Certain district energy systems are subject to rate regulation by state public utility commissions (although they may negotiate certain rates) while the other district energy systems have rates determined by negotiated bilateral contracts. As described in Note 13 , Related Party Transactions to the Consolidated Financial Statements, the Company has a management services agreement with NRG for various services, including human resources, accounting, tax, legal, information systems, treasury, and risk management. During the years ending December 31, 2017 and 2016 the Company completed four acquisitions of Drop Down Assets from NRG. The accounting guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect from the beginning of the financial statement period or from the date the entities were under common control (if later than the beginning of the financial statement period). For further discussion, see Note 3 , Business Acquisitions to the Consolidated Financial Statements.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation and Principles of Consolidation The Company's consolidated financial statements have been prepared in accordance with GAAP. The ASC is the source of authoritative GAAP to be applied by nongovernmental entities. In addition, the rules and interpretative releases of the SEC under authority of federal securities laws are also sources of authoritative GAAP for SEC registrants. The consolidated financial statements include the Company's accounts and operations and those of its subsidiaries in which it has a controlling interest. All significant intercompany transactions and balances have been eliminated in consolidation. The usual condition for a controlling financial interest is ownership of a majority of the voting interests of an entity. However, a controlling financial interest may also exist through arrangements that do not involve controlling voting interests. As such, the Company applies the guidance of ASC 810, Consolidations, or ASC 810, to determine when an entity that is insufficiently capitalized or not controlled through its voting interests, referred to as a variable interest entity, or VIE, should be consolidated. Cash and Cash Equivalents Cash and cash equivalents include highly liquid investments with an original maturity of three months or less at the time of purchase. Cash and cash equivalents held at project subsidiaries was $124 million and $111 million as of December 31, 2017 and 2016 , respectively. Restricted Cash The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the consolidated balance sheets that sum to the total of the same such amounts shown in the statements of cash flows. Year Ended December 31, 2017 2016 2015 (In millions) Cash and cash equivalents $ 146 $ 321 $ 110 Restricted cash 168 176 143 Cash, cash equivalents and restricted cash shown in the statement of cash flows 314 497 253 Restricted cash consists primarily of funds held to satisfy the requirements of certain debt agreements and funds held within the Company's projects that are restricted in their use. Of these funds as of December 31, 2017 , approximately $25 million is designated for current debt service payments, $25 million is designated to fund operating expenses and $36 million is designated for distributions to the Company, with the remaining $82 million restricted for reserves including debt service, performance obligations and other reserves, as well as capital expenditures. Trade Receivables and Allowance for Doubtful Accounts Trade receivables are reported on the balance sheet at the invoiced amount adjusted for any write-offs and the allowance for doubtful accounts. The allowance for doubtful accounts is reviewed periodically based on amounts past due and significance. The allowance for doubtful accounts was immaterial as of December 31, 2017 and 2016 . Inventory Inventory consists principally of spare parts and fuel oil. Spare parts inventory is valued at weighted average cost, unless evidence indicates that the weighted average cost will not be recovered with a normal profit in the ordinary course of business. Fuel oil inventory is valued at the lower of weighted average cost or market. The Company removes fuel inventories as they are used in the production of steam, chilled water or electricity. Spare parts inventory are removed when they are used for repairs, maintenance or capital projects. Property, Plant and Equipment Property, plant and equipment are stated at cost or, in the case of third party business acquisitions, fair value; however impairment adjustments are recorded whenever events or changes in circumstances indicate that their carrying values may not be recoverable. See Note 3 , Business Acquisitions , for more information on acquired property, plant and equipment. Significant additions or improvements extending asset lives are capitalized as incurred, while repairs and maintenance that do not improve or extend the life of the respective asset are charged to expense as incurred. Depreciation is computed using the straight-line method over the estimated useful lives. Certain assets and their related accumulated depreciation amounts are adjusted for asset retirements and disposals with the resulting gain or loss included in cost of operations in the consolidated statements of operations. For further discussion of the Company's property, plant and equipment refer to Note 4 , Property, Plant and Equipment to the Consolidated Financial Statements. Asset Impairments Long-lived assets that are held and used are reviewed for impairment whenever events or changes in circumstances indicate carrying values may not be recoverable. Such reviews are performed in accordance with ASC 360. An impairment loss is indicated if the total future estimated undiscounted cash flows expected from an asset are less than its carrying value. An impairment charge is measured by the difference between an asset's carrying amount and fair value with the difference recorded in operating costs and expenses in the statements of operations. Fair values are determined by a variety of valuation methods, including appraisals, sales prices of similar assets and present value techniques. For further discussion of the Company's long-lived asset impairments, refer to Note 9 , Asset Impairments to the Consolidated Financial Statements. Investments accounted for by the equity method are reviewed for impairment in accordance with ASC 323, Investments-Equity Method and Joint Ventures , which requires that a loss in value of an investment that is an other-than-temporary decline should be recognized. The Company identifies and measures losses in the value of equity method investments based upon a comparison of fair value to carrying value. Debt Issuance Costs Debt issuance costs are capitalized and amortized as interest expense on a basis which approximates the effective interest method over the term of the related debt. Debt issuance costs related to the long term debt are presented as a direct deduction from the carrying amount of the related debt in both the current and prior periods. Debt issuance costs related to the senior secured revolving credit facility line of credit are recorded as a non-current asset on the balance sheet and are amortized over the term of the credit facility. Intangible Assets Intangible assets represent contractual rights held by the Company. The Company recognizes specifically identifiable intangible assets including power purchase agreements, leasehold improvements, customer relationships, customer contracts, and development rights when specific rights and contracts are acquired. These intangible assets are amortized primarily on a straight-line basis. For further discussion of the Company's intangible assets, refer to Note 8 , Intangible Assets to the Consolidated Financial Statements. Notes Receivable Notes receivable consist of receivables related to the financing of required network upgrades. The notes issued with respect to network upgrades will be repaid within a 5-year period following the date each facility reached commercial operations. Income Taxes The Company is classified as a partnership for federal and state income tax purposes. Therefore, federal and state income taxes are assessed at the partner level. Accordingly, no provision has been made for federal or state income taxes in the accompanying financial statements. Revenue Recognition Thermal Revenues Steam and chilled water revenue is recognized based on customer usage as determined by meter readings taken at month-end. Some locations read customer meters throughout the month, and recognize estimated revenue for the period between meter read date and month-end. The Thermal Business subsidiaries collect and remit state and local taxes associated with sales to their customers, as required by governmental authorities. These taxes are presented on a net basis in the income statement. Power Purchase Agreements, or PPAs The majority of the Company’s revenues are obtained through PPAs or other contractual agreements, which are accounted for as operating leases under ASC 840. ASC 840 requires the minimum lease payments received to be amortized over the term of the lease and contingent rentals are recorded when the achievement of the contingency becomes probable. Judgment is required by management in determining the economic life of each generating facility, in evaluating whether certain lease provisions constitute minimum payments or represent contingent rent and other factors in determining whether a contract contains a lease and whether the lease is an operating lease or capital lease. Certain of these leases have no minimum lease payments and all of the rental income under these leases is recorded as contingent rent on an actual basis when the electricity is delivered. The contingent rental income recognized in the years ended December 31, 2017 , 2016 and 2015 was $559 million , $583 million and $443 million , respectively. These balances include intercompany revenue for Elbow Creek of $8 million for each of the years ended December 31, 2017 and 2016 , as further discussed in Note 13 Related Party Transactions . Derivative Financial Instruments The Company accounts for derivative financial instruments under ASC 815, Derivatives and Hedging , or ASC 815, which requires the Company to record all derivatives on the balance sheet at fair value unless they qualify for a NPNS exception. Changes in the fair value of non-hedge derivatives are immediately recognized in earnings. Changes in the fair value of derivatives accounted for as hedges, if elected for hedge accounting, are either: • Recognized in earnings as an offset to the changes in the fair value of the related hedged assets, liabilities and firm commitments; or • Deferred and recorded as a component of accumulated OCI until the hedged transactions occur and are recognized in earnings. The Company's primary derivative instruments are power purchase or sale contracts used to mitigate variability in earnings due to fluctuations in market prices, fuels purchase contracts used to control customer reimbursable fuel cost, and interest rate instruments used to mitigate variability in earnings due to fluctuations in interest rates. On an ongoing basis, the Company assesses the effectiveness of all derivatives that are designated as hedges for accounting purposes in order to determine that each derivative continues to be highly effective in offsetting changes in fair values or cash flows of hedged items. Internal analyses that measure the statistical correlation between the derivative and the associated hedged item determine the effectiveness of such a contract designated as a hedge. If it is determined that the derivative instrument is not highly effective as a hedge, hedge accounting will be discontinued prospectively. In this case, the gain or loss previously deferred in accumulated OCI would be frozen until the underlying hedged item is delivered unless the transaction being hedged is no longer probable of occurring in which case the amount in OCI would be immediately reclassified into earnings. If the derivative instrument is terminated, the effective portion of this derivative deferred in accumulated OCI will be frozen until the underlying hedged item is delivered. Revenues and expenses on contracts that qualify for the NPNS exception are recognized when the underlying physical transaction is delivered. While these contracts are considered derivative financial instruments under ASC 815, they are not recorded at fair value, but on an accrual basis of accounting. If it is determined that a transaction designated as NPNS no longer meets the scope exception, the fair value of the related contract is recorded on the balance sheet and immediately recognized through earnings. Concentrations of Credit Risk Financial instruments which potentially subject the Company to concentrations of credit risk consist primarily of accounts receivable, notes receivable and derivative instruments, which are concentrated within entities engaged in the energy and financial industry. These industry concentrations may impact the overall exposure to credit risk, either positively or negatively, in that the customers may be similarly affected by changes in economic, industry or other conditions. In addition, many of the Company's projects have only one customer. However, the Company believes that the credit risk posed by industry concentration is offset by the diversification and creditworthiness of its customer base. See Note 6 , Fair Value of Financial Instruments , for a further discussion of derivative concentrations and Note 12 , Segment Reporting , for concentration of counterparties. Fair Value of Financial Instruments The carrying amount of cash and cash equivalents, restricted cash, accounts receivable, accounts receivable - affiliate, accounts payable, current portion of account payable - affiliate, and accrued expenses and other current liabilities approximate fair value because of the short-term maturity of these instruments. See Note 6 , Fair Value of Financial Instruments , for a further discussion of fair value of financial instruments. Asset Retirement Obligations Asset retirement obligations, or AROs, are accounted for in accordance with ASC 410-20, Asset Retirement Obligations, or ASC 410-20. Retirement obligations associated with long-lived assets included within the scope of ASC 410-20 are those for which a legal obligation exists under enacted laws, statutes, and written or oral contracts, including obligations arising under the doctrine of promissory estoppel, and for which the timing and/or method of settlement may be conditional on a future event. ASC 410-20 requires an entity to recognize the fair value of a liability for an ARO in the period in which it is incurred and a reasonable estimate of fair value can be made. Upon initial recognition of a liability for an ARO, the asset retirement cost is capitalized by increasing the carrying amount of the related long-lived asset by the same amount. Over time, the liability is accreted to its future value, while the capitalized cost is depreciated over the useful life of the related asset. The Company's AROs are primarily related to the future dismantlement of equipment on leased property and environmental obligations related to site closures and fuel storage facilities. The Company records AROs as part of other non-current liabilities on its balance sheet. The following table represents the balance of ARO obligations as of December 31, 2017 and 2016 , along with the additions and accretion related to the Company's ARO obligations for the year ended December 31, 2017 : (In millions) Balance as of December 31, 2016 $ 49 Revisions in estimates for current obligations/Additions 2 Accretion — expense 4 Balance as of December 31, 2017 $ 55 Guarantees The Company enters into various contracts that include indemnification and guarantee provisions as a routine part of its business activities. Examples of these contracts include operation and maintenance agreements, service agreements, commercial sales arrangements and other types of contractual agreements with vendors and other third parties, as well as affiliates. These contracts generally indemnify the counterparty for tax, environmental liability, litigation and other matters, as well as breaches of representations, warranties and covenants set forth in these agreements. Because many of the guarantees and indemnities the Company issues to third parties and affiliates do not limit the amount or duration of its obligations to perform under them, there exists a risk that the Company may have obligations in excess of the amounts agreed upon in the contracts mentioned above. For those guarantees and indemnities that do not limit the liability exposure, the Company may not be able to estimate what the liability would be, until a claim is made for payment or performance, due to the contingent nature of these contracts. Investments Accounted for by the Equity Method The Company has investments in various energy projects accounted for by the equity method, several of which are VIEs, where the Company is not a primary beneficiary, as described in Note 5 , Investments Accounted for by the Equity Method and Variable Interest Entities . The equity method of accounting is applied to these investments in affiliates because the ownership structure prevents the Company from exercising a controlling influence over the operating and financial policies of the projects. Under this method, equity in pre-tax income or losses of the investments is reflected as equity in earnings of unconsolidated affiliates. Distributions from equity method investments that represent earnings on the Company's investment are included within cash flows from operating activities and distributions from equity method investments that represent a return of the Company's investment are included within cash flows from investing activities. Sale Leaseback Arrangements The Company is party to sale-leaseback arrangements that provide for the sale of certain assets to a third party and simultaneous leaseback to the Company. In accordance with ASC 840-40, Sale-Leaseback Transactions , if the seller-lessee retains, through the leaseback, substantially all of the benefits and risks incident to the ownership of the property sold, the sale-leaseback transaction is accounted for as a financing arrangement. An example of this type of continuing involvement would include an option to repurchase the assets or the buyer-lessor having the option to sell the assets back to the Company. This provision is included in most of the Company’s sale-leaseback arrangements. As such, the Company accounts for these arrangements as financings. Under the financing method, the Company does not recognize as income any of the sale proceeds received from the lessor that contractually constitutes payment to acquire the assets subject to these arrangements. Instead, the sale proceeds received are accounted for as financing obligations and leaseback payments made by the Company are allocated between interest expense and a reduction to the financing obligation. Interest on the financing obligation is calculated using the Company’s incremental borrowing rate at the inception of the arrangement on the outstanding financing obligation. Judgment is required to determine the appropriate borrowing rate for the arrangement and in determining any gain or loss on the transaction that would be recorded either at the end of or over the lease term. Business Combinations The Company accounts for its business combinations in accordance with ASC 805, Business Combinations, or ASC 805. For third party acquisitions, ASC 805 requires an acquirer to recognize and measure in its financial statements the identifiable assets acquired, the liabilities assumed, and any noncontrolling interest in the acquiree at fair value at the acquisition date. It also recognizes and measures the goodwill acquired or a gain from a bargain purchase in the business combination and determines what information to disclose to enable users of an entity's financial statements to evaluate the nature and financial effects of the business combination. In addition, transaction costs are expensed as incurred. For acquisitions that relate to entities under common control, ASC 805 requires retrospective combination of the entities for all periods presented as if the combination has been in effect from the beginning of the financial statement period of from the date the entities were under common control (if later than the beginning of the financial statement period). The difference between the cash paid and historical value of the entities' equity is recorded as a distribution/contribution from/to NRG with the offset to contributed capital. Transaction costs are expensed as incurred. Use of Estimates The preparation of consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions. These estimates and assumptions impact the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities as of the date of the consolidated financial statements. They also impact the reported amounts of net earnings during the reporting periods. Actual results could be different from these estimates. In recording transactions and balances resulting from business operations, the Company uses estimates based on the best information available. Estimates are used for such items as plant depreciable lives, uncollectible accounts, environmental liabilities, acquisition accounting and legal costs incurred in connection with recorded loss contingencies, among others. In addition, estimates are used to test long-lived assets for impairment and to determine the fair value of impaired assets. As better information becomes available or actual amounts are determinable, the recorded estimates are revised. Consequently, operating results can be affected by revisions to prior accounting estimates. Tax Equity Arrangements Certain portions of the Company’s noncontrolling interests in subsidiaries represent third-party interests in the net assets under certain tax equity arrangements, which are consolidated by the Company, that have been entered into to finance the cost of wind facilities eligible for certain tax credits. Additionally, certain portions of the Company’s investments in unconsolidated affiliates reflect the Company’s interests in tax equity arrangements, that are not consolidated by the Company, that have been entered into to finance the cost of distributed solar energy systems under operating leases or PPAs eligible for certain tax credits. The Company has determined that the provisions in the contractual agreements of these structures represent substantive profit sharing arrangements. Further, the Company has determined that the appropriate methodology for calculating the noncontrolling interest and investment in unconsolidated affiliates that reflects the substantive profit sharing arrangements is a balance sheet approach utilizing the hypothetical liquidation at book value, or HLBV, method. Under the HLBV method, the amounts reported as noncontrolling interests and investment in unconsolidated affiliates represent the amounts the investors to the tax equity arrangements would hypothetically receive at each balance sheet date under the liquidation provisions of the contractual agreements, assuming the net assets of the funding structures were liquidated at their recorded amounts determined in accordance with GAAP. The investors’ interests in the results of operations of the funding structures are determined as the difference in noncontrolling interests and investment in unconsolidated affiliates at the start and end of each reporting period, after taking into account any capital transactions between the structures and the funds’ investors. The calculations utilized to apply the HLBV method include estimated calculations of taxable income or losses for each reporting period. Reclassifications Certain prior year amounts have been reclassified for comparative purposes. Recent Accounting Developments - Adopted in 2017 ASU 2017-12 — In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815) , Targeted Improvements to Accounting for Hedging Activities, or ASU No. 2017-12. ASU No. 2017-12 amends ASU No. 2016-15. The amendments of ASU No. 2016-15 were issued to simplify the application of hedge accounting guidance and more closely aligning financial reporting for hedging relationships with economic results of an entity's risk management activities. The issues addressed by ASU No. 2017-12 include but are not limited to alignment of risk management activities and financial reporting, risk component hedging, accounting for the hedged item in fair value hedges of interest rate risk, recognition and presentation of the effects of hedging instruments, amounts excluded from the assessment of hedge effectiveness, and other simplifications of hedge accounting guidance. The amendments of ASU No. 2017-12 are effective for fiscal years beginning after December 15, 2018, and interim periods therein. Early adoption is permitted in any interim period and the effect of the adoption should be reflected as of the beginning of the fiscal year of adoption. The Company early adopted ASU No. 2017-12 during the fourth quarter 2017. The adoption of ASU No. 2017-12 did not have a material impact on our consolidated results of operations, cash flows, and statement of financial position. ASU 2016-18 — In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230) , Restricted Cash, or ASU No. 2016-18. The amendments of ASU No. 2016-18 require an entity to include amounts generally described as restricted cash and restricted cash equivalents with cash and cash equivalents when reconciling the beginning of period and end of period total amounts on the statement of cash flows. The amendments of ASU No. 2016-18 are effective for annual reporting periods beginning after December 15, 2017, and interim periods within those annual periods. Early adoption is permitted and the adoption of ASU No. 2016-18 will be applied retrospectively. The Company early adopted ASU No. 2016-18 during the second quarter of 2017. Net cash flows used in investing activities for the year ended December 31, 2016 decreased by $33 million . The sum of Company's cash and cash equivalents and restricted cash reported within the consolidated balance sheet as of December 31, 2016 equals the beginning balances of cash, cash equivalents and restricted cash shown in the consolidated statement of cash flows for the year ended December 31, 2017. The sum of Company's cash and cash equivalents and restricted cash reported within the consolidated balance sheet as of December 31, 2017 equals to the ending balances of cash, cash equivalents and restricted cash shown in the consolidated statement of cash flows for the year ended December 31, 2017. Recent Accounting Developments - Not Yet Adopted ASU 2016-02 — In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), or Topic 842, with the objective to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and to improve financial reporting by expanding the related disclosures. The guidance in Topic 842 provides that a lessee that may have previously accounted for a lease as an operating lease under current GAAP should recognize the assets and liabilities that arise from a lease on the balance sheet. In addition, Topic 842 expands the required quantitative and qualitative disclosures with regards to lease arrangements. The Company will adopt the standard effective January 1, 2019 and expects to elect certain of the practical expedients permitted, including the expedient that permits the Company to retain its existing lease assessment and classification. The Company is currently working through an adoption plan and evaluating the anticipated impact on the Company's results of operations, cash flows and financial position. While the Company is currently evaluating the impact the new guidance will have on its financial position and results of operations, the Company expects to recognize lease liabilities and right of use assets. The extent of the increase to assets and liabilities associated with these amounts remains to be determined pending the Company’s review of its existing lease contracts and service contracts which may contain embedded leases. While this review is still in process, the Company believes the adoption of Topic 842 may be material to its financial statements. The Company is continuing to monitor potential changes to Topic 842 that have been proposed by the FASB and will assess any necessary changes to the implementation as the guidance is updated. ASU 2014-09 — In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), or Topic 606, which was further amended through various updates issued by the FASB thereafter. The amendments of ASU No. 2014-09 completed the joint effort between the FASB and the IASB, to develop a common revenue standard for GAAP and IFRS, and to improve financial reporting. The guidance under Topic 606 provides that an entity should recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for the goods or services provided and establishes a five step model to be applied by an entity in evaluating its contracts with customers. The Company has elected the practical expedient available under Topic 606 for measuring progress toward complete satisfaction of a performance obligation and for disclosure requirements of remaining performance obligations. The practical expedient allows an entity to recognize revenue in the amount to which the entity has the right to invoice such that the entity has a right to the consideration in an amount that corresponds directly with the value to the customer for performance completed to date by the entity. The majority of the Company's revenues are obtained through PPAs, which are currently accounted for as operating leases. In connection with the implementation of Topic 842, as described above, the Company expects to elect certain of the practical expedients permitted, including the expedient that permits the Company to retain its existing lease assessment and classification. The Company adopted the standard effective January 1, 2018 under the modified retrospective transition method. As leases are excluded from the scope of Topic 606, the adoption of Topic 606 at the date of initial application will not have a material impact on the Company's financial statements. The adoption of Topic 606 also includes additional disclosure requirements beginning in the first quarter of 2018. As a significant portion of the Company's revenue is generated through operating leases, the majority of the new required disclosures will not be relevant or material to the Company.

Business Acquisitions

Business Acquisitions	12 Months Ended
	Dec. 31, 2017
Business Acquisition [Line Items]
Business Acquisition	Business Acquisitions 2017 Acquisitions November 2017 Drop Down Assets — On November 1, 2017, the Company acquired a 38 MW solar portfolio primarily comprised of assets from NRG's Solar Power Partners (SPP) funds and other projects developed by NRG, for cash consideration of $74 million , including working capital adjustments of $3 million , plus assumed non-recourse debt of $26 million . The purchase price for the November 2017 Drop Down Assets was funded with cash on hand. The assets and liabilities transferred to the Company relate to interests under common control by NRG and were recorded at historical cost in accordance with ASC 805-50, Business Combinations - Related Issues . The difference between the cash paid and historical value of the entities' equity was recorded as a contribution from NRG and increased the balance of contributed capital. Because the transaction constituted a transfer of net assets under common control, the guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control. The following is a summary of assets and liabilities transferred in connection with the acquisition of the November 2017 Drop Down Assets as of November 1, 2017: (In millions) Assets: Current assets $ 7 Property, plant and equipment 83 Non-current assets 12 Total assets 102 Liabilities: Debt (Current and non-current) (a) 23 Other current and non-current liabilities 3 Total liabilities assumed 26 Net assets acquired $ 76 (a) Net of $3 million of net debt issuance costs. Since the acquisition date, the November 2017 Drop Down Assets have contributed $1 million in operating revenues to the Company. August 2017 Drop Down Assets — On August 1, 2017, the Company acquired the remaining 25% interest in NRG Wind TE Holdco, a portfolio of 12 wind projects, from NRG for total cash consideration of $44 million , including working capital adjustment of $ 3 million . The purchase agreement also included potential additional payments to NRG dependent upon actual energy prices for merchant periods beginning in 2027, which were estimated and accrued as contingent consideration in the amount of $8 million as of September 30, 2017. The Company originally acquired 75% of NRG Wind TE Holdco on November 3, 2015, or November 2015 Drop Down Assets, which were consolidated with 25% of the net assets recorded as noncontrolling interest. The assets and liabilities transferred to the Company related to interests under common control by NRG and were recorded at historical cost in accordance with ASC 805-50, Business Combination - Related Issues. As the Company had reflected NRG's 25% ownership of NRG Wind TE Holdco in noncontrolling interest, the difference between the cash paid of $44 million , net of the contingent consideration of $8 million , and the historical value of the remaining 25% of $87 million as of July 31, 2017, was recorded as an adjustment to NRG's noncontrolling interest. Since the transaction constituted a transfer of entities under common control, the accounting guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect from the beginning of the financial statement period or from the date the entities were under common control (if later than the beginning of the financial statement period). The Class A interests of NRG Wind TE Holdco are owned by a tax equity investor, or TE Investor, who receives 99% of allocations of taxable income and other items until the flip point, which occurs when the TE Investor obtains a specified return on its initial investment, at which time the allocations to the TE Investor change to 8.53% . The Company generally receives 100% of CAFD until the flip point, at which time the allocations to the Company of CAFD change to 91.47% . If the flip point has not occurred by a specified date, 100% of CAFD is allocated to the TE Investor until the flip point occurs. NRG Wind TE Holdco is a VIE and the Company is the primary beneficiary, through its position as managing member, and consolidates NRG Wind TE Holdco. The following tables present a summary of the Company's historical information combining the financial information for the November 2017 Drop Down Assets and August 2017 Drop Down Assets transferred in connection with the acquisitions: Year ended December 31, 2016 Year ended December 31, 2015 As Previously Reported (a) November 2017 Drop Down Assets August 2017 Drop Down Assets As Currently Reported As Previously Reported (a) November 2017 Drop Down Assets August 2017 Drop Down Assets As Currently Reported (In millions) Total operating revenues $ 1,021 $ 14 $ — $ 1,035 $ 953 $ 15 $ — $ 968 Operating income 220 4 — 224 322 6 — 328 Net income 15 — — 15 93 2 — 95 Net income attributable to Yield LLC 157 — (31 ) 126 144 3 10 157 (a) As previously reported in the May 9, 2017 Form 8-K filed in connection with the March 2017 Drop Down completed on March 27, 2017 As of December 31, 2016 (In millions) As Previously Reported (a) November 2017 Drop Down Assets As Currently Reported Assets: Current assets $ 656 $ 14 $ 670 Property, plant and equipment 5,460 94 5,554 Non-current assets 2,504 18 2,522 Total assets 8,620 126 8,746 Liabilities: Debt (Current and non-current) 6,007 62 6,069 Other current and non-current liabilities 309 4 313 Total liabilities assumed 6,316 66 6,382 Net assets $ 2,304 $ 60 $ 8,746 (a) As previously reported in the May 9, 2017 Form 8-K filed in connection with the March 2017 Drop Down completed on March 27, 2017. March 2017 Drop Down Assets — On March 27, 2017, the Company acquired the following interests from NRG: (i) Agua Caliente Borrower 2 LLC, which owns a 16% interest (approximately 31% of NRG's 51% interest) in the Agua Caliente solar farm, one of the ROFO Assets, representing ownership of approximately 46 net MW of capacity and (ii) NRG's interests in the Utah Solar Portfolio. Agua Caliente is located in Yuma County, AZ and sells power subject to a 25 -year PPA with Pacific Gas and Electric, with 22 years remaining on that contract. The seven utility-scale solar farms in the Utah Solar Portfolio are owned by the following entities: Four Brothers Capital, LLC, Iron Springs Capital, LLC, and Granite Mountain Capital, LLC. These utility-scale solar farms achieved commercial operations in 2016, sell power subject to 20 -year PPAs with PacifiCorp, a subsidiary of Berkshire Hathaway and are part of a tax equity structure with Dominion Solar Projects III, Inc., or Dominion, through which the Company is entitled to receive 50% of cash to be distributed, as further described below. The Company paid cash consideration of $132 million , including $2 million of working capital. The acquisition of the March 2017 Drop Down Assets was funded with cash on hand. The Company recorded the acquired interests as equity method investments. The Company also assumed non-recourse debt of $41 million and $287 million on Agua Caliente Borrower 2 LLC and the Utah Solar Portfolio, respectively, as further described in Note 10 , Long-term Debt , as well as its pro-rata share of non-recourse project-level debt of Agua Caliente Solar LLC. The assets and liabilities transferred to the Company relate to interests under common control by NRG and were recorded at historical cost in accordance with ASC 805-50, Business Combination - Related Issues. The difference between the cash paid and the historical value of the entities' equity of $8 million was recorded as an adjustment to NRG's noncontrolling interest. Since the transaction constituted a transfer of entities under common control, the accounting guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect from the beginning of the financial statement period or from the date the entities were under common control (if later than the beginning of the financial statement period). Accordingly, in connection with the retrospective adjustment of prior periods, the Company adjusted its financial statements to reflect its results of operations, financial position and cash flows as if it recorded its interests in the Agua Caliente Borrower 2 LLC on January 1, 2016, and its interests in the Utah Solar Portfolio on November 2, 2016. The following is a summary of assets and liabilities transferred in connection with the acquisition of the March 2017 Drop Down Assets as of March 27, 2017: (In millions) Assets: Cash $ 6 Equity investment in projects 456 Total assets acquired 462 Liabilities: Debt (Current and non-current) (a) 320 Other current and non-current liabilities 3 Total liabilities assumed 323 Net assets acquired $ 139 (a) Net of $8 million of debt issuance costs. 2016 Acquisitions CVSR Drop Down — Prior to September 1, 2016, the Company had a 48.95% interest in CVSR, which was accounted for as an equity method investment. On September 1, 2016, the Company acquired from NRG the remaining 51.05% interest of CVSR Holdco LLC, which indirectly owns the CVSR solar facility, or the CVSR Drop Down, for total cash consideration of $78.5 million , plus an immaterial working capital adjustment. The acquisition was funded with cash on hand. The Company also assumed additional debt of $496 million , which represents 51.05% of the CVSR project level debt and 51.05% of the notes issued under the CVSR Holdco Financing Agreement, as of the closing date. The acquisition was funded with cash on hand. The assets and liabilities transferred to the Company relate to interests under common control by NRG and were recorded at historical cost in accordance with ASC 805-50, Business Combinations - Related Issues . The difference between the cash paid and historical value of the CVSR Drop Down of $112 million , as well as $6 million of AOCL, was recorded as a distribution to NRG with the offset to contributed capital. Because the transaction constituted a transfer of net assets under common control, the guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control. In connection with the retrospective adjustment of prior periods, the Company now consolidates CVSR and 100% of its debt, consisting of $771 million of project level debt and $200 million of notes issued under the CVSR Holdco Financing Agreement as of September 1, 2016 . In addition, the Company has removed the equity method investment from all prior periods and adjusted its financial statements to reflect its results of operations, financial position and cash flows as if it had consolidated CVSR from the beginning of the financial statement period. 2015 Acquisitions November 2015 Drop Down Assets from NRG — On November 3, 2015, the Company acquired the November 2015 Drop Down Assets, a portfolio of 12 wind facilities totaling 814 net MW, from NRG for cash consideration of $207 million . The Company was responsible for its pro-rata share of non-recourse project debt of $193 million and noncontrolling interest associated with a tax equity structure of $159 million (as of the acquisition date). The Company funded the acquisition with borrowings from its revolving credit facility. The assets and liabilities transferred to the Company relate to interests under common control by NRG and were recorded at historical cost. The difference between the cash paid and historical value of the entities' equity was recorded as a distribution from NRG with the offset to contributed capital. Desert Sunlight — On June 29, 2015, the Company acquired 25% of the membership interest in Desert Sunlight Investment Holdings, LLC, which owns two solar photovoltaic facilities that total 550 MW, located in Desert Center, California from EFS Desert Sun, LLC, an affiliate of GE Energy Financial Services for a purchase price of $285 million . Power generated by the facilities is sold to Southern California Edison and Pacific Gas and Electric under long-term PPAs with approximately 20 years and 25 years of remaining contract life, respectively. The Company accounts for its 25% investment as an equity method investment. Spring Canyon — On May 7, 2015, the Company acquired a 90.1% interest in Spring Canyon II, a 32 MW wind facility, and Spring Canyon III, a 28 MW wind facility, each located in Logan County, Colorado, from Invenergy Wind Global LLC. The purchase price was funded with cash on hand. Power generated by Spring Canyon II and Spring Canyon III is sold to Platte River Power Authority under long-term PPAs, each with approximately 24 years of remaining contract life. University of Bridgeport Fuel Cell — On April 30, 2015, the Company completed the acquisition of the University of Bridgeport Fuel Cell project in Bridgeport, Connecticut from FuelCell Energy, Inc. The project added an additional 1.4 MW of thermal capacity to the Company's portfolio, with a 12 -year contract, with the option for a 7 -year extension. The acquisition is reflected in the Company's Thermal segment. January 2015 Drop Down Assets from NRG — On January 2, 2015, the Company acquired the following projects from NRG: (i) Laredo Ridge, an 80 MW wind facility located in Petersburg, Nebraska, (ii) Tapestry, which includes Buffalo Bear, a 19 MW wind facility in Buffalo, Oklahoma; Taloga, a 130 MW wind facility in Putnam, Oklahoma; and Pinnacle, a 55 MW wind facility in Keyser, West Virginia, and (iii) Walnut Creek, a 485 MW natural gas facility located in City of Industry, California, for total cash consideration of $489 million , including $9 million for working capital, plus assumed project-level debt of $737 million . The Company funded the acquisition with cash on hand and drawings under its revolving credit facility. The assets and liabilities transferred to the Company relate to interests under common control by NRG and were recorded at historical cost. The difference between the cash paid and the historical value of the entities' equity of $61 million was recorded as a distribution to NRG and reduced the balance of its contributed capital.

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment [Table Text Block]	The Company’s major classes of property, plant, and equipment were as follows: December 31, 2017 December 31, 2016 Depreciable Lives (In millions) Facilities and equipment $ 6,289 $ 6,339 2 - 45 Years Land and improvements 166 167 Construction in progress (a) 34 24 Total property, plant and equipment 6,489 6,530 Accumulated depreciation (1,285 ) (976 ) Net property, plant and equipment $ 5,204 $ 5,554 (a) As of December 31, 2017 and 2016 , construction in progress includes $24 million and $20 million of capital expenditures that relate to prepaid long-term service agreements in the Conventional segment, respectively.
Property, Plant and Equipment Disclosure	Property, Plant and Equipment The Company’s major classes of property, plant, and equipment were as follows: December 31, 2017 December 31, 2016 Depreciable Lives (In millions) Facilities and equipment $ 6,289 $ 6,339 2 - 45 Years Land and improvements 166 167 Construction in progress (a) 34 24 Total property, plant and equipment 6,489 6,530 Accumulated depreciation (1,285 ) (976 ) Net property, plant and equipment $ 5,204 $ 5,554 (a) As of December 31, 2017 and 2016 , construction in progress includes $24 million and $20 million of capital expenditures that relate to prepaid long-term service agreements in the Conventional segment, respectively. The Company recorded long-lived asset impairments during the years ended December 31, 2017 and 2016, as further described in Note 9 , Asset Impairments .

Equity Method Investments and V

Equity Method Investments and VIEs	12 Months Ended
	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Investments Accounted for by the Equity Method and Variable Interest Entities	Investments Accounted for by the Equity Method and Variable Interest Entities Equity Method Investments The following table summarizes the Company's equity method investments as of December 31, 2017 : Name Economic Interest Investment Balance (In millions) Utah Solar Portfolio (a) 50% $345 Desert Sunlight 25% 272 GenConn (b) 50% 102 Agua Caliente Borrower 2 16% 92 Elkhorn Ridge (c) 66.7% 73 San Juan Mesa (c) 75% 66 NRG DGPV Holdco 1 LLC (d) 95% 76 NRG DGPV Holdco 2 LLC (d) 95% 61 NRG DGPV Holdco 3 LLC (d) 99% 39 NRG RPV Holdco 1 LLC (d) 95% 58 Avenal 50% (6) Total equity investments in affiliates $1,178 (a) Economic interest based on cash to be distributed. Four Brothers Solar, LLC, Granite Mountain Holdings, LLC and Iron Springs Holdings, LLC are tax equity structures and VIEs. The related allocations are described below. (b) GenConn is a variable interest entity. (c) San Juan Mesa and Elkhorn Ridge are part of the Wind TE Holdco tax equity structure, as described below. San Juan Mesa and Elkhorn Ridge are owned 75% and 66.7% , respectively, by Wind TE Holdco. The Company owns 100% of the Class B interests in Wind TE Holdco. (d) Economic interest based on cash to be distributed. NRG DGPV Holdco 1 LLC, NRG DGPV Holdco 2 LLC, NRG DGPV Holdco 3 LLC and NRG RPV Holdco 1 LLC are tax equity structures and VIEs. The related allocations are described below. As of December 31, 2017 and 2016 , the Company had $ 57 million and $ 51 million , respectively, of undistributed earnings from its equity method investments. The Company acquired its interest in Desert Sunlight on June 30, 2015, for $285 million , which resulted in a difference between the purchase price and the basis of the acquired assets and liabilities of $171 million . The difference is attributable to the fair value of the property, plant and equipment and power purchase agreements. In addition, the difference between the basis of the acquired assets and liabilities and the purchase price for the Utah Solar Portfolio (Four Brothers Solar, LLC, Granite Mountain Holdings, LLC and Iron Springs Holdings, LLC) of $106 million is attributable to the fair value of the property, plant and equipment. The Company is amortizing the related basis differences to equity in earnings (losses) over the related useful life of the underlying assets acquired. Non-recourse project-level debt of unconsolidated affiliates The Company's pro-rata share of non-recourse debt held by unconsolidated affiliates was $777 million as of December 31, 2017 . The following tables present summarized financial information for the Company's significant equity method investments: Year Ended December 31, 2017 2016 2015 Income Statement Data: (In millions) GenConn Operating revenues $ 71 $ 72 $ 78 Operating income 36 38 40 Net income 26 26 28 Desert Sunlight Operating revenues 207 211 206 Operating income 127 129 124 Net income 80 80 73 Utah Solar Portfolio (a) Operating revenues 75 13 — Operating income (loss) 18 (6 ) (1 ) Net income (loss) 18 (6 ) (1 ) DGPV entities (b) Operating revenues 37 14 1 Operating income 7 2 — Net loss (3 ) — — RPV Holdco Operating revenues 16 13 4 Operating income 3 2 (6 ) Net income (loss) 3 2 (6 ) As of December 31, 2017 2016 Balance Sheet Data: (In millions) GenConn Current assets $ 38 $ 36 Non-current assets 374 389 Current liabilities 18 16 Non-current liabilities 189 196 Desert Sunlight Current assets 133 281 Non-current assets 1,350 1,401 Current liabilities 64 64 Non-current liabilities 1,003 1,043 Utah Solar Portfolio (a) Current assets 13 20 Non-current assets 1,090 1,105 Current liabilities 5 14 Non-current liabilities 24 38 DGPV entities (b) Current assets 74 44 Non-current assets 671 562 Current liabilities 83 112 Non-current liabilities 216 23 Redeemable Noncontrolling Interest 44 28 RPV Holdco Current assets 3 15 Non-current assets 183 191 Current liabilities — 11 Non-current liabilities 7 7 Redeemable Noncontrolling Interest 16 — — (a) Utah Solar Portfolio was acquired by NRG on November 2, 2016. (b) Includes DGPV Holdco 1, DGPV Holdco 2 and DGPV Holdco 3 Variable Interest Entities, or VIEs Entities that are Consolidated NRG Wind TE Holdco — As described in Note 3 , Business Acquisitions , on August 1, 2017, the Company acquired from NRG the remaining 25% interest in NRG Wind TE Holdco. NRG Wind TE Holdco is a VIE and the Company is the primary beneficiary through its position as managing member and consolidates NRG Wind TE Holdco. The Class A interests of NRG Wind TE Holdco are owned by a tax equity investor, or TE Investor, who receives 99% of allocations of taxable income and other items until the flip point, which occurs when the TE Investor obtains a specified return on its initial investment, at which time the allocations to the TE Investor change to 8.53% . The Company generally receives 100% of CAFD until the flip point, at which time the allocations to the Company of CAFD change to 91.47% . If the flip point has not occurred by a specified date, 100% of CAFD is allocated to the TE Investor until the flip point occurs. The Company utilizes the HLBV method to determine the net income or loss allocated to the TE Investor noncontrolling interest. Alta TE Holdco — On June 30, 2015, the Company sold an economic interest in Alta TE Holdco to a financial institution in order to monetize certain cash and tax attributes, primarily PTCs. The financial institution, or Alta Investor, receives 99% of allocations of taxable income and other items until the flip point, which occurs when the Alta Investor obtains a specified return on its initial investment, at which time the allocations to the Alta Investor change to 5% . The Company receives 94.34% until the flip point, at which time the allocations to the Company of CAFD will change to 97.12% , unless the flip point will not have occurred by a specified date, which would result in 100% of CAFD allocated to the Alta Investor until the flip point occurs. Alta TE Holdco is a VIE and the Company is the primary beneficiary through its position as managing member, and therefore consolidates Alta TE Holdco, with the Alta Investor's interest shown as noncontrolling interest. The Company utilizes the HLBV method to determine the net income or loss allocated to the noncontrolling interest. Spring Canyon — The Company holds a 90.1% of the Class B interests in Spring Canyon II, a 32 MW wind facility, and Spring Canyon III, a 28 MW wind facility, each located in Logan County, Colorado, and Invenergy Wind Global LLC owns 9.9% of the Class B interests. The projects are financed with a partnership flip tax-equity structure with a financial institution, who owns the Class A interests, to monetize certain cash and tax attributes, primarily PTCs. Until the flip point, the Class A member receives a variable percentage of cash distributions based on the projects’ production level during the prior year. The Class A member received 34.81% of the cash distributions and the Company and Invenergy received 65.19% during the period ended December 31, 2017. After the flip point, cash distributions are allocated 5% to the Class A member and 95% to the Company and Invenergy. Spring Canyon is a VIE and the Company is the primary beneficiary through its position as managing member, and therefore consolidates Spring Canyon. The Class A member and Invenergy's interests are shown as noncontrolling interest. The Company utilizes the HLBV method to determine the net income or loss allocated to the Class A member. Net income or loss attributable to the Class B interests is allocated to Invenergy's noncontrolling interest based on its 9.9% ownership interest. Summarized financial information for the Company's consolidated VIEs consisted of the following as of December 31, 2017 : (In millions) NRG Wind TE Holdco Alta TE Holdco Spring Canyon Other current and non-current assets $ 172 $ 17 $ 2 Property, plant and equipment 376 436 95 Intangible assets 2 262 — Total assets 550 715 97 Current and non-current liabilities 197 9 5 Total liabilities 197 9 5 Noncontrolling interest 9 93 60 Net assets less noncontrolling interests $ 344 $ 613 $ 32 Entities that are not Consolidated The Company has interests in entities that are considered VIEs under ASC 810, Consolidation , but for which it is not considered the primary beneficiary. The Company accounts for its interests in these entities under the equity method of accounting. Utah Solar Portfolio Assets — As described in Note 3, Business Acquisitions , as part of the March 2017 Drop Down Assets acquisition, the Company acquired from NRG 100% of the Class A equity interests in the Utah Solar Portfolio, comprised of Four Brothers Solar, LLC, Granite Mountain Holdings, LLC, and Iron Springs Holdings, LLC. The Class B interests of the Utah Solar Portfolio are owned by a tax equity investor, or TE Investor, who receives 99% of allocations of taxable income and other items until the flip point, which occurs when the TE Investor obtains a specified return on its initial investment, at which time the allocations to the TE Investor change to 50% . The Company generally receives 50% of distributable cash throughout the term of the tax-equity arrangements. The three entities comprising the Utah Solar Portfolio are VIEs. As the Company is not the primary beneficiary, the Company uses the equity method of accounting to account for its interests in the Utah Solar Portfolio. The Company utilizes the HLBV method to determine its share of the income or losses in the investees. NRG DGPV Holdco 1 LLC — The Company and NRG are parties to the NRG DGPV Holdco 1 LLC partnership, or DGPV Holdco 1, the purpose of which is to own or purchase solar power generation projects and other ancillary related assets from NRG Renew LLC or its subsidiaries via intermediate funds. The Company owns approximately 47 MW of distributed solar capacity, based on cash to be distributed, with a weighted average contract life of 18 years . Under this partnership, the Company committed to fund up to $100 million of capital. NRG DGPV Holdco 2 LLC — The Company and NRG are parties to the NRG DGPV Holdco 2 LLC partnership, or DGPV Holdco 2, the purpose of which is to own or hold solar power generation projects as well as other ancillary related assets from NRG Renew LLC or its subsidiaries. The Company owns approximately 113 MW of distributed solar capacity, based on cash to be distributed, with a weighted average contract life of 21 years . Under this partnership, the Company committed to fund up to $60 million of capital. NRG DGPV Holdco 3 LLC — On September 26, 2017, the Company entered into an additional partnership with NRG by forming NRG DGPV Holdco 3 LLC, or DGPV Holdco 3, in which the Company would invest up to $50 million in an operating portfolio of distributed solar assets, primarily comprised of community solar projects, developed by NRG. The Company owns approximately 43 MW of distributed solar capacity, based on cash to be distributed, with a weighted average contract life of approximately 20 years as of December 31, 2017 . The Company's maximum exposure to loss is limited to its equity investment in DGPV Holdco 1, DGPV Holdco 2 and DGPV Holdco 3, which was $176 million on a combined basis. NRG RPV Holdco 1 LLC — The Company and NRG are parties to the NRG RPV Holdco 1 LLC partnership, or RPV Holdco, the purpose of which is to hold operating portfolios of residential solar assets developed by NRG's residential solar business, including: (i) an existing, unlevered portfolio of over 2,200 leases across nine states representing approximately 14 MW, based on cash to be distributed, with a weighted average remaining lease term of approximately 15 years that was acquired outside of the partnership; and (ii) a tax equity-financed portfolio of approximately 5,400 leases representing approximately 30 MW, based on cash to be distributed, with a weighted average remaining lease term for the existing and new leases of approximately 18 years . The Company has fully funded the partnership as of December 31, 2017. The Company's maximum exposure to loss is limited to its equity investment, which was $58 million as of December 31, 2017 .

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments For cash and cash equivalents, restricted cash, accounts receivable — affiliate, accounts receivable, accounts payable, current portion of accounts payable — affiliate, accrued expenses and other liabilities, the carrying amount approximates fair value because of the short-term maturity of those instruments and are classified as Level 1 within the fair value hierarchy. The estimated carrying amounts and fair values of the Company’s recorded financial instruments not carried at fair market value are as follows: As of December 31, 2017 As of December 31, 2016 Carrying Amount Fair Value Carrying Amount Fair Value (In millions) Assets: Notes receivable, including current portion $ 13 $ 13 $ 30 $ 30 Liabilities: Long-term debt, including current portion — affiliate 618 618 618 608 Long-term debt, including current portion — external $ 5,281 $ 5,297 $ 5,516 $ 5,500 Fair Value Accounting under ASC 820 ASC 820 establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three levels as follows: • Level 1—quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access as of the measurement date. • Level 2—inputs other than quoted prices included within Level 1 that are directly observable for the asset or liability or indirectly observable through corroboration with observable market data. • Level 3—unobservable inputs for the asset or liability only used when there is little, if any, market activity for the asset or liability at the measurement date. In accordance with ASC 820, the Company determines the level in the fair value hierarchy within which each fair value measurement in its entirety falls, based on the lowest level input that is significant to the fair value measurement. The fair value of the Company's publicly-traded long-term debt is based on quoted market prices and is classified as Level 2 within the fair value hierarchy. The fair value of debt securities, non-publicly traded long-term debt, affiliate debt and certain notes receivable of the Company are based on expected future cash flows discounted at market interest rates, or current interest rates for similar instruments with equivalent credit quality and are classified as Level 3 within the fair value hierarchy. The following table presents the level within the fair value hierarchy for long-term debt, including current portion as of December 31, 2017 and 2016 : As of December 31, 2017 As of December 31, 2016 Level 2 Level 3 Level 2 Level 3 (In millions) Long-term debt, including current portion $ 870 $ 5,045 $ 833 $ 5,275 Recurring Fair Value Measurements The Company records its derivative assets and liabilities at fair market value on its consolidated balance sheet. The following table presents assets and liabilities measured and recorded at fair value on the Company's consolidated balance sheets on a recurring basis and their level within the fair value hierarchy: As of December 31, 2017 As of December 31, 2016 Fair Value (a) Fair Value (a) Fair Value (a) (In millions) Level 2 Level 1 Level 2 Derivative assets: Commodity contracts $ 1 $ 1 $ 1 Interest rate contracts 1 — 1 Total assets $ 2 1 2 Derivative liabilities: Commodity contracts $ 1 — 1 Interest rate contracts 47 — 78 Total liabilities $ 48 $ — $ 79 (a) There were no derivative assets or liabilities classified Level 1 as of December 31, 2017 . There were no derivative assets or liabilities classified Level 3 as of December 31, 2017 and 2016 . Derivative Fair Value Measurements The Company's contracts are non-exchange-traded and valued using prices provided by external sources. For the Company’s energy markets, management receives quotes from multiple sources. To the extent that multiple quotes are received, the prices reflect the average of the bid-ask mid-point prices obtained from all sources believed to provide the most liquid market for the commodity. The fair value of each contract is discounted using a risk free interest rate. In addition, a credit reserve is applied to reflect credit risk, which for interest rate swaps, is calculated based on credit default swaps utilizing the bilateral method. For commodities, to the extent that NRG's net exposure under a specific master agreement is an asset, the Company uses the counterparty's default swap rate. If the exposure under a specific master agreement is a liability, the Company uses NRG's default swap rate. For interest rate swaps and commodities, the credit reserve is added to the discounted fair value to reflect the exit price that a market participant would be willing to receive to assume the liabilities or that a market participant would be willing to pay for the assets. As of December 31, 2017 , the credit reserve resulted in a $1 million increase in fair value in interest expense. It is possible that future market prices could vary from those used in recording assets and liabilities and such variations could be material. Concentration of Credit Risk In addition to the credit risk discussion as disclosed in Note 2 , Summary of Significant Accounting Policies , the following item is a discussion of the concentration of credit risk for the Company's financial instruments. Credit risk relates to the risk of loss resulting from non-performance or non-payment by counterparties pursuant to the terms of their contractual obligations. The Company monitors and manages credit risk through credit policies that include: (i) an established credit approval process; (ii) daily monitoring of counterparties' credit limits; (iii) the use of credit mitigation measures such as margin, collateral, prepayment arrangements, or volumetric limits; (iv) the use of payment netting agreements; and (v) the use of master netting agreements that allow for the netting of positive and negative exposures of various contracts associated with a single counterparty. Risks surrounding counterparty performance and credit could ultimately impact the amount and timing of expected cash flows. The Company seeks to mitigate counterparty risk by having a diversified portfolio of counterparties. Counterparty credit exposure includes credit risk exposure under certain long-term agreements, including solar and other PPAs. As external sources or observable market quotes are not available to estimate such exposure, the Company estimates the exposure related to these contracts based on various techniques including but not limited to internal models based on a fundamental analysis of the market and extrapolation of observable market data with similar characteristics. Based on these valuation techniques, as of December 31, 2017 , credit risk exposure to these counterparties attributable to the Company's ownership interests was approximately $2.7 billion for the next five years . The majority of these power contracts are with utilities with strong credit quality and public utility commission or other regulatory support. However, such regulated utility counterparties can be impacted by changes in government regulations, which the Company is unable to predict.

Accounting for Derivative Instr

Accounting for Derivative Instruments and Hedging Activities (Notes)	12 Months Ended
	Dec. 31, 2017
Derivative [Line Items]
Accounting for Derivative Instruments and Hedging Activities	Accounting for Derivative Instruments and Hedging Activities ASC 815 requires the Company to recognize all derivative instruments on the balance sheet as either assets or liabilities and to measure them at fair value each reporting period unless they qualify for a NPNS exception. The Company may elect to designate certain derivatives as cash flow hedges, if certain conditions are met, and defer the change in fair value of the derivatives to accumulated OCI/OCL, until the hedged transactions occur and are recognized in earnings. For derivatives that are not designated as cash flow hedges or do not qualify for hedge accounting treatment, the changes in the fair value will be immediately recognized in earnings. Certain derivative instruments may qualify for the NPNS exception and are therefore exempt from fair value accounting treatment. ASC 815 applies to the Company's energy related commodity contracts and interest rate swaps. Energy-Related Commodities To manage the commodity price risk associated with its competitive supply activities and the price risk associated with wholesale power sales, the Company may enter into derivative hedging instruments, namely, forward contracts that commit the Company to sell energy commodities or purchase fuels/electricity in the future. The objectives for entering into derivatives contracts designated as hedges include fixing the price for a portion of anticipated future electricity sales and fixing the price of a portion of anticipated fuel/electricity purchases for the operation of its subsidiaries. As of December 31, 2017 , the Company had forward contracts for the purchase of fuel commodities relating to the forecasted usage of the Company’s district energy centers extending through 2020 and electricity contracts to supply retail power to the Company's district energy centers extending through 2020. At December 31, 2017 , these contracts were not designated as cash flow or fair value hedges. Also, as of December 31, 2017 , the Company had other energy-related contracts that did not meet the definition of a derivative instrument or qualified for the NPNS exception and were therefore exempt from fair value accounting treatment as follows: • Power tolling contracts through 2039, and • Natural gas transportation contracts through 2028. Interest Rate Swaps The Company is exposed to changes in interest rates through the issuance of variable rate debt. In order to manage interest rate risk, it enters into interest rate swap agreements. As of December 31, 2017 , the Company had interest rate derivative instruments on non-recourse debt extending through 2036, a portion of which are designated as cash flow hedges. Volumetric Underlying Derivative Transactions The following table summarizes the net notional volume buy/(sell) of the Company's open derivative transactions broken out by commodity as of December 31, 2017 and 2016 : Total Volume December 31, 2017 December 31, 2016 Commodity Units (In millions) Natural Gas MMBtu 2 3 Interest Dollars $ 1,940 $ 2,090 Fair Value of Derivative Instruments The following table summarizes the fair value within the derivative instrument valuation on the balance sheet: Fair Value Derivative Assets (a) Derivative Liabilities December 31, 2017 December 31, 2016 December 31, 2017 December 31, 2016 (In millions) Derivatives Designated as Cash Flow Hedges: Interest rate contracts current $ — $ — $ 4 $ 26 Interest rate contracts long-term 1 1 9 39 Total Derivatives Designated as Cash Flow Hedges 1 1 13 65 Derivatives Not Designated as Cash Flow Hedges : Interest rate contracts current — — 12 6 Interest rate contracts long-term — — 22 7 Commodity contracts current 1 2 1 1 Total Derivatives Not Designated as Cash Flow Hedges 1 2 35 14 Total Derivatives $ 2 $ 3 $ 48 $ 79 (a) Derivative Asset balances classified as current are included within the prepayments and other current assets line item of the Consolidated Balance Sheet. Derivative Asset balances classified as long-term are included within the other non-current assets line item of the Consolidated Balance Sheet. The Company has elected to present derivative assets and liabilities on the balance sheet on a trade-by-trade basis and does not offset amounts at the counterparty master agreement level. As of December 31, 2017 and 2016 , there was no outstanding collateral paid or received. The following tables summarize the offsetting of derivatives by counterparty master agreement level: Gross Amounts Not Offset in the Statement of Financial Position As of December 31, 2017 Gross Amounts of Recognized Assets/Liabilities Derivative Instruments Net Amount Commodity contracts: (In millions) Derivative assets $ 1 $ — $ 1 Derivative liabilities (1 ) — (1 ) Total commodity contracts — — — Interest rate contracts: Derivative assets 1 (1 ) — Derivative liabilities (47 ) 1 (46 ) Total interest rate contracts (46 ) — (46 ) Total derivative instruments $ (46 ) $ — $ (46 ) Gross Amounts Not Offset in the Statement of Financial Position As of December 31, 2016 Gross Amounts of Recognized Assets/Liabilities Derivative Instruments Net Amount Commodity contracts: (In millions) Derivative assets $ 2 $ — $ 2 Derivative liabilities (1 ) — (1 ) Total commodity contracts 1 — 1 Interest rate contracts: Derivative assets 1 (1 ) — Derivative liabilities (78 ) 1 (77 ) Total interest rate contracts (77 ) — (77 ) Total derivative instruments $ (76 ) $ — $ (76 ) Accumulated Other Comprehensive Loss The following table summarizes the effects on the Company’s accumulated OCL balance attributable to interest rate swaps designated as cash flow hedge derivatives: Year ended December 31, 2017 2016 2015 (In millions) Accumulated OCL beginning balance $ (86 ) $ (99 ) $ (82 ) Reclassified from accumulated OCL to income due to realization of previously deferred amounts 17 17 17 Mark-to-market of cash flow hedge accounting contracts — (4 ) (34 ) Accumulated OCL ending balance (69 ) (86 ) (99 ) Accumulated OCL attributable to noncontrolling interests (1 ) (1 ) (1 ) Accumulated OCL attributable to NRG Yield LLC $ (68 ) $ (85 ) $ (98 ) Losses expected to be realized from OCL during the next 12 months $ 15 Amounts reclassified from accumulated OCL into income are recorded to interest expense. Accounting guidelines require a high degree of correlation between the derivative and the hedged item throughout the period in order to qualify as a cash flow hedge. As of December 31, 2016, the Company's regression analysis for Viento Funding II interest rate swaps, while positively correlated, did not meet the required threshold for cash flow hedge accounting. As a result, the Company de-designated the Viento Funding II cash flow hedges as of December 31, 2016, and will prospectively mark these derivatives to market through the income statement. The Company's regression analysis for Marsh Landing, Walnut Creek and Avra Valley interest rate swaps, while positively correlated, no longer contain matching terms for cash flow hedge accounting. As a result, the Company voluntarily de-designated the Marsh Landing, Walnut Creek and Avra Valley cash flow hedges as of April 28, 2017, and will prospectively mark these derivatives to market through the income statement. Impact of Derivative Instruments on the Statements of Income The Company has interest rate derivative instruments that are not designated as cash flow hedges. The effect of interest rate hedges is recorded to interest expense. For the years ended December 31, 2017 , 2016 and 2015 the impact to the consolidated statements of income was a gain of $7 million , loss of $2 million and a gain of $17 million , respectively. A portion of the Company’s derivative commodity contracts relates to its Thermal Business for the purchase of fuel/electricity commodities based on the forecasted usage of the thermal district energy centers. Realized gains and losses on these contracts are reflected in the costs that are permitted to be billed to customers through the related customer contracts or tariffs and, accordingly, no gains or losses are reflected in the consolidated statements of income for these contracts. In 2015, commodity contracts also hedged the forecasted sale of power for the Elbow Creek until the start of the PPA with NRG Power Marketing LLC, or Power Marketing, with effective date of November 1, 2015. The effect of these commodity hedges was recorded to operating revenues. For the year ended December 31, 2015 , the impact to the consolidated statements of income was an unrealized loss of $2 million . See Note 6 , Fair Value of Financial Instruments , for a discussion regarding concentration of credit risk.

Intangible Assets Intangible As

Intangible Assets Intangible Assets - (Notes)	12 Months Ended
	Dec. 31, 2017
Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets Disclosure [Text Block]	Intangible Assets Intangible Assets — The Company's intangible assets as of December 31, 2017 and 2016 primarily reflect intangible assets established from its business acquisitions and are comprised of the following: • PPAs — Established predominantly with the acquisitions of the Alta Wind Portfolio, Walnut Creek, Tapestry and Laredo Ridge, these represent the fair value of the PPAs acquired. These are amortized, generally on a straight-line basis, over the term of the PPA. • Leasehold Rights — Established with the acquisition of the Alta Wind Portfolio, this represents the fair value of contractual rights to receive royalty payments equal to a percentage of PPA revenue from certain projects. These are amortized on a straight-line basis. • Customer relationships — Established with the acquisition of NRG Energy Center Phoenix and NRG Energy Center Omaha, these intangibles represent the fair value at the acquisition date of the businesses' customer base. The customer relationships are amortized to depreciation and amortization expense based on the expected discounted future net cash flows by year. • Customer contracts — Established with the acquisition of NRG Energy Center Phoenix, these intangibles represent the fair value at the acquisition date of contracts that primarily provide chilled water, steam and electricity to its customers. These contracts are amortized to revenues based on expected volumes. • Emission Allowances — These intangibles primarily consist of SO 2 and NO x emission allowances established with the El Segundo and Walnut Creek acquisitions. These emission allowances are held-for-use and are amortized to cost of operations, with NO x allowances amortized on a straight-line basis and SO 2 allowances amortized based on units of production. • Development rights — Arising primarily from the acquisition of solar businesses in 2010 and 2011, these intangibles are amortized to depreciation and amortization expense on a straight-line basis over the estimated life of the related project portfolio. • Other — Consists primarily of the acquisition date fair value of the contractual rights to a ground lease for South Trent and to utilize certain interconnection facilities for Blythe, as well as land rights acquired in connection with the acquisition of Elbow Creek. The following tables summarize the components of intangible assets subject to amortization: Year ended December 31, 2017 PPAs Leasehold Rights Customer Customer Contracts Emission Allowances Development Other Total (In millions) January 1, 2017 $ 1,286 $ 86 $ 66 $ 15 $ 9 $ 3 $ 6 $ 1,471 Asset impairments (a) (6 ) — — — — — — (6 ) December 31, 2017 1,280 86 66 15 9 3 6 1,465 Less accumulated amortization (205 ) (13 ) (5 ) (8 ) (3 ) (1 ) (2 ) (237 ) Net carrying amount $ 1,075 $ 73 $ 61 $ 7 $ 6 $ 2 $ 4 $ 1,228 (a) $6 million of asset impairments relate to one of the November 2017 Drop Down Assets that was recorded by NRG during the quarter ended September 30, 2017, as further described in Note 9 , Asset Impairments . Year ended December 31, 2016 PPAs Leasehold Rights Customer Customer Contracts Emission Allowances Development Other Total (In millions) January 1, 2016 $ 1,286 $ 86 $ 66 $ 15 $ 15 $ 3 $ 6 $ 1,477 Other — — — — (6 ) — — (6 ) December 31, 2016 1,286 86 66 15 9 3 6 1,471 Less accumulated amortization (143 ) (9 ) (4 ) (7 ) (2 ) (1 ) (2 ) (168 ) Net carrying amount $ 1,143 $ 77 $ 62 $ 8 $ 7 $ 2 $ 4 $ 1,303 The Company recorded amortization expense of $71 million during each of years ended December 31, 2017 and 2016 , and $56 million during the year ended December 31, 2015 . Of these amounts, $70 million for each of the years ended December 31, 2017 and 2016 , and $55 million for the year ended December 31, 2015 , were recorded to contract amortization expense and reduced operating revenues in the consolidated statements of operations. The Company estimates the future amortization expense for its intangibles to be $71 million for the next five years through 2022. Out-of-market contracts — The out-of-market contract liability represents the out-of-market value of the PPAs for the Blythe solar project and Spring Canyon wind projects and the out-of-market value of the land lease for Alta Wind XI, LLC, as of their respective acquisition dates. The Blythe solar project's liability of $7 million was recorded to other non-current liabilities on the consolidated balance sheet and is amortized to revenue in the consolidated statements of income on a units-of-production basis over the twenty -year term of the agreement. Spring Canyon's liability of $3 million was recorded to other non-current liabilities and is amortized to revenue on a straight-line basis over the twenty-five year term of the agreement. The Alta Wind XI, LLC's liability of $5 million was recorded to other non-current liabilities and is amortized as a reduction to cost of operations on a straight-line basis over the thirty-four year term of the land lease. At December 31, 2017 , accumulated amortization of out-of-market contracts was $4 million and amortization expense was $1 million for each of the years ended December 31, 2017 and 2016 .

Asset Impairments Asset Impairm

Asset Impairments Asset Impairments (Notes)	12 Months Ended
	Dec. 31, 2017
Asset Impairments [Abstract]
Asset Impairment Charges [Text Block]	Asset Impairments During the quarter ended December 31, 2017 , as the Company updated its estimated cash flows in connection with the preparation and review of the Company's annual budget, the Company determined that the cash flows for Elbow Creek, located in Texas, and the Forward project, located in Pennsylvania, were below the carrying value of the related assets, primarily driven by continued declining merchant power prices in post-contract periods, and that the assets were considered impaired. The fair value of the facilities was determined using an income approach by applying a discounted cash flow methodology to the long-term budgets for each respective plant. The income approach utilized estimates of discounted future cash flows, which were Level 3 fair value measurement and include key inputs, such as forecasted power prices, operations and maintenance expense, and discount rates. The Company measured the impairment loss as the difference between the carrying amount and the fair value of the assets and recorded impairment losses of $26 million and $5 million for Elbow Creek and Forward, respectively. Additionally, during the quarter ended September 30, 2017, in connection with the preparation of the model for sale of the November 2017 Drop Down Assets, it was identified that undiscounted cash flows were lower than the book value of certain SPP funds and NRG recorded an impairment expense of $13 million , $8 million of which relates to property, plant, and equipment and $5 million to PPAs, as described in Note 8 , Intangible Assets . In accordance with the guidance for transfer of assets under common control, the impairment is reflected in the Company's consolidated statements of operations for the period ended December 31, 2017 . During the fourth quarter of 2016, as the Company updated its estimated cash flows in connection with the preparation and review of the Company's annual budget, the Company determined that the cash flows for the Elbow Creek and Goat Wind projects and the Forward project were below the carrying value of the related assets, primarily driven by declining merchant power prices in post-contract periods, and that the assets were considered impaired. These projects were acquired in connection with the acquisition of the November 2015 Drop Down Assets and were recorded as part of the Renewables segment of the Company. The projects were recorded at historical cost at acquisition date as they were related to interests under common control by NRG. The fair value of the facilities was determined using an income approach by applying a discounted cash flow methodology to the long-term budgets for each respective plant. The income approach utilized estimates of discounted future cash flows, which were Level 3 fair value measurement and include key inputs, such as forecasted power prices, operations and maintenance expense, and discount rates. The Company measured the impairment loss as the difference between the carrying amount and the fair value of the assets and recorded impairment losses of $117 million , $60 million and $6 million for Elbow Creek, Goat Wind, and Forward, respectively. Other Impairments — During the fourth quarters of 2016 and 2015, NRG recorded impairment losses of approximately $2 million and $1 million , respectively, related to the projects that were part of the November 2017 Drop Down Assets. Since the acquisition by the Company of the November 2017 Drop Down Assets related to transfer of assets under common control, these impairments were reflected in the Company's consolidated statements of operations for the periods ending December 31, 2016 and 2015.

Long-term Debt

Long-term Debt	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Long-term Debt	Long-term Debt The Company's borrowings, including short term and long term portions consisted of the following: December 31, 2017 December 31, 2016 Interest rate % (a) Letters of Credit Outstanding at December 31, 2017 (In millions, except rates) 2026 Senior Notes $ 350 $ 350 5.000 2024 Senior Notes 500 500 5.375 Long-term debt - affiliate, due 2020 281 281 3.325 Long-term debt - affiliate, due 2019 337 337 3.580 NRG Yield LLC and NRG Yield Operating LLC Revolving Credit Facility, due 2019 (b) 55 — L+2.500 74 Project-level debt: Agua Caliente Borrower 2, due 2038 41 — 5.430 17 Alpine, due 2022 135 145 L+1.750 16 Alta Wind I - V lease financing arrangements, due 2034 and 2035 926 965 5.696 - 7.015 119 CVSR, due 2037 746 771 2.339 - 3.775 — CVSR Holdco Notes, due 2037 194 199 4.680 13 El Segundo Energy Center, due 2023 400 443 L+1.75 - L+2.375 102 Energy Center Minneapolis, due 2025 83 96 5.950 — Energy Center Minneapolis Series D Notes, due 2031 125 125 3.550 — Laredo Ridge, due 2028 95 100 L+1.875 10 Marsh Landing, due 2023 318 370 L+1.875 22 Tapestry, due 2021 162 172 L+1.625 20 Utah Solar Portfolio, due 2022 278 287 various 13 Viento, due 2023 163 178 L+3.00 27 Walnut Creek, due 2023 267 310 L+1.625 41 Other 443 505 various 38 Subtotal project-level debt 4,376 4,666 Total debt 5,899 6,134 Less current maturities (306 ) (323 ) Less net debt issuance costs (54 ) (65 ) Total long-term debt $ 5,539 $ 5,746 (a) As of December 31, 2017 , L+ equals 3 month LIBOR plus x%, except for Viento, due 2023, where L + equals 6 month LIBOR plus 3.00%. (b) Applicable rate is determined by the borrower leverage ratio, as defined in the credit agreement. The financing arrangements listed above contain certain covenants, including financial covenants, that the Company is required to be in compliance with during the term of the respective arrangement. As of December 31, 2017 , the Company was in compliance with all of the required covenants. NRG Yield Operating LLC 2026 Senior Notes On August 18, 2016, Yield Operating LLC issued $350 million of senior unsecured notes, or the 2026 Senior Notes. The 2026 Senior Notes bear interest at 5.00% and mature on September 15, 2026. Interest on the notes is payable semi-annually on March 15 and September 15 of each year. The 2026 Senior Notes are senior unsecured obligations of Yield Operating LLC and are guaranteed by the Company, and by certain of Yield Operating LLC's wholly owned current and future subsidiaries. A portion of the proceeds of the 2026 Senior Notes were used to repay the Company's revolving credit facility during 2016, as described below. Yield, Inc. 2020 Convertible Senior Notes and Related Intercompany Note On June 29, 2015, Yield, Inc. closed on its offering of $288 million aggregate principal amount of 3.25% Convertible Senior Notes due 2020, or the 2020 Convertible Notes. The 2020 Convertible Notes are convertible, under certain circumstances, into Yield, Inc.'s Class C common stock, cash or a combination thereof at an initial conversion price of $27.50 per Class C common share, which is equivalent to a conversion rate of approximately 36.3636 shares of Class C common stock per $1,000 principal amount of 2020 Convertible Notes. The Company and Yield Operating LLC provided a guarantee to Yield, Inc. with respect to the 2020 Convertible Notes. In addition, Yield Operating LLC and Yield, Inc. entered into an intercompany borrowing arrangement, under which Yield Operating LLC received $281 million of the proceeds of the 2020 Convertible Notes. The intercompany note bears interest at a rate of 3.325% and matures in 2020. Yield, Inc. 2019 Convertible Senior Notes and Related Intercompany Note During the first quarter of 2014, Yield, Inc. closed on its offering of $345 million aggregate principal amount of 3.50% Convertible Senior Notes due 2019, or the 2019 Convertible Notes. The 2019 Convertible Notes were convertible, under certain circumstances, into Yield, Inc.’s Class A common stock, cash or a combination thereof at an initial conversion price of $46.55 per Class A common share, which is equivalent to a conversion rate of approximately 42.9644 shares of Class A common stock per $1,000 principal amount of 2019 Convertible Notes in accordance with the terms of the related indenture. The Company and Yield Operating LLC provided a guarantee to Yield, Inc. with respect to the 2019 Convertible Notes. In addition, Yield Operating and Yield, Inc. entered into an intercompany borrowing arrangement, under which Yield Operating borrowed $337 million of the proceeds of the 2019 Convertible Notes. The intercompany note bears interest at a rate of 3.580% and matures in 2019. NRG Yield LLC and NRG Yield Operating LLC Revolving Credit Facility The Company borrowed $55 million from the revolving credit facility during the year ended December 31, 2017 for general corporate needs as well as to fund dividend payments. The Company used its proceeds of $97.5 million from the CVSR Holdco Financing Arrangement, a portion of its proceeds from the issuance of the 2026 Senior Notes, as well as its cash on hand to repay the outstanding borrowings under the revolving credit facility during the year ended December 31, 2016. On February 6, 2018, NRG Yield Operating LLC and NRG Yield LLC amended the revolving credit facility to modify the "change of control" provisions to permit the consummation of the NRG Transaction, and also to permit NRG Yield Operating LLC, NRG Yield LLC and certain subsidiaries to incur up to $1.5 billion of unsecured indebtedness in order to repurchase or make other required cash payments, in each case if applicable, with respect to NRG Yield Operating LLC’s outstanding senior notes and NRG Yield's outstanding convertible notes in connection with the NRG Transaction. Project - level Debt November 2017 Drop Down Assets Debt As part of the November 2017 Drop Down acquisition, the Company assumed non-recourse debt of $26 million relating to certain SPP funds. The assumed debt consisted of the following: a) a term loan under a credit agreement with a bank, with a maturity date of December 31, 2038 and interest rate of 4.69% . The credit agreement includes a letter of credit supporting debt service requirements and a letter of credit in support of the PPA; b) and financing obligation in connection with a sale-leaseback transaction with a bank for a period through March 31, 2032. The company will accrete the financing obligation over the lease term based on the lease's implicit interest rate of 8% . Agua Caliente Borrower 2, due 2038 On February 17, 2017, Agua Caliente Borrower 1 LLC, an indirect subsidiary of NRG, and Agua Caliente Borrower 2 LLC, issued $130 million of senior secured notes under the Agua Caliente Borrower 1 LLC and Agua Caliente Borrower 2 LLC financing agreement, or Agua Caliente Holdco Financing Agreement, that bear interest at 5.43% and mature on December 31, 2038. As described in Note 3 , Business Acquisitions , on March 27, 2017, the Company acquired Agua Caliente Borrower 2 LLC from NRG as part of the March 2017 Drop Down Assets acquisition and assumed NRG's portion of senior secured notes under the Agua Caliente Holdco Financing Agreement. Agua Caliente Borrower 2 LLC holds $41 million of the Agua Caliente Holdco debt as of December 31, 2017 . The debt is joint and several with respect to Agua Caliente Borrower 1 LLC and Agua Caliente Borrower 2 LLC and is secured by the equity interests of each borrower in the Agua Caliente solar facility. Utah Solar Portfolio, due 2022 As part of the March 2017 Drop Down Assets acquisition, the Company assumed non-recourse debt of $287 million relating to the Utah Solar Portfolio at an interest rate of LIBOR plus 2.625% . The debt matures on December 16, 2022. The $287 million consisted of $222 million outstanding at the time of NRG's acquisition of the Utah Solar Portfolio on November 2, 2016, and additional borrowings of $65 million , net of debt issuance costs, incurred during 2016. The Company holds $278 million of the Utah Solar Portfolio debt as of December 31, 2017 . Thermal Financing On October 31, 2016, NRG Energy Center Minneapolis LLC, a subsidiary of the Company, received proceeds of $125 million from the issuance of 3.55% Series D notes due October 31, 2031, or the Series D Notes, and entered into a shelf facility for the anticipated issuance of an additional $70 million of Series E notes at a 4.80% fixed rate. The Series D Notes will be secured by substantially all of the assets of NRG Energy Center Minneapolis LLC. NRG Thermal LLC has guaranteed the indebtedness and its guarantee is secured by a pledge of the equity interests in all of NRG Thermal LLC’s subsidiaries. NRG Energy Center Minneapolis LLC distributed the proceeds of the Series D Notes to NRG Thermal LLC, which in turn distributed the proceeds to NRG Yield Operating LLC to be utilized for general corporate purposes, including potential acquisitions. On March 16, 2017, NRG Energy Center Minneapolis LLC, a subsidiary of NRG Thermal LLC, amended the shelf facility of its existing Thermal financing arrangement to allow for the issuance of an additional $10 million of Series F notes at a 4.60% interest rate, or Series F Notes, increasing the total principal amount of notes available for issuance under the shelf facility to $80 million . The Series E and Series F Notes will be secured by substantially all of the assets of NRG Energy Center Minneapolis LLC. NRG Thermal LLC has guaranteed the indebtedness and its guarantee is secured by a pledge of the equity interests in all of NRG Thermal LLC’s subsidiaries. CVSR Holdco Notes, due 2037 On July 15, 2016, CVSR Holdco, the indirect owner of the CVSR solar facility, issued $200 million of senior secured notes under the CVSR Holdco Financing Agreement, or 2037 CVSR Holdco Notes, that bear interest at 4.68% and mature on March 31, 2037. Net proceeds were distributed to the Company and NRG based on their respective ownership as of July 15, 2016, and, accordingly, the Company received net proceeds of $97.5 million . As described in Note 3 , Business Acquisitions , on September 1, 2016, the Company acquired the remaining 51.05% of CVSR, and assumed additional debt of $496 million , which represents 51.05% of the CVSR project level debt and 51.05% of the 2037 CVSR Holdco Notes. In connection with the retrospective adjustment of prior periods, as described in Note 1 , Nature of Business , the Company now consolidates CVSR and 100% of its debt, consisting of $771 million of project level debt and $200 million of 2037 CVSR Holdco Notes as of September 1, 2016. Interest Rate Swaps — Project Financings Many of the Company's project subsidiaries entered into interest rate swaps, intended to hedge the risks associated with interest rates on non-recourse project level debt. These swaps amortize in proportion to their respective loans and are floating for fixed where the project subsidiary pays its counterparty the equivalent of a fixed interest payment on a predetermined notional value and will receive quarterly the equivalent of a floating interest payment based on the same notional value. All interest rate swap payments by the project subsidiary and its counterparty are made quarterly and the LIBOR is determined in advance of each interest period. The following table summarizes the swaps, some of which are forward starting as indicated, related to the Company's project level debt as of December 31, 2017 : % of Principal Fixed Interest Rate Floating Interest Rate Notional Amount at December 31, 2017 (In millions) Effective Date Maturity Date Alpine 85 % various 3-Month LIBOR $ 115 various various Avra Valley 85 % 2.333 % 3-Month LIBOR 46 November 30, 2012 November 30, 2030 AWAM 100 % 2.47 % 3-Month LIBOR 17 May 22, 2013 May 15, 2031 Blythe 75 % 3.563 % 3-Month LIBOR 13 June 25, 2010 June 25, 2028 Borrego 75 % 1.125 % 3-Month LIBOR 5 April 3, 2013 June 30, 2020 El Segundo 75 % various 3-Month LIBOR 340 various various Kansas South 75 % 2.368 % 6-Month LIBOR 21 June 28, 2013 December 31, 2030 Laredo Ridge 75 % 2.31 % 3-Month LIBOR 75 March 31, 2011 March 31, 2026 Marsh Landing 75 % 3.244 % 3-Month LIBOR 295 June 28, 2013 June 30, 2023 Roadrunner 75 % 4.313 % 3-Month LIBOR 26 September 30, 2011 December 31, 2029 South Trent 75 % 3.265 % 3-Month LIBOR 40 June 15, 2010 June 14, 2020 South Trent 75 % 4.95 % 3-Month LIBOR 21 June 30, 2020 June 14, 2028 Tapestry 75 % 2.21 % 3-Month LIBOR 146 December 30, 2011 December 21, 2021 Tapestry 50 % 3.57 % 3-Month LIBOR 60 December 21, 2021 December 21, 2029 Utah Solar Portfolio 80 % various 1-Month LIBOR 223 various September 30, 2036 Viento Funding II 90 % various 6-Month LIBOR 148 various various Viento Funding II 90 % 4.985 % 6-Month LIBOR 65 July 11, 2023 June 30, 2028 Walnut Creek Energy 75 % various 3-Month LIBOR 239 June 28, 2013 May 31, 2023 WCEP Holdings 90 % 4.003 % 3-Month LIBOR 45 June 28, 2013 May 31, 2023 Total $ 1,940 Annual Maturities Annual payments based on the maturities of the Company's debt, for the years ending after December 31, 2017 , are as follows: (In millions) 2018 $ 306 2019 714 2020 650 2021 455 2022 653 Thereafter 3,121 Total $ 5,899

Members' Equity (Notes)

Members' Equity (Notes)	12 Months Ended
	Dec. 31, 2017
Members' Equity [Abstract]
Stockholders' Equity Note Disclosure [Text Block]	Members' Equity The following table lists the distributions paid on the Company's Class A, Class B, Class C and Class D units during the year ended December 31, 2017 : Fourth Quarter 2017 Third Quarter 2017 Second Quarter 2017 First Quarter 2017 Distributions per Class A and Class B units $ 0.288 $ 0.28 $ 0.27 $ 0.26 Distributions per Class C and Class D units $ 0.288 $ 0.28 $ 0.27 $ 0.26 On February 15, 2018 , the Company declared a quarterly distribution on its Class A, Class B, Class C and Class D units of $0.298 per share payable on March 15, 2018 . During 2017 , 2016 , and 2015 , the Company acquired the Drop Down Assets from NRG, as described in Note 3 , Business Acquisitions . The difference between the cash paid and historical value of the acquired Drop Down Assets was recorded as a distribution to/contribution from NRG with the offset to contributed capital. Prior to the date of acquisition, certain of the projects made distributions to NRG and NRG made contributions into certain projects. These amounts are reflected within the Company’s statement of stockholders’ equity as changes in the contributed capital balance.

Segment Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2017
Segment Reporting	Segment Reporting The Company’s segment structure reflects how management currently operates and allocates resources. The Company's businesses are segregated based on conventional power generation, renewable businesses which consist of solar and wind, and the thermal and chilled water business. The Corporate segment reflects the Company's corporate costs. The Company's chief operating decision maker, its Chief Executive Officer, evaluates the performance of its segments based on operational measures including adjusted earnings before interest, taxes, depreciation and amortization, or Adjusted EBITDA, and CAFD, as well as economic gross margin and net income (loss). The Company generated more than 10% of its revenues from the following customers for the years ended December 31, 2017 , 2016 and 2015 : 2017 2016 2015 Customer Conventional (%) Renewables (%) Conventional (%) Renewables (%) Conventional (%) Renewables (%) SCE 21% 20% 21% 21% 22% 17% PG&E 12% 11% 12% 11% 12% 12% Year ended December 31, 2017 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues $ 336 $ 501 $ 172 $ — $ 1,009 Cost of operations 77 133 116 — 326 Depreciation and amortization 103 210 21 — 334 Impairment losses — 44 — — 44 General and administrative — — — 19 19 Acquisition-related transaction and integration costs — — — 3 3 Operating income (loss) 156 114 35 (22 ) 283 Equity in earnings of unconsolidated affiliates 12 59 — — 71 Other income, net 1 2 — 1 4 Loss on debt extinguishment — (3 ) — — (3 ) Interest expense (49 ) (163 ) (10 ) (71 ) (293 ) Net Income (Loss) $ 120 $ 9 $ 25 $ (92 ) $ 62 Balance Sheet Equity investment in affiliates $ 102 $ 1,076 $ — $ — $ 1,178 Capital expenditures (a) 15 4 16 — 35 Total Assets $ 1,897 $ 5,811 $ 422 $ 24 $ 8,154 (a) Includes accruals. Year ended December 31, 2016 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues $ 333 $ 532 $ 170 $ — $ 1,035 Cost of operations 66 128 114 — 308 Depreciation and amortization 80 203 20 — 303 Impairment losses — 185 — — 185 General and administrative — — — 14 14 Acquisition-related transaction and integration costs — — — 1 1 Operating income (loss) 187 16 36 (15 ) 224 Equity in earnings of unconsolidated affiliates 13 47 — — 60 Other income, net 1 2 — — 3 Interest expense (48 ) (151 ) (7 ) (66 ) (272 ) Net Income (Loss) $ 153 $ (86 ) $ 29 $ (81 ) $ 15 Balance Sheet Equity investments in affiliates $ 106 $ 1,046 $ — $ — $ 1,152 Capital expenditures (a) 7 2 14 — 23 Total Assets $ 1,993 $ 6,114 $ 426 $ 213 $ 8,746 (a) Includes accruals. Year ended December 31, 2015 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues $ 336 $ 458 $ 174 $ — $ 968 Cost of operations 59 138 126 — 323 Depreciation and amortization 81 203 19 — 303 Impairment losses — 1 — — 1 General and administrative — — — 10 10 Acquisition-related transaction and integration costs — — — 3 3 Operating income (loss) 196 116 29 (13 ) 328 Equity in earnings of unconsolidated affiliates 14 17 — — 31 Other income, net 1 2 — — 3 Loss on debt extinguishment (7 ) (2 ) — — (9 ) Interest expense (48 ) (151 ) (7 ) (52 ) (258 ) Net Income (Loss) $ 156 $ (18 ) $ 22 $ (65 ) $ 95

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2017
Related Party Transaction [Line Items]
Related Party Transactions Disclosure	Related Party Transactions In addition to the transactions and relationships described elsewhere in the notes to the consolidated financial statements, certain subsidiaries of NRG provide services to the Company's project entities. Amounts due to NRG subsidiaries are recorded as accounts payable — affiliate and amounts due to the Company from NRG subsidiaries are recorded as accounts receivable — affiliate in the Company's balance sheet. The disclosures below summarize the Company's material related party transactions with NRG and its subsidiaries that are included in the Company's operating revenues and operating costs. Power Hedge Contracts by and between Renewable Entities and NRG Texas Power LLC Certain NRG Wind TE Holdco entities, which are subsidiaries in the Renewables segment, entered into power hedge contracts with NRG Texas Power LLC, a subsidiary of NRG, and generated $16 million of revenue during the year ended December 31, 2015. Effective October 2015, Elbow Creek entered into a PPA with NRG Power Marketing LLC, or NRG Power Marketing, a wholly-owned subsidiary of NRG, as further described below, and the hedge agreement between Elbow Creek and NRG Texas Power LLC was terminated. Power Purchase Agreements (PPAs) between the Company and NRG Power Marketing Elbow Creek and Dover are parties to PPAs with NRG Power Marketing and generate revenue under the PPAs, which are recorded to operating revenues in the Company's consolidated statements of operations. For the years ended December 31, 2017 and 2016 , Elbow Creek generated revenues of $8 million each year, and Dover generated revenues of $4 million and $5 million , respectively. Energy Marketing Services Agreement by and between Thermal entities and NRG Power Marketing NRG Energy Center Dover LLC, NRG Energy Center Minneapolis, NRG Energy Center Phoenix LLC, and NRG Energy Center Paxton LLC, or Thermal entities, are parties to Energy Marketing Services Agreements with NRG Power Marketing, a wholly-owned subsidiary of NRG. Under the agreements, NRG Power Marketing procures fuel and fuel transportation for the operation of Thermal entities. The Thermal entities purchased a total of $9 million of natural gas during each of the years ended December 31, 2017 and 2016. During the year ended December 31, 2015 total purchases of natural gas under the agreement were $13 million . Operation and Maintenance (O&M) Services Agreements by and between Company's subsidiaries and NRG Certain of the Company's subsidiaries are party to O&M Services Agreements with NRG, pursuant to which NRG subsidiaries provide necessary and appropriate services to operate and maintain the subsidiaries' plant operations, businesses and thermal facilities. NRG is reimbursed for the provided services, as well as for all reasonable and related expenses and expenditures, and payments to third parties for services and materials rendered to or on behalf of the parties to the agreements. NRG is not entitled to any management fee or mark-up under the agreements. The fees incurred under this agreement were $39 million for the year ended December 31, 2017, and $36 million for each year ended December 31, 2016 and 2015 . The Company had $13 million due to NRG for the services performed during the year ended December 31, 2017 under the O&M Agreements, $5 million of which was paid off as of March 1, 2018. The Company had $22 million due to NRG for the services performed during the year ended December 31, 2016 under the O&M Agreements. O&M Services Agreements by and between GenConn and NRG GenConn incurs fees under two O&M agreements with wholly-owned subsidiaries of NRG. The fees incurred under the agreements were $5 million each year for the years ended December 31, 2017 and 2016 , and $4 million for the year ended December 31, 2015 . Administrative Services Agreement by and between Marsh Landing and NRG West Coast LLC On December 19, 2016, Marsh Landing entered into an administrative services agreement with NRG West Coast LLC, a wholly owned subsidiary of NRG. The administrative services agreement was previously between Marsh Landing and GenOn Energy Services, LLC, a wholly-owned subsidiary of NRG and was subsequently assigned to and assumed by NRG West Coast LLC. The Company reimbursed costs under this agreement of approximately $15 million , $14 million and $13 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. There was a balance of $1 million due to NRG West Coast LLC in accounts payable — affiliate as of December 31, 2017 and 2016 . Administrative Services Agreements by and between the Company and NRG Renew Operation & Maintenance LLC Various wholly-owned subsidiaries of the Company in the Renewables segment are party to administrative services agreements with NRG Renew Operation & Maintenance LLC, or RENOM, a wholly-owned subsidiary of NRG, which provides O&M services to these subsidiaries. The Company incurred total expenses for these services in the amount of $23 million , $13 million and $7 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. There was a balance of $5 million due to RENOM as of December 31, 2017 and 2016 . Management Services Agreement by and between the Company and NRG NRG provides the Company with various operational, management, and administrative services, which include human resources, accounting, tax, legal, information systems, treasury, and risk management, as set forth in the Management Services Agreement. As of December 31, 2017 , the base management fee was approximately $8.5 million per year, subject to an inflation-based adjustment annually, at an inflation factor based on the year-over-year U.S. consumer price index. The fee is also subject to adjustments following the consummation of future acquisitions and as a result of a change in the scope of services provided under the Management Services Agreement. During the year ended December 31, 2017 , the fee was increased by approximately $1 million per year, primarily due to the acquisition of the March 2017, August 2017 and November 2017 Drop Down Assets, as further described in Note 3 , Business Acquisitions . In addition to the base management fee, the Company is also responsible for any expenses that are directly incurred and paid for by NRG on behalf of the Company. Costs incurred under this agreement were approximately $10 million for each of the years ended December 31, 2017 and 2016 , and $8 million for the year ended December 31, 2015 . There was a balance of $4 million in accounts payable — affiliate due to NRG as of December 31, 2017 , which the Company paid off in January 2018. EPC Agreement by and between NECP and NRG On October 31, 2016, NRG Business Services LLC, a subsidiary of NRG, and NECP, a wholly owned subsidiary of the Company, entered into an EPC agreement for the construction of a 73 MWt district energy system for NECP to provide 150 kpph of steam, 6,750 tons of chilled water and 7.5 MW of emergency backup power service to UPMC Mercy. The initial term of the energy services agreement with UPMC Mercy will be for a period of twenty years from the service commencement date. Pursuant to the terms of the EPC agreement, NECP agreed to pay NRG Business Services LLC $79 million , subject to adjustment based upon certain conditions in the EPC agreement, upon substantial completion of the project. The project is expected to reach COD in the first half of 2018. As of December 31, 2017, the parties made a number of amendments to the EPC Agreement, based on customer change orders, to increase the capacity of the district energy system from 73 MWt to 80 MWt, which also increased the payment from $79 million to $88 million .

Commitments and Contingencies (

Commitments and Contingencies (Notes)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Text Block]	Commitments and Contingencies Operating Lease Commitments The Company leases certain facilities and equipment under operating leases, some of which include escalation clauses, expiring on various dates through 2048. The effects of these scheduled rent increases, leasehold incentives, and rent concessions are recognized on a straight-line basis over the lease term unless another systematic and rational allocation basis is more representative of the time pattern in which the leased property is physically employed. Lease expense under operating leases was $17 million , $15 million and $10 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. The Company's future minimum lease commitments under operating leases are $9 million for each of the years ending December 31, 2018 through 2022, and $151 million thereafter. Period Gas and Transportation Commitments The Company has entered into contractual arrangements to procure power, fuel and associated transportation services. For the years ended December 31, 2017 , 2016 and 2015 , the Company purchased $34 million , $32 million and $40 million , respectively, under such arrangements. As further described in Note 13 Related Party Transactions , these purchases include intercompany transactions between certain Thermal entities and NRG Power Marketing under the Energy Marketing Services Agreements in the amount of $9 million for each of the years ended December 31, 2017 and 2016 . Total intercompany purchases of natural gas under the agreement were $13 million for the year ended December 31, 2015. As of December 31, 2017 , the Company's commitments under such outstanding agreements are estimated as follows: Period (In millions) 2018 $ 11 2019 5 2020 3 2021 3 2022 3 Thereafter 16 Total $ 41 Contingencies The Company's material legal proceedings are described below. The Company believes that it has valid defenses to these legal proceedings and intends to defend them vigorously. The Company records reserves for estimated losses from contingencies when information available indicates that a loss is probable and the amount of the loss, or range of loss, can be reasonably estimated. As applicable, the Company has established an adequate reserve for the matters discussed below. In addition, legal costs are expensed as incurred. Management assesses such matters based on current information and makes a judgment concerning its potential outcome, considering the nature of the claim, the amount and nature of damages sought and the probability of success. The Company is unable to predict the outcome of the legal proceedings below or reasonably estimate the scope or amount of any associated costs and potential liabilities. As additional information becomes available, management adjusts its assessment and estimates of such contingencies accordingly. Because litigation is subject to inherent uncertainties and unfavorable rulings or developments, it is possible that the ultimate resolution of the Company's liabilities and contingencies could be at amounts that are different from its currently recorded reserves and that such difference could be material. In addition to the legal proceedings noted below, the Company and its subsidiaries are party to other litigation or legal proceedings arising in the ordinary course of business. In management's opinion, the disposition of these ordinary course matters will not materially adversely affect the Company's consolidated financial position, results of operations, or cash flows. Braun v. NRG Yield, Inc. — On April 19, 2016, plaintiffs filed a putative class action lawsuit against NRG Yield, Inc., the current and former members of its board of directors individually, and other parties in California Superior Court in Kern County, CA. Plaintiffs allege various violations of the Securities Act due to the defendants’ alleged failure to disclose material facts related to low wind production prior to NRG Yield, Inc.'s June 22, 2015 Class C common stock offering. Plaintiffs seek compensatory damages, rescission, attorney’s fees and costs. The defendants filed objections and a motion challenging jurisdiction on October 18, 2016. On December 1, 2017, the parties agreed to a stipulation which provides the plaintiffs' opposition is due on March 6, 2018 and the defendants' reply is due on May 4, 2018. Ahmed v. NRG Energy, Inc. and the NRG Yield Board of Directors — On September 15, 2016, plaintiffs filed a putative class action lawsuit against NRG Energy, Inc., the directors of NRG Yield, Inc., and other parties in the Delaware Chancery Court. The complaint alleges that the defendants breached their respective fiduciary duties with regard to the recapitalization of NRG Yield, Inc. common stock in 2015. The plaintiffs generally seek economic damages, attorney’s fees and injunctive relief. The defendants filed a motion to dismiss the lawsuit on December 21, 2016. Plaintiffs filed their objection to the motion to dismiss on February 15, 2017. The defendants' reply was filed on March 24, 2017. The court heard oral argument on the defendants' motion to dismiss on June 20, 2017. On September 7, 2017, the court requested additional briefing which the parties provided on September 21, 2017. On December 11, 2017, the court dismissed the lawsuit with prejudice, thereby ending the case. GenOn Noteholders' Lawsuit — On December 13, 2016, certain indenture trustees for an ad hoc group of holders, or the Noteholders, of the GenOn Energy, Inc., or GenOn, 7.875% Senior Notes due 2017, 9.500% Notes due 2018, and 9.875% Notes due 2020, and the GenOn Americas Generation, LLC 8.50% Senior Notes due 2021 and 9.125% Senior Notes due 2031, along with certain of the Noteholders, filed a complaint in the Superior Court of the State of Delaware against NRG and GenOn alleging certain claims related to the Services Agreement between NRG and GenOn. On April 30, 2017, the Noteholders filed an amended complaint that asserts additional claims of fraudulent transfer, insider preference and breach of fiduciary duties. In addition to NRG and GenOn, the amended complaint names NRG Yield LLC and certain current and former officers and directors of GenOn as defendants. The plaintiffs, among other things, generally seek return of all monies paid under the Services Agreement and any other damages that the court deems appropriate. On April 28, 2017, the bondholders filed an amended complaint adding the GenOn directors and officers as defendants and asserting claims that they breached certain fiduciary duties. Plaintiffs specifically allege that the transfer of Marsh Landing to NRG Yield LLC constituted a fraudulent transfer. On June 12, 2017, certain GenOn entities, NRG and certain holders of the GenOn and GenOn Americas Generation, LLC senior notes entered into a restructuring support and lock-up agreement. On December 14, 2017, a settlement agreement was entered into between GenOn and NRG which should ultimately resolve this lawsuit.

Unaudited Quarterly Financial D

Unaudited Quarterly Financial Data (Notes)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Quarterly Financial Information [Text Block]	Unaudited Quarterly Data Refer to Note 2 , Summary of Significant Accounting Policies and Note 3 , Business Acquisitions for a description of the effect of unusual or infrequently occurring events during the quarterly periods. Below is summarized unaudited quarterly financial data, which includes the results of the November 2017 Drop Down Assets Acquisition and its impact on every quarter of the 2017 and 2016 results, which were recast to include the November 2017 Drop Down Assets, where applicable: Quarter Ended December 31, September 30, June 30, March 31, 2017 (In millions) Operating Revenues $ 231 $ 269 $ 288 $ 221 Operating Revenues (as previously reported) N/A 265 284 218 Change N/A 4 4 3 Operating Income 19 85 124 55 Operating Income (as previously reported) N/A 95 122 54 Change N/A (10 ) 2 1 Net (Loss) Income (38 ) 41 59 — Net Income (as previously reported) N/A 52 57 1 Change N/A $ (11 ) $ 2 $ (1 ) Quarter Ended December 31, September 30, June 30, March 31, 2016 (In millions) Operating Revenues $ 235 $ 276 $ 287 $ 237 Operating Revenues (as previously reported) 232 272 283 234 Change 3 4 4 3 Operating (Loss) Income (100 ) 120 130 74 Operating (Loss) Income (as previously reported) (99 ) 118 128 73 Change (1 ) 2 2 1 Net (Loss) Income (138 ) 68 80 5 Net (Loss) Income (as previously reported) (137 ) 67 79 6 Change $ (1 ) $ 1 $ 1 $ (1 )

Condensed Consolidating Financi

Condensed Consolidating Financial Information Condensed Consolidating Financial Information	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Leases [Abstract]
Condensed Financial Statements [Text Block]	Condensed Consolidating Financial Information As of December 31, 2017 , Yield Operating LLC had outstanding $500 million of the 2024 Senior Notes and $350 million of the 2026 Senior Notes, collectively Senior Notes, as described in Note 10 , Long-term Debt . These Senior Notes are guaranteed by the Company, as well as certain of the Company's subsidiaries, or guarantor subsidiaries. These guarantees are both joint and several. The non-guarantor subsidiaries include the rest of the Company's subsidiaries, including the ones that are subject to project financing. Unless otherwise noted below, each of the following guarantor subsidiaries fully and unconditionally guaranteed the Senior Notes as of December 31, 2017 : NRG Yield LLC Alta Wind 1-5 Holding Company, LLC Alta Wind Company, LLC NRG Energy Center Omaha Holdings LLC NRG Energy Center Omaha LLC NYLD Fuel Cell Holdings LLC UB Fuel Cell, LLC NRG South Trent Holdings LLC NRG Yield DGPV Holding LLC NRG Yield RPV Holding LLC Yield Operating LLC conducts much of its business through and derives much of its income from its subsidiaries. Therefore, its ability to make required payments with respect to its indebtedness and other obligations depends on the financial results and condition of its subsidiaries and Yield Operating LLC's ability to receive funds from its subsidiaries. There are no restrictions on the ability of any of the guarantor subsidiaries to transfer funds to Yield Operating LLC. However, there may be restrictions for certain non-guarantor subsidiaries. The following condensed consolidating financial information presents the financial information of Yield LLC, Yield Operating LLC, the issuer of the Senior Notes, the guarantor subsidiaries and the non-guarantor subsidiaries in accordance with Rule 3-10 under the SEC Regulation S-X. The financial information may not necessarily be indicative of results of operations or financial position had the guarantor subsidiaries or non-guarantor subsidiaries operated as independent entities. In this presentation, Yield LLC consists of parent company operations. Guarantor subsidiaries and non-guarantor subsidiaries of Yield LLC are reported on an equity basis. For companies acquired, the fair values of the assets and liabilities acquired have been presented on a push-down accounting basis. As described in Note 3 , Business Acquisitions , the Company completed the acquisition of the November 2017 Drop Down Assets, August 2017 Drop Down Assets, and March 2017 Drop Down Assets from NRG on November 1, 2017, August 1, 2017 and March 27, 2017, respectively. The guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control. Accordingly, the Company prepared its condensed consolidating financial statements to reflect the transfers as if they had taken place from the beginning of the financial statements period. In addition, the condensed parent company financial statements are provided in accordance with Rule 12-04, Schedule I of Regulation S-X, as the restricted net assets of Yield LLC’s subsidiaries exceed 25 percent of the consolidated net assets of Yield LLC. These statements should be read in conjunction with the consolidated statements and notes thereto of NRG Yield LLC. For a discussion of Yield LLC's long-term debt, see Note 10 , Long-term Debt . For a discussion of Yield LLC's commitments and contingencies, see Note 14 , Commitments and Contingencies . For a discussion of Yield LLC's distributions to Yield, Inc. and NRG Energy, see Note 11 , Members' Equity . For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 988 $ 1 $ (1 ) $ 1,009 Operating Costs and Expenses — Cost of operations — 14 312 1 (1 ) 326 Depreciation and amortization — 5 329 — — 334 Impairment losses — — 44 — — 44 General and administrative — — — 19 — 19 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 19 685 23 (1 ) 726 Operating (Loss) Income — 2 303 (22 ) — 283 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 136 (16 ) — 126 (246 ) — Equity in earnings of unconsolidated affiliates — 22 21 28 — 71 Other income, net 1 — 3 — — 4 Loss on debt extinguishment — — (3 ) — — (3 ) Interest expense — — (222 ) (71 ) — (293 ) Total other income (expense), net 137 6 (201 ) 83 (246 ) (221 ) Net Income 137 8 102 61 (246 ) 62 Less: Net loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Net Income Attributable to NRG Yield LLC $ 137 $ 8 $ 107 $ 136 $ (251 ) $ 137 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. For the year ended December 31, 2017 NRG Yield LLC (a) Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 137 $ 8 $ 102 $ 61 $ (246 ) $ 62 Other Comprehensive Income Unrealized gain on derivatives 17 1 16 17 (34 ) 17 Other comprehensive income 17 1 16 17 (34 ) 17 Comprehensive Income 154 9 118 78 (280 ) 79 Less: Comprehensive loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Comprehensive Income Attributable to NRG Yield LLC $ 154 $ 9 $ 123 $ 153 $ (285 ) $ 154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 22 $ — $ 124 $ — $ — $ 146 Restricted cash — — 168 — — 168 Accounts receivable — trade 1 2 92 1 — 96 Inventory — 1 38 — — 39 Notes receivable — current — — 13 — — 13 Prepayments and other current assets — — 18 1 — 19 Total current assets 23 3 453 2 — 481 Property, plant and equipment, net — 58 5,146 — — 5,204 Other Assets Investment in consolidated subsidiaries 1,823 460 — 3,177 (5,460 ) — Equity investments in affiliates — 233 577 368 — 1,178 Intangible assets, net — 55 1,173 — — 1,228 Other non-current assets — — 63 — — 63 Total other assets 1,823 748 1,813 3,545 (5,460 ) 2,469 Total Assets $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 306 $ — $ — $ 306 Accounts payable — trade — 2 25 — — 27 Accounts payable — affiliate — 5 27 16 — 48 Derivative instruments — — 17 — — 17 Accrued expenses and other current liabilities — 1 61 25 — 87 Total current liabilities — 8 436 41 — 485 Other Liabilities Long-term debt — external — — 4,025 896 — 4,921 Long-term debt — affiliate — — — 618 — 618 Derivative instruments — — 31 — — 31 Other non-current liabilities — — 84 7 — 91 Total non-current liabilities — — 4,140 1,521 — 5,661 Total Liabilities — 8 4,576 1,562 — 6,146 Commitments and Contingencies Members' Equity Contributed capital 1,897 863 2,871 2,097 (5,831 ) 1,897 Retained earnings (accumulated deficit) 17 (61 ) (21 ) (206 ) 288 17 Accumulated other comprehensive loss (68 ) (1 ) (71 ) (68 ) 140 (68 ) Noncontrolling interest — — 57 162 (57 ) 162 Total Members' Equity 1,846 801 2,836 1,985 (5,460 ) 2,008 Total Liabilities and Members’ Equity $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 58 $ 529 $ (71 ) $ 516 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (15 ) — — 15 — Acquisition of Drop Down Assets, net of cash acquired — — — (250 ) (250 ) Capital expenditures — (4 ) (27 ) — (31 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 10 14 23 47 Investments in unconsolidated affiliates — (64 ) (7 ) (2 ) (73 ) Other — — 7 — 7 Net Cash Provided by (Used in) Investing Activities (15 ) (58 ) 4 (214 ) (283 ) Cash Flows from Financing Activities Net contributions from noncontrolling interests — — 2 11 13 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (13 ) (7 ) (20 ) Transfer of funds under intercompany cash management arrangement (5 ) — (1 ) 6 — Proceeds from the issuance of Class C units 33 — — — 33 (Payments of) proceeds from distributions (202 ) — (220 ) 220 (202 ) Proceeds from the revolving credit facility — — — 55 55 Proceeds from issuance of long-term debt — — 41 — 41 Payments of debt issuance costs — — (4 ) — (4 ) Payments for long-term debt — external — — (332 ) — (332 ) Net Cash (Used in) Provided by Financing Activities (174 ) — (527 ) 285 (416 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (189 ) — 6 — (183 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 211 — 286 — 497 Cash, Cash Equivalents and Restricted Cash at End of Period $ 22 $ — $ 292 $ — $ 314 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 22 $ 1,013 $ 1 $ (1 ) $ 1,035 Operating Costs and Expenses Cost of operations — 14 294 1 (1 ) 308 Depreciation and amortization — 5 298 — — 303 Impairment losses — — 185 — — 185 General and administrative 2 — — 12 — 14 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses 2 19 777 14 (1 ) 811 Operating Income (Loss) (2 ) 3 236 (13 ) — 224 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 128 10 — 66 (204 ) — Equity in earnings of unconsolidated affiliates — 9 21 30 — 60 Other income, net — — 3 — — 3 Interest expense — — (206 ) (66 ) — (272 ) Total other income (expense) 128 19 (182 ) 30 (204 ) (209 ) Net Income 126 22 54 17 (204 ) 15 Less: Net loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Net Income Attributable to NRG Yield LLC $ 126 $ 22 $ 55 $ 128 $ (205 ) $ 126 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income $ 126 $ 22 $ 54 $ 17 $ (204 ) $ 15 Other Comprehensive Income Unrealized gain on derivatives 13 1 10 13 (24 ) 13 Other comprehensive income 13 1 10 13 (24 ) 13 Comprehensive Income 139 23 64 30 (228 ) 28 Less: Comprehensive loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Comprehensive Income Attributable to NRG Yield LLC $ 139 $ 23 $ 65 $ 141 $ (229 ) $ 139 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2016 NRG Yield LLC (a)(c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b)(c) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 211 $ — $ 110 $ — $ — $ 321 Restricted cash — — 176 — — 176 Accounts receivable — trade — 2 94 — — 96 Inventory — 2 37 — — 39 Notes receivable — current — — 16 — — 16 Prepayments and other current assets — — 21 1 — 22 Total current assets 211 4 454 1 — 670 Property, plant and equipment, net — 59 5,495 — — 5,554 Other Assets Investment in consolidated subsidiaries 1,927 527 — 3,272 (5,726 ) — Equity investments in affiliates — 171 600 381 — 1,152 Intangible assets, net — 56 1,247 — — 1,303 Other non-current assets — — 66 1 — 67 Total other assets 1,927 754 1,913 3,654 (5,726 ) 2,522 Total Assets $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b) (c) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 323 $ — $ — $ 323 Accounts payable — trade — 2 18 3 — 23 Accounts payable — affiliate — 7 15 18 — 40 Derivative instruments — — 33 — — 33 Accrued expenses and other current liabilities — 1 60 24 — 85 Total current liabilities — 10 449 45 — 504 Other Liabilities Long-term debt — external — — 4,289 839 — 5,128 Long-term debt — affiliate — — — 618 — 618 Accounts payable — affiliate — — 9 — — 9 Derivative instruments — — 46 — — 46 Other non-current liabilities — — 77 — — 77 Total non-current liabilities — — 4,421 1,457 — 5,878 Total Liabilities — 10 4,870 1,502 — 6,382 Commitments and Contingencies Members' Equity Contributed capital 2,179 874 2,972 2,155 (6,001 ) 2,179 Retained earnings (accumulated deficit) 44 (65 ) 43 (143 ) 165 44 Accumulated other comprehensive loss (85 ) (2 ) (87 ) (85 ) 174 (85 ) Noncontrolling interest — — 64 226 (64 ) 226 Total Members' Equity 2,138 807 2,992 2,153 (5,726 ) 2,364 Total Liabilities and Members’ Equity $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2016 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated Net Cash Provided by (Used in) Operating Activities $ — $ 62 $ 554 $ (39 ) $ 577 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 325 — (21 ) (304 ) — Acquisition of Drop Down Assets — — — (77 ) (77 ) Capital expenditures — — (20 ) — (20 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 16 — 12 28 Investments in unconsolidated affiliates — (80 ) (3 ) — (83 ) Other — — 4 — 4 Net Cash Used in Investing Activities 325 (64 ) (23 ) (369 ) (131 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement 44 2 — (46 ) — Net contributions from noncontrolling interests — — — 5 5 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (174 ) (10 ) (184 ) (Payments of) proceeds from distributions (173 ) — (420 ) 420 (173 ) Proceeds from the revolving credit facility — — — 60 60 Payments for the revolving credit facility — — — (366 ) (366 ) Proceeds from the issuance of long-term debt - external — — 390 350 740 Payments of debt issuance costs — — (10 ) (5 ) (15 ) Payments for long-term debt — external — — (269 ) — (269 ) Net Cash Provided by (Used in) Financing Activities (129 ) 2 (483 ) 408 (202 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash 196 — 48 — 244 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 15 — 238 — 253 Cash, Cash Equivalents and Restricted Cash at End of Period $ 211 $ — $ 286 $ — $ 497 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 937 $ 10 $ — $ 968 Operating Costs and Expenses Cost of operations — 14 309 — — 323 Depreciation and amortization — 4 299 — — 303 Impairment losses — — 1 — — 1 General and administrative — — — 10 — 10 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 18 609 13 — 640 Operating Income (Loss) — 3 328 (3 ) — 328 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 157 (43 ) — 125 (239 ) — Equity in (losses) earnings of unconsolidated affiliates — (2 ) 8 25 — 31 Other income, net — — 3 — — 3 Loss on debt extinguishment — — (9 ) — — (9 ) Interest expense — — (206 ) (52 ) — (258 ) Total other income (expense), net 157 (45 ) (204 ) 98 (239 ) (233 ) Net Income (Loss) 157 (42 ) 124 95 (239 ) 95 Less: Net loss attributable to noncontrolling interests — — (2 ) (62 ) 2 (62 ) Net Income (Loss) Attributable to NRG Yield LLC $ 157 $ (42 ) $ 126 $ 157 $ (241 ) $ 157 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income (Loss) $ 157 $ (42 ) $ 124 $ 95 $ (239 ) $ 95 Other Comprehensive Loss Unrealized loss on derivatives (16 ) — (16 ) (17 ) 32 (17 ) Other comprehensive loss (16 ) — (16 ) (17 ) 32 (17 ) Comprehensive Income (Loss) 141 (42 ) 108 78 (207 ) 78 Less: Comprehensive loss attributable to noncontrolling interests — — (2 ) (63 ) 2 (63 ) Comprehensive Income (Loss) Attributable to NRG Yield LLC $ 141 $ (42 ) $ 110 $ 141 $ (209 ) $ 141 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2015 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 19 $ 423 $ (18 ) $ 424 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (464 ) — 285 179 — Acquisition of businesses, net of cash acquired — — — (37 ) (37 ) Acquisition of Drop Down Assets, net of cash acquired — — — (698 ) (698 ) Capital expenditures — — (29 ) — (29 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — — — 42 42 Investments in unconsolidated affiliates — (28 ) — — (374 ) (402 ) Other — — 9 — 9 Net Cash (Used in) Provided by Investing Activities (464 ) (28 ) 282 (888 ) (1,098 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (309 ) 9 — 300 — Net contributions from noncontrolling interests — — — 122 122 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (79 ) — (79 ) Proceeds from the issuance of Class C units 599 — — — 599 (Payments of) proceeds from distributions (139 ) — (392 ) 392 (139 ) Proceeds from the revolving credit facility — — — 551 551 Payments for the revolving credit facility — — — (245 ) (245 ) Proceeds from issuance of long-term debt — external — — 6 — 6 Proceeds from issuance of long-term debt — affiliate — — — 281 281 Payments for long-term debt — external — — (241 ) (494 ) (735 ) Payment of debt issuance costs — — (6 ) (1 ) (7 ) Net Cash Provided by (Used in) Financing Activities 151 9 (712 ) 906 354 Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (313 ) — (7 ) — (320 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 328 — 245 — 573 Cash, Cash Equivalents and Restricted Cash at End of Period $ 15 $ — $ 238 $ — $ 253 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan24

Condensed Consolidating Financial Information CP Income Statement CP Income Statement (Notes)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Condensed Financial Statements [Text Block]	Condensed Consolidating Financial Information As of December 31, 2017 , Yield Operating LLC had outstanding $500 million of the 2024 Senior Notes and $350 million of the 2026 Senior Notes, collectively Senior Notes, as described in Note 10 , Long-term Debt . These Senior Notes are guaranteed by the Company, as well as certain of the Company's subsidiaries, or guarantor subsidiaries. These guarantees are both joint and several. The non-guarantor subsidiaries include the rest of the Company's subsidiaries, including the ones that are subject to project financing. Unless otherwise noted below, each of the following guarantor subsidiaries fully and unconditionally guaranteed the Senior Notes as of December 31, 2017 : NRG Yield LLC Alta Wind 1-5 Holding Company, LLC Alta Wind Company, LLC NRG Energy Center Omaha Holdings LLC NRG Energy Center Omaha LLC NYLD Fuel Cell Holdings LLC UB Fuel Cell, LLC NRG South Trent Holdings LLC NRG Yield DGPV Holding LLC NRG Yield RPV Holding LLC Yield Operating LLC conducts much of its business through and derives much of its income from its subsidiaries. Therefore, its ability to make required payments with respect to its indebtedness and other obligations depends on the financial results and condition of its subsidiaries and Yield Operating LLC's ability to receive funds from its subsidiaries. There are no restrictions on the ability of any of the guarantor subsidiaries to transfer funds to Yield Operating LLC. However, there may be restrictions for certain non-guarantor subsidiaries. The following condensed consolidating financial information presents the financial information of Yield LLC, Yield Operating LLC, the issuer of the Senior Notes, the guarantor subsidiaries and the non-guarantor subsidiaries in accordance with Rule 3-10 under the SEC Regulation S-X. The financial information may not necessarily be indicative of results of operations or financial position had the guarantor subsidiaries or non-guarantor subsidiaries operated as independent entities. In this presentation, Yield LLC consists of parent company operations. Guarantor subsidiaries and non-guarantor subsidiaries of Yield LLC are reported on an equity basis. For companies acquired, the fair values of the assets and liabilities acquired have been presented on a push-down accounting basis. As described in Note 3 , Business Acquisitions , the Company completed the acquisition of the November 2017 Drop Down Assets, August 2017 Drop Down Assets, and March 2017 Drop Down Assets from NRG on November 1, 2017, August 1, 2017 and March 27, 2017, respectively. The guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control. Accordingly, the Company prepared its condensed consolidating financial statements to reflect the transfers as if they had taken place from the beginning of the financial statements period. In addition, the condensed parent company financial statements are provided in accordance with Rule 12-04, Schedule I of Regulation S-X, as the restricted net assets of Yield LLC’s subsidiaries exceed 25 percent of the consolidated net assets of Yield LLC. These statements should be read in conjunction with the consolidated statements and notes thereto of NRG Yield LLC. For a discussion of Yield LLC's long-term debt, see Note 10 , Long-term Debt . For a discussion of Yield LLC's commitments and contingencies, see Note 14 , Commitments and Contingencies . For a discussion of Yield LLC's distributions to Yield, Inc. and NRG Energy, see Note 11 , Members' Equity . For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 988 $ 1 $ (1 ) $ 1,009 Operating Costs and Expenses — Cost of operations — 14 312 1 (1 ) 326 Depreciation and amortization — 5 329 — — 334 Impairment losses — — 44 — — 44 General and administrative — — — 19 — 19 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 19 685 23 (1 ) 726 Operating (Loss) Income — 2 303 (22 ) — 283 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 136 (16 ) — 126 (246 ) — Equity in earnings of unconsolidated affiliates — 22 21 28 — 71 Other income, net 1 — 3 — — 4 Loss on debt extinguishment — — (3 ) — — (3 ) Interest expense — — (222 ) (71 ) — (293 ) Total other income (expense), net 137 6 (201 ) 83 (246 ) (221 ) Net Income 137 8 102 61 (246 ) 62 Less: Net loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Net Income Attributable to NRG Yield LLC $ 137 $ 8 $ 107 $ 136 $ (251 ) $ 137 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. For the year ended December 31, 2017 NRG Yield LLC (a) Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 137 $ 8 $ 102 $ 61 $ (246 ) $ 62 Other Comprehensive Income Unrealized gain on derivatives 17 1 16 17 (34 ) 17 Other comprehensive income 17 1 16 17 (34 ) 17 Comprehensive Income 154 9 118 78 (280 ) 79 Less: Comprehensive loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Comprehensive Income Attributable to NRG Yield LLC $ 154 $ 9 $ 123 $ 153 $ (285 ) $ 154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 22 $ — $ 124 $ — $ — $ 146 Restricted cash — — 168 — — 168 Accounts receivable — trade 1 2 92 1 — 96 Inventory — 1 38 — — 39 Notes receivable — current — — 13 — — 13 Prepayments and other current assets — — 18 1 — 19 Total current assets 23 3 453 2 — 481 Property, plant and equipment, net — 58 5,146 — — 5,204 Other Assets Investment in consolidated subsidiaries 1,823 460 — 3,177 (5,460 ) — Equity investments in affiliates — 233 577 368 — 1,178 Intangible assets, net — 55 1,173 — — 1,228 Other non-current assets — — 63 — — 63 Total other assets 1,823 748 1,813 3,545 (5,460 ) 2,469 Total Assets $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 306 $ — $ — $ 306 Accounts payable — trade — 2 25 — — 27 Accounts payable — affiliate — 5 27 16 — 48 Derivative instruments — — 17 — — 17 Accrued expenses and other current liabilities — 1 61 25 — 87 Total current liabilities — 8 436 41 — 485 Other Liabilities Long-term debt — external — — 4,025 896 — 4,921 Long-term debt — affiliate — — — 618 — 618 Derivative instruments — — 31 — — 31 Other non-current liabilities — — 84 7 — 91 Total non-current liabilities — — 4,140 1,521 — 5,661 Total Liabilities — 8 4,576 1,562 — 6,146 Commitments and Contingencies Members' Equity Contributed capital 1,897 863 2,871 2,097 (5,831 ) 1,897 Retained earnings (accumulated deficit) 17 (61 ) (21 ) (206 ) 288 17 Accumulated other comprehensive loss (68 ) (1 ) (71 ) (68 ) 140 (68 ) Noncontrolling interest — — 57 162 (57 ) 162 Total Members' Equity 1,846 801 2,836 1,985 (5,460 ) 2,008 Total Liabilities and Members’ Equity $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 58 $ 529 $ (71 ) $ 516 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (15 ) — — 15 — Acquisition of Drop Down Assets, net of cash acquired — — — (250 ) (250 ) Capital expenditures — (4 ) (27 ) — (31 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 10 14 23 47 Investments in unconsolidated affiliates — (64 ) (7 ) (2 ) (73 ) Other — — 7 — 7 Net Cash Provided by (Used in) Investing Activities (15 ) (58 ) 4 (214 ) (283 ) Cash Flows from Financing Activities Net contributions from noncontrolling interests — — 2 11 13 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (13 ) (7 ) (20 ) Transfer of funds under intercompany cash management arrangement (5 ) — (1 ) 6 — Proceeds from the issuance of Class C units 33 — — — 33 (Payments of) proceeds from distributions (202 ) — (220 ) 220 (202 ) Proceeds from the revolving credit facility — — — 55 55 Proceeds from issuance of long-term debt — — 41 — 41 Payments of debt issuance costs — — (4 ) — (4 ) Payments for long-term debt — external — — (332 ) — (332 ) Net Cash (Used in) Provided by Financing Activities (174 ) — (527 ) 285 (416 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (189 ) — 6 — (183 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 211 — 286 — 497 Cash, Cash Equivalents and Restricted Cash at End of Period $ 22 $ — $ 292 $ — $ 314 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 22 $ 1,013 $ 1 $ (1 ) $ 1,035 Operating Costs and Expenses Cost of operations — 14 294 1 (1 ) 308 Depreciation and amortization — 5 298 — — 303 Impairment losses — — 185 — — 185 General and administrative 2 — — 12 — 14 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses 2 19 777 14 (1 ) 811 Operating Income (Loss) (2 ) 3 236 (13 ) — 224 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 128 10 — 66 (204 ) — Equity in earnings of unconsolidated affiliates — 9 21 30 — 60 Other income, net — — 3 — — 3 Interest expense — — (206 ) (66 ) — (272 ) Total other income (expense) 128 19 (182 ) 30 (204 ) (209 ) Net Income 126 22 54 17 (204 ) 15 Less: Net loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Net Income Attributable to NRG Yield LLC $ 126 $ 22 $ 55 $ 128 $ (205 ) $ 126 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income $ 126 $ 22 $ 54 $ 17 $ (204 ) $ 15 Other Comprehensive Income Unrealized gain on derivatives 13 1 10 13 (24 ) 13 Other comprehensive income 13 1 10 13 (24 ) 13 Comprehensive Income 139 23 64 30 (228 ) 28 Less: Comprehensive loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Comprehensive Income Attributable to NRG Yield LLC $ 139 $ 23 $ 65 $ 141 $ (229 ) $ 139 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2016 NRG Yield LLC (a)(c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b)(c) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 211 $ — $ 110 $ — $ — $ 321 Restricted cash — — 176 — — 176 Accounts receivable — trade — 2 94 — — 96 Inventory — 2 37 — — 39 Notes receivable — current — — 16 — — 16 Prepayments and other current assets — — 21 1 — 22 Total current assets 211 4 454 1 — 670 Property, plant and equipment, net — 59 5,495 — — 5,554 Other Assets Investment in consolidated subsidiaries 1,927 527 — 3,272 (5,726 ) — Equity investments in affiliates — 171 600 381 — 1,152 Intangible assets, net — 56 1,247 — — 1,303 Other non-current assets — — 66 1 — 67 Total other assets 1,927 754 1,913 3,654 (5,726 ) 2,522 Total Assets $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b) (c) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 323 $ — $ — $ 323 Accounts payable — trade — 2 18 3 — 23 Accounts payable — affiliate — 7 15 18 — 40 Derivative instruments — — 33 — — 33 Accrued expenses and other current liabilities — 1 60 24 — 85 Total current liabilities — 10 449 45 — 504 Other Liabilities Long-term debt — external — — 4,289 839 — 5,128 Long-term debt — affiliate — — — 618 — 618 Accounts payable — affiliate — — 9 — — 9 Derivative instruments — — 46 — — 46 Other non-current liabilities — — 77 — — 77 Total non-current liabilities — — 4,421 1,457 — 5,878 Total Liabilities — 10 4,870 1,502 — 6,382 Commitments and Contingencies Members' Equity Contributed capital 2,179 874 2,972 2,155 (6,001 ) 2,179 Retained earnings (accumulated deficit) 44 (65 ) 43 (143 ) 165 44 Accumulated other comprehensive loss (85 ) (2 ) (87 ) (85 ) 174 (85 ) Noncontrolling interest — — 64 226 (64 ) 226 Total Members' Equity 2,138 807 2,992 2,153 (5,726 ) 2,364 Total Liabilities and Members’ Equity $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2016 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated Net Cash Provided by (Used in) Operating Activities $ — $ 62 $ 554 $ (39 ) $ 577 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 325 — (21 ) (304 ) — Acquisition of Drop Down Assets — — — (77 ) (77 ) Capital expenditures — — (20 ) — (20 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 16 — 12 28 Investments in unconsolidated affiliates — (80 ) (3 ) — (83 ) Other — — 4 — 4 Net Cash Used in Investing Activities 325 (64 ) (23 ) (369 ) (131 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement 44 2 — (46 ) — Net contributions from noncontrolling interests — — — 5 5 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (174 ) (10 ) (184 ) (Payments of) proceeds from distributions (173 ) — (420 ) 420 (173 ) Proceeds from the revolving credit facility — — — 60 60 Payments for the revolving credit facility — — — (366 ) (366 ) Proceeds from the issuance of long-term debt - external — — 390 350 740 Payments of debt issuance costs — — (10 ) (5 ) (15 ) Payments for long-term debt — external — — (269 ) — (269 ) Net Cash Provided by (Used in) Financing Activities (129 ) 2 (483 ) 408 (202 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash 196 — 48 — 244 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 15 — 238 — 253 Cash, Cash Equivalents and Restricted Cash at End of Period $ 211 $ — $ 286 $ — $ 497 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 937 $ 10 $ — $ 968 Operating Costs and Expenses Cost of operations — 14 309 — — 323 Depreciation and amortization — 4 299 — — 303 Impairment losses — — 1 — — 1 General and administrative — — — 10 — 10 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 18 609 13 — 640 Operating Income (Loss) — 3 328 (3 ) — 328 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 157 (43 ) — 125 (239 ) — Equity in (losses) earnings of unconsolidated affiliates — (2 ) 8 25 — 31 Other income, net — — 3 — — 3 Loss on debt extinguishment — — (9 ) — — (9 ) Interest expense — — (206 ) (52 ) — (258 ) Total other income (expense), net 157 (45 ) (204 ) 98 (239 ) (233 ) Net Income (Loss) 157 (42 ) 124 95 (239 ) 95 Less: Net loss attributable to noncontrolling interests — — (2 ) (62 ) 2 (62 ) Net Income (Loss) Attributable to NRG Yield LLC $ 157 $ (42 ) $ 126 $ 157 $ (241 ) $ 157 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income (Loss) $ 157 $ (42 ) $ 124 $ 95 $ (239 ) $ 95 Other Comprehensive Loss Unrealized loss on derivatives (16 ) — (16 ) (17 ) 32 (17 ) Other comprehensive loss (16 ) — (16 ) (17 ) 32 (17 ) Comprehensive Income (Loss) 141 (42 ) 108 78 (207 ) 78 Less: Comprehensive loss attributable to noncontrolling interests — — (2 ) (63 ) 2 (63 ) Comprehensive Income (Loss) Attributable to NRG Yield LLC $ 141 $ (42 ) $ 110 $ 141 $ (209 ) $ 141 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2015 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 19 $ 423 $ (18 ) $ 424 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (464 ) — 285 179 — Acquisition of businesses, net of cash acquired — — — (37 ) (37 ) Acquisition of Drop Down Assets, net of cash acquired — — — (698 ) (698 ) Capital expenditures — — (29 ) — (29 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — — — 42 42 Investments in unconsolidated affiliates — (28 ) — — (374 ) (402 ) Other — — 9 — 9 Net Cash (Used in) Provided by Investing Activities (464 ) (28 ) 282 (888 ) (1,098 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (309 ) 9 — 300 — Net contributions from noncontrolling interests — — — 122 122 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (79 ) — (79 ) Proceeds from the issuance of Class C units 599 — — — 599 (Payments of) proceeds from distributions (139 ) — (392 ) 392 (139 ) Proceeds from the revolving credit facility — — — 551 551 Payments for the revolving credit facility — — — (245 ) (245 ) Proceeds from issuance of long-term debt — external — — 6 — 6 Proceeds from issuance of long-term debt — affiliate — — — 281 281 Payments for long-term debt — external — — (241 ) (494 ) (735 ) Payment of debt issuance costs — — (6 ) (1 ) (7 ) Net Cash Provided by (Used in) Financing Activities 151 9 (712 ) 906 354 Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (313 ) — (7 ) — (320 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 328 — 245 — 573 Cash, Cash Equivalents and Restricted Cash at End of Period $ 15 $ — $ 238 $ — $ 253 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan25

Condensed Consolidating Financial Information CP Comprehensive Income Condensed Consolidating Financial Information CP Comprehensive Income (Notes)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Information [Abstract]
Condensed Statement of Comprehensive Income [Table Text Block]	Condensed Consolidating Financial Information As of December 31, 2017 , Yield Operating LLC had outstanding $500 million of the 2024 Senior Notes and $350 million of the 2026 Senior Notes, collectively Senior Notes, as described in Note 10 , Long-term Debt . These Senior Notes are guaranteed by the Company, as well as certain of the Company's subsidiaries, or guarantor subsidiaries. These guarantees are both joint and several. The non-guarantor subsidiaries include the rest of the Company's subsidiaries, including the ones that are subject to project financing. Unless otherwise noted below, each of the following guarantor subsidiaries fully and unconditionally guaranteed the Senior Notes as of December 31, 2017 : NRG Yield LLC Alta Wind 1-5 Holding Company, LLC Alta Wind Company, LLC NRG Energy Center Omaha Holdings LLC NRG Energy Center Omaha LLC NYLD Fuel Cell Holdings LLC UB Fuel Cell, LLC NRG South Trent Holdings LLC NRG Yield DGPV Holding LLC NRG Yield RPV Holding LLC Yield Operating LLC conducts much of its business through and derives much of its income from its subsidiaries. Therefore, its ability to make required payments with respect to its indebtedness and other obligations depends on the financial results and condition of its subsidiaries and Yield Operating LLC's ability to receive funds from its subsidiaries. There are no restrictions on the ability of any of the guarantor subsidiaries to transfer funds to Yield Operating LLC. However, there may be restrictions for certain non-guarantor subsidiaries. The following condensed consolidating financial information presents the financial information of Yield LLC, Yield Operating LLC, the issuer of the Senior Notes, the guarantor subsidiaries and the non-guarantor subsidiaries in accordance with Rule 3-10 under the SEC Regulation S-X. The financial information may not necessarily be indicative of results of operations or financial position had the guarantor subsidiaries or non-guarantor subsidiaries operated as independent entities. In this presentation, Yield LLC consists of parent company operations. Guarantor subsidiaries and non-guarantor subsidiaries of Yield LLC are reported on an equity basis. For companies acquired, the fair values of the assets and liabilities acquired have been presented on a push-down accounting basis. As described in Note 3 , Business Acquisitions , the Company completed the acquisition of the November 2017 Drop Down Assets, August 2017 Drop Down Assets, and March 2017 Drop Down Assets from NRG on November 1, 2017, August 1, 2017 and March 27, 2017, respectively. The guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control. Accordingly, the Company prepared its condensed consolidating financial statements to reflect the transfers as if they had taken place from the beginning of the financial statements period. In addition, the condensed parent company financial statements are provided in accordance with Rule 12-04, Schedule I of Regulation S-X, as the restricted net assets of Yield LLC’s subsidiaries exceed 25 percent of the consolidated net assets of Yield LLC. These statements should be read in conjunction with the consolidated statements and notes thereto of NRG Yield LLC. For a discussion of Yield LLC's long-term debt, see Note 10 , Long-term Debt . For a discussion of Yield LLC's commitments and contingencies, see Note 14 , Commitments and Contingencies . For a discussion of Yield LLC's distributions to Yield, Inc. and NRG Energy, see Note 11 , Members' Equity . For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 988 $ 1 $ (1 ) $ 1,009 Operating Costs and Expenses — Cost of operations — 14 312 1 (1 ) 326 Depreciation and amortization — 5 329 — — 334 Impairment losses — — 44 — — 44 General and administrative — — — 19 — 19 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 19 685 23 (1 ) 726 Operating (Loss) Income — 2 303 (22 ) — 283 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 136 (16 ) — 126 (246 ) — Equity in earnings of unconsolidated affiliates — 22 21 28 — 71 Other income, net 1 — 3 — — 4 Loss on debt extinguishment — — (3 ) — — (3 ) Interest expense — — (222 ) (71 ) — (293 ) Total other income (expense), net 137 6 (201 ) 83 (246 ) (221 ) Net Income 137 8 102 61 (246 ) 62 Less: Net loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Net Income Attributable to NRG Yield LLC $ 137 $ 8 $ 107 $ 136 $ (251 ) $ 137 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. For the year ended December 31, 2017 NRG Yield LLC (a) Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 137 $ 8 $ 102 $ 61 $ (246 ) $ 62 Other Comprehensive Income Unrealized gain on derivatives 17 1 16 17 (34 ) 17 Other comprehensive income 17 1 16 17 (34 ) 17 Comprehensive Income 154 9 118 78 (280 ) 79 Less: Comprehensive loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Comprehensive Income Attributable to NRG Yield LLC $ 154 $ 9 $ 123 $ 153 $ (285 ) $ 154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 22 $ — $ 124 $ — $ — $ 146 Restricted cash — — 168 — — 168 Accounts receivable — trade 1 2 92 1 — 96 Inventory — 1 38 — — 39 Notes receivable — current — — 13 — — 13 Prepayments and other current assets — — 18 1 — 19 Total current assets 23 3 453 2 — 481 Property, plant and equipment, net — 58 5,146 — — 5,204 Other Assets Investment in consolidated subsidiaries 1,823 460 — 3,177 (5,460 ) — Equity investments in affiliates — 233 577 368 — 1,178 Intangible assets, net — 55 1,173 — — 1,228 Other non-current assets — — 63 — — 63 Total other assets 1,823 748 1,813 3,545 (5,460 ) 2,469 Total Assets $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 306 $ — $ — $ 306 Accounts payable — trade — 2 25 — — 27 Accounts payable — affiliate — 5 27 16 — 48 Derivative instruments — — 17 — — 17 Accrued expenses and other current liabilities — 1 61 25 — 87 Total current liabilities — 8 436 41 — 485 Other Liabilities Long-term debt — external — — 4,025 896 — 4,921 Long-term debt — affiliate — — — 618 — 618 Derivative instruments — — 31 — — 31 Other non-current liabilities — — 84 7 — 91 Total non-current liabilities — — 4,140 1,521 — 5,661 Total Liabilities — 8 4,576 1,562 — 6,146 Commitments and Contingencies Members' Equity Contributed capital 1,897 863 2,871 2,097 (5,831 ) 1,897 Retained earnings (accumulated deficit) 17 (61 ) (21 ) (206 ) 288 17 Accumulated other comprehensive loss (68 ) (1 ) (71 ) (68 ) 140 (68 ) Noncontrolling interest — — 57 162 (57 ) 162 Total Members' Equity 1,846 801 2,836 1,985 (5,460 ) 2,008 Total Liabilities and Members’ Equity $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 58 $ 529 $ (71 ) $ 516 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (15 ) — — 15 — Acquisition of Drop Down Assets, net of cash acquired — — — (250 ) (250 ) Capital expenditures — (4 ) (27 ) — (31 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 10 14 23 47 Investments in unconsolidated affiliates — (64 ) (7 ) (2 ) (73 ) Other — — 7 — 7 Net Cash Provided by (Used in) Investing Activities (15 ) (58 ) 4 (214 ) (283 ) Cash Flows from Financing Activities Net contributions from noncontrolling interests — — 2 11 13 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (13 ) (7 ) (20 ) Transfer of funds under intercompany cash management arrangement (5 ) — (1 ) 6 — Proceeds from the issuance of Class C units 33 — — — 33 (Payments of) proceeds from distributions (202 ) — (220 ) 220 (202 ) Proceeds from the revolving credit facility — — — 55 55 Proceeds from issuance of long-term debt — — 41 — 41 Payments of debt issuance costs — — (4 ) — (4 ) Payments for long-term debt — external — — (332 ) — (332 ) Net Cash (Used in) Provided by Financing Activities (174 ) — (527 ) 285 (416 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (189 ) — 6 — (183 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 211 — 286 — 497 Cash, Cash Equivalents and Restricted Cash at End of Period $ 22 $ — $ 292 $ — $ 314 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 22 $ 1,013 $ 1 $ (1 ) $ 1,035 Operating Costs and Expenses Cost of operations — 14 294 1 (1 ) 308 Depreciation and amortization — 5 298 — — 303 Impairment losses — — 185 — — 185 General and administrative 2 — — 12 — 14 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses 2 19 777 14 (1 ) 811 Operating Income (Loss) (2 ) 3 236 (13 ) — 224 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 128 10 — 66 (204 ) — Equity in earnings of unconsolidated affiliates — 9 21 30 — 60 Other income, net — — 3 — — 3 Interest expense — — (206 ) (66 ) — (272 ) Total other income (expense) 128 19 (182 ) 30 (204 ) (209 ) Net Income 126 22 54 17 (204 ) 15 Less: Net loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Net Income Attributable to NRG Yield LLC $ 126 $ 22 $ 55 $ 128 $ (205 ) $ 126 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income $ 126 $ 22 $ 54 $ 17 $ (204 ) $ 15 Other Comprehensive Income Unrealized gain on derivatives 13 1 10 13 (24 ) 13 Other comprehensive income 13 1 10 13 (24 ) 13 Comprehensive Income 139 23 64 30 (228 ) 28 Less: Comprehensive loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Comprehensive Income Attributable to NRG Yield LLC $ 139 $ 23 $ 65 $ 141 $ (229 ) $ 139 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2016 NRG Yield LLC (a)(c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b)(c) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 211 $ — $ 110 $ — $ — $ 321 Restricted cash — — 176 — — 176 Accounts receivable — trade — 2 94 — — 96 Inventory — 2 37 — — 39 Notes receivable — current — — 16 — — 16 Prepayments and other current assets — — 21 1 — 22 Total current assets 211 4 454 1 — 670 Property, plant and equipment, net — 59 5,495 — — 5,554 Other Assets Investment in consolidated subsidiaries 1,927 527 — 3,272 (5,726 ) — Equity investments in affiliates — 171 600 381 — 1,152 Intangible assets, net — 56 1,247 — — 1,303 Other non-current assets — — 66 1 — 67 Total other assets 1,927 754 1,913 3,654 (5,726 ) 2,522 Total Assets $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b) (c) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 323 $ — $ — $ 323 Accounts payable — trade — 2 18 3 — 23 Accounts payable — affiliate — 7 15 18 — 40 Derivative instruments — — 33 — — 33 Accrued expenses and other current liabilities — 1 60 24 — 85 Total current liabilities — 10 449 45 — 504 Other Liabilities Long-term debt — external — — 4,289 839 — 5,128 Long-term debt — affiliate — — — 618 — 618 Accounts payable — affiliate — — 9 — — 9 Derivative instruments — — 46 — — 46 Other non-current liabilities — — 77 — — 77 Total non-current liabilities — — 4,421 1,457 — 5,878 Total Liabilities — 10 4,870 1,502 — 6,382 Commitments and Contingencies Members' Equity Contributed capital 2,179 874 2,972 2,155 (6,001 ) 2,179 Retained earnings (accumulated deficit) 44 (65 ) 43 (143 ) 165 44 Accumulated other comprehensive loss (85 ) (2 ) (87 ) (85 ) 174 (85 ) Noncontrolling interest — — 64 226 (64 ) 226 Total Members' Equity 2,138 807 2,992 2,153 (5,726 ) 2,364 Total Liabilities and Members’ Equity $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2016 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated Net Cash Provided by (Used in) Operating Activities $ — $ 62 $ 554 $ (39 ) $ 577 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 325 — (21 ) (304 ) — Acquisition of Drop Down Assets — — — (77 ) (77 ) Capital expenditures — — (20 ) — (20 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 16 — 12 28 Investments in unconsolidated affiliates — (80 ) (3 ) — (83 ) Other — — 4 — 4 Net Cash Used in Investing Activities 325 (64 ) (23 ) (369 ) (131 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement 44 2 — (46 ) — Net contributions from noncontrolling interests — — — 5 5 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (174 ) (10 ) (184 ) (Payments of) proceeds from distributions (173 ) — (420 ) 420 (173 ) Proceeds from the revolving credit facility — — — 60 60 Payments for the revolving credit facility — — — (366 ) (366 ) Proceeds from the issuance of long-term debt - external — — 390 350 740 Payments of debt issuance costs — — (10 ) (5 ) (15 ) Payments for long-term debt — external — — (269 ) — (269 ) Net Cash Provided by (Used in) Financing Activities (129 ) 2 (483 ) 408 (202 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash 196 — 48 — 244 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 15 — 238 — 253 Cash, Cash Equivalents and Restricted Cash at End of Period $ 211 $ — $ 286 $ — $ 497 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 937 $ 10 $ — $ 968 Operating Costs and Expenses Cost of operations — 14 309 — — 323 Depreciation and amortization — 4 299 — — 303 Impairment losses — — 1 — — 1 General and administrative — — — 10 — 10 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 18 609 13 — 640 Operating Income (Loss) — 3 328 (3 ) — 328 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 157 (43 ) — 125 (239 ) — Equity in (losses) earnings of unconsolidated affiliates — (2 ) 8 25 — 31 Other income, net — — 3 — — 3 Loss on debt extinguishment — — (9 ) — — (9 ) Interest expense — — (206 ) (52 ) — (258 ) Total other income (expense), net 157 (45 ) (204 ) 98 (239 ) (233 ) Net Income (Loss) 157 (42 ) 124 95 (239 ) 95 Less: Net loss attributable to noncontrolling interests — — (2 ) (62 ) 2 (62 ) Net Income (Loss) Attributable to NRG Yield LLC $ 157 $ (42 ) $ 126 $ 157 $ (241 ) $ 157 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income (Loss) $ 157 $ (42 ) $ 124 $ 95 $ (239 ) $ 95 Other Comprehensive Loss Unrealized loss on derivatives (16 ) — (16 ) (17 ) 32 (17 ) Other comprehensive loss (16 ) — (16 ) (17 ) 32 (17 ) Comprehensive Income (Loss) 141 (42 ) 108 78 (207 ) 78 Less: Comprehensive loss attributable to noncontrolling interests — — (2 ) (63 ) 2 (63 ) Comprehensive Income (Loss) Attributable to NRG Yield LLC $ 141 $ (42 ) $ 110 $ 141 $ (209 ) $ 141 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2015 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 19 $ 423 $ (18 ) $ 424 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (464 ) — 285 179 — Acquisition of businesses, net of cash acquired — — — (37 ) (37 ) Acquisition of Drop Down Assets, net of cash acquired — — — (698 ) (698 ) Capital expenditures — — (29 ) — (29 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — — — 42 42 Investments in unconsolidated affiliates — (28 ) — — (374 ) (402 ) Other — — 9 — 9 Net Cash (Used in) Provided by Investing Activities (464 ) (28 ) 282 (888 ) (1,098 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (309 ) 9 — 300 — Net contributions from noncontrolling interests — — — 122 122 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (79 ) — (79 ) Proceeds from the issuance of Class C units 599 — — — 599 (Payments of) proceeds from distributions (139 ) — (392 ) 392 (139 ) Proceeds from the revolving credit facility — — — 551 551 Payments for the revolving credit facility — — — (245 ) (245 ) Proceeds from issuance of long-term debt — external — — 6 — 6 Proceeds from issuance of long-term debt — affiliate — — — 281 281 Payments for long-term debt — external — — (241 ) (494 ) (735 ) Payment of debt issuance costs — — (6 ) (1 ) (7 ) Net Cash Provided by (Used in) Financing Activities 151 9 (712 ) 906 354 Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (313 ) — (7 ) — (320 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 328 — 245 — 573 Cash, Cash Equivalents and Restricted Cash at End of Period $ 15 $ — $ 238 $ — $ 253 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan26

Condensed Consolidating Financial Information CP Balance Sheet Condensed Consolidating CP Balance Sheet (Notes)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Information [Abstract]
Condensed Financial Statements [Text Block]	Condensed Consolidating Financial Information As of December 31, 2017 , Yield Operating LLC had outstanding $500 million of the 2024 Senior Notes and $350 million of the 2026 Senior Notes, collectively Senior Notes, as described in Note 10 , Long-term Debt . These Senior Notes are guaranteed by the Company, as well as certain of the Company's subsidiaries, or guarantor subsidiaries. These guarantees are both joint and several. The non-guarantor subsidiaries include the rest of the Company's subsidiaries, including the ones that are subject to project financing. Unless otherwise noted below, each of the following guarantor subsidiaries fully and unconditionally guaranteed the Senior Notes as of December 31, 2017 : NRG Yield LLC Alta Wind 1-5 Holding Company, LLC Alta Wind Company, LLC NRG Energy Center Omaha Holdings LLC NRG Energy Center Omaha LLC NYLD Fuel Cell Holdings LLC UB Fuel Cell, LLC NRG South Trent Holdings LLC NRG Yield DGPV Holding LLC NRG Yield RPV Holding LLC Yield Operating LLC conducts much of its business through and derives much of its income from its subsidiaries. Therefore, its ability to make required payments with respect to its indebtedness and other obligations depends on the financial results and condition of its subsidiaries and Yield Operating LLC's ability to receive funds from its subsidiaries. There are no restrictions on the ability of any of the guarantor subsidiaries to transfer funds to Yield Operating LLC. However, there may be restrictions for certain non-guarantor subsidiaries. The following condensed consolidating financial information presents the financial information of Yield LLC, Yield Operating LLC, the issuer of the Senior Notes, the guarantor subsidiaries and the non-guarantor subsidiaries in accordance with Rule 3-10 under the SEC Regulation S-X. The financial information may not necessarily be indicative of results of operations or financial position had the guarantor subsidiaries or non-guarantor subsidiaries operated as independent entities. In this presentation, Yield LLC consists of parent company operations. Guarantor subsidiaries and non-guarantor subsidiaries of Yield LLC are reported on an equity basis. For companies acquired, the fair values of the assets and liabilities acquired have been presented on a push-down accounting basis. As described in Note 3 , Business Acquisitions , the Company completed the acquisition of the November 2017 Drop Down Assets, August 2017 Drop Down Assets, and March 2017 Drop Down Assets from NRG on November 1, 2017, August 1, 2017 and March 27, 2017, respectively. The guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control. Accordingly, the Company prepared its condensed consolidating financial statements to reflect the transfers as if they had taken place from the beginning of the financial statements period. In addition, the condensed parent company financial statements are provided in accordance with Rule 12-04, Schedule I of Regulation S-X, as the restricted net assets of Yield LLC’s subsidiaries exceed 25 percent of the consolidated net assets of Yield LLC. These statements should be read in conjunction with the consolidated statements and notes thereto of NRG Yield LLC. For a discussion of Yield LLC's long-term debt, see Note 10 , Long-term Debt . For a discussion of Yield LLC's commitments and contingencies, see Note 14 , Commitments and Contingencies . For a discussion of Yield LLC's distributions to Yield, Inc. and NRG Energy, see Note 11 , Members' Equity . For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 988 $ 1 $ (1 ) $ 1,009 Operating Costs and Expenses — Cost of operations — 14 312 1 (1 ) 326 Depreciation and amortization — 5 329 — — 334 Impairment losses — — 44 — — 44 General and administrative — — — 19 — 19 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 19 685 23 (1 ) 726 Operating (Loss) Income — 2 303 (22 ) — 283 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 136 (16 ) — 126 (246 ) — Equity in earnings of unconsolidated affiliates — 22 21 28 — 71 Other income, net 1 — 3 — — 4 Loss on debt extinguishment — — (3 ) — — (3 ) Interest expense — — (222 ) (71 ) — (293 ) Total other income (expense), net 137 6 (201 ) 83 (246 ) (221 ) Net Income 137 8 102 61 (246 ) 62 Less: Net loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Net Income Attributable to NRG Yield LLC $ 137 $ 8 $ 107 $ 136 $ (251 ) $ 137 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. For the year ended December 31, 2017 NRG Yield LLC (a) Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 137 $ 8 $ 102 $ 61 $ (246 ) $ 62 Other Comprehensive Income Unrealized gain on derivatives 17 1 16 17 (34 ) 17 Other comprehensive income 17 1 16 17 (34 ) 17 Comprehensive Income 154 9 118 78 (280 ) 79 Less: Comprehensive loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Comprehensive Income Attributable to NRG Yield LLC $ 154 $ 9 $ 123 $ 153 $ (285 ) $ 154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 22 $ — $ 124 $ — $ — $ 146 Restricted cash — — 168 — — 168 Accounts receivable — trade 1 2 92 1 — 96 Inventory — 1 38 — — 39 Notes receivable — current — — 13 — — 13 Prepayments and other current assets — — 18 1 — 19 Total current assets 23 3 453 2 — 481 Property, plant and equipment, net — 58 5,146 — — 5,204 Other Assets Investment in consolidated subsidiaries 1,823 460 — 3,177 (5,460 ) — Equity investments in affiliates — 233 577 368 — 1,178 Intangible assets, net — 55 1,173 — — 1,228 Other non-current assets — — 63 — — 63 Total other assets 1,823 748 1,813 3,545 (5,460 ) 2,469 Total Assets $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 306 $ — $ — $ 306 Accounts payable — trade — 2 25 — — 27 Accounts payable — affiliate — 5 27 16 — 48 Derivative instruments — — 17 — — 17 Accrued expenses and other current liabilities — 1 61 25 — 87 Total current liabilities — 8 436 41 — 485 Other Liabilities Long-term debt — external — — 4,025 896 — 4,921 Long-term debt — affiliate — — — 618 — 618 Derivative instruments — — 31 — — 31 Other non-current liabilities — — 84 7 — 91 Total non-current liabilities — — 4,140 1,521 — 5,661 Total Liabilities — 8 4,576 1,562 — 6,146 Commitments and Contingencies Members' Equity Contributed capital 1,897 863 2,871 2,097 (5,831 ) 1,897 Retained earnings (accumulated deficit) 17 (61 ) (21 ) (206 ) 288 17 Accumulated other comprehensive loss (68 ) (1 ) (71 ) (68 ) 140 (68 ) Noncontrolling interest — — 57 162 (57 ) 162 Total Members' Equity 1,846 801 2,836 1,985 (5,460 ) 2,008 Total Liabilities and Members’ Equity $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 58 $ 529 $ (71 ) $ 516 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (15 ) — — 15 — Acquisition of Drop Down Assets, net of cash acquired — — — (250 ) (250 ) Capital expenditures — (4 ) (27 ) — (31 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 10 14 23 47 Investments in unconsolidated affiliates — (64 ) (7 ) (2 ) (73 ) Other — — 7 — 7 Net Cash Provided by (Used in) Investing Activities (15 ) (58 ) 4 (214 ) (283 ) Cash Flows from Financing Activities Net contributions from noncontrolling interests — — 2 11 13 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (13 ) (7 ) (20 ) Transfer of funds under intercompany cash management arrangement (5 ) — (1 ) 6 — Proceeds from the issuance of Class C units 33 — — — 33 (Payments of) proceeds from distributions (202 ) — (220 ) 220 (202 ) Proceeds from the revolving credit facility — — — 55 55 Proceeds from issuance of long-term debt — — 41 — 41 Payments of debt issuance costs — — (4 ) — (4 ) Payments for long-term debt — external — — (332 ) — (332 ) Net Cash (Used in) Provided by Financing Activities (174 ) — (527 ) 285 (416 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (189 ) — 6 — (183 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 211 — 286 — 497 Cash, Cash Equivalents and Restricted Cash at End of Period $ 22 $ — $ 292 $ — $ 314 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 22 $ 1,013 $ 1 $ (1 ) $ 1,035 Operating Costs and Expenses Cost of operations — 14 294 1 (1 ) 308 Depreciation and amortization — 5 298 — — 303 Impairment losses — — 185 — — 185 General and administrative 2 — — 12 — 14 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses 2 19 777 14 (1 ) 811 Operating Income (Loss) (2 ) 3 236 (13 ) — 224 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 128 10 — 66 (204 ) — Equity in earnings of unconsolidated affiliates — 9 21 30 — 60 Other income, net — — 3 — — 3 Interest expense — — (206 ) (66 ) — (272 ) Total other income (expense) 128 19 (182 ) 30 (204 ) (209 ) Net Income 126 22 54 17 (204 ) 15 Less: Net loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Net Income Attributable to NRG Yield LLC $ 126 $ 22 $ 55 $ 128 $ (205 ) $ 126 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income $ 126 $ 22 $ 54 $ 17 $ (204 ) $ 15 Other Comprehensive Income Unrealized gain on derivatives 13 1 10 13 (24 ) 13 Other comprehensive income 13 1 10 13 (24 ) 13 Comprehensive Income 139 23 64 30 (228 ) 28 Less: Comprehensive loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Comprehensive Income Attributable to NRG Yield LLC $ 139 $ 23 $ 65 $ 141 $ (229 ) $ 139 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2016 NRG Yield LLC (a)(c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b)(c) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 211 $ — $ 110 $ — $ — $ 321 Restricted cash — — 176 — — 176 Accounts receivable — trade — 2 94 — — 96 Inventory — 2 37 — — 39 Notes receivable — current — — 16 — — 16 Prepayments and other current assets — — 21 1 — 22 Total current assets 211 4 454 1 — 670 Property, plant and equipment, net — 59 5,495 — — 5,554 Other Assets Investment in consolidated subsidiaries 1,927 527 — 3,272 (5,726 ) — Equity investments in affiliates — 171 600 381 — 1,152 Intangible assets, net — 56 1,247 — — 1,303 Other non-current assets — — 66 1 — 67 Total other assets 1,927 754 1,913 3,654 (5,726 ) 2,522 Total Assets $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b) (c) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 323 $ — $ — $ 323 Accounts payable — trade — 2 18 3 — 23 Accounts payable — affiliate — 7 15 18 — 40 Derivative instruments — — 33 — — 33 Accrued expenses and other current liabilities — 1 60 24 — 85 Total current liabilities — 10 449 45 — 504 Other Liabilities Long-term debt — external — — 4,289 839 — 5,128 Long-term debt — affiliate — — — 618 — 618 Accounts payable — affiliate — — 9 — — 9 Derivative instruments — — 46 — — 46 Other non-current liabilities — — 77 — — 77 Total non-current liabilities — — 4,421 1,457 — 5,878 Total Liabilities — 10 4,870 1,502 — 6,382 Commitments and Contingencies Members' Equity Contributed capital 2,179 874 2,972 2,155 (6,001 ) 2,179 Retained earnings (accumulated deficit) 44 (65 ) 43 (143 ) 165 44 Accumulated other comprehensive loss (85 ) (2 ) (87 ) (85 ) 174 (85 ) Noncontrolling interest — — 64 226 (64 ) 226 Total Members' Equity 2,138 807 2,992 2,153 (5,726 ) 2,364 Total Liabilities and Members’ Equity $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2016 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated Net Cash Provided by (Used in) Operating Activities $ — $ 62 $ 554 $ (39 ) $ 577 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 325 — (21 ) (304 ) — Acquisition of Drop Down Assets — — — (77 ) (77 ) Capital expenditures — — (20 ) — (20 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 16 — 12 28 Investments in unconsolidated affiliates — (80 ) (3 ) — (83 ) Other — — 4 — 4 Net Cash Used in Investing Activities 325 (64 ) (23 ) (369 ) (131 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement 44 2 — (46 ) — Net contributions from noncontrolling interests — — — 5 5 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (174 ) (10 ) (184 ) (Payments of) proceeds from distributions (173 ) — (420 ) 420 (173 ) Proceeds from the revolving credit facility — — — 60 60 Payments for the revolving credit facility — — — (366 ) (366 ) Proceeds from the issuance of long-term debt - external — — 390 350 740 Payments of debt issuance costs — — (10 ) (5 ) (15 ) Payments for long-term debt — external — — (269 ) — (269 ) Net Cash Provided by (Used in) Financing Activities (129 ) 2 (483 ) 408 (202 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash 196 — 48 — 244 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 15 — 238 — 253 Cash, Cash Equivalents and Restricted Cash at End of Period $ 211 $ — $ 286 $ — $ 497 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 937 $ 10 $ — $ 968 Operating Costs and Expenses Cost of operations — 14 309 — — 323 Depreciation and amortization — 4 299 — — 303 Impairment losses — — 1 — — 1 General and administrative — — — 10 — 10 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 18 609 13 — 640 Operating Income (Loss) — 3 328 (3 ) — 328 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 157 (43 ) — 125 (239 ) — Equity in (losses) earnings of unconsolidated affiliates — (2 ) 8 25 — 31 Other income, net — — 3 — — 3 Loss on debt extinguishment — — (9 ) — — (9 ) Interest expense — — (206 ) (52 ) — (258 ) Total other income (expense), net 157 (45 ) (204 ) 98 (239 ) (233 ) Net Income (Loss) 157 (42 ) 124 95 (239 ) 95 Less: Net loss attributable to noncontrolling interests — — (2 ) (62 ) 2 (62 ) Net Income (Loss) Attributable to NRG Yield LLC $ 157 $ (42 ) $ 126 $ 157 $ (241 ) $ 157 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income (Loss) $ 157 $ (42 ) $ 124 $ 95 $ (239 ) $ 95 Other Comprehensive Loss Unrealized loss on derivatives (16 ) — (16 ) (17 ) 32 (17 ) Other comprehensive loss (16 ) — (16 ) (17 ) 32 (17 ) Comprehensive Income (Loss) 141 (42 ) 108 78 (207 ) 78 Less: Comprehensive loss attributable to noncontrolling interests — — (2 ) (63 ) 2 (63 ) Comprehensive Income (Loss) Attributable to NRG Yield LLC $ 141 $ (42 ) $ 110 $ 141 $ (209 ) $ 141 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2015 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 19 $ 423 $ (18 ) $ 424 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (464 ) — 285 179 — Acquisition of businesses, net of cash acquired — — — (37 ) (37 ) Acquisition of Drop Down Assets, net of cash acquired — — — (698 ) (698 ) Capital expenditures — — (29 ) — (29 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — — — 42 42 Investments in unconsolidated affiliates — (28 ) — — (374 ) (402 ) Other — — 9 — 9 Net Cash (Used in) Provided by Investing Activities (464 ) (28 ) 282 (888 ) (1,098 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (309 ) 9 — 300 — Net contributions from noncontrolling interests — — — 122 122 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (79 ) — (79 ) Proceeds from the issuance of Class C units 599 — — — 599 (Payments of) proceeds from distributions (139 ) — (392 ) 392 (139 ) Proceeds from the revolving credit facility — — — 551 551 Payments for the revolving credit facility — — — (245 ) (245 ) Proceeds from issuance of long-term debt — external — — 6 — 6 Proceeds from issuance of long-term debt — affiliate — — — 281 281 Payments for long-term debt — external — — (241 ) (494 ) (735 ) Payment of debt issuance costs — — (6 ) (1 ) (7 ) Net Cash Provided by (Used in) Financing Activities 151 9 (712 ) 906 354 Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (313 ) — (7 ) — (320 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 328 — 245 — 573 Cash, Cash Equivalents and Restricted Cash at End of Period $ 15 $ — $ 238 $ — $ 253 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan27

Condensed Consolidating Financial Information CP Cash Flows Condensed Consolidating CP Cash Flows (Notes)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Information [Abstract]
Condensed Financial Statements [Text Block]	Condensed Consolidating Financial Information As of December 31, 2017 , Yield Operating LLC had outstanding $500 million of the 2024 Senior Notes and $350 million of the 2026 Senior Notes, collectively Senior Notes, as described in Note 10 , Long-term Debt . These Senior Notes are guaranteed by the Company, as well as certain of the Company's subsidiaries, or guarantor subsidiaries. These guarantees are both joint and several. The non-guarantor subsidiaries include the rest of the Company's subsidiaries, including the ones that are subject to project financing. Unless otherwise noted below, each of the following guarantor subsidiaries fully and unconditionally guaranteed the Senior Notes as of December 31, 2017 : NRG Yield LLC Alta Wind 1-5 Holding Company, LLC Alta Wind Company, LLC NRG Energy Center Omaha Holdings LLC NRG Energy Center Omaha LLC NYLD Fuel Cell Holdings LLC UB Fuel Cell, LLC NRG South Trent Holdings LLC NRG Yield DGPV Holding LLC NRG Yield RPV Holding LLC Yield Operating LLC conducts much of its business through and derives much of its income from its subsidiaries. Therefore, its ability to make required payments with respect to its indebtedness and other obligations depends on the financial results and condition of its subsidiaries and Yield Operating LLC's ability to receive funds from its subsidiaries. There are no restrictions on the ability of any of the guarantor subsidiaries to transfer funds to Yield Operating LLC. However, there may be restrictions for certain non-guarantor subsidiaries. The following condensed consolidating financial information presents the financial information of Yield LLC, Yield Operating LLC, the issuer of the Senior Notes, the guarantor subsidiaries and the non-guarantor subsidiaries in accordance with Rule 3-10 under the SEC Regulation S-X. The financial information may not necessarily be indicative of results of operations or financial position had the guarantor subsidiaries or non-guarantor subsidiaries operated as independent entities. In this presentation, Yield LLC consists of parent company operations. Guarantor subsidiaries and non-guarantor subsidiaries of Yield LLC are reported on an equity basis. For companies acquired, the fair values of the assets and liabilities acquired have been presented on a push-down accounting basis. As described in Note 3 , Business Acquisitions , the Company completed the acquisition of the November 2017 Drop Down Assets, August 2017 Drop Down Assets, and March 2017 Drop Down Assets from NRG on November 1, 2017, August 1, 2017 and March 27, 2017, respectively. The guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control. Accordingly, the Company prepared its condensed consolidating financial statements to reflect the transfers as if they had taken place from the beginning of the financial statements period. In addition, the condensed parent company financial statements are provided in accordance with Rule 12-04, Schedule I of Regulation S-X, as the restricted net assets of Yield LLC’s subsidiaries exceed 25 percent of the consolidated net assets of Yield LLC. These statements should be read in conjunction with the consolidated statements and notes thereto of NRG Yield LLC. For a discussion of Yield LLC's long-term debt, see Note 10 , Long-term Debt . For a discussion of Yield LLC's commitments and contingencies, see Note 14 , Commitments and Contingencies . For a discussion of Yield LLC's distributions to Yield, Inc. and NRG Energy, see Note 11 , Members' Equity . For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 988 $ 1 $ (1 ) $ 1,009 Operating Costs and Expenses — Cost of operations — 14 312 1 (1 ) 326 Depreciation and amortization — 5 329 — — 334 Impairment losses — — 44 — — 44 General and administrative — — — 19 — 19 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 19 685 23 (1 ) 726 Operating (Loss) Income — 2 303 (22 ) — 283 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 136 (16 ) — 126 (246 ) — Equity in earnings of unconsolidated affiliates — 22 21 28 — 71 Other income, net 1 — 3 — — 4 Loss on debt extinguishment — — (3 ) — — (3 ) Interest expense — — (222 ) (71 ) — (293 ) Total other income (expense), net 137 6 (201 ) 83 (246 ) (221 ) Net Income 137 8 102 61 (246 ) 62 Less: Net loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Net Income Attributable to NRG Yield LLC $ 137 $ 8 $ 107 $ 136 $ (251 ) $ 137 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. For the year ended December 31, 2017 NRG Yield LLC (a) Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 137 $ 8 $ 102 $ 61 $ (246 ) $ 62 Other Comprehensive Income Unrealized gain on derivatives 17 1 16 17 (34 ) 17 Other comprehensive income 17 1 16 17 (34 ) 17 Comprehensive Income 154 9 118 78 (280 ) 79 Less: Comprehensive loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Comprehensive Income Attributable to NRG Yield LLC $ 154 $ 9 $ 123 $ 153 $ (285 ) $ 154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 22 $ — $ 124 $ — $ — $ 146 Restricted cash — — 168 — — 168 Accounts receivable — trade 1 2 92 1 — 96 Inventory — 1 38 — — 39 Notes receivable — current — — 13 — — 13 Prepayments and other current assets — — 18 1 — 19 Total current assets 23 3 453 2 — 481 Property, plant and equipment, net — 58 5,146 — — 5,204 Other Assets Investment in consolidated subsidiaries 1,823 460 — 3,177 (5,460 ) — Equity investments in affiliates — 233 577 368 — 1,178 Intangible assets, net — 55 1,173 — — 1,228 Other non-current assets — — 63 — — 63 Total other assets 1,823 748 1,813 3,545 (5,460 ) 2,469 Total Assets $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 306 $ — $ — $ 306 Accounts payable — trade — 2 25 — — 27 Accounts payable — affiliate — 5 27 16 — 48 Derivative instruments — — 17 — — 17 Accrued expenses and other current liabilities — 1 61 25 — 87 Total current liabilities — 8 436 41 — 485 Other Liabilities Long-term debt — external — — 4,025 896 — 4,921 Long-term debt — affiliate — — — 618 — 618 Derivative instruments — — 31 — — 31 Other non-current liabilities — — 84 7 — 91 Total non-current liabilities — — 4,140 1,521 — 5,661 Total Liabilities — 8 4,576 1,562 — 6,146 Commitments and Contingencies Members' Equity Contributed capital 1,897 863 2,871 2,097 (5,831 ) 1,897 Retained earnings (accumulated deficit) 17 (61 ) (21 ) (206 ) 288 17 Accumulated other comprehensive loss (68 ) (1 ) (71 ) (68 ) 140 (68 ) Noncontrolling interest — — 57 162 (57 ) 162 Total Members' Equity 1,846 801 2,836 1,985 (5,460 ) 2,008 Total Liabilities and Members’ Equity $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 58 $ 529 $ (71 ) $ 516 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (15 ) — — 15 — Acquisition of Drop Down Assets, net of cash acquired — — — (250 ) (250 ) Capital expenditures — (4 ) (27 ) — (31 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 10 14 23 47 Investments in unconsolidated affiliates — (64 ) (7 ) (2 ) (73 ) Other — — 7 — 7 Net Cash Provided by (Used in) Investing Activities (15 ) (58 ) 4 (214 ) (283 ) Cash Flows from Financing Activities Net contributions from noncontrolling interests — — 2 11 13 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (13 ) (7 ) (20 ) Transfer of funds under intercompany cash management arrangement (5 ) — (1 ) 6 — Proceeds from the issuance of Class C units 33 — — — 33 (Payments of) proceeds from distributions (202 ) — (220 ) 220 (202 ) Proceeds from the revolving credit facility — — — 55 55 Proceeds from issuance of long-term debt — — 41 — 41 Payments of debt issuance costs — — (4 ) — (4 ) Payments for long-term debt — external — — (332 ) — (332 ) Net Cash (Used in) Provided by Financing Activities (174 ) — (527 ) 285 (416 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (189 ) — 6 — (183 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 211 — 286 — 497 Cash, Cash Equivalents and Restricted Cash at End of Period $ 22 $ — $ 292 $ — $ 314 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 22 $ 1,013 $ 1 $ (1 ) $ 1,035 Operating Costs and Expenses Cost of operations — 14 294 1 (1 ) 308 Depreciation and amortization — 5 298 — — 303 Impairment losses — — 185 — — 185 General and administrative 2 — — 12 — 14 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses 2 19 777 14 (1 ) 811 Operating Income (Loss) (2 ) 3 236 (13 ) — 224 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 128 10 — 66 (204 ) — Equity in earnings of unconsolidated affiliates — 9 21 30 — 60 Other income, net — — 3 — — 3 Interest expense — — (206 ) (66 ) — (272 ) Total other income (expense) 128 19 (182 ) 30 (204 ) (209 ) Net Income 126 22 54 17 (204 ) 15 Less: Net loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Net Income Attributable to NRG Yield LLC $ 126 $ 22 $ 55 $ 128 $ (205 ) $ 126 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income $ 126 $ 22 $ 54 $ 17 $ (204 ) $ 15 Other Comprehensive Income Unrealized gain on derivatives 13 1 10 13 (24 ) 13 Other comprehensive income 13 1 10 13 (24 ) 13 Comprehensive Income 139 23 64 30 (228 ) 28 Less: Comprehensive loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Comprehensive Income Attributable to NRG Yield LLC $ 139 $ 23 $ 65 $ 141 $ (229 ) $ 139 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2016 NRG Yield LLC (a)(c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b)(c) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 211 $ — $ 110 $ — $ — $ 321 Restricted cash — — 176 — — 176 Accounts receivable — trade — 2 94 — — 96 Inventory — 2 37 — — 39 Notes receivable — current — — 16 — — 16 Prepayments and other current assets — — 21 1 — 22 Total current assets 211 4 454 1 — 670 Property, plant and equipment, net — 59 5,495 — — 5,554 Other Assets Investment in consolidated subsidiaries 1,927 527 — 3,272 (5,726 ) — Equity investments in affiliates — 171 600 381 — 1,152 Intangible assets, net — 56 1,247 — — 1,303 Other non-current assets — — 66 1 — 67 Total other assets 1,927 754 1,913 3,654 (5,726 ) 2,522 Total Assets $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b) (c) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 323 $ — $ — $ 323 Accounts payable — trade — 2 18 3 — 23 Accounts payable — affiliate — 7 15 18 — 40 Derivative instruments — — 33 — — 33 Accrued expenses and other current liabilities — 1 60 24 — 85 Total current liabilities — 10 449 45 — 504 Other Liabilities Long-term debt — external — — 4,289 839 — 5,128 Long-term debt — affiliate — — — 618 — 618 Accounts payable — affiliate — — 9 — — 9 Derivative instruments — — 46 — — 46 Other non-current liabilities — — 77 — — 77 Total non-current liabilities — — 4,421 1,457 — 5,878 Total Liabilities — 10 4,870 1,502 — 6,382 Commitments and Contingencies Members' Equity Contributed capital 2,179 874 2,972 2,155 (6,001 ) 2,179 Retained earnings (accumulated deficit) 44 (65 ) 43 (143 ) 165 44 Accumulated other comprehensive loss (85 ) (2 ) (87 ) (85 ) 174 (85 ) Noncontrolling interest — — 64 226 (64 ) 226 Total Members' Equity 2,138 807 2,992 2,153 (5,726 ) 2,364 Total Liabilities and Members’ Equity $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2016 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated Net Cash Provided by (Used in) Operating Activities $ — $ 62 $ 554 $ (39 ) $ 577 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 325 — (21 ) (304 ) — Acquisition of Drop Down Assets — — — (77 ) (77 ) Capital expenditures — — (20 ) — (20 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 16 — 12 28 Investments in unconsolidated affiliates — (80 ) (3 ) — (83 ) Other — — 4 — 4 Net Cash Used in Investing Activities 325 (64 ) (23 ) (369 ) (131 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement 44 2 — (46 ) — Net contributions from noncontrolling interests — — — 5 5 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (174 ) (10 ) (184 ) (Payments of) proceeds from distributions (173 ) — (420 ) 420 (173 ) Proceeds from the revolving credit facility — — — 60 60 Payments for the revolving credit facility — — — (366 ) (366 ) Proceeds from the issuance of long-term debt - external — — 390 350 740 Payments of debt issuance costs — — (10 ) (5 ) (15 ) Payments for long-term debt — external — — (269 ) — (269 ) Net Cash Provided by (Used in) Financing Activities (129 ) 2 (483 ) 408 (202 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash 196 — 48 — 244 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 15 — 238 — 253 Cash, Cash Equivalents and Restricted Cash at End of Period $ 211 $ — $ 286 $ — $ 497 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 937 $ 10 $ — $ 968 Operating Costs and Expenses Cost of operations — 14 309 — — 323 Depreciation and amortization — 4 299 — — 303 Impairment losses — — 1 — — 1 General and administrative — — — 10 — 10 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 18 609 13 — 640 Operating Income (Loss) — 3 328 (3 ) — 328 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 157 (43 ) — 125 (239 ) — Equity in (losses) earnings of unconsolidated affiliates — (2 ) 8 25 — 31 Other income, net — — 3 — — 3 Loss on debt extinguishment — — (9 ) — — (9 ) Interest expense — — (206 ) (52 ) — (258 ) Total other income (expense), net 157 (45 ) (204 ) 98 (239 ) (233 ) Net Income (Loss) 157 (42 ) 124 95 (239 ) 95 Less: Net loss attributable to noncontrolling interests — — (2 ) (62 ) 2 (62 ) Net Income (Loss) Attributable to NRG Yield LLC $ 157 $ (42 ) $ 126 $ 157 $ (241 ) $ 157 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income (Loss) $ 157 $ (42 ) $ 124 $ 95 $ (239 ) $ 95 Other Comprehensive Loss Unrealized loss on derivatives (16 ) — (16 ) (17 ) 32 (17 ) Other comprehensive loss (16 ) — (16 ) (17 ) 32 (17 ) Comprehensive Income (Loss) 141 (42 ) 108 78 (207 ) 78 Less: Comprehensive loss attributable to noncontrolling interests — — (2 ) (63 ) 2 (63 ) Comprehensive Income (Loss) Attributable to NRG Yield LLC $ 141 $ (42 ) $ 110 $ 141 $ (209 ) $ 141 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2015 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 19 $ 423 $ (18 ) $ 424 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (464 ) — 285 179 — Acquisition of businesses, net of cash acquired — — — (37 ) (37 ) Acquisition of Drop Down Assets, net of cash acquired — — — (698 ) (698 ) Capital expenditures — — (29 ) — (29 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — — — 42 42 Investments in unconsolidated affiliates — (28 ) — — (374 ) (402 ) Other — — 9 — 9 Net Cash (Used in) Provided by Investing Activities (464 ) (28 ) 282 (888 ) (1,098 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (309 ) 9 — 300 — Net contributions from noncontrolling interests — — — 122 122 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (79 ) — (79 ) Proceeds from the issuance of Class C units 599 — — — 599 (Payments of) proceeds from distributions (139 ) — (392 ) 392 (139 ) Proceeds from the revolving credit facility — — — 551 551 Payments for the revolving credit facility — — — (245 ) (245 ) Proceeds from issuance of long-term debt — external — — 6 — 6 Proceeds from issuance of long-term debt — affiliate — — — 281 281 Payments for long-term debt — external — — (241 ) (494 ) (735 ) Payment of debt issuance costs — — (6 ) (1 ) (7 ) Net Cash Provided by (Used in) Financing Activities 151 9 (712 ) 906 354 Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (313 ) — (7 ) — (320 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 328 — 245 — 573 Cash, Cash Equivalents and Restricted Cash at End of Period $ 15 $ — $ 238 $ — $ 253 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan28

Condensed Consolidating Financial Information PP Income Statement Condensed Consolidating PP Income Statement (Notes)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Information [Abstract]
Condensed Financial Statements [Text Block]	Condensed Consolidating Financial Information As of December 31, 2017 , Yield Operating LLC had outstanding $500 million of the 2024 Senior Notes and $350 million of the 2026 Senior Notes, collectively Senior Notes, as described in Note 10 , Long-term Debt . These Senior Notes are guaranteed by the Company, as well as certain of the Company's subsidiaries, or guarantor subsidiaries. These guarantees are both joint and several. The non-guarantor subsidiaries include the rest of the Company's subsidiaries, including the ones that are subject to project financing. Unless otherwise noted below, each of the following guarantor subsidiaries fully and unconditionally guaranteed the Senior Notes as of December 31, 2017 : NRG Yield LLC Alta Wind 1-5 Holding Company, LLC Alta Wind Company, LLC NRG Energy Center Omaha Holdings LLC NRG Energy Center Omaha LLC NYLD Fuel Cell Holdings LLC UB Fuel Cell, LLC NRG South Trent Holdings LLC NRG Yield DGPV Holding LLC NRG Yield RPV Holding LLC Yield Operating LLC conducts much of its business through and derives much of its income from its subsidiaries. Therefore, its ability to make required payments with respect to its indebtedness and other obligations depends on the financial results and condition of its subsidiaries and Yield Operating LLC's ability to receive funds from its subsidiaries. There are no restrictions on the ability of any of the guarantor subsidiaries to transfer funds to Yield Operating LLC. However, there may be restrictions for certain non-guarantor subsidiaries. The following condensed consolidating financial information presents the financial information of Yield LLC, Yield Operating LLC, the issuer of the Senior Notes, the guarantor subsidiaries and the non-guarantor subsidiaries in accordance with Rule 3-10 under the SEC Regulation S-X. The financial information may not necessarily be indicative of results of operations or financial position had the guarantor subsidiaries or non-guarantor subsidiaries operated as independent entities. In this presentation, Yield LLC consists of parent company operations. Guarantor subsidiaries and non-guarantor subsidiaries of Yield LLC are reported on an equity basis. For companies acquired, the fair values of the assets and liabilities acquired have been presented on a push-down accounting basis. As described in Note 3 , Business Acquisitions , the Company completed the acquisition of the November 2017 Drop Down Assets, August 2017 Drop Down Assets, and March 2017 Drop Down Assets from NRG on November 1, 2017, August 1, 2017 and March 27, 2017, respectively. The guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control. Accordingly, the Company prepared its condensed consolidating financial statements to reflect the transfers as if they had taken place from the beginning of the financial statements period. In addition, the condensed parent company financial statements are provided in accordance with Rule 12-04, Schedule I of Regulation S-X, as the restricted net assets of Yield LLC’s subsidiaries exceed 25 percent of the consolidated net assets of Yield LLC. These statements should be read in conjunction with the consolidated statements and notes thereto of NRG Yield LLC. For a discussion of Yield LLC's long-term debt, see Note 10 , Long-term Debt . For a discussion of Yield LLC's commitments and contingencies, see Note 14 , Commitments and Contingencies . For a discussion of Yield LLC's distributions to Yield, Inc. and NRG Energy, see Note 11 , Members' Equity . For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 988 $ 1 $ (1 ) $ 1,009 Operating Costs and Expenses — Cost of operations — 14 312 1 (1 ) 326 Depreciation and amortization — 5 329 — — 334 Impairment losses — — 44 — — 44 General and administrative — — — 19 — 19 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 19 685 23 (1 ) 726 Operating (Loss) Income — 2 303 (22 ) — 283 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 136 (16 ) — 126 (246 ) — Equity in earnings of unconsolidated affiliates — 22 21 28 — 71 Other income, net 1 — 3 — — 4 Loss on debt extinguishment — — (3 ) — — (3 ) Interest expense — — (222 ) (71 ) — (293 ) Total other income (expense), net 137 6 (201 ) 83 (246 ) (221 ) Net Income 137 8 102 61 (246 ) 62 Less: Net loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Net Income Attributable to NRG Yield LLC $ 137 $ 8 $ 107 $ 136 $ (251 ) $ 137 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. For the year ended December 31, 2017 NRG Yield LLC (a) Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 137 $ 8 $ 102 $ 61 $ (246 ) $ 62 Other Comprehensive Income Unrealized gain on derivatives 17 1 16 17 (34 ) 17 Other comprehensive income 17 1 16 17 (34 ) 17 Comprehensive Income 154 9 118 78 (280 ) 79 Less: Comprehensive loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Comprehensive Income Attributable to NRG Yield LLC $ 154 $ 9 $ 123 $ 153 $ (285 ) $ 154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 22 $ — $ 124 $ — $ — $ 146 Restricted cash — — 168 — — 168 Accounts receivable — trade 1 2 92 1 — 96 Inventory — 1 38 — — 39 Notes receivable — current — — 13 — — 13 Prepayments and other current assets — — 18 1 — 19 Total current assets 23 3 453 2 — 481 Property, plant and equipment, net — 58 5,146 — — 5,204 Other Assets Investment in consolidated subsidiaries 1,823 460 — 3,177 (5,460 ) — Equity investments in affiliates — 233 577 368 — 1,178 Intangible assets, net — 55 1,173 — — 1,228 Other non-current assets — — 63 — — 63 Total other assets 1,823 748 1,813 3,545 (5,460 ) 2,469 Total Assets $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 306 $ — $ — $ 306 Accounts payable — trade — 2 25 — — 27 Accounts payable — affiliate — 5 27 16 — 48 Derivative instruments — — 17 — — 17 Accrued expenses and other current liabilities — 1 61 25 — 87 Total current liabilities — 8 436 41 — 485 Other Liabilities Long-term debt — external — — 4,025 896 — 4,921 Long-term debt — affiliate — — — 618 — 618 Derivative instruments — — 31 — — 31 Other non-current liabilities — — 84 7 — 91 Total non-current liabilities — — 4,140 1,521 — 5,661 Total Liabilities — 8 4,576 1,562 — 6,146 Commitments and Contingencies Members' Equity Contributed capital 1,897 863 2,871 2,097 (5,831 ) 1,897 Retained earnings (accumulated deficit) 17 (61 ) (21 ) (206 ) 288 17 Accumulated other comprehensive loss (68 ) (1 ) (71 ) (68 ) 140 (68 ) Noncontrolling interest — — 57 162 (57 ) 162 Total Members' Equity 1,846 801 2,836 1,985 (5,460 ) 2,008 Total Liabilities and Members’ Equity $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 58 $ 529 $ (71 ) $ 516 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (15 ) — — 15 — Acquisition of Drop Down Assets, net of cash acquired — — — (250 ) (250 ) Capital expenditures — (4 ) (27 ) — (31 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 10 14 23 47 Investments in unconsolidated affiliates — (64 ) (7 ) (2 ) (73 ) Other — — 7 — 7 Net Cash Provided by (Used in) Investing Activities (15 ) (58 ) 4 (214 ) (283 ) Cash Flows from Financing Activities Net contributions from noncontrolling interests — — 2 11 13 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (13 ) (7 ) (20 ) Transfer of funds under intercompany cash management arrangement (5 ) — (1 ) 6 — Proceeds from the issuance of Class C units 33 — — — 33 (Payments of) proceeds from distributions (202 ) — (220 ) 220 (202 ) Proceeds from the revolving credit facility — — — 55 55 Proceeds from issuance of long-term debt — — 41 — 41 Payments of debt issuance costs — — (4 ) — (4 ) Payments for long-term debt — external — — (332 ) — (332 ) Net Cash (Used in) Provided by Financing Activities (174 ) — (527 ) 285 (416 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (189 ) — 6 — (183 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 211 — 286 — 497 Cash, Cash Equivalents and Restricted Cash at End of Period $ 22 $ — $ 292 $ — $ 314 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 22 $ 1,013 $ 1 $ (1 ) $ 1,035 Operating Costs and Expenses Cost of operations — 14 294 1 (1 ) 308 Depreciation and amortization — 5 298 — — 303 Impairment losses — — 185 — — 185 General and administrative 2 — — 12 — 14 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses 2 19 777 14 (1 ) 811 Operating Income (Loss) (2 ) 3 236 (13 ) — 224 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 128 10 — 66 (204 ) — Equity in earnings of unconsolidated affiliates — 9 21 30 — 60 Other income, net — — 3 — — 3 Interest expense — — (206 ) (66 ) — (272 ) Total other income (expense) 128 19 (182 ) 30 (204 ) (209 ) Net Income 126 22 54 17 (204 ) 15 Less: Net loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Net Income Attributable to NRG Yield LLC $ 126 $ 22 $ 55 $ 128 $ (205 ) $ 126 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income $ 126 $ 22 $ 54 $ 17 $ (204 ) $ 15 Other Comprehensive Income Unrealized gain on derivatives 13 1 10 13 (24 ) 13 Other comprehensive income 13 1 10 13 (24 ) 13 Comprehensive Income 139 23 64 30 (228 ) 28 Less: Comprehensive loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Comprehensive Income Attributable to NRG Yield LLC $ 139 $ 23 $ 65 $ 141 $ (229 ) $ 139 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2016 NRG Yield LLC (a)(c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b)(c) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 211 $ — $ 110 $ — $ — $ 321 Restricted cash — — 176 — — 176 Accounts receivable — trade — 2 94 — — 96 Inventory — 2 37 — — 39 Notes receivable — current — — 16 — — 16 Prepayments and other current assets — — 21 1 — 22 Total current assets 211 4 454 1 — 670 Property, plant and equipment, net — 59 5,495 — — 5,554 Other Assets Investment in consolidated subsidiaries 1,927 527 — 3,272 (5,726 ) — Equity investments in affiliates — 171 600 381 — 1,152 Intangible assets, net — 56 1,247 — — 1,303 Other non-current assets — — 66 1 — 67 Total other assets 1,927 754 1,913 3,654 (5,726 ) 2,522 Total Assets $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b) (c) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 323 $ — $ — $ 323 Accounts payable — trade — 2 18 3 — 23 Accounts payable — affiliate — 7 15 18 — 40 Derivative instruments — — 33 — — 33 Accrued expenses and other current liabilities — 1 60 24 — 85 Total current liabilities — 10 449 45 — 504 Other Liabilities Long-term debt — external — — 4,289 839 — 5,128 Long-term debt — affiliate — — — 618 — 618 Accounts payable — affiliate — — 9 — — 9 Derivative instruments — — 46 — — 46 Other non-current liabilities — — 77 — — 77 Total non-current liabilities — — 4,421 1,457 — 5,878 Total Liabilities — 10 4,870 1,502 — 6,382 Commitments and Contingencies Members' Equity Contributed capital 2,179 874 2,972 2,155 (6,001 ) 2,179 Retained earnings (accumulated deficit) 44 (65 ) 43 (143 ) 165 44 Accumulated other comprehensive loss (85 ) (2 ) (87 ) (85 ) 174 (85 ) Noncontrolling interest — — 64 226 (64 ) 226 Total Members' Equity 2,138 807 2,992 2,153 (5,726 ) 2,364 Total Liabilities and Members’ Equity $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2016 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated Net Cash Provided by (Used in) Operating Activities $ — $ 62 $ 554 $ (39 ) $ 577 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 325 — (21 ) (304 ) — Acquisition of Drop Down Assets — — — (77 ) (77 ) Capital expenditures — — (20 ) — (20 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 16 — 12 28 Investments in unconsolidated affiliates — (80 ) (3 ) — (83 ) Other — — 4 — 4 Net Cash Used in Investing Activities 325 (64 ) (23 ) (369 ) (131 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement 44 2 — (46 ) — Net contributions from noncontrolling interests — — — 5 5 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (174 ) (10 ) (184 ) (Payments of) proceeds from distributions (173 ) — (420 ) 420 (173 ) Proceeds from the revolving credit facility — — — 60 60 Payments for the revolving credit facility — — — (366 ) (366 ) Proceeds from the issuance of long-term debt - external — — 390 350 740 Payments of debt issuance costs — — (10 ) (5 ) (15 ) Payments for long-term debt — external — — (269 ) — (269 ) Net Cash Provided by (Used in) Financing Activities (129 ) 2 (483 ) 408 (202 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash 196 — 48 — 244 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 15 — 238 — 253 Cash, Cash Equivalents and Restricted Cash at End of Period $ 211 $ — $ 286 $ — $ 497 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 937 $ 10 $ — $ 968 Operating Costs and Expenses Cost of operations — 14 309 — — 323 Depreciation and amortization — 4 299 — — 303 Impairment losses — — 1 — — 1 General and administrative — — — 10 — 10 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 18 609 13 — 640 Operating Income (Loss) — 3 328 (3 ) — 328 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 157 (43 ) — 125 (239 ) — Equity in (losses) earnings of unconsolidated affiliates — (2 ) 8 25 — 31 Other income, net — — 3 — — 3 Loss on debt extinguishment — — (9 ) — — (9 ) Interest expense — — (206 ) (52 ) — (258 ) Total other income (expense), net 157 (45 ) (204 ) 98 (239 ) (233 ) Net Income (Loss) 157 (42 ) 124 95 (239 ) 95 Less: Net loss attributable to noncontrolling interests — — (2 ) (62 ) 2 (62 ) Net Income (Loss) Attributable to NRG Yield LLC $ 157 $ (42 ) $ 126 $ 157 $ (241 ) $ 157 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income (Loss) $ 157 $ (42 ) $ 124 $ 95 $ (239 ) $ 95 Other Comprehensive Loss Unrealized loss on derivatives (16 ) — (16 ) (17 ) 32 (17 ) Other comprehensive loss (16 ) — (16 ) (17 ) 32 (17 ) Comprehensive Income (Loss) 141 (42 ) 108 78 (207 ) 78 Less: Comprehensive loss attributable to noncontrolling interests — — (2 ) (63 ) 2 (63 ) Comprehensive Income (Loss) Attributable to NRG Yield LLC $ 141 $ (42 ) $ 110 $ 141 $ (209 ) $ 141 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2015 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 19 $ 423 $ (18 ) $ 424 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (464 ) — 285 179 — Acquisition of businesses, net of cash acquired — — — (37 ) (37 ) Acquisition of Drop Down Assets, net of cash acquired — — — (698 ) (698 ) Capital expenditures — — (29 ) — (29 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — — — 42 42 Investments in unconsolidated affiliates — (28 ) — — (374 ) (402 ) Other — — 9 — 9 Net Cash (Used in) Provided by Investing Activities (464 ) (28 ) 282 (888 ) (1,098 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (309 ) 9 — 300 — Net contributions from noncontrolling interests — — — 122 122 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (79 ) — (79 ) Proceeds from the issuance of Class C units 599 — — — 599 (Payments of) proceeds from distributions (139 ) — (392 ) 392 (139 ) Proceeds from the revolving credit facility — — — 551 551 Payments for the revolving credit facility — — — (245 ) (245 ) Proceeds from issuance of long-term debt — external — — 6 — 6 Proceeds from issuance of long-term debt — affiliate — — — 281 281 Payments for long-term debt — external — — (241 ) (494 ) (735 ) Payment of debt issuance costs — — (6 ) (1 ) (7 ) Net Cash Provided by (Used in) Financing Activities 151 9 (712 ) 906 354 Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (313 ) — (7 ) — (320 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 328 — 245 — 573 Cash, Cash Equivalents and Restricted Cash at End of Period $ 15 $ — $ 238 $ — $ 253 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan29

Condensed Consolidating Financial Information PP Comprehensive Income Condensed Consolidating PP Comprehensive Income (Notes)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Information [Abstract]
Condensed Financial Statements [Text Block]	Condensed Consolidating Financial Information As of December 31, 2017 , Yield Operating LLC had outstanding $500 million of the 2024 Senior Notes and $350 million of the 2026 Senior Notes, collectively Senior Notes, as described in Note 10 , Long-term Debt . These Senior Notes are guaranteed by the Company, as well as certain of the Company's subsidiaries, or guarantor subsidiaries. These guarantees are both joint and several. The non-guarantor subsidiaries include the rest of the Company's subsidiaries, including the ones that are subject to project financing. Unless otherwise noted below, each of the following guarantor subsidiaries fully and unconditionally guaranteed the Senior Notes as of December 31, 2017 : NRG Yield LLC Alta Wind 1-5 Holding Company, LLC Alta Wind Company, LLC NRG Energy Center Omaha Holdings LLC NRG Energy Center Omaha LLC NYLD Fuel Cell Holdings LLC UB Fuel Cell, LLC NRG South Trent Holdings LLC NRG Yield DGPV Holding LLC NRG Yield RPV Holding LLC Yield Operating LLC conducts much of its business through and derives much of its income from its subsidiaries. Therefore, its ability to make required payments with respect to its indebtedness and other obligations depends on the financial results and condition of its subsidiaries and Yield Operating LLC's ability to receive funds from its subsidiaries. There are no restrictions on the ability of any of the guarantor subsidiaries to transfer funds to Yield Operating LLC. However, there may be restrictions for certain non-guarantor subsidiaries. The following condensed consolidating financial information presents the financial information of Yield LLC, Yield Operating LLC, the issuer of the Senior Notes, the guarantor subsidiaries and the non-guarantor subsidiaries in accordance with Rule 3-10 under the SEC Regulation S-X. The financial information may not necessarily be indicative of results of operations or financial position had the guarantor subsidiaries or non-guarantor subsidiaries operated as independent entities. In this presentation, Yield LLC consists of parent company operations. Guarantor subsidiaries and non-guarantor subsidiaries of Yield LLC are reported on an equity basis. For companies acquired, the fair values of the assets and liabilities acquired have been presented on a push-down accounting basis. As described in Note 3 , Business Acquisitions , the Company completed the acquisition of the November 2017 Drop Down Assets, August 2017 Drop Down Assets, and March 2017 Drop Down Assets from NRG on November 1, 2017, August 1, 2017 and March 27, 2017, respectively. The guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control. Accordingly, the Company prepared its condensed consolidating financial statements to reflect the transfers as if they had taken place from the beginning of the financial statements period. In addition, the condensed parent company financial statements are provided in accordance with Rule 12-04, Schedule I of Regulation S-X, as the restricted net assets of Yield LLC’s subsidiaries exceed 25 percent of the consolidated net assets of Yield LLC. These statements should be read in conjunction with the consolidated statements and notes thereto of NRG Yield LLC. For a discussion of Yield LLC's long-term debt, see Note 10 , Long-term Debt . For a discussion of Yield LLC's commitments and contingencies, see Note 14 , Commitments and Contingencies . For a discussion of Yield LLC's distributions to Yield, Inc. and NRG Energy, see Note 11 , Members' Equity . For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 988 $ 1 $ (1 ) $ 1,009 Operating Costs and Expenses — Cost of operations — 14 312 1 (1 ) 326 Depreciation and amortization — 5 329 — — 334 Impairment losses — — 44 — — 44 General and administrative — — — 19 — 19 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 19 685 23 (1 ) 726 Operating (Loss) Income — 2 303 (22 ) — 283 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 136 (16 ) — 126 (246 ) — Equity in earnings of unconsolidated affiliates — 22 21 28 — 71 Other income, net 1 — 3 — — 4 Loss on debt extinguishment — — (3 ) — — (3 ) Interest expense — — (222 ) (71 ) — (293 ) Total other income (expense), net 137 6 (201 ) 83 (246 ) (221 ) Net Income 137 8 102 61 (246 ) 62 Less: Net loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Net Income Attributable to NRG Yield LLC $ 137 $ 8 $ 107 $ 136 $ (251 ) $ 137 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. For the year ended December 31, 2017 NRG Yield LLC (a) Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 137 $ 8 $ 102 $ 61 $ (246 ) $ 62 Other Comprehensive Income Unrealized gain on derivatives 17 1 16 17 (34 ) 17 Other comprehensive income 17 1 16 17 (34 ) 17 Comprehensive Income 154 9 118 78 (280 ) 79 Less: Comprehensive loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Comprehensive Income Attributable to NRG Yield LLC $ 154 $ 9 $ 123 $ 153 $ (285 ) $ 154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 22 $ — $ 124 $ — $ — $ 146 Restricted cash — — 168 — — 168 Accounts receivable — trade 1 2 92 1 — 96 Inventory — 1 38 — — 39 Notes receivable — current — — 13 — — 13 Prepayments and other current assets — — 18 1 — 19 Total current assets 23 3 453 2 — 481 Property, plant and equipment, net — 58 5,146 — — 5,204 Other Assets Investment in consolidated subsidiaries 1,823 460 — 3,177 (5,460 ) — Equity investments in affiliates — 233 577 368 — 1,178 Intangible assets, net — 55 1,173 — — 1,228 Other non-current assets — — 63 — — 63 Total other assets 1,823 748 1,813 3,545 (5,460 ) 2,469 Total Assets $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 306 $ — $ — $ 306 Accounts payable — trade — 2 25 — — 27 Accounts payable — affiliate — 5 27 16 — 48 Derivative instruments — — 17 — — 17 Accrued expenses and other current liabilities — 1 61 25 — 87 Total current liabilities — 8 436 41 — 485 Other Liabilities Long-term debt — external — — 4,025 896 — 4,921 Long-term debt — affiliate — — — 618 — 618 Derivative instruments — — 31 — — 31 Other non-current liabilities — — 84 7 — 91 Total non-current liabilities — — 4,140 1,521 — 5,661 Total Liabilities — 8 4,576 1,562 — 6,146 Commitments and Contingencies Members' Equity Contributed capital 1,897 863 2,871 2,097 (5,831 ) 1,897 Retained earnings (accumulated deficit) 17 (61 ) (21 ) (206 ) 288 17 Accumulated other comprehensive loss (68 ) (1 ) (71 ) (68 ) 140 (68 ) Noncontrolling interest — — 57 162 (57 ) 162 Total Members' Equity 1,846 801 2,836 1,985 (5,460 ) 2,008 Total Liabilities and Members’ Equity $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 58 $ 529 $ (71 ) $ 516 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (15 ) — — 15 — Acquisition of Drop Down Assets, net of cash acquired — — — (250 ) (250 ) Capital expenditures — (4 ) (27 ) — (31 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 10 14 23 47 Investments in unconsolidated affiliates — (64 ) (7 ) (2 ) (73 ) Other — — 7 — 7 Net Cash Provided by (Used in) Investing Activities (15 ) (58 ) 4 (214 ) (283 ) Cash Flows from Financing Activities Net contributions from noncontrolling interests — — 2 11 13 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (13 ) (7 ) (20 ) Transfer of funds under intercompany cash management arrangement (5 ) — (1 ) 6 — Proceeds from the issuance of Class C units 33 — — — 33 (Payments of) proceeds from distributions (202 ) — (220 ) 220 (202 ) Proceeds from the revolving credit facility — — — 55 55 Proceeds from issuance of long-term debt — — 41 — 41 Payments of debt issuance costs — — (4 ) — (4 ) Payments for long-term debt — external — — (332 ) — (332 ) Net Cash (Used in) Provided by Financing Activities (174 ) — (527 ) 285 (416 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (189 ) — 6 — (183 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 211 — 286 — 497 Cash, Cash Equivalents and Restricted Cash at End of Period $ 22 $ — $ 292 $ — $ 314 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 22 $ 1,013 $ 1 $ (1 ) $ 1,035 Operating Costs and Expenses Cost of operations — 14 294 1 (1 ) 308 Depreciation and amortization — 5 298 — — 303 Impairment losses — — 185 — — 185 General and administrative 2 — — 12 — 14 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses 2 19 777 14 (1 ) 811 Operating Income (Loss) (2 ) 3 236 (13 ) — 224 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 128 10 — 66 (204 ) — Equity in earnings of unconsolidated affiliates — 9 21 30 — 60 Other income, net — — 3 — — 3 Interest expense — — (206 ) (66 ) — (272 ) Total other income (expense) 128 19 (182 ) 30 (204 ) (209 ) Net Income 126 22 54 17 (204 ) 15 Less: Net loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Net Income Attributable to NRG Yield LLC $ 126 $ 22 $ 55 $ 128 $ (205 ) $ 126 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income $ 126 $ 22 $ 54 $ 17 $ (204 ) $ 15 Other Comprehensive Income Unrealized gain on derivatives 13 1 10 13 (24 ) 13 Other comprehensive income 13 1 10 13 (24 ) 13 Comprehensive Income 139 23 64 30 (228 ) 28 Less: Comprehensive loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Comprehensive Income Attributable to NRG Yield LLC $ 139 $ 23 $ 65 $ 141 $ (229 ) $ 139 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2016 NRG Yield LLC (a)(c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b)(c) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 211 $ — $ 110 $ — $ — $ 321 Restricted cash — — 176 — — 176 Accounts receivable — trade — 2 94 — — 96 Inventory — 2 37 — — 39 Notes receivable — current — — 16 — — 16 Prepayments and other current assets — — 21 1 — 22 Total current assets 211 4 454 1 — 670 Property, plant and equipment, net — 59 5,495 — — 5,554 Other Assets Investment in consolidated subsidiaries 1,927 527 — 3,272 (5,726 ) — Equity investments in affiliates — 171 600 381 — 1,152 Intangible assets, net — 56 1,247 — — 1,303 Other non-current assets — — 66 1 — 67 Total other assets 1,927 754 1,913 3,654 (5,726 ) 2,522 Total Assets $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b) (c) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 323 $ — $ — $ 323 Accounts payable — trade — 2 18 3 — 23 Accounts payable — affiliate — 7 15 18 — 40 Derivative instruments — — 33 — — 33 Accrued expenses and other current liabilities — 1 60 24 — 85 Total current liabilities — 10 449 45 — 504 Other Liabilities Long-term debt — external — — 4,289 839 — 5,128 Long-term debt — affiliate — — — 618 — 618 Accounts payable — affiliate — — 9 — — 9 Derivative instruments — — 46 — — 46 Other non-current liabilities — — 77 — — 77 Total non-current liabilities — — 4,421 1,457 — 5,878 Total Liabilities — 10 4,870 1,502 — 6,382 Commitments and Contingencies Members' Equity Contributed capital 2,179 874 2,972 2,155 (6,001 ) 2,179 Retained earnings (accumulated deficit) 44 (65 ) 43 (143 ) 165 44 Accumulated other comprehensive loss (85 ) (2 ) (87 ) (85 ) 174 (85 ) Noncontrolling interest — — 64 226 (64 ) 226 Total Members' Equity 2,138 807 2,992 2,153 (5,726 ) 2,364 Total Liabilities and Members’ Equity $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2016 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated Net Cash Provided by (Used in) Operating Activities $ — $ 62 $ 554 $ (39 ) $ 577 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 325 — (21 ) (304 ) — Acquisition of Drop Down Assets — — — (77 ) (77 ) Capital expenditures — — (20 ) — (20 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 16 — 12 28 Investments in unconsolidated affiliates — (80 ) (3 ) — (83 ) Other — — 4 — 4 Net Cash Used in Investing Activities 325 (64 ) (23 ) (369 ) (131 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement 44 2 — (46 ) — Net contributions from noncontrolling interests — — — 5 5 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (174 ) (10 ) (184 ) (Payments of) proceeds from distributions (173 ) — (420 ) 420 (173 ) Proceeds from the revolving credit facility — — — 60 60 Payments for the revolving credit facility — — — (366 ) (366 ) Proceeds from the issuance of long-term debt - external — — 390 350 740 Payments of debt issuance costs — — (10 ) (5 ) (15 ) Payments for long-term debt — external — — (269 ) — (269 ) Net Cash Provided by (Used in) Financing Activities (129 ) 2 (483 ) 408 (202 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash 196 — 48 — 244 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 15 — 238 — 253 Cash, Cash Equivalents and Restricted Cash at End of Period $ 211 $ — $ 286 $ — $ 497 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 937 $ 10 $ — $ 968 Operating Costs and Expenses Cost of operations — 14 309 — — 323 Depreciation and amortization — 4 299 — — 303 Impairment losses — — 1 — — 1 General and administrative — — — 10 — 10 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 18 609 13 — 640 Operating Income (Loss) — 3 328 (3 ) — 328 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 157 (43 ) — 125 (239 ) — Equity in (losses) earnings of unconsolidated affiliates — (2 ) 8 25 — 31 Other income, net — — 3 — — 3 Loss on debt extinguishment — — (9 ) — — (9 ) Interest expense — — (206 ) (52 ) — (258 ) Total other income (expense), net 157 (45 ) (204 ) 98 (239 ) (233 ) Net Income (Loss) 157 (42 ) 124 95 (239 ) 95 Less: Net loss attributable to noncontrolling interests — — (2 ) (62 ) 2 (62 ) Net Income (Loss) Attributable to NRG Yield LLC $ 157 $ (42 ) $ 126 $ 157 $ (241 ) $ 157 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income (Loss) $ 157 $ (42 ) $ 124 $ 95 $ (239 ) $ 95 Other Comprehensive Loss Unrealized loss on derivatives (16 ) — (16 ) (17 ) 32 (17 ) Other comprehensive loss (16 ) — (16 ) (17 ) 32 (17 ) Comprehensive Income (Loss) 141 (42 ) 108 78 (207 ) 78 Less: Comprehensive loss attributable to noncontrolling interests — — (2 ) (63 ) 2 (63 ) Comprehensive Income (Loss) Attributable to NRG Yield LLC $ 141 $ (42 ) $ 110 $ 141 $ (209 ) $ 141 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2015 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 19 $ 423 $ (18 ) $ 424 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (464 ) — 285 179 — Acquisition of businesses, net of cash acquired — — — (37 ) (37 ) Acquisition of Drop Down Assets, net of cash acquired — — — (698 ) (698 ) Capital expenditures — — (29 ) — (29 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — — — 42 42 Investments in unconsolidated affiliates — (28 ) — — (374 ) (402 ) Other — — 9 — 9 Net Cash (Used in) Provided by Investing Activities (464 ) (28 ) 282 (888 ) (1,098 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (309 ) 9 — 300 — Net contributions from noncontrolling interests — — — 122 122 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (79 ) — (79 ) Proceeds from the issuance of Class C units 599 — — — 599 (Payments of) proceeds from distributions (139 ) — (392 ) 392 (139 ) Proceeds from the revolving credit facility — — — 551 551 Payments for the revolving credit facility — — — (245 ) (245 ) Proceeds from issuance of long-term debt — external — — 6 — 6 Proceeds from issuance of long-term debt — affiliate — — — 281 281 Payments for long-term debt — external — — (241 ) (494 ) (735 ) Payment of debt issuance costs — — (6 ) (1 ) (7 ) Net Cash Provided by (Used in) Financing Activities 151 9 (712 ) 906 354 Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (313 ) — (7 ) — (320 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 328 — 245 — 573 Cash, Cash Equivalents and Restricted Cash at End of Period $ 15 $ — $ 238 $ — $ 253 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan30

Condensed Consolidating Financial Information PP Balance Sheet Condensed Consolidating PP Balance Sheet (Notes)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Information [Abstract]
Condensed Financial Statements [Text Block]	Condensed Consolidating Financial Information As of December 31, 2017 , Yield Operating LLC had outstanding $500 million of the 2024 Senior Notes and $350 million of the 2026 Senior Notes, collectively Senior Notes, as described in Note 10 , Long-term Debt . These Senior Notes are guaranteed by the Company, as well as certain of the Company's subsidiaries, or guarantor subsidiaries. These guarantees are both joint and several. The non-guarantor subsidiaries include the rest of the Company's subsidiaries, including the ones that are subject to project financing. Unless otherwise noted below, each of the following guarantor subsidiaries fully and unconditionally guaranteed the Senior Notes as of December 31, 2017 : NRG Yield LLC Alta Wind 1-5 Holding Company, LLC Alta Wind Company, LLC NRG Energy Center Omaha Holdings LLC NRG Energy Center Omaha LLC NYLD Fuel Cell Holdings LLC UB Fuel Cell, LLC NRG South Trent Holdings LLC NRG Yield DGPV Holding LLC NRG Yield RPV Holding LLC Yield Operating LLC conducts much of its business through and derives much of its income from its subsidiaries. Therefore, its ability to make required payments with respect to its indebtedness and other obligations depends on the financial results and condition of its subsidiaries and Yield Operating LLC's ability to receive funds from its subsidiaries. There are no restrictions on the ability of any of the guarantor subsidiaries to transfer funds to Yield Operating LLC. However, there may be restrictions for certain non-guarantor subsidiaries. The following condensed consolidating financial information presents the financial information of Yield LLC, Yield Operating LLC, the issuer of the Senior Notes, the guarantor subsidiaries and the non-guarantor subsidiaries in accordance with Rule 3-10 under the SEC Regulation S-X. The financial information may not necessarily be indicative of results of operations or financial position had the guarantor subsidiaries or non-guarantor subsidiaries operated as independent entities. In this presentation, Yield LLC consists of parent company operations. Guarantor subsidiaries and non-guarantor subsidiaries of Yield LLC are reported on an equity basis. For companies acquired, the fair values of the assets and liabilities acquired have been presented on a push-down accounting basis. As described in Note 3 , Business Acquisitions , the Company completed the acquisition of the November 2017 Drop Down Assets, August 2017 Drop Down Assets, and March 2017 Drop Down Assets from NRG on November 1, 2017, August 1, 2017 and March 27, 2017, respectively. The guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control. Accordingly, the Company prepared its condensed consolidating financial statements to reflect the transfers as if they had taken place from the beginning of the financial statements period. In addition, the condensed parent company financial statements are provided in accordance with Rule 12-04, Schedule I of Regulation S-X, as the restricted net assets of Yield LLC’s subsidiaries exceed 25 percent of the consolidated net assets of Yield LLC. These statements should be read in conjunction with the consolidated statements and notes thereto of NRG Yield LLC. For a discussion of Yield LLC's long-term debt, see Note 10 , Long-term Debt . For a discussion of Yield LLC's commitments and contingencies, see Note 14 , Commitments and Contingencies . For a discussion of Yield LLC's distributions to Yield, Inc. and NRG Energy, see Note 11 , Members' Equity . For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 988 $ 1 $ (1 ) $ 1,009 Operating Costs and Expenses — Cost of operations — 14 312 1 (1 ) 326 Depreciation and amortization — 5 329 — — 334 Impairment losses — — 44 — — 44 General and administrative — — — 19 — 19 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 19 685 23 (1 ) 726 Operating (Loss) Income — 2 303 (22 ) — 283 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 136 (16 ) — 126 (246 ) — Equity in earnings of unconsolidated affiliates — 22 21 28 — 71 Other income, net 1 — 3 — — 4 Loss on debt extinguishment — — (3 ) — — (3 ) Interest expense — — (222 ) (71 ) — (293 ) Total other income (expense), net 137 6 (201 ) 83 (246 ) (221 ) Net Income 137 8 102 61 (246 ) 62 Less: Net loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Net Income Attributable to NRG Yield LLC $ 137 $ 8 $ 107 $ 136 $ (251 ) $ 137 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. For the year ended December 31, 2017 NRG Yield LLC (a) Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 137 $ 8 $ 102 $ 61 $ (246 ) $ 62 Other Comprehensive Income Unrealized gain on derivatives 17 1 16 17 (34 ) 17 Other comprehensive income 17 1 16 17 (34 ) 17 Comprehensive Income 154 9 118 78 (280 ) 79 Less: Comprehensive loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Comprehensive Income Attributable to NRG Yield LLC $ 154 $ 9 $ 123 $ 153 $ (285 ) $ 154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 22 $ — $ 124 $ — $ — $ 146 Restricted cash — — 168 — — 168 Accounts receivable — trade 1 2 92 1 — 96 Inventory — 1 38 — — 39 Notes receivable — current — — 13 — — 13 Prepayments and other current assets — — 18 1 — 19 Total current assets 23 3 453 2 — 481 Property, plant and equipment, net — 58 5,146 — — 5,204 Other Assets Investment in consolidated subsidiaries 1,823 460 — 3,177 (5,460 ) — Equity investments in affiliates — 233 577 368 — 1,178 Intangible assets, net — 55 1,173 — — 1,228 Other non-current assets — — 63 — — 63 Total other assets 1,823 748 1,813 3,545 (5,460 ) 2,469 Total Assets $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 306 $ — $ — $ 306 Accounts payable — trade — 2 25 — — 27 Accounts payable — affiliate — 5 27 16 — 48 Derivative instruments — — 17 — — 17 Accrued expenses and other current liabilities — 1 61 25 — 87 Total current liabilities — 8 436 41 — 485 Other Liabilities Long-term debt — external — — 4,025 896 — 4,921 Long-term debt — affiliate — — — 618 — 618 Derivative instruments — — 31 — — 31 Other non-current liabilities — — 84 7 — 91 Total non-current liabilities — — 4,140 1,521 — 5,661 Total Liabilities — 8 4,576 1,562 — 6,146 Commitments and Contingencies Members' Equity Contributed capital 1,897 863 2,871 2,097 (5,831 ) 1,897 Retained earnings (accumulated deficit) 17 (61 ) (21 ) (206 ) 288 17 Accumulated other comprehensive loss (68 ) (1 ) (71 ) (68 ) 140 (68 ) Noncontrolling interest — — 57 162 (57 ) 162 Total Members' Equity 1,846 801 2,836 1,985 (5,460 ) 2,008 Total Liabilities and Members’ Equity $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 58 $ 529 $ (71 ) $ 516 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (15 ) — — 15 — Acquisition of Drop Down Assets, net of cash acquired — — — (250 ) (250 ) Capital expenditures — (4 ) (27 ) — (31 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 10 14 23 47 Investments in unconsolidated affiliates — (64 ) (7 ) (2 ) (73 ) Other — — 7 — 7 Net Cash Provided by (Used in) Investing Activities (15 ) (58 ) 4 (214 ) (283 ) Cash Flows from Financing Activities Net contributions from noncontrolling interests — — 2 11 13 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (13 ) (7 ) (20 ) Transfer of funds under intercompany cash management arrangement (5 ) — (1 ) 6 — Proceeds from the issuance of Class C units 33 — — — 33 (Payments of) proceeds from distributions (202 ) — (220 ) 220 (202 ) Proceeds from the revolving credit facility — — — 55 55 Proceeds from issuance of long-term debt — — 41 — 41 Payments of debt issuance costs — — (4 ) — (4 ) Payments for long-term debt — external — — (332 ) — (332 ) Net Cash (Used in) Provided by Financing Activities (174 ) — (527 ) 285 (416 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (189 ) — 6 — (183 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 211 — 286 — 497 Cash, Cash Equivalents and Restricted Cash at End of Period $ 22 $ — $ 292 $ — $ 314 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 22 $ 1,013 $ 1 $ (1 ) $ 1,035 Operating Costs and Expenses Cost of operations — 14 294 1 (1 ) 308 Depreciation and amortization — 5 298 — — 303 Impairment losses — — 185 — — 185 General and administrative 2 — — 12 — 14 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses 2 19 777 14 (1 ) 811 Operating Income (Loss) (2 ) 3 236 (13 ) — 224 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 128 10 — 66 (204 ) — Equity in earnings of unconsolidated affiliates — 9 21 30 — 60 Other income, net — — 3 — — 3 Interest expense — — (206 ) (66 ) — (272 ) Total other income (expense) 128 19 (182 ) 30 (204 ) (209 ) Net Income 126 22 54 17 (204 ) 15 Less: Net loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Net Income Attributable to NRG Yield LLC $ 126 $ 22 $ 55 $ 128 $ (205 ) $ 126 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income $ 126 $ 22 $ 54 $ 17 $ (204 ) $ 15 Other Comprehensive Income Unrealized gain on derivatives 13 1 10 13 (24 ) 13 Other comprehensive income 13 1 10 13 (24 ) 13 Comprehensive Income 139 23 64 30 (228 ) 28 Less: Comprehensive loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Comprehensive Income Attributable to NRG Yield LLC $ 139 $ 23 $ 65 $ 141 $ (229 ) $ 139 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2016 NRG Yield LLC (a)(c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b)(c) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 211 $ — $ 110 $ — $ — $ 321 Restricted cash — — 176 — — 176 Accounts receivable — trade — 2 94 — — 96 Inventory — 2 37 — — 39 Notes receivable — current — — 16 — — 16 Prepayments and other current assets — — 21 1 — 22 Total current assets 211 4 454 1 — 670 Property, plant and equipment, net — 59 5,495 — — 5,554 Other Assets Investment in consolidated subsidiaries 1,927 527 — 3,272 (5,726 ) — Equity investments in affiliates — 171 600 381 — 1,152 Intangible assets, net — 56 1,247 — — 1,303 Other non-current assets — — 66 1 — 67 Total other assets 1,927 754 1,913 3,654 (5,726 ) 2,522 Total Assets $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b) (c) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 323 $ — $ — $ 323 Accounts payable — trade — 2 18 3 — 23 Accounts payable — affiliate — 7 15 18 — 40 Derivative instruments — — 33 — — 33 Accrued expenses and other current liabilities — 1 60 24 — 85 Total current liabilities — 10 449 45 — 504 Other Liabilities Long-term debt — external — — 4,289 839 — 5,128 Long-term debt — affiliate — — — 618 — 618 Accounts payable — affiliate — — 9 — — 9 Derivative instruments — — 46 — — 46 Other non-current liabilities — — 77 — — 77 Total non-current liabilities — — 4,421 1,457 — 5,878 Total Liabilities — 10 4,870 1,502 — 6,382 Commitments and Contingencies Members' Equity Contributed capital 2,179 874 2,972 2,155 (6,001 ) 2,179 Retained earnings (accumulated deficit) 44 (65 ) 43 (143 ) 165 44 Accumulated other comprehensive loss (85 ) (2 ) (87 ) (85 ) 174 (85 ) Noncontrolling interest — — 64 226 (64 ) 226 Total Members' Equity 2,138 807 2,992 2,153 (5,726 ) 2,364 Total Liabilities and Members’ Equity $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2016 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated Net Cash Provided by (Used in) Operating Activities $ — $ 62 $ 554 $ (39 ) $ 577 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 325 — (21 ) (304 ) — Acquisition of Drop Down Assets — — — (77 ) (77 ) Capital expenditures — — (20 ) — (20 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 16 — 12 28 Investments in unconsolidated affiliates — (80 ) (3 ) — (83 ) Other — — 4 — 4 Net Cash Used in Investing Activities 325 (64 ) (23 ) (369 ) (131 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement 44 2 — (46 ) — Net contributions from noncontrolling interests — — — 5 5 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (174 ) (10 ) (184 ) (Payments of) proceeds from distributions (173 ) — (420 ) 420 (173 ) Proceeds from the revolving credit facility — — — 60 60 Payments for the revolving credit facility — — — (366 ) (366 ) Proceeds from the issuance of long-term debt - external — — 390 350 740 Payments of debt issuance costs — — (10 ) (5 ) (15 ) Payments for long-term debt — external — — (269 ) — (269 ) Net Cash Provided by (Used in) Financing Activities (129 ) 2 (483 ) 408 (202 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash 196 — 48 — 244 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 15 — 238 — 253 Cash, Cash Equivalents and Restricted Cash at End of Period $ 211 $ — $ 286 $ — $ 497 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 937 $ 10 $ — $ 968 Operating Costs and Expenses Cost of operations — 14 309 — — 323 Depreciation and amortization — 4 299 — — 303 Impairment losses — — 1 — — 1 General and administrative — — — 10 — 10 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 18 609 13 — 640 Operating Income (Loss) — 3 328 (3 ) — 328 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 157 (43 ) — 125 (239 ) — Equity in (losses) earnings of unconsolidated affiliates — (2 ) 8 25 — 31 Other income, net — — 3 — — 3 Loss on debt extinguishment — — (9 ) — — (9 ) Interest expense — — (206 ) (52 ) — (258 ) Total other income (expense), net 157 (45 ) (204 ) 98 (239 ) (233 ) Net Income (Loss) 157 (42 ) 124 95 (239 ) 95 Less: Net loss attributable to noncontrolling interests — — (2 ) (62 ) 2 (62 ) Net Income (Loss) Attributable to NRG Yield LLC $ 157 $ (42 ) $ 126 $ 157 $ (241 ) $ 157 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income (Loss) $ 157 $ (42 ) $ 124 $ 95 $ (239 ) $ 95 Other Comprehensive Loss Unrealized loss on derivatives (16 ) — (16 ) (17 ) 32 (17 ) Other comprehensive loss (16 ) — (16 ) (17 ) 32 (17 ) Comprehensive Income (Loss) 141 (42 ) 108 78 (207 ) 78 Less: Comprehensive loss attributable to noncontrolling interests — — (2 ) (63 ) 2 (63 ) Comprehensive Income (Loss) Attributable to NRG Yield LLC $ 141 $ (42 ) $ 110 $ 141 $ (209 ) $ 141 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2015 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 19 $ 423 $ (18 ) $ 424 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (464 ) — 285 179 — Acquisition of businesses, net of cash acquired — — — (37 ) (37 ) Acquisition of Drop Down Assets, net of cash acquired — — — (698 ) (698 ) Capital expenditures — — (29 ) — (29 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — — — 42 42 Investments in unconsolidated affiliates — (28 ) — — (374 ) (402 ) Other — — 9 — 9 Net Cash (Used in) Provided by Investing Activities (464 ) (28 ) 282 (888 ) (1,098 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (309 ) 9 — 300 — Net contributions from noncontrolling interests — — — 122 122 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (79 ) — (79 ) Proceeds from the issuance of Class C units 599 — — — 599 (Payments of) proceeds from distributions (139 ) — (392 ) 392 (139 ) Proceeds from the revolving credit facility — — — 551 551 Payments for the revolving credit facility — — — (245 ) (245 ) Proceeds from issuance of long-term debt — external — — 6 — 6 Proceeds from issuance of long-term debt — affiliate — — — 281 281 Payments for long-term debt — external — — (241 ) (494 ) (735 ) Payment of debt issuance costs — — (6 ) (1 ) (7 ) Net Cash Provided by (Used in) Financing Activities 151 9 (712 ) 906 354 Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (313 ) — (7 ) — (320 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 328 — 245 — 573 Cash, Cash Equivalents and Restricted Cash at End of Period $ 15 $ — $ 238 $ — $ 253 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan31

Condensed Consolidating Financial Information PP Cash Flows Condensed Consolidating PP Cash Flows (Notes)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Information [Abstract]
Condensed Financial Statements [Text Block]	Condensed Consolidating Financial Information As of December 31, 2017 , Yield Operating LLC had outstanding $500 million of the 2024 Senior Notes and $350 million of the 2026 Senior Notes, collectively Senior Notes, as described in Note 10 , Long-term Debt . These Senior Notes are guaranteed by the Company, as well as certain of the Company's subsidiaries, or guarantor subsidiaries. These guarantees are both joint and several. The non-guarantor subsidiaries include the rest of the Company's subsidiaries, including the ones that are subject to project financing. Unless otherwise noted below, each of the following guarantor subsidiaries fully and unconditionally guaranteed the Senior Notes as of December 31, 2017 : NRG Yield LLC Alta Wind 1-5 Holding Company, LLC Alta Wind Company, LLC NRG Energy Center Omaha Holdings LLC NRG Energy Center Omaha LLC NYLD Fuel Cell Holdings LLC UB Fuel Cell, LLC NRG South Trent Holdings LLC NRG Yield DGPV Holding LLC NRG Yield RPV Holding LLC Yield Operating LLC conducts much of its business through and derives much of its income from its subsidiaries. Therefore, its ability to make required payments with respect to its indebtedness and other obligations depends on the financial results and condition of its subsidiaries and Yield Operating LLC's ability to receive funds from its subsidiaries. There are no restrictions on the ability of any of the guarantor subsidiaries to transfer funds to Yield Operating LLC. However, there may be restrictions for certain non-guarantor subsidiaries. The following condensed consolidating financial information presents the financial information of Yield LLC, Yield Operating LLC, the issuer of the Senior Notes, the guarantor subsidiaries and the non-guarantor subsidiaries in accordance with Rule 3-10 under the SEC Regulation S-X. The financial information may not necessarily be indicative of results of operations or financial position had the guarantor subsidiaries or non-guarantor subsidiaries operated as independent entities. In this presentation, Yield LLC consists of parent company operations. Guarantor subsidiaries and non-guarantor subsidiaries of Yield LLC are reported on an equity basis. For companies acquired, the fair values of the assets and liabilities acquired have been presented on a push-down accounting basis. As described in Note 3 , Business Acquisitions , the Company completed the acquisition of the November 2017 Drop Down Assets, August 2017 Drop Down Assets, and March 2017 Drop Down Assets from NRG on November 1, 2017, August 1, 2017 and March 27, 2017, respectively. The guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control. Accordingly, the Company prepared its condensed consolidating financial statements to reflect the transfers as if they had taken place from the beginning of the financial statements period. In addition, the condensed parent company financial statements are provided in accordance with Rule 12-04, Schedule I of Regulation S-X, as the restricted net assets of Yield LLC’s subsidiaries exceed 25 percent of the consolidated net assets of Yield LLC. These statements should be read in conjunction with the consolidated statements and notes thereto of NRG Yield LLC. For a discussion of Yield LLC's long-term debt, see Note 10 , Long-term Debt . For a discussion of Yield LLC's commitments and contingencies, see Note 14 , Commitments and Contingencies . For a discussion of Yield LLC's distributions to Yield, Inc. and NRG Energy, see Note 11 , Members' Equity . For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 988 $ 1 $ (1 ) $ 1,009 Operating Costs and Expenses — Cost of operations — 14 312 1 (1 ) 326 Depreciation and amortization — 5 329 — — 334 Impairment losses — — 44 — — 44 General and administrative — — — 19 — 19 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 19 685 23 (1 ) 726 Operating (Loss) Income — 2 303 (22 ) — 283 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 136 (16 ) — 126 (246 ) — Equity in earnings of unconsolidated affiliates — 22 21 28 — 71 Other income, net 1 — 3 — — 4 Loss on debt extinguishment — — (3 ) — — (3 ) Interest expense — — (222 ) (71 ) — (293 ) Total other income (expense), net 137 6 (201 ) 83 (246 ) (221 ) Net Income 137 8 102 61 (246 ) 62 Less: Net loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Net Income Attributable to NRG Yield LLC $ 137 $ 8 $ 107 $ 136 $ (251 ) $ 137 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. For the year ended December 31, 2017 NRG Yield LLC (a) Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 137 $ 8 $ 102 $ 61 $ (246 ) $ 62 Other Comprehensive Income Unrealized gain on derivatives 17 1 16 17 (34 ) 17 Other comprehensive income 17 1 16 17 (34 ) 17 Comprehensive Income 154 9 118 78 (280 ) 79 Less: Comprehensive loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Comprehensive Income Attributable to NRG Yield LLC $ 154 $ 9 $ 123 $ 153 $ (285 ) $ 154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 22 $ — $ 124 $ — $ — $ 146 Restricted cash — — 168 — — 168 Accounts receivable — trade 1 2 92 1 — 96 Inventory — 1 38 — — 39 Notes receivable — current — — 13 — — 13 Prepayments and other current assets — — 18 1 — 19 Total current assets 23 3 453 2 — 481 Property, plant and equipment, net — 58 5,146 — — 5,204 Other Assets Investment in consolidated subsidiaries 1,823 460 — 3,177 (5,460 ) — Equity investments in affiliates — 233 577 368 — 1,178 Intangible assets, net — 55 1,173 — — 1,228 Other non-current assets — — 63 — — 63 Total other assets 1,823 748 1,813 3,545 (5,460 ) 2,469 Total Assets $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 306 $ — $ — $ 306 Accounts payable — trade — 2 25 — — 27 Accounts payable — affiliate — 5 27 16 — 48 Derivative instruments — — 17 — — 17 Accrued expenses and other current liabilities — 1 61 25 — 87 Total current liabilities — 8 436 41 — 485 Other Liabilities Long-term debt — external — — 4,025 896 — 4,921 Long-term debt — affiliate — — — 618 — 618 Derivative instruments — — 31 — — 31 Other non-current liabilities — — 84 7 — 91 Total non-current liabilities — — 4,140 1,521 — 5,661 Total Liabilities — 8 4,576 1,562 — 6,146 Commitments and Contingencies Members' Equity Contributed capital 1,897 863 2,871 2,097 (5,831 ) 1,897 Retained earnings (accumulated deficit) 17 (61 ) (21 ) (206 ) 288 17 Accumulated other comprehensive loss (68 ) (1 ) (71 ) (68 ) 140 (68 ) Noncontrolling interest — — 57 162 (57 ) 162 Total Members' Equity 1,846 801 2,836 1,985 (5,460 ) 2,008 Total Liabilities and Members’ Equity $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 58 $ 529 $ (71 ) $ 516 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (15 ) — — 15 — Acquisition of Drop Down Assets, net of cash acquired — — — (250 ) (250 ) Capital expenditures — (4 ) (27 ) — (31 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 10 14 23 47 Investments in unconsolidated affiliates — (64 ) (7 ) (2 ) (73 ) Other — — 7 — 7 Net Cash Provided by (Used in) Investing Activities (15 ) (58 ) 4 (214 ) (283 ) Cash Flows from Financing Activities Net contributions from noncontrolling interests — — 2 11 13 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (13 ) (7 ) (20 ) Transfer of funds under intercompany cash management arrangement (5 ) — (1 ) 6 — Proceeds from the issuance of Class C units 33 — — — 33 (Payments of) proceeds from distributions (202 ) — (220 ) 220 (202 ) Proceeds from the revolving credit facility — — — 55 55 Proceeds from issuance of long-term debt — — 41 — 41 Payments of debt issuance costs — — (4 ) — (4 ) Payments for long-term debt — external — — (332 ) — (332 ) Net Cash (Used in) Provided by Financing Activities (174 ) — (527 ) 285 (416 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (189 ) — 6 — (183 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 211 — 286 — 497 Cash, Cash Equivalents and Restricted Cash at End of Period $ 22 $ — $ 292 $ — $ 314 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 22 $ 1,013 $ 1 $ (1 ) $ 1,035 Operating Costs and Expenses Cost of operations — 14 294 1 (1 ) 308 Depreciation and amortization — 5 298 — — 303 Impairment losses — — 185 — — 185 General and administrative 2 — — 12 — 14 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses 2 19 777 14 (1 ) 811 Operating Income (Loss) (2 ) 3 236 (13 ) — 224 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 128 10 — 66 (204 ) — Equity in earnings of unconsolidated affiliates — 9 21 30 — 60 Other income, net — — 3 — — 3 Interest expense — — (206 ) (66 ) — (272 ) Total other income (expense) 128 19 (182 ) 30 (204 ) (209 ) Net Income 126 22 54 17 (204 ) 15 Less: Net loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Net Income Attributable to NRG Yield LLC $ 126 $ 22 $ 55 $ 128 $ (205 ) $ 126 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income $ 126 $ 22 $ 54 $ 17 $ (204 ) $ 15 Other Comprehensive Income Unrealized gain on derivatives 13 1 10 13 (24 ) 13 Other comprehensive income 13 1 10 13 (24 ) 13 Comprehensive Income 139 23 64 30 (228 ) 28 Less: Comprehensive loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Comprehensive Income Attributable to NRG Yield LLC $ 139 $ 23 $ 65 $ 141 $ (229 ) $ 139 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2016 NRG Yield LLC (a)(c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b)(c) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 211 $ — $ 110 $ — $ — $ 321 Restricted cash — — 176 — — 176 Accounts receivable — trade — 2 94 — — 96 Inventory — 2 37 — — 39 Notes receivable — current — — 16 — — 16 Prepayments and other current assets — — 21 1 — 22 Total current assets 211 4 454 1 — 670 Property, plant and equipment, net — 59 5,495 — — 5,554 Other Assets Investment in consolidated subsidiaries 1,927 527 — 3,272 (5,726 ) — Equity investments in affiliates — 171 600 381 — 1,152 Intangible assets, net — 56 1,247 — — 1,303 Other non-current assets — — 66 1 — 67 Total other assets 1,927 754 1,913 3,654 (5,726 ) 2,522 Total Assets $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b) (c) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 323 $ — $ — $ 323 Accounts payable — trade — 2 18 3 — 23 Accounts payable — affiliate — 7 15 18 — 40 Derivative instruments — — 33 — — 33 Accrued expenses and other current liabilities — 1 60 24 — 85 Total current liabilities — 10 449 45 — 504 Other Liabilities Long-term debt — external — — 4,289 839 — 5,128 Long-term debt — affiliate — — — 618 — 618 Accounts payable — affiliate — — 9 — — 9 Derivative instruments — — 46 — — 46 Other non-current liabilities — — 77 — — 77 Total non-current liabilities — — 4,421 1,457 — 5,878 Total Liabilities — 10 4,870 1,502 — 6,382 Commitments and Contingencies Members' Equity Contributed capital 2,179 874 2,972 2,155 (6,001 ) 2,179 Retained earnings (accumulated deficit) 44 (65 ) 43 (143 ) 165 44 Accumulated other comprehensive loss (85 ) (2 ) (87 ) (85 ) 174 (85 ) Noncontrolling interest — — 64 226 (64 ) 226 Total Members' Equity 2,138 807 2,992 2,153 (5,726 ) 2,364 Total Liabilities and Members’ Equity $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2016 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated Net Cash Provided by (Used in) Operating Activities $ — $ 62 $ 554 $ (39 ) $ 577 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 325 — (21 ) (304 ) — Acquisition of Drop Down Assets — — — (77 ) (77 ) Capital expenditures — — (20 ) — (20 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 16 — 12 28 Investments in unconsolidated affiliates — (80 ) (3 ) — (83 ) Other — — 4 — 4 Net Cash Used in Investing Activities 325 (64 ) (23 ) (369 ) (131 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement 44 2 — (46 ) — Net contributions from noncontrolling interests — — — 5 5 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (174 ) (10 ) (184 ) (Payments of) proceeds from distributions (173 ) — (420 ) 420 (173 ) Proceeds from the revolving credit facility — — — 60 60 Payments for the revolving credit facility — — — (366 ) (366 ) Proceeds from the issuance of long-term debt - external — — 390 350 740 Payments of debt issuance costs — — (10 ) (5 ) (15 ) Payments for long-term debt — external — — (269 ) — (269 ) Net Cash Provided by (Used in) Financing Activities (129 ) 2 (483 ) 408 (202 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash 196 — 48 — 244 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 15 — 238 — 253 Cash, Cash Equivalents and Restricted Cash at End of Period $ 211 $ — $ 286 $ — $ 497 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 937 $ 10 $ — $ 968 Operating Costs and Expenses Cost of operations — 14 309 — — 323 Depreciation and amortization — 4 299 — — 303 Impairment losses — — 1 — — 1 General and administrative — — — 10 — 10 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 18 609 13 — 640 Operating Income (Loss) — 3 328 (3 ) — 328 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 157 (43 ) — 125 (239 ) — Equity in (losses) earnings of unconsolidated affiliates — (2 ) 8 25 — 31 Other income, net — — 3 — — 3 Loss on debt extinguishment — — (9 ) — — (9 ) Interest expense — — (206 ) (52 ) — (258 ) Total other income (expense), net 157 (45 ) (204 ) 98 (239 ) (233 ) Net Income (Loss) 157 (42 ) 124 95 (239 ) 95 Less: Net loss attributable to noncontrolling interests — — (2 ) (62 ) 2 (62 ) Net Income (Loss) Attributable to NRG Yield LLC $ 157 $ (42 ) $ 126 $ 157 $ (241 ) $ 157 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income (Loss) $ 157 $ (42 ) $ 124 $ 95 $ (239 ) $ 95 Other Comprehensive Loss Unrealized loss on derivatives (16 ) — (16 ) (17 ) 32 (17 ) Other comprehensive loss (16 ) — (16 ) (17 ) 32 (17 ) Comprehensive Income (Loss) 141 (42 ) 108 78 (207 ) 78 Less: Comprehensive loss attributable to noncontrolling interests — — (2 ) (63 ) 2 (63 ) Comprehensive Income (Loss) Attributable to NRG Yield LLC $ 141 $ (42 ) $ 110 $ 141 $ (209 ) $ 141 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2015 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 19 $ 423 $ (18 ) $ 424 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (464 ) — 285 179 — Acquisition of businesses, net of cash acquired — — — (37 ) (37 ) Acquisition of Drop Down Assets, net of cash acquired — — — (698 ) (698 ) Capital expenditures — — (29 ) — (29 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — — — 42 42 Investments in unconsolidated affiliates — (28 ) — — (374 ) (402 ) Other — — 9 — 9 Net Cash (Used in) Provided by Investing Activities (464 ) (28 ) 282 (888 ) (1,098 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (309 ) 9 — 300 — Net contributions from noncontrolling interests — — — 122 122 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (79 ) — (79 ) Proceeds from the issuance of Class C units 599 — — — 599 (Payments of) proceeds from distributions (139 ) — (392 ) 392 (139 ) Proceeds from the revolving credit facility — — — 551 551 Payments for the revolving credit facility — — — (245 ) (245 ) Proceeds from issuance of long-term debt — external — — 6 — 6 Proceeds from issuance of long-term debt — affiliate — — — 281 281 Payments for long-term debt — external — — (241 ) (494 ) (735 ) Payment of debt issuance costs — — (6 ) (1 ) (7 ) Net Cash Provided by (Used in) Financing Activities 151 9 (712 ) 906 354 Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (313 ) — (7 ) — (320 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 328 — 245 — 573 Cash, Cash Equivalents and Restricted Cash at End of Period $ 15 $ — $ 238 $ — $ 253 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan32

Condensed Consolidating Financial Information PP2 Income Statement (Notes)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Condensed Financial Statements [Text Block]	Condensed Consolidating Financial Information As of December 31, 2017 , Yield Operating LLC had outstanding $500 million of the 2024 Senior Notes and $350 million of the 2026 Senior Notes, collectively Senior Notes, as described in Note 10 , Long-term Debt . These Senior Notes are guaranteed by the Company, as well as certain of the Company's subsidiaries, or guarantor subsidiaries. These guarantees are both joint and several. The non-guarantor subsidiaries include the rest of the Company's subsidiaries, including the ones that are subject to project financing. Unless otherwise noted below, each of the following guarantor subsidiaries fully and unconditionally guaranteed the Senior Notes as of December 31, 2017 : NRG Yield LLC Alta Wind 1-5 Holding Company, LLC Alta Wind Company, LLC NRG Energy Center Omaha Holdings LLC NRG Energy Center Omaha LLC NYLD Fuel Cell Holdings LLC UB Fuel Cell, LLC NRG South Trent Holdings LLC NRG Yield DGPV Holding LLC NRG Yield RPV Holding LLC Yield Operating LLC conducts much of its business through and derives much of its income from its subsidiaries. Therefore, its ability to make required payments with respect to its indebtedness and other obligations depends on the financial results and condition of its subsidiaries and Yield Operating LLC's ability to receive funds from its subsidiaries. There are no restrictions on the ability of any of the guarantor subsidiaries to transfer funds to Yield Operating LLC. However, there may be restrictions for certain non-guarantor subsidiaries. The following condensed consolidating financial information presents the financial information of Yield LLC, Yield Operating LLC, the issuer of the Senior Notes, the guarantor subsidiaries and the non-guarantor subsidiaries in accordance with Rule 3-10 under the SEC Regulation S-X. The financial information may not necessarily be indicative of results of operations or financial position had the guarantor subsidiaries or non-guarantor subsidiaries operated as independent entities. In this presentation, Yield LLC consists of parent company operations. Guarantor subsidiaries and non-guarantor subsidiaries of Yield LLC are reported on an equity basis. For companies acquired, the fair values of the assets and liabilities acquired have been presented on a push-down accounting basis. As described in Note 3 , Business Acquisitions , the Company completed the acquisition of the November 2017 Drop Down Assets, August 2017 Drop Down Assets, and March 2017 Drop Down Assets from NRG on November 1, 2017, August 1, 2017 and March 27, 2017, respectively. The guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control. Accordingly, the Company prepared its condensed consolidating financial statements to reflect the transfers as if they had taken place from the beginning of the financial statements period. In addition, the condensed parent company financial statements are provided in accordance with Rule 12-04, Schedule I of Regulation S-X, as the restricted net assets of Yield LLC’s subsidiaries exceed 25 percent of the consolidated net assets of Yield LLC. These statements should be read in conjunction with the consolidated statements and notes thereto of NRG Yield LLC. For a discussion of Yield LLC's long-term debt, see Note 10 , Long-term Debt . For a discussion of Yield LLC's commitments and contingencies, see Note 14 , Commitments and Contingencies . For a discussion of Yield LLC's distributions to Yield, Inc. and NRG Energy, see Note 11 , Members' Equity . For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 988 $ 1 $ (1 ) $ 1,009 Operating Costs and Expenses — Cost of operations — 14 312 1 (1 ) 326 Depreciation and amortization — 5 329 — — 334 Impairment losses — — 44 — — 44 General and administrative — — — 19 — 19 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 19 685 23 (1 ) 726 Operating (Loss) Income — 2 303 (22 ) — 283 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 136 (16 ) — 126 (246 ) — Equity in earnings of unconsolidated affiliates — 22 21 28 — 71 Other income, net 1 — 3 — — 4 Loss on debt extinguishment — — (3 ) — — (3 ) Interest expense — — (222 ) (71 ) — (293 ) Total other income (expense), net 137 6 (201 ) 83 (246 ) (221 ) Net Income 137 8 102 61 (246 ) 62 Less: Net loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Net Income Attributable to NRG Yield LLC $ 137 $ 8 $ 107 $ 136 $ (251 ) $ 137 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. For the year ended December 31, 2017 NRG Yield LLC (a) Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 137 $ 8 $ 102 $ 61 $ (246 ) $ 62 Other Comprehensive Income Unrealized gain on derivatives 17 1 16 17 (34 ) 17 Other comprehensive income 17 1 16 17 (34 ) 17 Comprehensive Income 154 9 118 78 (280 ) 79 Less: Comprehensive loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Comprehensive Income Attributable to NRG Yield LLC $ 154 $ 9 $ 123 $ 153 $ (285 ) $ 154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 22 $ — $ 124 $ — $ — $ 146 Restricted cash — — 168 — — 168 Accounts receivable — trade 1 2 92 1 — 96 Inventory — 1 38 — — 39 Notes receivable — current — — 13 — — 13 Prepayments and other current assets — — 18 1 — 19 Total current assets 23 3 453 2 — 481 Property, plant and equipment, net — 58 5,146 — — 5,204 Other Assets Investment in consolidated subsidiaries 1,823 460 — 3,177 (5,460 ) — Equity investments in affiliates — 233 577 368 — 1,178 Intangible assets, net — 55 1,173 — — 1,228 Other non-current assets — — 63 — — 63 Total other assets 1,823 748 1,813 3,545 (5,460 ) 2,469 Total Assets $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 306 $ — $ — $ 306 Accounts payable — trade — 2 25 — — 27 Accounts payable — affiliate — 5 27 16 — 48 Derivative instruments — — 17 — — 17 Accrued expenses and other current liabilities — 1 61 25 — 87 Total current liabilities — 8 436 41 — 485 Other Liabilities Long-term debt — external — — 4,025 896 — 4,921 Long-term debt — affiliate — — — 618 — 618 Derivative instruments — — 31 — — 31 Other non-current liabilities — — 84 7 — 91 Total non-current liabilities — — 4,140 1,521 — 5,661 Total Liabilities — 8 4,576 1,562 — 6,146 Commitments and Contingencies Members' Equity Contributed capital 1,897 863 2,871 2,097 (5,831 ) 1,897 Retained earnings (accumulated deficit) 17 (61 ) (21 ) (206 ) 288 17 Accumulated other comprehensive loss (68 ) (1 ) (71 ) (68 ) 140 (68 ) Noncontrolling interest — — 57 162 (57 ) 162 Total Members' Equity 1,846 801 2,836 1,985 (5,460 ) 2,008 Total Liabilities and Members’ Equity $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 58 $ 529 $ (71 ) $ 516 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (15 ) — — 15 — Acquisition of Drop Down Assets, net of cash acquired — — — (250 ) (250 ) Capital expenditures — (4 ) (27 ) — (31 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 10 14 23 47 Investments in unconsolidated affiliates — (64 ) (7 ) (2 ) (73 ) Other — — 7 — 7 Net Cash Provided by (Used in) Investing Activities (15 ) (58 ) 4 (214 ) (283 ) Cash Flows from Financing Activities Net contributions from noncontrolling interests — — 2 11 13 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (13 ) (7 ) (20 ) Transfer of funds under intercompany cash management arrangement (5 ) — (1 ) 6 — Proceeds from the issuance of Class C units 33 — — — 33 (Payments of) proceeds from distributions (202 ) — (220 ) 220 (202 ) Proceeds from the revolving credit facility — — — 55 55 Proceeds from issuance of long-term debt — — 41 — 41 Payments of debt issuance costs — — (4 ) — (4 ) Payments for long-term debt — external — — (332 ) — (332 ) Net Cash (Used in) Provided by Financing Activities (174 ) — (527 ) 285 (416 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (189 ) — 6 — (183 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 211 — 286 — 497 Cash, Cash Equivalents and Restricted Cash at End of Period $ 22 $ — $ 292 $ — $ 314 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 22 $ 1,013 $ 1 $ (1 ) $ 1,035 Operating Costs and Expenses Cost of operations — 14 294 1 (1 ) 308 Depreciation and amortization — 5 298 — — 303 Impairment losses — — 185 — — 185 General and administrative 2 — — 12 — 14 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses 2 19 777 14 (1 ) 811 Operating Income (Loss) (2 ) 3 236 (13 ) — 224 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 128 10 — 66 (204 ) — Equity in earnings of unconsolidated affiliates — 9 21 30 — 60 Other income, net — — 3 — — 3 Interest expense — — (206 ) (66 ) — (272 ) Total other income (expense) 128 19 (182 ) 30 (204 ) (209 ) Net Income 126 22 54 17 (204 ) 15 Less: Net loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Net Income Attributable to NRG Yield LLC $ 126 $ 22 $ 55 $ 128 $ (205 ) $ 126 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income $ 126 $ 22 $ 54 $ 17 $ (204 ) $ 15 Other Comprehensive Income Unrealized gain on derivatives 13 1 10 13 (24 ) 13 Other comprehensive income 13 1 10 13 (24 ) 13 Comprehensive Income 139 23 64 30 (228 ) 28 Less: Comprehensive loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Comprehensive Income Attributable to NRG Yield LLC $ 139 $ 23 $ 65 $ 141 $ (229 ) $ 139 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2016 NRG Yield LLC (a)(c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b)(c) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 211 $ — $ 110 $ — $ — $ 321 Restricted cash — — 176 — — 176 Accounts receivable — trade — 2 94 — — 96 Inventory — 2 37 — — 39 Notes receivable — current — — 16 — — 16 Prepayments and other current assets — — 21 1 — 22 Total current assets 211 4 454 1 — 670 Property, plant and equipment, net — 59 5,495 — — 5,554 Other Assets Investment in consolidated subsidiaries 1,927 527 — 3,272 (5,726 ) — Equity investments in affiliates — 171 600 381 — 1,152 Intangible assets, net — 56 1,247 — — 1,303 Other non-current assets — — 66 1 — 67 Total other assets 1,927 754 1,913 3,654 (5,726 ) 2,522 Total Assets $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b) (c) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 323 $ — $ — $ 323 Accounts payable — trade — 2 18 3 — 23 Accounts payable — affiliate — 7 15 18 — 40 Derivative instruments — — 33 — — 33 Accrued expenses and other current liabilities — 1 60 24 — 85 Total current liabilities — 10 449 45 — 504 Other Liabilities Long-term debt — external — — 4,289 839 — 5,128 Long-term debt — affiliate — — — 618 — 618 Accounts payable — affiliate — — 9 — — 9 Derivative instruments — — 46 — — 46 Other non-current liabilities — — 77 — — 77 Total non-current liabilities — — 4,421 1,457 — 5,878 Total Liabilities — 10 4,870 1,502 — 6,382 Commitments and Contingencies Members' Equity Contributed capital 2,179 874 2,972 2,155 (6,001 ) 2,179 Retained earnings (accumulated deficit) 44 (65 ) 43 (143 ) 165 44 Accumulated other comprehensive loss (85 ) (2 ) (87 ) (85 ) 174 (85 ) Noncontrolling interest — — 64 226 (64 ) 226 Total Members' Equity 2,138 807 2,992 2,153 (5,726 ) 2,364 Total Liabilities and Members’ Equity $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2016 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated Net Cash Provided by (Used in) Operating Activities $ — $ 62 $ 554 $ (39 ) $ 577 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 325 — (21 ) (304 ) — Acquisition of Drop Down Assets — — — (77 ) (77 ) Capital expenditures — — (20 ) — (20 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 16 — 12 28 Investments in unconsolidated affiliates — (80 ) (3 ) — (83 ) Other — — 4 — 4 Net Cash Used in Investing Activities 325 (64 ) (23 ) (369 ) (131 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement 44 2 — (46 ) — Net contributions from noncontrolling interests — — — 5 5 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (174 ) (10 ) (184 ) (Payments of) proceeds from distributions (173 ) — (420 ) 420 (173 ) Proceeds from the revolving credit facility — — — 60 60 Payments for the revolving credit facility — — — (366 ) (366 ) Proceeds from the issuance of long-term debt - external — — 390 350 740 Payments of debt issuance costs — — (10 ) (5 ) (15 ) Payments for long-term debt — external — — (269 ) — (269 ) Net Cash Provided by (Used in) Financing Activities (129 ) 2 (483 ) 408 (202 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash 196 — 48 — 244 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 15 — 238 — 253 Cash, Cash Equivalents and Restricted Cash at End of Period $ 211 $ — $ 286 $ — $ 497 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 937 $ 10 $ — $ 968 Operating Costs and Expenses Cost of operations — 14 309 — — 323 Depreciation and amortization — 4 299 — — 303 Impairment losses — — 1 — — 1 General and administrative — — — 10 — 10 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 18 609 13 — 640 Operating Income (Loss) — 3 328 (3 ) — 328 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 157 (43 ) — 125 (239 ) — Equity in (losses) earnings of unconsolidated affiliates — (2 ) 8 25 — 31 Other income, net — — 3 — — 3 Loss on debt extinguishment — — (9 ) — — (9 ) Interest expense — — (206 ) (52 ) — (258 ) Total other income (expense), net 157 (45 ) (204 ) 98 (239 ) (233 ) Net Income (Loss) 157 (42 ) 124 95 (239 ) 95 Less: Net loss attributable to noncontrolling interests — — (2 ) (62 ) 2 (62 ) Net Income (Loss) Attributable to NRG Yield LLC $ 157 $ (42 ) $ 126 $ 157 $ (241 ) $ 157 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income (Loss) $ 157 $ (42 ) $ 124 $ 95 $ (239 ) $ 95 Other Comprehensive Loss Unrealized loss on derivatives (16 ) — (16 ) (17 ) 32 (17 ) Other comprehensive loss (16 ) — (16 ) (17 ) 32 (17 ) Comprehensive Income (Loss) 141 (42 ) 108 78 (207 ) 78 Less: Comprehensive loss attributable to noncontrolling interests — — (2 ) (63 ) 2 (63 ) Comprehensive Income (Loss) Attributable to NRG Yield LLC $ 141 $ (42 ) $ 110 $ 141 $ (209 ) $ 141 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2015 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 19 $ 423 $ (18 ) $ 424 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (464 ) — 285 179 — Acquisition of businesses, net of cash acquired — — — (37 ) (37 ) Acquisition of Drop Down Assets, net of cash acquired — — — (698 ) (698 ) Capital expenditures — — (29 ) — (29 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — — — 42 42 Investments in unconsolidated affiliates — (28 ) — — (374 ) (402 ) Other — — 9 — 9 Net Cash (Used in) Provided by Investing Activities (464 ) (28 ) 282 (888 ) (1,098 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (309 ) 9 — 300 — Net contributions from noncontrolling interests — — — 122 122 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (79 ) — (79 ) Proceeds from the issuance of Class C units 599 — — — 599 (Payments of) proceeds from distributions (139 ) — (392 ) 392 (139 ) Proceeds from the revolving credit facility — — — 551 551 Payments for the revolving credit facility — — — (245 ) (245 ) Proceeds from issuance of long-term debt — external — — 6 — 6 Proceeds from issuance of long-term debt — affiliate — — — 281 281 Payments for long-term debt — external — — (241 ) (494 ) (735 ) Payment of debt issuance costs — — (6 ) (1 ) (7 ) Net Cash Provided by (Used in) Financing Activities 151 9 (712 ) 906 354 Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (313 ) — (7 ) — (320 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 328 — 245 — 573 Cash, Cash Equivalents and Restricted Cash at End of Period $ 15 $ — $ 238 $ — $ 253 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan33

Condensed Consolidating Financial Information PP2 Comprehensive Income (Notes)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Condensed Financial Statements [Text Block]	Condensed Consolidating Financial Information As of December 31, 2017 , Yield Operating LLC had outstanding $500 million of the 2024 Senior Notes and $350 million of the 2026 Senior Notes, collectively Senior Notes, as described in Note 10 , Long-term Debt . These Senior Notes are guaranteed by the Company, as well as certain of the Company's subsidiaries, or guarantor subsidiaries. These guarantees are both joint and several. The non-guarantor subsidiaries include the rest of the Company's subsidiaries, including the ones that are subject to project financing. Unless otherwise noted below, each of the following guarantor subsidiaries fully and unconditionally guaranteed the Senior Notes as of December 31, 2017 : NRG Yield LLC Alta Wind 1-5 Holding Company, LLC Alta Wind Company, LLC NRG Energy Center Omaha Holdings LLC NRG Energy Center Omaha LLC NYLD Fuel Cell Holdings LLC UB Fuel Cell, LLC NRG South Trent Holdings LLC NRG Yield DGPV Holding LLC NRG Yield RPV Holding LLC Yield Operating LLC conducts much of its business through and derives much of its income from its subsidiaries. Therefore, its ability to make required payments with respect to its indebtedness and other obligations depends on the financial results and condition of its subsidiaries and Yield Operating LLC's ability to receive funds from its subsidiaries. There are no restrictions on the ability of any of the guarantor subsidiaries to transfer funds to Yield Operating LLC. However, there may be restrictions for certain non-guarantor subsidiaries. The following condensed consolidating financial information presents the financial information of Yield LLC, Yield Operating LLC, the issuer of the Senior Notes, the guarantor subsidiaries and the non-guarantor subsidiaries in accordance with Rule 3-10 under the SEC Regulation S-X. The financial information may not necessarily be indicative of results of operations or financial position had the guarantor subsidiaries or non-guarantor subsidiaries operated as independent entities. In this presentation, Yield LLC consists of parent company operations. Guarantor subsidiaries and non-guarantor subsidiaries of Yield LLC are reported on an equity basis. For companies acquired, the fair values of the assets and liabilities acquired have been presented on a push-down accounting basis. As described in Note 3 , Business Acquisitions , the Company completed the acquisition of the November 2017 Drop Down Assets, August 2017 Drop Down Assets, and March 2017 Drop Down Assets from NRG on November 1, 2017, August 1, 2017 and March 27, 2017, respectively. The guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control. Accordingly, the Company prepared its condensed consolidating financial statements to reflect the transfers as if they had taken place from the beginning of the financial statements period. In addition, the condensed parent company financial statements are provided in accordance with Rule 12-04, Schedule I of Regulation S-X, as the restricted net assets of Yield LLC’s subsidiaries exceed 25 percent of the consolidated net assets of Yield LLC. These statements should be read in conjunction with the consolidated statements and notes thereto of NRG Yield LLC. For a discussion of Yield LLC's long-term debt, see Note 10 , Long-term Debt . For a discussion of Yield LLC's commitments and contingencies, see Note 14 , Commitments and Contingencies . For a discussion of Yield LLC's distributions to Yield, Inc. and NRG Energy, see Note 11 , Members' Equity . For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 988 $ 1 $ (1 ) $ 1,009 Operating Costs and Expenses — Cost of operations — 14 312 1 (1 ) 326 Depreciation and amortization — 5 329 — — 334 Impairment losses — — 44 — — 44 General and administrative — — — 19 — 19 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 19 685 23 (1 ) 726 Operating (Loss) Income — 2 303 (22 ) — 283 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 136 (16 ) — 126 (246 ) — Equity in earnings of unconsolidated affiliates — 22 21 28 — 71 Other income, net 1 — 3 — — 4 Loss on debt extinguishment — — (3 ) — — (3 ) Interest expense — — (222 ) (71 ) — (293 ) Total other income (expense), net 137 6 (201 ) 83 (246 ) (221 ) Net Income 137 8 102 61 (246 ) 62 Less: Net loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Net Income Attributable to NRG Yield LLC $ 137 $ 8 $ 107 $ 136 $ (251 ) $ 137 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. For the year ended December 31, 2017 NRG Yield LLC (a) Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 137 $ 8 $ 102 $ 61 $ (246 ) $ 62 Other Comprehensive Income Unrealized gain on derivatives 17 1 16 17 (34 ) 17 Other comprehensive income 17 1 16 17 (34 ) 17 Comprehensive Income 154 9 118 78 (280 ) 79 Less: Comprehensive loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Comprehensive Income Attributable to NRG Yield LLC $ 154 $ 9 $ 123 $ 153 $ (285 ) $ 154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 22 $ — $ 124 $ — $ — $ 146 Restricted cash — — 168 — — 168 Accounts receivable — trade 1 2 92 1 — 96 Inventory — 1 38 — — 39 Notes receivable — current — — 13 — — 13 Prepayments and other current assets — — 18 1 — 19 Total current assets 23 3 453 2 — 481 Property, plant and equipment, net — 58 5,146 — — 5,204 Other Assets Investment in consolidated subsidiaries 1,823 460 — 3,177 (5,460 ) — Equity investments in affiliates — 233 577 368 — 1,178 Intangible assets, net — 55 1,173 — — 1,228 Other non-current assets — — 63 — — 63 Total other assets 1,823 748 1,813 3,545 (5,460 ) 2,469 Total Assets $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 306 $ — $ — $ 306 Accounts payable — trade — 2 25 — — 27 Accounts payable — affiliate — 5 27 16 — 48 Derivative instruments — — 17 — — 17 Accrued expenses and other current liabilities — 1 61 25 — 87 Total current liabilities — 8 436 41 — 485 Other Liabilities Long-term debt — external — — 4,025 896 — 4,921 Long-term debt — affiliate — — — 618 — 618 Derivative instruments — — 31 — — 31 Other non-current liabilities — — 84 7 — 91 Total non-current liabilities — — 4,140 1,521 — 5,661 Total Liabilities — 8 4,576 1,562 — 6,146 Commitments and Contingencies Members' Equity Contributed capital 1,897 863 2,871 2,097 (5,831 ) 1,897 Retained earnings (accumulated deficit) 17 (61 ) (21 ) (206 ) 288 17 Accumulated other comprehensive loss (68 ) (1 ) (71 ) (68 ) 140 (68 ) Noncontrolling interest — — 57 162 (57 ) 162 Total Members' Equity 1,846 801 2,836 1,985 (5,460 ) 2,008 Total Liabilities and Members’ Equity $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 58 $ 529 $ (71 ) $ 516 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (15 ) — — 15 — Acquisition of Drop Down Assets, net of cash acquired — — — (250 ) (250 ) Capital expenditures — (4 ) (27 ) — (31 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 10 14 23 47 Investments in unconsolidated affiliates — (64 ) (7 ) (2 ) (73 ) Other — — 7 — 7 Net Cash Provided by (Used in) Investing Activities (15 ) (58 ) 4 (214 ) (283 ) Cash Flows from Financing Activities Net contributions from noncontrolling interests — — 2 11 13 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (13 ) (7 ) (20 ) Transfer of funds under intercompany cash management arrangement (5 ) — (1 ) 6 — Proceeds from the issuance of Class C units 33 — — — 33 (Payments of) proceeds from distributions (202 ) — (220 ) 220 (202 ) Proceeds from the revolving credit facility — — — 55 55 Proceeds from issuance of long-term debt — — 41 — 41 Payments of debt issuance costs — — (4 ) — (4 ) Payments for long-term debt — external — — (332 ) — (332 ) Net Cash (Used in) Provided by Financing Activities (174 ) — (527 ) 285 (416 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (189 ) — 6 — (183 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 211 — 286 — 497 Cash, Cash Equivalents and Restricted Cash at End of Period $ 22 $ — $ 292 $ — $ 314 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 22 $ 1,013 $ 1 $ (1 ) $ 1,035 Operating Costs and Expenses Cost of operations — 14 294 1 (1 ) 308 Depreciation and amortization — 5 298 — — 303 Impairment losses — — 185 — — 185 General and administrative 2 — — 12 — 14 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses 2 19 777 14 (1 ) 811 Operating Income (Loss) (2 ) 3 236 (13 ) — 224 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 128 10 — 66 (204 ) — Equity in earnings of unconsolidated affiliates — 9 21 30 — 60 Other income, net — — 3 — — 3 Interest expense — — (206 ) (66 ) — (272 ) Total other income (expense) 128 19 (182 ) 30 (204 ) (209 ) Net Income 126 22 54 17 (204 ) 15 Less: Net loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Net Income Attributable to NRG Yield LLC $ 126 $ 22 $ 55 $ 128 $ (205 ) $ 126 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income $ 126 $ 22 $ 54 $ 17 $ (204 ) $ 15 Other Comprehensive Income Unrealized gain on derivatives 13 1 10 13 (24 ) 13 Other comprehensive income 13 1 10 13 (24 ) 13 Comprehensive Income 139 23 64 30 (228 ) 28 Less: Comprehensive loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Comprehensive Income Attributable to NRG Yield LLC $ 139 $ 23 $ 65 $ 141 $ (229 ) $ 139 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2016 NRG Yield LLC (a)(c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b)(c) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 211 $ — $ 110 $ — $ — $ 321 Restricted cash — — 176 — — 176 Accounts receivable — trade — 2 94 — — 96 Inventory — 2 37 — — 39 Notes receivable — current — — 16 — — 16 Prepayments and other current assets — — 21 1 — 22 Total current assets 211 4 454 1 — 670 Property, plant and equipment, net — 59 5,495 — — 5,554 Other Assets Investment in consolidated subsidiaries 1,927 527 — 3,272 (5,726 ) — Equity investments in affiliates — 171 600 381 — 1,152 Intangible assets, net — 56 1,247 — — 1,303 Other non-current assets — — 66 1 — 67 Total other assets 1,927 754 1,913 3,654 (5,726 ) 2,522 Total Assets $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b) (c) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 323 $ — $ — $ 323 Accounts payable — trade — 2 18 3 — 23 Accounts payable — affiliate — 7 15 18 — 40 Derivative instruments — — 33 — — 33 Accrued expenses and other current liabilities — 1 60 24 — 85 Total current liabilities — 10 449 45 — 504 Other Liabilities Long-term debt — external — — 4,289 839 — 5,128 Long-term debt — affiliate — — — 618 — 618 Accounts payable — affiliate — — 9 — — 9 Derivative instruments — — 46 — — 46 Other non-current liabilities — — 77 — — 77 Total non-current liabilities — — 4,421 1,457 — 5,878 Total Liabilities — 10 4,870 1,502 — 6,382 Commitments and Contingencies Members' Equity Contributed capital 2,179 874 2,972 2,155 (6,001 ) 2,179 Retained earnings (accumulated deficit) 44 (65 ) 43 (143 ) 165 44 Accumulated other comprehensive loss (85 ) (2 ) (87 ) (85 ) 174 (85 ) Noncontrolling interest — — 64 226 (64 ) 226 Total Members' Equity 2,138 807 2,992 2,153 (5,726 ) 2,364 Total Liabilities and Members’ Equity $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2016 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated Net Cash Provided by (Used in) Operating Activities $ — $ 62 $ 554 $ (39 ) $ 577 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 325 — (21 ) (304 ) — Acquisition of Drop Down Assets — — — (77 ) (77 ) Capital expenditures — — (20 ) — (20 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 16 — 12 28 Investments in unconsolidated affiliates — (80 ) (3 ) — (83 ) Other — — 4 — 4 Net Cash Used in Investing Activities 325 (64 ) (23 ) (369 ) (131 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement 44 2 — (46 ) — Net contributions from noncontrolling interests — — — 5 5 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (174 ) (10 ) (184 ) (Payments of) proceeds from distributions (173 ) — (420 ) 420 (173 ) Proceeds from the revolving credit facility — — — 60 60 Payments for the revolving credit facility — — — (366 ) (366 ) Proceeds from the issuance of long-term debt - external — — 390 350 740 Payments of debt issuance costs — — (10 ) (5 ) (15 ) Payments for long-term debt — external — — (269 ) — (269 ) Net Cash Provided by (Used in) Financing Activities (129 ) 2 (483 ) 408 (202 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash 196 — 48 — 244 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 15 — 238 — 253 Cash, Cash Equivalents and Restricted Cash at End of Period $ 211 $ — $ 286 $ — $ 497 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 937 $ 10 $ — $ 968 Operating Costs and Expenses Cost of operations — 14 309 — — 323 Depreciation and amortization — 4 299 — — 303 Impairment losses — — 1 — — 1 General and administrative — — — 10 — 10 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 18 609 13 — 640 Operating Income (Loss) — 3 328 (3 ) — 328 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 157 (43 ) — 125 (239 ) — Equity in (losses) earnings of unconsolidated affiliates — (2 ) 8 25 — 31 Other income, net — — 3 — — 3 Loss on debt extinguishment — — (9 ) — — (9 ) Interest expense — — (206 ) (52 ) — (258 ) Total other income (expense), net 157 (45 ) (204 ) 98 (239 ) (233 ) Net Income (Loss) 157 (42 ) 124 95 (239 ) 95 Less: Net loss attributable to noncontrolling interests — — (2 ) (62 ) 2 (62 ) Net Income (Loss) Attributable to NRG Yield LLC $ 157 $ (42 ) $ 126 $ 157 $ (241 ) $ 157 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income (Loss) $ 157 $ (42 ) $ 124 $ 95 $ (239 ) $ 95 Other Comprehensive Loss Unrealized loss on derivatives (16 ) — (16 ) (17 ) 32 (17 ) Other comprehensive loss (16 ) — (16 ) (17 ) 32 (17 ) Comprehensive Income (Loss) 141 (42 ) 108 78 (207 ) 78 Less: Comprehensive loss attributable to noncontrolling interests — — (2 ) (63 ) 2 (63 ) Comprehensive Income (Loss) Attributable to NRG Yield LLC $ 141 $ (42 ) $ 110 $ 141 $ (209 ) $ 141 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2015 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 19 $ 423 $ (18 ) $ 424 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (464 ) — 285 179 — Acquisition of businesses, net of cash acquired — — — (37 ) (37 ) Acquisition of Drop Down Assets, net of cash acquired — — — (698 ) (698 ) Capital expenditures — — (29 ) — (29 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — — — 42 42 Investments in unconsolidated affiliates — (28 ) — — (374 ) (402 ) Other — — 9 — 9 Net Cash (Used in) Provided by Investing Activities (464 ) (28 ) 282 (888 ) (1,098 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (309 ) 9 — 300 — Net contributions from noncontrolling interests — — — 122 122 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (79 ) — (79 ) Proceeds from the issuance of Class C units 599 — — — 599 (Payments of) proceeds from distributions (139 ) — (392 ) 392 (139 ) Proceeds from the revolving credit facility — — — 551 551 Payments for the revolving credit facility — — — (245 ) (245 ) Proceeds from issuance of long-term debt — external — — 6 — 6 Proceeds from issuance of long-term debt — affiliate — — — 281 281 Payments for long-term debt — external — — (241 ) (494 ) (735 ) Payment of debt issuance costs — — (6 ) (1 ) (7 ) Net Cash Provided by (Used in) Financing Activities 151 9 (712 ) 906 354 Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (313 ) — (7 ) — (320 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 328 — 245 — 573 Cash, Cash Equivalents and Restricted Cash at End of Period $ 15 $ — $ 238 $ — $ 253 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan34

Condensed Consolidating Financial Information PP2 Cash Flows (Notes)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Cash Flows [Abstract]
Condensed Financial Statements [Text Block]	Condensed Consolidating Financial Information As of December 31, 2017 , Yield Operating LLC had outstanding $500 million of the 2024 Senior Notes and $350 million of the 2026 Senior Notes, collectively Senior Notes, as described in Note 10 , Long-term Debt . These Senior Notes are guaranteed by the Company, as well as certain of the Company's subsidiaries, or guarantor subsidiaries. These guarantees are both joint and several. The non-guarantor subsidiaries include the rest of the Company's subsidiaries, including the ones that are subject to project financing. Unless otherwise noted below, each of the following guarantor subsidiaries fully and unconditionally guaranteed the Senior Notes as of December 31, 2017 : NRG Yield LLC Alta Wind 1-5 Holding Company, LLC Alta Wind Company, LLC NRG Energy Center Omaha Holdings LLC NRG Energy Center Omaha LLC NYLD Fuel Cell Holdings LLC UB Fuel Cell, LLC NRG South Trent Holdings LLC NRG Yield DGPV Holding LLC NRG Yield RPV Holding LLC Yield Operating LLC conducts much of its business through and derives much of its income from its subsidiaries. Therefore, its ability to make required payments with respect to its indebtedness and other obligations depends on the financial results and condition of its subsidiaries and Yield Operating LLC's ability to receive funds from its subsidiaries. There are no restrictions on the ability of any of the guarantor subsidiaries to transfer funds to Yield Operating LLC. However, there may be restrictions for certain non-guarantor subsidiaries. The following condensed consolidating financial information presents the financial information of Yield LLC, Yield Operating LLC, the issuer of the Senior Notes, the guarantor subsidiaries and the non-guarantor subsidiaries in accordance with Rule 3-10 under the SEC Regulation S-X. The financial information may not necessarily be indicative of results of operations or financial position had the guarantor subsidiaries or non-guarantor subsidiaries operated as independent entities. In this presentation, Yield LLC consists of parent company operations. Guarantor subsidiaries and non-guarantor subsidiaries of Yield LLC are reported on an equity basis. For companies acquired, the fair values of the assets and liabilities acquired have been presented on a push-down accounting basis. As described in Note 3 , Business Acquisitions , the Company completed the acquisition of the November 2017 Drop Down Assets, August 2017 Drop Down Assets, and March 2017 Drop Down Assets from NRG on November 1, 2017, August 1, 2017 and March 27, 2017, respectively. The guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control. Accordingly, the Company prepared its condensed consolidating financial statements to reflect the transfers as if they had taken place from the beginning of the financial statements period. In addition, the condensed parent company financial statements are provided in accordance with Rule 12-04, Schedule I of Regulation S-X, as the restricted net assets of Yield LLC’s subsidiaries exceed 25 percent of the consolidated net assets of Yield LLC. These statements should be read in conjunction with the consolidated statements and notes thereto of NRG Yield LLC. For a discussion of Yield LLC's long-term debt, see Note 10 , Long-term Debt . For a discussion of Yield LLC's commitments and contingencies, see Note 14 , Commitments and Contingencies . For a discussion of Yield LLC's distributions to Yield, Inc. and NRG Energy, see Note 11 , Members' Equity . For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 988 $ 1 $ (1 ) $ 1,009 Operating Costs and Expenses — Cost of operations — 14 312 1 (1 ) 326 Depreciation and amortization — 5 329 — — 334 Impairment losses — — 44 — — 44 General and administrative — — — 19 — 19 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 19 685 23 (1 ) 726 Operating (Loss) Income — 2 303 (22 ) — 283 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 136 (16 ) — 126 (246 ) — Equity in earnings of unconsolidated affiliates — 22 21 28 — 71 Other income, net 1 — 3 — — 4 Loss on debt extinguishment — — (3 ) — — (3 ) Interest expense — — (222 ) (71 ) — (293 ) Total other income (expense), net 137 6 (201 ) 83 (246 ) (221 ) Net Income 137 8 102 61 (246 ) 62 Less: Net loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Net Income Attributable to NRG Yield LLC $ 137 $ 8 $ 107 $ 136 $ (251 ) $ 137 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. For the year ended December 31, 2017 NRG Yield LLC (a) Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 137 $ 8 $ 102 $ 61 $ (246 ) $ 62 Other Comprehensive Income Unrealized gain on derivatives 17 1 16 17 (34 ) 17 Other comprehensive income 17 1 16 17 (34 ) 17 Comprehensive Income 154 9 118 78 (280 ) 79 Less: Comprehensive loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Comprehensive Income Attributable to NRG Yield LLC $ 154 $ 9 $ 123 $ 153 $ (285 ) $ 154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 22 $ — $ 124 $ — $ — $ 146 Restricted cash — — 168 — — 168 Accounts receivable — trade 1 2 92 1 — 96 Inventory — 1 38 — — 39 Notes receivable — current — — 13 — — 13 Prepayments and other current assets — — 18 1 — 19 Total current assets 23 3 453 2 — 481 Property, plant and equipment, net — 58 5,146 — — 5,204 Other Assets Investment in consolidated subsidiaries 1,823 460 — 3,177 (5,460 ) — Equity investments in affiliates — 233 577 368 — 1,178 Intangible assets, net — 55 1,173 — — 1,228 Other non-current assets — — 63 — — 63 Total other assets 1,823 748 1,813 3,545 (5,460 ) 2,469 Total Assets $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 306 $ — $ — $ 306 Accounts payable — trade — 2 25 — — 27 Accounts payable — affiliate — 5 27 16 — 48 Derivative instruments — — 17 — — 17 Accrued expenses and other current liabilities — 1 61 25 — 87 Total current liabilities — 8 436 41 — 485 Other Liabilities Long-term debt — external — — 4,025 896 — 4,921 Long-term debt — affiliate — — — 618 — 618 Derivative instruments — — 31 — — 31 Other non-current liabilities — — 84 7 — 91 Total non-current liabilities — — 4,140 1,521 — 5,661 Total Liabilities — 8 4,576 1,562 — 6,146 Commitments and Contingencies Members' Equity Contributed capital 1,897 863 2,871 2,097 (5,831 ) 1,897 Retained earnings (accumulated deficit) 17 (61 ) (21 ) (206 ) 288 17 Accumulated other comprehensive loss (68 ) (1 ) (71 ) (68 ) 140 (68 ) Noncontrolling interest — — 57 162 (57 ) 162 Total Members' Equity 1,846 801 2,836 1,985 (5,460 ) 2,008 Total Liabilities and Members’ Equity $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 58 $ 529 $ (71 ) $ 516 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (15 ) — — 15 — Acquisition of Drop Down Assets, net of cash acquired — — — (250 ) (250 ) Capital expenditures — (4 ) (27 ) — (31 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 10 14 23 47 Investments in unconsolidated affiliates — (64 ) (7 ) (2 ) (73 ) Other — — 7 — 7 Net Cash Provided by (Used in) Investing Activities (15 ) (58 ) 4 (214 ) (283 ) Cash Flows from Financing Activities Net contributions from noncontrolling interests — — 2 11 13 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (13 ) (7 ) (20 ) Transfer of funds under intercompany cash management arrangement (5 ) — (1 ) 6 — Proceeds from the issuance of Class C units 33 — — — 33 (Payments of) proceeds from distributions (202 ) — (220 ) 220 (202 ) Proceeds from the revolving credit facility — — — 55 55 Proceeds from issuance of long-term debt — — 41 — 41 Payments of debt issuance costs — — (4 ) — (4 ) Payments for long-term debt — external — — (332 ) — (332 ) Net Cash (Used in) Provided by Financing Activities (174 ) — (527 ) 285 (416 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (189 ) — 6 — (183 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 211 — 286 — 497 Cash, Cash Equivalents and Restricted Cash at End of Period $ 22 $ — $ 292 $ — $ 314 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 22 $ 1,013 $ 1 $ (1 ) $ 1,035 Operating Costs and Expenses Cost of operations — 14 294 1 (1 ) 308 Depreciation and amortization — 5 298 — — 303 Impairment losses — — 185 — — 185 General and administrative 2 — — 12 — 14 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses 2 19 777 14 (1 ) 811 Operating Income (Loss) (2 ) 3 236 (13 ) — 224 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 128 10 — 66 (204 ) — Equity in earnings of unconsolidated affiliates — 9 21 30 — 60 Other income, net — — 3 — — 3 Interest expense — — (206 ) (66 ) — (272 ) Total other income (expense) 128 19 (182 ) 30 (204 ) (209 ) Net Income 126 22 54 17 (204 ) 15 Less: Net loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Net Income Attributable to NRG Yield LLC $ 126 $ 22 $ 55 $ 128 $ (205 ) $ 126 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income $ 126 $ 22 $ 54 $ 17 $ (204 ) $ 15 Other Comprehensive Income Unrealized gain on derivatives 13 1 10 13 (24 ) 13 Other comprehensive income 13 1 10 13 (24 ) 13 Comprehensive Income 139 23 64 30 (228 ) 28 Less: Comprehensive loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Comprehensive Income Attributable to NRG Yield LLC $ 139 $ 23 $ 65 $ 141 $ (229 ) $ 139 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2016 NRG Yield LLC (a)(c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b)(c) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 211 $ — $ 110 $ — $ — $ 321 Restricted cash — — 176 — — 176 Accounts receivable — trade — 2 94 — — 96 Inventory — 2 37 — — 39 Notes receivable — current — — 16 — — 16 Prepayments and other current assets — — 21 1 — 22 Total current assets 211 4 454 1 — 670 Property, plant and equipment, net — 59 5,495 — — 5,554 Other Assets Investment in consolidated subsidiaries 1,927 527 — 3,272 (5,726 ) — Equity investments in affiliates — 171 600 381 — 1,152 Intangible assets, net — 56 1,247 — — 1,303 Other non-current assets — — 66 1 — 67 Total other assets 1,927 754 1,913 3,654 (5,726 ) 2,522 Total Assets $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b) (c) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 323 $ — $ — $ 323 Accounts payable — trade — 2 18 3 — 23 Accounts payable — affiliate — 7 15 18 — 40 Derivative instruments — — 33 — — 33 Accrued expenses and other current liabilities — 1 60 24 — 85 Total current liabilities — 10 449 45 — 504 Other Liabilities Long-term debt — external — — 4,289 839 — 5,128 Long-term debt — affiliate — — — 618 — 618 Accounts payable — affiliate — — 9 — — 9 Derivative instruments — — 46 — — 46 Other non-current liabilities — — 77 — — 77 Total non-current liabilities — — 4,421 1,457 — 5,878 Total Liabilities — 10 4,870 1,502 — 6,382 Commitments and Contingencies Members' Equity Contributed capital 2,179 874 2,972 2,155 (6,001 ) 2,179 Retained earnings (accumulated deficit) 44 (65 ) 43 (143 ) 165 44 Accumulated other comprehensive loss (85 ) (2 ) (87 ) (85 ) 174 (85 ) Noncontrolling interest — — 64 226 (64 ) 226 Total Members' Equity 2,138 807 2,992 2,153 (5,726 ) 2,364 Total Liabilities and Members’ Equity $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2016 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated Net Cash Provided by (Used in) Operating Activities $ — $ 62 $ 554 $ (39 ) $ 577 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 325 — (21 ) (304 ) — Acquisition of Drop Down Assets — — — (77 ) (77 ) Capital expenditures — — (20 ) — (20 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 16 — 12 28 Investments in unconsolidated affiliates — (80 ) (3 ) — (83 ) Other — — 4 — 4 Net Cash Used in Investing Activities 325 (64 ) (23 ) (369 ) (131 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement 44 2 — (46 ) — Net contributions from noncontrolling interests — — — 5 5 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (174 ) (10 ) (184 ) (Payments of) proceeds from distributions (173 ) — (420 ) 420 (173 ) Proceeds from the revolving credit facility — — — 60 60 Payments for the revolving credit facility — — — (366 ) (366 ) Proceeds from the issuance of long-term debt - external — — 390 350 740 Payments of debt issuance costs — — (10 ) (5 ) (15 ) Payments for long-term debt — external — — (269 ) — (269 ) Net Cash Provided by (Used in) Financing Activities (129 ) 2 (483 ) 408 (202 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash 196 — 48 — 244 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 15 — 238 — 253 Cash, Cash Equivalents and Restricted Cash at End of Period $ 211 $ — $ 286 $ — $ 497 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 937 $ 10 $ — $ 968 Operating Costs and Expenses Cost of operations — 14 309 — — 323 Depreciation and amortization — 4 299 — — 303 Impairment losses — — 1 — — 1 General and administrative — — — 10 — 10 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 18 609 13 — 640 Operating Income (Loss) — 3 328 (3 ) — 328 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 157 (43 ) — 125 (239 ) — Equity in (losses) earnings of unconsolidated affiliates — (2 ) 8 25 — 31 Other income, net — — 3 — — 3 Loss on debt extinguishment — — (9 ) — — (9 ) Interest expense — — (206 ) (52 ) — (258 ) Total other income (expense), net 157 (45 ) (204 ) 98 (239 ) (233 ) Net Income (Loss) 157 (42 ) 124 95 (239 ) 95 Less: Net loss attributable to noncontrolling interests — — (2 ) (62 ) 2 (62 ) Net Income (Loss) Attributable to NRG Yield LLC $ 157 $ (42 ) $ 126 $ 157 $ (241 ) $ 157 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income (Loss) $ 157 $ (42 ) $ 124 $ 95 $ (239 ) $ 95 Other Comprehensive Loss Unrealized loss on derivatives (16 ) — (16 ) (17 ) 32 (17 ) Other comprehensive loss (16 ) — (16 ) (17 ) 32 (17 ) Comprehensive Income (Loss) 141 (42 ) 108 78 (207 ) 78 Less: Comprehensive loss attributable to noncontrolling interests — — (2 ) (63 ) 2 (63 ) Comprehensive Income (Loss) Attributable to NRG Yield LLC $ 141 $ (42 ) $ 110 $ 141 $ (209 ) $ 141 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2015 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 19 $ 423 $ (18 ) $ 424 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (464 ) — 285 179 — Acquisition of businesses, net of cash acquired — — — (37 ) (37 ) Acquisition of Drop Down Assets, net of cash acquired — — — (698 ) (698 ) Capital expenditures — — (29 ) — (29 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — — — 42 42 Investments in unconsolidated affiliates — (28 ) — — (374 ) (402 ) Other — — 9 — 9 Net Cash (Used in) Provided by Investing Activities (464 ) (28 ) 282 (888 ) (1,098 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (309 ) 9 — 300 — Net contributions from noncontrolling interests — — — 122 122 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (79 ) — (79 ) Proceeds from the issuance of Class C units 599 — — — 599 (Payments of) proceeds from distributions (139 ) — (392 ) 392 (139 ) Proceeds from the revolving credit facility — — — 551 551 Payments for the revolving credit facility — — — (245 ) (245 ) Proceeds from issuance of long-term debt — external — — 6 — 6 Proceeds from issuance of long-term debt — affiliate — — — 281 281 Payments for long-term debt — external — — (241 ) (494 ) (735 ) Payment of debt issuance costs — — (6 ) (1 ) (7 ) Net Cash Provided by (Used in) Financing Activities 151 9 (712 ) 906 354 Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (313 ) — (7 ) — (320 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 328 — 245 — 573 Cash, Cash Equivalents and Restricted Cash at End of Period $ 15 $ — $ 238 $ — $ 253 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Summary of Significant Accoun35

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Guarantees, Indemnifications and Warranties Policies [Policy Text Block]	Guarantees The Company enters into various contracts that include indemnification and guarantee provisions as a routine part of its business activities. Examples of these contracts include operation and maintenance agreements, service agreements, commercial sales arrangements and other types of contractual agreements with vendors and other third parties, as well as affiliates. These contracts generally indemnify the counterparty for tax, environmental liability, litigation and other matters, as well as breaches of representations, warranties and covenants set forth in these agreements. Because many of the guarantees and indemnities the Company issues to third parties and affiliates do not limit the amount or duration of its obligations to perform under them, there exists a risk that the Company may have obligations in excess of the amounts agreed upon in the contracts mentioned above. For those guarantees and indemnities that do not limit the liability exposure, the Company may not be able to estimate what the liability would be, until a claim is made for payment or performance, due to the contingent nature of these contracts.
Equity Method Investments [Policy Text Block]	Investments Accounted for by the Equity Method The Company has investments in various energy projects accounted for by the equity method, several of which are VIEs, where the Company is not a primary beneficiary, as described in Note 5 , Investments Accounted for by the Equity Method and Variable Interest Entities . The equity method of accounting is applied to these investments in affiliates because the ownership structure prevents the Company from exercising a controlling influence over the operating and financial policies of the projects. Under this method, equity in pre-tax income or losses of the investments is reflected as equity in earnings of unconsolidated affiliates. Distributions from equity method investments that represent earnings on the Company's investment are included within cash flows from operating activities and distributions from equity method investments that represent a return of the Company's investment are included within cash flows from investing activities.
Derivatives, Policy [Policy Text Block]	Derivative Financial Instruments The Company accounts for derivative financial instruments under ASC 815, Derivatives and Hedging , or ASC 815, which requires the Company to record all derivatives on the balance sheet at fair value unless they qualify for a NPNS exception. Changes in the fair value of non-hedge derivatives are immediately recognized in earnings. Changes in the fair value of derivatives accounted for as hedges, if elected for hedge accounting, are either: • Recognized in earnings as an offset to the changes in the fair value of the related hedged assets, liabilities and firm commitments; or • Deferred and recorded as a component of accumulated OCI until the hedged transactions occur and are recognized in earnings. The Company's primary derivative instruments are power purchase or sale contracts used to mitigate variability in earnings due to fluctuations in market prices, fuels purchase contracts used to control customer reimbursable fuel cost, and interest rate instruments used to mitigate variability in earnings due to fluctuations in interest rates. On an ongoing basis, the Company assesses the effectiveness of all derivatives that are designated as hedges for accounting purposes in order to determine that each derivative continues to be highly effective in offsetting changes in fair values or cash flows of hedged items. Internal analyses that measure the statistical correlation between the derivative and the associated hedged item determine the effectiveness of such a contract designated as a hedge. If it is determined that the derivative instrument is not highly effective as a hedge, hedge accounting will be discontinued prospectively. In this case, the gain or loss previously deferred in accumulated OCI would be frozen until the underlying hedged item is delivered unless the transaction being hedged is no longer probable of occurring in which case the amount in OCI would be immediately reclassified into earnings. If the derivative instrument is terminated, the effective portion of this derivative deferred in accumulated OCI will be frozen until the underlying hedged item is delivered. Revenues and expenses on contracts that qualify for the NPNS exception are recognized when the underlying physical transaction is delivered. While these contracts are considered derivative financial instruments under ASC 815, they are not recorded at fair value, but on an accrual basis of accounting. If it is determined that a transaction designated as NPNS no longer meets the scope exception, the fair value of the related contract is recorded on the balance sheet and immediately recognized through earnings.
Debt, Policy [Policy Text Block]	Debt Issuance Costs Debt issuance costs are capitalized and amortized as interest expense on a basis which approximates the effective interest method over the term of the related debt. Debt issuance costs related to the long term debt are presented as a direct deduction from the carrying amount of the related debt in both the current and prior periods. Debt issuance costs related to the senior secured revolving credit facility line of credit are recorded as a non-current asset on the balance sheet and are amortized over the term of the credit facility.
Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block]	Intangible Assets Intangible assets represent contractual rights held by the Company. The Company recognizes specifically identifiable intangible assets including power purchase agreements, leasehold improvements, customer relationships, customer contracts, and development rights when specific rights and contracts are acquired. These intangible assets are amortized primarily on a straight-line basis. For further discussion of the Company's intangible assets, refer to Note 8 , Intangible Assets to the Consolidated Financial Statements.
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation and Principles of Consolidation The Company's consolidated financial statements have been prepared in accordance with GAAP. The ASC is the source of authoritative GAAP to be applied by nongovernmental entities. In addition, the rules and interpretative releases of the SEC under authority of federal securities laws are also sources of authoritative GAAP for SEC registrants.
Concentration Risk, Credit Risk, Policy [Policy Text Block]	Concentrations of Credit Risk Financial instruments which potentially subject the Company to concentrations of credit risk consist primarily of accounts receivable, notes receivable and derivative instruments, which are concentrated within entities engaged in the energy and financial industry. These industry concentrations may impact the overall exposure to credit risk, either positively or negatively, in that the customers may be similarly affected by changes in economic, industry or other conditions. In addition, many of the Company's projects have only one customer. However, the Company believes that the credit risk posed by industry concentration is offset by the diversification and creditworthiness of its customer base. See Note 6 , Fair Value of Financial Instruments , for a further discussion of derivative concentrations and Note 12 , Segment Reporting , for concentration of counterparties.
Fair Value of Financial Instruments, Policy [Policy Text Block]	Fair Value of Financial Instruments The carrying amount of cash and cash equivalents, restricted cash, accounts receivable, accounts receivable - affiliate, accounts payable, current portion of account payable - affiliate, and accrued expenses and other current liabilities approximate fair value because of the short-term maturity of these instruments. See Note 6 , Fair Value of Financial Instruments , for a further discussion of fair value of financial instruments.
Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block]	Asset Impairments Long-lived assets that are held and used are reviewed for impairment whenever events or changes in circumstances indicate carrying values may not be recoverable. Such reviews are performed in accordance with ASC 360. An impairment loss is indicated if the total future estimated undiscounted cash flows expected from an asset are less than its carrying value. An impairment charge is measured by the difference between an asset's carrying amount and fair value with the difference recorded in operating costs and expenses in the statements of operations. Fair values are determined by a variety of valuation methods, including appraisals, sales prices of similar assets and present value techniques. For further discussion of the Company's long-lived asset impairments, refer to Note 9 , Asset Impairments to the Consolidated Financial Statements. Investments accounted for by the equity method are reviewed for impairment in accordance with ASC 323, Investments-Equity Method and Joint Ventures , which requires that a loss in value of an investment that is an other-than-temporary decline should be recognized. The Company identifies and measures losses in the value of equity method investments based upon a comparison of fair value to carrying value.
Asset Retirement Obligation [Policy Text Block]	Asset Retirement Obligations Asset retirement obligations, or AROs, are accounted for in accordance with ASC 410-20, Asset Retirement Obligations, or ASC 410-20. Retirement obligations associated with long-lived assets included within the scope of ASC 410-20 are those for which a legal obligation exists under enacted laws, statutes, and written or oral contracts, including obligations arising under the doctrine of promissory estoppel, and for which the timing and/or method of settlement may be conditional on a future event. ASC 410-20 requires an entity to recognize the fair value of a liability for an ARO in the period in which it is incurred and a reasonable estimate of fair value can be made. Upon initial recognition of a liability for an ARO, the asset retirement cost is capitalized by increasing the carrying amount of the related long-lived asset by the same amount. Over time, the liability is accreted to its future value, while the capitalized cost is depreciated over the useful life of the related asset. The Company's AROs are primarily related to the future dismantlement of equipment on leased property and environmental obligations related to site closures and fuel storage facilities. The Company records AROs as part of other non-current liabilities on its balance sheet. The following table represents the balance of ARO obligations as of December 31, 2017 and 2016 , along with the additions and accretion related to the Company's ARO obligations for the year ended December 31, 2017 : (In millions) Balance as of December 31, 2016 $ 49 Revisions in estimates for current obligations/Additions 2 Accretion — expense 4 Balance as of December 31, 2017 $ 55
Consolidation, Policy [Policy Text Block]	The consolidated financial statements include the Company's accounts and operations and those of its subsidiaries in which it has a controlling interest. All significant intercompany transactions and balances have been eliminated in consolidation. The usual condition for a controlling financial interest is ownership of a majority of the voting interests of an entity. However, a controlling financial interest may also exist through arrangements that do not involve controlling voting interests. As such, the Company applies the guidance of ASC 810, Consolidations, or ASC 810, to determine when an entity that is insufficiently capitalized or not controlled through its voting interests, referred to as a variable interest entity, or VIE, should be consolidated.
Cash and Cash Equivalents, Unrestricted Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents Cash and cash equivalents include highly liquid investments with an original maturity of three months or less at the time of purchase. Cash and cash equivalents held at project subsidiaries was $124 million and $111 million as of December 31, 2017 and 2016 , respectively.
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]	Restricted Cash The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the consolidated balance sheets that sum to the total of the same such amounts shown in the statements of cash flows. Year Ended December 31, 2017 2016 2015 (In millions) Cash and cash equivalents $ 146 $ 321 $ 110 Restricted cash 168 176 143 Cash, cash equivalents and restricted cash shown in the statement of cash flows 314 497 253 Restricted cash consists primarily of funds held to satisfy the requirements of certain debt agreements and funds held within the Company's projects that are restricted in their use. Of these funds as of December 31, 2017 , approximately $25 million is designated for current debt service payments, $25 million is designated to fund operating expenses and $36 million is designated for distributions to the Company, with the remaining $82 million restricted for reserves including debt service, performance obligations and other reserves, as well as capital expenditures.
Trade and Other Accounts Receivable, Policy [Policy Text Block]	Trade Receivables and Allowance for Doubtful Accounts Trade receivables are reported on the balance sheet at the invoiced amount adjusted for any write-offs and the allowance for doubtful accounts. The allowance for doubtful accounts is reviewed periodically based on amounts past due and significance. The allowance for doubtful accounts was immaterial as of December 31, 2017 and 2016 . Notes Receivable Notes receivable consist of receivables related to the financing of required network upgrades. The notes issued with respect to network upgrades will be repaid within a 5-year period following the date each facility reached commercial operations.
Income Tax, Policy [Policy Text Block]	Income Taxes The Company is classified as a partnership for federal and state income tax purposes. Therefore, federal and state income taxes are assessed at the partner level. Accordingly, no provision has been made for federal or state income taxes in the accompanying financial statements.
Inventory, Policy [Policy Text Block]	Inventory Inventory consists principally of spare parts and fuel oil. Spare parts inventory is valued at weighted average cost, unless evidence indicates that the weighted average cost will not be recovered with a normal profit in the ordinary course of business. Fuel oil inventory is valued at the lower of weighted average cost or market. The Company removes fuel inventories as they are used in the production of steam, chilled water or electricity. Spare parts inventory are removed when they are used for repairs, maintenance or capital projects.
Property, Plant and Equipment, Policy [Policy Text Block]	Property, Plant and Equipment Property, plant and equipment are stated at cost or, in the case of third party business acquisitions, fair value; however impairment adjustments are recorded whenever events or changes in circumstances indicate that their carrying values may not be recoverable. See Note 3 , Business Acquisitions , for more information on acquired property, plant and equipment. Significant additions or improvements extending asset lives are capitalized as incurred, while repairs and maintenance that do not improve or extend the life of the respective asset are charged to expense as incurred. Depreciation is computed using the straight-line method over the estimated useful lives. Certain assets and their related accumulated depreciation amounts are adjusted for asset retirements and disposals with the resulting gain or loss included in cost of operations in the consolidated statements of operations. For further discussion of the Company's property, plant and equipment refer to Note 4 , Property, Plant and Equipment to the Consolidated Financial Statements.
Revenue Recognition, Policy [Policy Text Block]	Revenue Recognition Thermal Revenues Steam and chilled water revenue is recognized based on customer usage as determined by meter readings taken at month-end. Some locations read customer meters throughout the month, and recognize estimated revenue for the period between meter read date and month-end. The Thermal Business subsidiaries collect and remit state and local taxes associated with sales to their customers, as required by governmental authorities. These taxes are presented on a net basis in the income statement. Power Purchase Agreements, or PPAs The majority of the Company’s revenues are obtained through PPAs or other contractual agreements, which are accounted for as operating leases under ASC 840. ASC 840 requires the minimum lease payments received to be amortized over the term of the lease and contingent rentals are recorded when the achievement of the contingency becomes probable. Judgment is required by management in determining the economic life of each generating facility, in evaluating whether certain lease provisions constitute minimum payments or represent contingent rent and other factors in determining whether a contract contains a lease and whether the lease is an operating lease or capital lease. Certain of these leases have no minimum lease payments and all of the rental income under these leases is recorded as contingent rent on an actual basis when the electricity is delivered. The contingent rental income recognized in the years ended December 31, 2017 , 2016 and 2015 was $559 million , $583 million and $443 million , respectively. These balances include intercompany revenue for Elbow Creek of $8 million for each of the years ended December 31, 2017 and 2016 , as further discussed in Note 13 Related Party Transactions .
Lease, Policy [Policy Text Block] (Deprecated 2017-01-31)	Sale Leaseback Arrangements The Company is party to sale-leaseback arrangements that provide for the sale of certain assets to a third party and simultaneous leaseback to the Company. In accordance with ASC 840-40, Sale-Leaseback Transactions , if the seller-lessee retains, through the leaseback, substantially all of the benefits and risks incident to the ownership of the property sold, the sale-leaseback transaction is accounted for as a financing arrangement. An example of this type of continuing involvement would include an option to repurchase the assets or the buyer-lessor having the option to sell the assets back to the Company. This provision is included in most of the Company’s sale-leaseback arrangements. As such, the Company accounts for these arrangements as financings. Under the financing method, the Company does not recognize as income any of the sale proceeds received from the lessor that contractually constitutes payment to acquire the assets subject to these arrangements. Instead, the sale proceeds received are accounted for as financing obligations and leaseback payments made by the Company are allocated between interest expense and a reduction to the financing obligation. Interest on the financing obligation is calculated using the Company’s incremental borrowing rate at the inception of the arrangement on the outstanding financing obligation. Judgment is required to determine the appropriate borrowing rate for the arrangement and in determining any gain or loss on the transaction that would be recorded either at the end of or over the lease term.
Business Combinations Policy [Policy Text Block]	Business Combinations The Company accounts for its business combinations in accordance with ASC 805, Business Combinations, or ASC 805. For third party acquisitions, ASC 805 requires an acquirer to recognize and measure in its financial statements the identifiable assets acquired, the liabilities assumed, and any noncontrolling interest in the acquiree at fair value at the acquisition date. It also recognizes and measures the goodwill acquired or a gain from a bargain purchase in the business combination and determines what information to disclose to enable users of an entity's financial statements to evaluate the nature and financial effects of the business combination. In addition, transaction costs are expensed as incurred. For acquisitions that relate to entities under common control, ASC 805 requires retrospective combination of the entities for all periods presented as if the combination has been in effect from the beginning of the financial statement period of from the date the entities were under common control (if later than the beginning of the financial statement period). The difference between the cash paid and historical value of the entities' equity is recorded as a distribution/contribution from/to NRG with the offset to contributed capital. Transaction costs are expensed as incurred.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in accordance with GAAP requires management to make estimates and assumptions. These estimates and assumptions impact the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities as of the date of the consolidated financial statements. They also impact the reported amounts of net earnings during the reporting periods. Actual results could be different from these estimates. In recording transactions and balances resulting from business operations, the Company uses estimates based on the best information available. Estimates are used for such items as plant depreciable lives, uncollectible accounts, environmental liabilities, acquisition accounting and legal costs incurred in connection with recorded loss contingencies, among others. In addition, estimates are used to test long-lived assets for impairment and to determine the fair value of impaired assets. As better information becomes available or actual amounts are determinable, the recorded estimates are revised. Consequently, operating results can be affected by revisions to prior accounting estimates.
Tax Equity Arrangements, Policy [Policy Text Block]	Tax Equity Arrangements Certain portions of the Company’s noncontrolling interests in subsidiaries represent third-party interests in the net assets under certain tax equity arrangements, which are consolidated by the Company, that have been entered into to finance the cost of wind facilities eligible for certain tax credits. Additionally, certain portions of the Company’s investments in unconsolidated affiliates reflect the Company’s interests in tax equity arrangements, that are not consolidated by the Company, that have been entered into to finance the cost of distributed solar energy systems under operating leases or PPAs eligible for certain tax credits. The Company has determined that the provisions in the contractual agreements of these structures represent substantive profit sharing arrangements. Further, the Company has determined that the appropriate methodology for calculating the noncontrolling interest and investment in unconsolidated affiliates that reflects the substantive profit sharing arrangements is a balance sheet approach utilizing the hypothetical liquidation at book value, or HLBV, method. Under the HLBV method, the amounts reported as noncontrolling interests and investment in unconsolidated affiliates represent the amounts the investors to the tax equity arrangements would hypothetically receive at each balance sheet date under the liquidation provisions of the contractual agreements, assuming the net assets of the funding structures were liquidated at their recorded amounts determined in accordance with GAAP. The investors’ interests in the results of operations of the funding structures are determined as the difference in noncontrolling interests and investment in unconsolidated affiliates at the start and end of each reporting period, after taking into account any capital transactions between the structures and the funds’ investors. The calculations utilized to apply the HLBV method include estimated calculations of taxable income or losses for each reporting period.
Reclassification, Policy [Policy Text Block]	Reclassifications Certain prior year amounts have been reclassified for comparative purposes.
Recent Accounting Developments	Recent Accounting Developments - Adopted in 2017 ASU 2017-12 — In August 2017, the FASB issued ASU No. 2017-12, Derivatives and Hedging (Topic 815) , Targeted Improvements to Accounting for Hedging Activities, or ASU No. 2017-12. ASU No. 2017-12 amends ASU No. 2016-15. The amendments of ASU No. 2016-15 were issued to simplify the application of hedge accounting guidance and more closely aligning financial reporting for hedging relationships with economic results of an entity's risk management activities. The issues addressed by ASU No. 2017-12 include but are not limited to alignment of risk management activities and financial reporting, risk component hedging, accounting for the hedged item in fair value hedges of interest rate risk, recognition and presentation of the effects of hedging instruments, amounts excluded from the assessment of hedge effectiveness, and other simplifications of hedge accounting guidance. The amendments of ASU No. 2017-12 are effective for fiscal years beginning after December 15, 2018, and interim periods therein. Early adoption is permitted in any interim period and the effect of the adoption should be reflected as of the beginning of the fiscal year of adoption. The Company early adopted ASU No. 2017-12 during the fourth quarter 2017. The adoption of ASU No. 2017-12 did not have a material impact on our consolidated results of operations, cash flows, and statement of financial position. ASU 2016-18 — In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230) , Restricted Cash, or ASU No. 2016-18. The amendments of ASU No. 2016-18 require an entity to include amounts generally described as restricted cash and restricted cash equivalents with cash and cash equivalents when reconciling the beginning of period and end of period total amounts on the statement of cash flows. The amendments of ASU No. 2016-18 are effective for annual reporting periods beginning after December 15, 2017, and interim periods within those annual periods. Early adoption is permitted and the adoption of ASU No. 2016-18 will be applied retrospectively. The Company early adopted ASU No. 2016-18 during the second quarter of 2017. Net cash flows used in investing activities for the year ended December 31, 2016 decreased by $33 million . The sum of Company's cash and cash equivalents and restricted cash reported within the consolidated balance sheet as of December 31, 2016 equals the beginning balances of cash, cash equivalents and restricted cash shown in the consolidated statement of cash flows for the year ended December 31, 2017. The sum of Company's cash and cash equivalents and restricted cash reported within the consolidated balance sheet as of December 31, 2017 equals to the ending balances of cash, cash equivalents and restricted cash shown in the consolidated statement of cash flows for the year ended December 31, 2017. Recent Accounting Developments - Not Yet Adopted ASU 2016-02 — In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), or Topic 842, with the objective to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and to improve financial reporting by expanding the related disclosures. The guidance in Topic 842 provides that a lessee that may have previously accounted for a lease as an operating lease under current GAAP should recognize the assets and liabilities that arise from a lease on the balance sheet. In addition, Topic 842 expands the required quantitative and qualitative disclosures with regards to lease arrangements. The Company will adopt the standard effective January 1, 2019 and expects to elect certain of the practical expedients permitted, including the expedient that permits the Company to retain its existing lease assessment and classification. The Company is currently working through an adoption plan and evaluating the anticipated impact on the Company's results of operations, cash flows and financial position. While the Company is currently evaluating the impact the new guidance will have on its financial position and results of operations, the Company expects to recognize lease liabilities and right of use assets. The extent of the increase to assets and liabilities associated with these amounts remains to be determined pending the Company’s review of its existing lease contracts and service contracts which may contain embedded leases. While this review is still in process, the Company believes the adoption of Topic 842 may be material to its financial statements. The Company is continuing to monitor potential changes to Topic 842 that have been proposed by the FASB and will assess any necessary changes to the implementation as the guidance is updated. ASU 2014-09 — In May 2014, the FASB issued ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), or Topic 606, which was further amended through various updates issued by the FASB thereafter. The amendments of ASU No. 2014-09 completed the joint effort between the FASB and the IASB, to develop a common revenue standard for GAAP and IFRS, and to improve financial reporting. The guidance under Topic 606 provides that an entity should recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled to in exchange for the goods or services provided and establishes a five step model to be applied by an entity in evaluating its contracts with customers. The Company has elected the practical expedient available under Topic 606 for measuring progress toward complete satisfaction of a performance obligation and for disclosure requirements of remaining performance obligations. The practical expedient allows an entity to recognize revenue in the amount to which the entity has the right to invoice such that the entity has a right to the consideration in an amount that corresponds directly with the value to the customer for performance completed to date by the entity. The majority of the Company's revenues are obtained through PPAs, which are currently accounted for as operating leases. In connection with the implementation of Topic 842, as described above, the Company expects to elect certain of the practical expedients permitted, including the expedient that permits the Company to retain its existing lease assessment and classification. The Company adopted the standard effective January 1, 2018 under the modified retrospective transition method. As leases are excluded from the scope of Topic 606, the adoption of Topic 606 at the date of initial application will not have a material impact on the Company's financial statements. The adoption of Topic 606 also includes additional disclosure requirements beginning in the first quarter of 2018. As a significant portion of the Company's revenue is generated through operating leases, the majority of the new required disclosures will not be relevant or material to the Company.

Segment Reporting Segment Repor

Segment Reporting Segment Reporting (Policies)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment Reporting, Policy [Policy Text Block]	The Company’s segment structure reflects how management currently operates and allocates resources. The Company's businesses are segregated based on conventional power generation, renewable businesses which consist of solar and wind, and the thermal and chilled water business. The Corporate segment reflects the Company's corporate costs. The Company's chief operating decision maker, its Chief Executive Officer, evaluates the performance of its segments based on operational measures including adjusted earnings before interest, taxes, depreciation and amortization, or Adjusted EBITDA, and CAFD, as well as economic gross margin and net income (loss).

Nature of Business Nature of Bu

Nature of Business Nature of Business (Tables)	12 Months Ended
	Dec. 31, 2017
IPO of NRG Yield [Abstract]
IPO of NRG Yield [Table Text Block]	The following table represents the structure of the Company as of December 31, 2017 :
Schedule of Ownership Percentage, Net Capacity, Offtake Counterparty and Year of Offtake Expiration by Operating Asset [Table Text Block]	As of December 31, 2017 , the Company's operating assets are comprised of the following projects: Projects Percentage Ownership Net Capacity (MW) (a) Offtake Counterparty Expiration Conventional El Segundo 100 % 550 Southern California Edison 2023 GenConn Devon 50 % 95 Connecticut Light & Power 2040 GenConn Middletown 50 % 95 Connecticut Light & Power 2041 Marsh Landing 100 % 720 Pacific Gas and Electric 2023 Walnut Creek 100 % 485 Southern California Edison 2023 1,945 Utility Scale Solar Agua Caliente 16 % 46 Pacific Gas and Electric 2039 Alpine 100 % 66 Pacific Gas and Electric 2033 Avenal 50 % 23 Pacific Gas and Electric 2031 Avra Valley 100 % 26 Tucson Electric Power 2032 Blythe 100 % 21 Southern California Edison 2029 Borrego 100 % 26 San Diego Gas and Electric 2038 CVSR 100 % 250 Pacific Gas and Electric 2038 Desert Sunlight 250 25 % 63 Southern California Edison 2034 Desert Sunlight 300 25 % 75 Pacific Gas and Electric 2039 Kansas South 100 % 20 Pacific Gas and Electric 2033 Roadrunner 100 % 20 El Paso Electric 2031 TA High Desert 100 % 20 Southern California Edison 2033 Utah Solar Portfolio (b)(e) 50 % 265 PacifiCorp 2036 921 Distributed Solar Apple I LLC Projects 100 % 9 Various 2032 AZ DG Solar Projects 100 % 5 Various 2025-2033 SPP Projects 100 % 25 Various 2026-2037 Other DG Projects 100 % 13 Various 2023-2039 52 Wind Alta I 100 % 150 Southern California Edison 2035 Alta II 100 % 150 Southern California Edison 2035 Alta III 100 % 150 Southern California Edison 2035 Alta IV 100 % 102 Southern California Edison 2035 Alta V 100 % 168 Southern California Edison 2035 Alta X (b) 100 % 137 Southern California Edison 2038 Alta XI (b) 100 % 90 Southern California Edison 2038 Buffalo Bear 100 % 19 Western Farmers Electric Co-operative 2033 Projects Percentage Ownership Net Capacity (MW) (a) Offtake Counterparty Expiration Crosswinds (b)(f) 99 % 21 Corn Belt Power Cooperative 2027 Elbow Creek (b)(f) 100 % 122 NRG Power Marketing LLC 2022 Elkhorn Ridge (b)(f) 66.7 % 54 Nebraska Public Power District 2029 Forward (b)(f) 100 % 29 Constellation NewEnergy, Inc. 2022 Goat Wind (b)(f) 100 % 150 Dow Pipeline Company 2025 Hardin (b)(f) 99 % 15 Interstate Power and Light Company 2027 Laredo Ridge 100 % 80 Nebraska Public Power District 2031 Lookout (b)(f) 100 % 38 Southern Maryland Electric Cooperative 2030 Odin (b)(f) 99.9 % 20 Missouri River Energy Services 2028 Pinnacle 100 % 55 Maryland Department of General Services and University System of Maryland 2031 San Juan Mesa (b)(f) 75 % 90 Southwestern Public Service Company 2025 Sleeping Bear (b)(f) 100 % 95 Public Service Company of Oklahoma 2032 South Trent 100 % 101 AEP Energy Partners 2029 Spanish Fork (b)(f) 100 % 19 PacifiCorp 2028 Spring Canyon II (b) 90.1 % 29 Platte River Power Authority 2039 Spring Canyon III (b) 90.1 % 25 Platte River Power Authority 2039 Taloga 100 % 130 Oklahoma Gas & Electric 2031 Wildorado (b)(f) 100 % 161 Southwestern Public Service Company 2027 2,200 Thermal NRG Energy Center Dover LLC 100 % 103 NRG Power Marketing LLC 2018 Thermal generation 100 % 20 Various Various 123 Total net generation capacity (c) 5,241 Thermal equivalent MWt (d) 100 % 1,319 Various Various

Summary of Significant Accoun38

Summary of Significant Accounting Policies Noncontrolling Interest Disclosure (Tables)	12 Months Ended
	Dec. 31, 2017
Summary of Significant Accounting Policies [Abstract]
Schedule of Change in Asset Retirement Obligation [Table Text Block]	The following table represents the balance of ARO obligations as of December 31, 2017 and 2016 , along with the additions and accretion related to the Company's ARO obligations for the year ended December 31, 2017 : (In millions) Balance as of December 31, 2016 $ 49 Revisions in estimates for current obligations/Additions 2 Accretion — expense 4 Balance as of December 31, 2017 $ 55

Business Acquisitions (Tables)

Business Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2017
November 2017 Drop Down Assets [Member]
Business Acquisition [Line Items]
Business Acquisition, Pro Forma Information [Table Text Block]	The following tables present a summary of the Company's historical information combining the financial information for the November 2017 Drop Down Assets and August 2017 Drop Down Assets transferred in connection with the acquisitions: Year ended December 31, 2016 Year ended December 31, 2015 As Previously Reported (a) November 2017 Drop Down Assets August 2017 Drop Down Assets As Currently Reported As Previously Reported (a) November 2017 Drop Down Assets August 2017 Drop Down Assets As Currently Reported (In millions) Total operating revenues $ 1,021 $ 14 $ — $ 1,035 $ 953 $ 15 $ — $ 968 Operating income 220 4 — 224 322 6 — 328 Net income 15 — — 15 93 2 — 95 Net income attributable to Yield LLC 157 — (31 ) 126 144 3 10 157 (a) As previously reported in the May 9, 2017 Form 8-K filed in connection with the March 2017 Drop Down completed on March 27, 2017 As of December 31, 2016 (In millions) As Previously Reported (a) November 2017 Drop Down Assets As Currently Reported Assets: Current assets $ 656 $ 14 $ 670 Property, plant and equipment 5,460 94 5,554 Non-current assets 2,504 18 2,522 Total assets 8,620 126 8,746 Liabilities: Debt (Current and non-current) 6,007 62 6,069 Other current and non-current liabilities 309 4 313 Total liabilities assumed 6,316 66 6,382 Net assets $ 2,304 $ 60 $ 8,746 (a) As previously reported in the May 9, 2017 Form 8-K filed in connection with the March 2017 Drop Down completed on March 27, 2017.
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	The following is a summary of assets and liabilities transferred in connection with the acquisition of the November 2017 Drop Down Assets as of November 1, 2017: (In millions) Assets: Current assets $ 7 Property, plant and equipment 83 Non-current assets 12 Total assets 102 Liabilities: Debt (Current and non-current) (a) 23 Other current and non-current liabilities 3 Total liabilities assumed 26 Net assets acquired $ 76 (a) Net of $3 million of net debt issuance costs.
March 2017 Drop Down Assets [Member]
Business Acquisition [Line Items]
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	The following is a summary of assets and liabilities transferred in connection with the acquisition of the March 2017 Drop Down Assets as of March 27, 2017: (In millions) Assets: Cash $ 6 Equity investment in projects 456 Total assets acquired 462 Liabilities: Debt (Current and non-current) (a) 320 Other current and non-current liabilities 3 Total liabilities assumed 323 Net assets acquired $ 139 (a) Net of $8 million of debt issuance costs.

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	The Company’s major classes of property, plant, and equipment were as follows: December 31, 2017 December 31, 2016 Depreciable Lives (In millions) Facilities and equipment $ 6,289 $ 6,339 2 - 45 Years Land and improvements 166 167 Construction in progress (a) 34 24 Total property, plant and equipment 6,489 6,530 Accumulated depreciation (1,285 ) (976 ) Net property, plant and equipment $ 5,204 $ 5,554 (a) As of December 31, 2017 and 2016 , construction in progress includes $24 million and $20 million of capital expenditures that relate to prepaid long-term service agreements in the Conventional segment, respectively.

Equity Method Investments and41

Equity Method Investments and VIEs (Tables)	12 Months Ended
	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Schedule of Variable Interest Entities [Table Text Block]	Summarized financial information for the Company's consolidated VIEs consisted of the following as of December 31, 2017 : (In millions) NRG Wind TE Holdco Alta TE Holdco Spring Canyon Other current and non-current assets $ 172 $ 17 $ 2 Property, plant and equipment 376 436 95 Intangible assets 2 262 — Total assets 550 715 97 Current and non-current liabilities 197 9 5 Total liabilities 197 9 5 Noncontrolling interest 9 93 60 Net assets less noncontrolling interests $ 344 $ 613 $ 32
Equity Method Investments [Table Text Block]	The following table summarizes the Company's equity method investments as of December 31, 2017 : Name Economic Interest Investment Balance (In millions) Utah Solar Portfolio (a) 50% $345 Desert Sunlight 25% 272 GenConn (b) 50% 102 Agua Caliente Borrower 2 16% 92 Elkhorn Ridge (c) 66.7% 73 San Juan Mesa (c) 75% 66 NRG DGPV Holdco 1 LLC (d) 95% 76 NRG DGPV Holdco 2 LLC (d) 95% 61 NRG DGPV Holdco 3 LLC (d) 99% 39 NRG RPV Holdco 1 LLC (d) 95% 58 Avenal 50% (6) Total equity investments in affiliates $1,178 (a) Economic interest based on cash to be distributed. Four Brothers Solar, LLC, Granite Mountain Holdings, LLC and Iron Springs Holdings, LLC are tax equity structures and VIEs. The related allocations are described below. (b) GenConn is a variable interest entity. (c) San Juan Mesa and Elkhorn Ridge are part of the Wind TE Holdco tax equity structure, as described below. San Juan Mesa and Elkhorn Ridge are owned 75% and 66.7% , respectively, by Wind TE Holdco. The Company owns 100% of the Class B interests in Wind TE Holdco. (d) Economic interest based on cash to be distributed. NRG DGPV Holdco 1 LLC, NRG DGPV Holdco 2 LLC, NRG DGPV Holdco 3 LLC and NRG RPV Holdco 1 LLC are tax equity structures and VIEs. The related allocations are described below.
Entities that are not consolidated [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investments [Table Text Block]	The following tables present summarized financial information for the Company's significant equity method investments: Year Ended December 31, 2017 2016 2015 Income Statement Data: (In millions) GenConn Operating revenues $ 71 $ 72 $ 78 Operating income 36 38 40 Net income 26 26 28 Desert Sunlight Operating revenues 207 211 206 Operating income 127 129 124 Net income 80 80 73 Utah Solar Portfolio (a) Operating revenues 75 13 — Operating income (loss) 18 (6 ) (1 ) Net income (loss) 18 (6 ) (1 ) DGPV entities (b) Operating revenues 37 14 1 Operating income 7 2 — Net loss (3 ) — — RPV Holdco Operating revenues 16 13 4 Operating income 3 2 (6 ) Net income (loss) 3 2 (6 ) As of December 31, 2017 2016 Balance Sheet Data: (In millions) GenConn Current assets $ 38 $ 36 Non-current assets 374 389 Current liabilities 18 16 Non-current liabilities 189 196 Desert Sunlight Current assets 133 281 Non-current assets 1,350 1,401 Current liabilities 64 64 Non-current liabilities 1,003 1,043 Utah Solar Portfolio (a) Current assets 13 20 Non-current assets 1,090 1,105 Current liabilities 5 14 Non-current liabilities 24 38 DGPV entities (b) Current assets 74 44 Non-current assets 671 562 Current liabilities 83 112 Non-current liabilities 216 23 Redeemable Noncontrolling Interest 44 28 RPV Holdco Current assets 3 15 Non-current assets 183 191 Current liabilities — 11 Non-current liabilities 7 7 Redeemable Noncontrolling Interest 16 — — (a) Utah Solar Portfolio was acquired by NRG on November 2, 2016. (b) Includes DGPV Holdco 1, DGPV Holdco 2 and DGPV Holdco 3

Fair Value of Financial Instr42

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value, by Balance Sheet Grouping [Table Text Block]	The estimated carrying amounts and fair values of the Company’s recorded financial instruments not carried at fair market value are as follows: As of December 31, 2017 As of December 31, 2016 Carrying Amount Fair Value Carrying Amount Fair Value (In millions) Assets: Notes receivable, including current portion $ 13 $ 13 $ 30 $ 30 Liabilities: Long-term debt, including current portion — affiliate 618 618 618 608 Long-term debt, including current portion — external $ 5,281 $ 5,297 $ 5,516 $ 5,500
Fair Value, Option, Quantitative Disclosures [Table Text Block]	The following table presents the level within the fair value hierarchy for long-term debt, including current portion as of December 31, 2017 and 2016 : As of December 31, 2017 As of December 31, 2016 Level 2 Level 3 Level 2 Level 3 (In millions) Long-term debt, including current portion $ 870 $ 5,045 $ 833 $ 5,275
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The following table presents assets and liabilities measured and recorded at fair value on the Company's consolidated balance sheets on a recurring basis and their level within the fair value hierarchy: As of December 31, 2017 As of December 31, 2016 Fair Value (a) Fair Value (a) Fair Value (a) (In millions) Level 2 Level 1 Level 2 Derivative assets: Commodity contracts $ 1 $ 1 $ 1 Interest rate contracts 1 — 1 Total assets $ 2 1 2 Derivative liabilities: Commodity contracts $ 1 — 1 Interest rate contracts 47 — 78 Total liabilities $ 48 $ — $ 79 (a) There were no derivative assets or liabilities classified Level 1 as of December 31, 2017 . There were no derivative assets or liabilities classified Level 3 as of December 31, 2017 and 2016 .

Accounting for Derivative Ins43

Accounting for Derivative Instruments and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative [Line Items]
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]	The following table summarizes the net notional volume buy/(sell) of the Company's open derivative transactions broken out by commodity as of December 31, 2017 and 2016 : Total Volume December 31, 2017 December 31, 2016 Commodity Units (In millions) Natural Gas MMBtu 2 3 Interest Dollars $ 1,940 $ 2,090
Schedule of Derivatives Instruments Statements of Financial Performance and Financial Position, Location [Table Text Block]	The following table summarizes the fair value within the derivative instrument valuation on the balance sheet: Fair Value Derivative Assets (a) Derivative Liabilities December 31, 2017 December 31, 2016 December 31, 2017 December 31, 2016 (In millions) Derivatives Designated as Cash Flow Hedges: Interest rate contracts current $ — $ — $ 4 $ 26 Interest rate contracts long-term 1 1 9 39 Total Derivatives Designated as Cash Flow Hedges 1 1 13 65 Derivatives Not Designated as Cash Flow Hedges : Interest rate contracts current — — 12 6 Interest rate contracts long-term — — 22 7 Commodity contracts current 1 2 1 1 Total Derivatives Not Designated as Cash Flow Hedges 1 2 35 14 Total Derivatives $ 2 $ 3 $ 48 $ 79 (a) Derivative Asset balances classified as current are included within the prepayments and other current assets line item of the Consolidated Balance Sheet. Derivative Asset balances classified as long-term are included within the other non-current assets line item of the Consolidated Balance Sheet.
Offsetting Liabilities [Table Text Block]	Gross Amounts Not Offset in the Statement of Financial Position As of December 31, 2017 Gross Amounts of Recognized Assets/Liabilities Derivative Instruments Net Amount Commodity contracts: (In millions) Derivative assets $ 1 $ — $ 1 Derivative liabilities (1 ) — (1 ) Total commodity contracts — — — Interest rate contracts: Derivative assets 1 (1 ) — Derivative liabilities (47 ) 1 (46 ) Total interest rate contracts (46 ) — (46 ) Total derivative instruments $ (46 ) $ — $ (46 ) Gross Amounts Not Offset in the Statement of Financial Position As of December 31, 2016 Gross Amounts of Recognized Assets/Liabilities Derivative Instruments Net Amount Commodity contracts: (In millions) Derivative assets $ 2 $ — $ 2 Derivative liabilities (1 ) — (1 ) Total commodity contracts 1 — 1 Interest rate contracts: Derivative assets 1 (1 ) — Derivative liabilities (78 ) 1 (77 ) Total interest rate contracts (77 ) — (77 ) Total derivative instruments $ (76 ) $ — $ (76 )
Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The following table summarizes the effects on the Company’s accumulated OCL balance attributable to interest rate swaps designated as cash flow hedge derivatives: Year ended December 31, 2017 2016 2015 (In millions) Accumulated OCL beginning balance $ (86 ) $ (99 ) $ (82 ) Reclassified from accumulated OCL to income due to realization of previously deferred amounts 17 17 17 Mark-to-market of cash flow hedge accounting contracts — (4 ) (34 ) Accumulated OCL ending balance (69 ) (86 ) (99 ) Accumulated OCL attributable to noncontrolling interests (1 ) (1 ) (1 ) Accumulated OCL attributable to NRG Yield LLC $ (68 ) $ (85 ) $ (98 ) Losses expected to be realized from OCL during the next 12 months $ 15 Amounts reclassified from accumulated OCL into income are recorded to interest expense.

Intangible Assets Intangible 44

Intangible Assets Intangible Assets - (Tables)	12 Months Ended
	Dec. 31, 2017
Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets [Table Text Block]	The following tables summarize the components of intangible assets subject to amortization: Year ended December 31, 2017 PPAs Leasehold Rights Customer Customer Contracts Emission Allowances Development Other Total (In millions) January 1, 2017 $ 1,286 $ 86 $ 66 $ 15 $ 9 $ 3 $ 6 $ 1,471 Asset impairments (a) (6 ) — — — — — — (6 ) December 31, 2017 1,280 86 66 15 9 3 6 1,465 Less accumulated amortization (205 ) (13 ) (5 ) (8 ) (3 ) (1 ) (2 ) (237 ) Net carrying amount $ 1,075 $ 73 $ 61 $ 7 $ 6 $ 2 $ 4 $ 1,228 (a) $6 million of asset impairments relate to one of the November 2017 Drop Down Assets that was recorded by NRG during the quarter ended September 30, 2017, as further described in Note 9 , Asset Impairments . Year ended December 31, 2016 PPAs Leasehold Rights Customer Customer Contracts Emission Allowances Development Other Total (In millions) January 1, 2016 $ 1,286 $ 86 $ 66 $ 15 $ 15 $ 3 $ 6 $ 1,477 Other — — — — (6 ) — — (6 ) December 31, 2016 1,286 86 66 15 9 3 6 1,471 Less accumulated amortization (143 ) (9 ) (4 ) (7 ) (2 ) (1 ) (2 ) (168 ) Net carrying amount $ 1,143 $ 77 $ 62 $ 8 $ 7 $ 2 $ 4 $ 1,303

Long-term Debt (Tables)

Long-term Debt (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Instrument [Line Items]
Schedule of Derivative Instruments [Table Text Block]	The following table summarizes the swaps, some of which are forward starting as indicated, related to the Company's project level debt as of December 31, 2017 : % of Principal Fixed Interest Rate Floating Interest Rate Notional Amount at December 31, 2017 (In millions) Effective Date Maturity Date Alpine 85 % various 3-Month LIBOR $ 115 various various Avra Valley 85 % 2.333 % 3-Month LIBOR 46 November 30, 2012 November 30, 2030 AWAM 100 % 2.47 % 3-Month LIBOR 17 May 22, 2013 May 15, 2031 Blythe 75 % 3.563 % 3-Month LIBOR 13 June 25, 2010 June 25, 2028 Borrego 75 % 1.125 % 3-Month LIBOR 5 April 3, 2013 June 30, 2020 El Segundo 75 % various 3-Month LIBOR 340 various various Kansas South 75 % 2.368 % 6-Month LIBOR 21 June 28, 2013 December 31, 2030 Laredo Ridge 75 % 2.31 % 3-Month LIBOR 75 March 31, 2011 March 31, 2026 Marsh Landing 75 % 3.244 % 3-Month LIBOR 295 June 28, 2013 June 30, 2023 Roadrunner 75 % 4.313 % 3-Month LIBOR 26 September 30, 2011 December 31, 2029 South Trent 75 % 3.265 % 3-Month LIBOR 40 June 15, 2010 June 14, 2020 South Trent 75 % 4.95 % 3-Month LIBOR 21 June 30, 2020 June 14, 2028 Tapestry 75 % 2.21 % 3-Month LIBOR 146 December 30, 2011 December 21, 2021 Tapestry 50 % 3.57 % 3-Month LIBOR 60 December 21, 2021 December 21, 2029 Utah Solar Portfolio 80 % various 1-Month LIBOR 223 various September 30, 2036 Viento Funding II 90 % various 6-Month LIBOR 148 various various Viento Funding II 90 % 4.985 % 6-Month LIBOR 65 July 11, 2023 June 30, 2028 Walnut Creek Energy 75 % various 3-Month LIBOR 239 June 28, 2013 May 31, 2023 WCEP Holdings 90 % 4.003 % 3-Month LIBOR 45 June 28, 2013 May 31, 2023 Total $ 1,940
Schedule of Maturities of Long-term Debt [Table Text Block]	Annual Maturities Annual payments based on the maturities of the Company's debt, for the years ending after December 31, 2017 , are as follows: (In millions) 2018 $ 306 2019 714 2020 650 2021 455 2022 653 Thereafter 3,121 Total $ 5,899
Schedule of long-term debt	The Company's borrowings, including short term and long term portions consisted of the following: December 31, 2017 December 31, 2016 Interest rate % (a) Letters of Credit Outstanding at December 31, 2017 (In millions, except rates) 2026 Senior Notes $ 350 $ 350 5.000 2024 Senior Notes 500 500 5.375 Long-term debt - affiliate, due 2020 281 281 3.325 Long-term debt - affiliate, due 2019 337 337 3.580 NRG Yield LLC and NRG Yield Operating LLC Revolving Credit Facility, due 2019 (b) 55 — L+2.500 74 Project-level debt: Agua Caliente Borrower 2, due 2038 41 — 5.430 17 Alpine, due 2022 135 145 L+1.750 16 Alta Wind I - V lease financing arrangements, due 2034 and 2035 926 965 5.696 - 7.015 119 CVSR, due 2037 746 771 2.339 - 3.775 — CVSR Holdco Notes, due 2037 194 199 4.680 13 El Segundo Energy Center, due 2023 400 443 L+1.75 - L+2.375 102 Energy Center Minneapolis, due 2025 83 96 5.950 — Energy Center Minneapolis Series D Notes, due 2031 125 125 3.550 — Laredo Ridge, due 2028 95 100 L+1.875 10 Marsh Landing, due 2023 318 370 L+1.875 22 Tapestry, due 2021 162 172 L+1.625 20 Utah Solar Portfolio, due 2022 278 287 various 13 Viento, due 2023 163 178 L+3.00 27 Walnut Creek, due 2023 267 310 L+1.625 41 Other 443 505 various 38 Subtotal project-level debt 4,376 4,666 Total debt 5,899 6,134 Less current maturities (306 ) (323 ) Less net debt issuance costs (54 ) (65 ) Total long-term debt $ 5,539 $ 5,746

Members' Equity (Tables)

Members' Equity (Tables)	12 Months Ended
	Dec. 31, 2017
Members' Equity [Abstract]
Schedule of Dividends Paid [Table Text Block]	The following table lists the distributions paid on the Company's Class A, Class B, Class C and Class D units during the year ended December 31, 2017 : Fourth Quarter 2017 Third Quarter 2017 Second Quarter 2017 First Quarter 2017 Distributions per Class A and Class B units $ 0.288 $ 0.28 $ 0.27 $ 0.26 Distributions per Class C and Class D units $ 0.288 $ 0.28 $ 0.27 $ 0.26

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting [Abstract]
Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]	The Company generated more than 10% of its revenues from the following customers for the years ended December 31, 2017 , 2016 and 2015 : 2017 2016 2015 Customer Conventional (%) Renewables (%) Conventional (%) Renewables (%) Conventional (%) Renewables (%) SCE 21% 20% 21% 21% 22% 17% PG&E 12% 11% 12% 11% 12% 12%
Schedule of Segment Reporting Information, by Segment [Table Text Block]	Year ended December 31, 2017 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues $ 336 $ 501 $ 172 $ — $ 1,009 Cost of operations 77 133 116 — 326 Depreciation and amortization 103 210 21 — 334 Impairment losses — 44 — — 44 General and administrative — — — 19 19 Acquisition-related transaction and integration costs — — — 3 3 Operating income (loss) 156 114 35 (22 ) 283 Equity in earnings of unconsolidated affiliates 12 59 — — 71 Other income, net 1 2 — 1 4 Loss on debt extinguishment — (3 ) — — (3 ) Interest expense (49 ) (163 ) (10 ) (71 ) (293 ) Net Income (Loss) $ 120 $ 9 $ 25 $ (92 ) $ 62 Balance Sheet Equity investment in affiliates $ 102 $ 1,076 $ — $ — $ 1,178 Capital expenditures (a) 15 4 16 — 35 Total Assets $ 1,897 $ 5,811 $ 422 $ 24 $ 8,154 (a) Includes accruals.	Year ended December 31, 2016 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues $ 333 $ 532 $ 170 $ — $ 1,035 Cost of operations 66 128 114 — 308 Depreciation and amortization 80 203 20 — 303 Impairment losses — 185 — — 185 General and administrative — — — 14 14 Acquisition-related transaction and integration costs — — — 1 1 Operating income (loss) 187 16 36 (15 ) 224 Equity in earnings of unconsolidated affiliates 13 47 — — 60 Other income, net 1 2 — — 3 Interest expense (48 ) (151 ) (7 ) (66 ) (272 ) Net Income (Loss) $ 153 $ (86 ) $ 29 $ (81 ) $ 15 Balance Sheet Equity investments in affiliates $ 106 $ 1,046 $ — $ — $ 1,152 Capital expenditures (a) 7 2 14 — 23 Total Assets $ 1,993 $ 6,114 $ 426 $ 213 $ 8,746 (a) Includes accruals.	Year ended December 31, 2015 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues $ 336 $ 458 $ 174 $ — $ 968 Cost of operations 59 138 126 — 323 Depreciation and amortization 81 203 19 — 303 Impairment losses — 1 — — 1 General and administrative — — — 10 10 Acquisition-related transaction and integration costs — — — 3 3 Operating income (loss) 196 116 29 (13 ) 328 Equity in earnings of unconsolidated affiliates 14 17 — — 31 Other income, net 1 2 — — 3 Loss on debt extinguishment (7 ) (2 ) — — (9 ) Interest expense (48 ) (151 ) (7 ) (52 ) (258 ) Net Income (Loss) $ 156 $ (18 ) $ 22 $ (65 ) $ 95

Commitments and Contingencies48

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Text Block]	Commitments and Contingencies Operating Lease Commitments The Company leases certain facilities and equipment under operating leases, some of which include escalation clauses, expiring on various dates through 2048. The effects of these scheduled rent increases, leasehold incentives, and rent concessions are recognized on a straight-line basis over the lease term unless another systematic and rational allocation basis is more representative of the time pattern in which the leased property is physically employed. Lease expense under operating leases was $17 million , $15 million and $10 million for the years ended December 31, 2017 , 2016 and 2015 , respectively. The Company's future minimum lease commitments under operating leases are $9 million for each of the years ending December 31, 2018 through 2022, and $151 million thereafter. Period Gas and Transportation Commitments The Company has entered into contractual arrangements to procure power, fuel and associated transportation services. For the years ended December 31, 2017 , 2016 and 2015 , the Company purchased $34 million , $32 million and $40 million , respectively, under such arrangements. As further described in Note 13 Related Party Transactions , these purchases include intercompany transactions between certain Thermal entities and NRG Power Marketing under the Energy Marketing Services Agreements in the amount of $9 million for each of the years ended December 31, 2017 and 2016 . Total intercompany purchases of natural gas under the agreement were $13 million for the year ended December 31, 2015. As of December 31, 2017 , the Company's commitments under such outstanding agreements are estimated as follows: Period (In millions) 2018 $ 11 2019 5 2020 3 2021 3 2022 3 Thereafter 16 Total $ 41 Contingencies The Company's material legal proceedings are described below. The Company believes that it has valid defenses to these legal proceedings and intends to defend them vigorously. The Company records reserves for estimated losses from contingencies when information available indicates that a loss is probable and the amount of the loss, or range of loss, can be reasonably estimated. As applicable, the Company has established an adequate reserve for the matters discussed below. In addition, legal costs are expensed as incurred. Management assesses such matters based on current information and makes a judgment concerning its potential outcome, considering the nature of the claim, the amount and nature of damages sought and the probability of success. The Company is unable to predict the outcome of the legal proceedings below or reasonably estimate the scope or amount of any associated costs and potential liabilities. As additional information becomes available, management adjusts its assessment and estimates of such contingencies accordingly. Because litigation is subject to inherent uncertainties and unfavorable rulings or developments, it is possible that the ultimate resolution of the Company's liabilities and contingencies could be at amounts that are different from its currently recorded reserves and that such difference could be material. In addition to the legal proceedings noted below, the Company and its subsidiaries are party to other litigation or legal proceedings arising in the ordinary course of business. In management's opinion, the disposition of these ordinary course matters will not materially adversely affect the Company's consolidated financial position, results of operations, or cash flows. Braun v. NRG Yield, Inc. — On April 19, 2016, plaintiffs filed a putative class action lawsuit against NRG Yield, Inc., the current and former members of its board of directors individually, and other parties in California Superior Court in Kern County, CA. Plaintiffs allege various violations of the Securities Act due to the defendants’ alleged failure to disclose material facts related to low wind production prior to NRG Yield, Inc.'s June 22, 2015 Class C common stock offering. Plaintiffs seek compensatory damages, rescission, attorney’s fees and costs. The defendants filed objections and a motion challenging jurisdiction on October 18, 2016. On December 1, 2017, the parties agreed to a stipulation which provides the plaintiffs' opposition is due on March 6, 2018 and the defendants' reply is due on May 4, 2018. Ahmed v. NRG Energy, Inc. and the NRG Yield Board of Directors — On September 15, 2016, plaintiffs filed a putative class action lawsuit against NRG Energy, Inc., the directors of NRG Yield, Inc., and other parties in the Delaware Chancery Court. The complaint alleges that the defendants breached their respective fiduciary duties with regard to the recapitalization of NRG Yield, Inc. common stock in 2015. The plaintiffs generally seek economic damages, attorney’s fees and injunctive relief. The defendants filed a motion to dismiss the lawsuit on December 21, 2016. Plaintiffs filed their objection to the motion to dismiss on February 15, 2017. The defendants' reply was filed on March 24, 2017. The court heard oral argument on the defendants' motion to dismiss on June 20, 2017. On September 7, 2017, the court requested additional briefing which the parties provided on September 21, 2017. On December 11, 2017, the court dismissed the lawsuit with prejudice, thereby ending the case. GenOn Noteholders' Lawsuit — On December 13, 2016, certain indenture trustees for an ad hoc group of holders, or the Noteholders, of the GenOn Energy, Inc., or GenOn, 7.875% Senior Notes due 2017, 9.500% Notes due 2018, and 9.875% Notes due 2020, and the GenOn Americas Generation, LLC 8.50% Senior Notes due 2021 and 9.125% Senior Notes due 2031, along with certain of the Noteholders, filed a complaint in the Superior Court of the State of Delaware against NRG and GenOn alleging certain claims related to the Services Agreement between NRG and GenOn. On April 30, 2017, the Noteholders filed an amended complaint that asserts additional claims of fraudulent transfer, insider preference and breach of fiduciary duties. In addition to NRG and GenOn, the amended complaint names NRG Yield LLC and certain current and former officers and directors of GenOn as defendants. The plaintiffs, among other things, generally seek return of all monies paid under the Services Agreement and any other damages that the court deems appropriate. On April 28, 2017, the bondholders filed an amended complaint adding the GenOn directors and officers as defendants and asserting claims that they breached certain fiduciary duties. Plaintiffs specifically allege that the transfer of Marsh Landing to NRG Yield LLC constituted a fraudulent transfer. On June 12, 2017, certain GenOn entities, NRG and certain holders of the GenOn and GenOn Americas Generation, LLC senior notes entered into a restructuring support and lock-up agreement. On December 14, 2017, a settlement agreement was entered into between GenOn and NRG which should ultimately resolve this lawsuit.
Long-term Purchase Commitment [Table Text Block]	As of December 31, 2017 , the Company's commitments under such outstanding agreements are estimated as follows: Period (In millions) 2018 $ 11 2019 5 2020 3 2021 3 2022 3 Thereafter 16 Total $ 41
Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block]	The Company's future minimum lease commitments under operating leases are $9 million for each of the years ending December 31, 2018 through 2022, and $151 million thereafter. Period

Unaudited Quarterly Financial49

Unaudited Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information [Table Text Block]	Quarter Ended December 31, September 30, June 30, March 31, 2017 (In millions) Operating Revenues $ 231 $ 269 $ 288 $ 221 Operating Revenues (as previously reported) N/A 265 284 218 Change N/A 4 4 3 Operating Income 19 85 124 55 Operating Income (as previously reported) N/A 95 122 54 Change N/A (10 ) 2 1 Net (Loss) Income (38 ) 41 59 — Net Income (as previously reported) N/A 52 57 1 Change N/A $ (11 ) $ 2 $ (1 ) Quarter Ended December 31, September 30, June 30, March 31, 2016 (In millions) Operating Revenues $ 235 $ 276 $ 287 $ 237 Operating Revenues (as previously reported) 232 272 283 234 Change 3 4 4 3 Operating (Loss) Income (100 ) 120 130 74 Operating (Loss) Income (as previously reported) (99 ) 118 128 73 Change (1 ) 2 2 1 Net (Loss) Income (138 ) 68 80 5 Net (Loss) Income (as previously reported) (137 ) 67 79 6 Change $ (1 ) $ 1 $ 1 $ (1 )

Condensed Consolidating Finan50

Condensed Consolidating Financial Information CP Income Statement Condensed Income Statement (Tables)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Leases [Abstract]
Condensed Income Statement [Table Text Block]	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 988 $ 1 $ (1 ) $ 1,009 Operating Costs and Expenses — Cost of operations — 14 312 1 (1 ) 326 Depreciation and amortization — 5 329 — — 334 Impairment losses — — 44 — — 44 General and administrative — — — 19 — 19 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 19 685 23 (1 ) 726 Operating (Loss) Income — 2 303 (22 ) — 283 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 136 (16 ) — 126 (246 ) — Equity in earnings of unconsolidated affiliates — 22 21 28 — 71 Other income, net 1 — 3 — — 4 Loss on debt extinguishment — — (3 ) — — (3 ) Interest expense — — (222 ) (71 ) — (293 ) Total other income (expense), net 137 6 (201 ) 83 (246 ) (221 ) Net Income 137 8 102 61 (246 ) 62 Less: Net loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Net Income Attributable to NRG Yield LLC $ 137 $ 8 $ 107 $ 136 $ (251 ) $ 137 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 22 $ 1,013 $ 1 $ (1 ) $ 1,035 Operating Costs and Expenses Cost of operations — 14 294 1 (1 ) 308 Depreciation and amortization — 5 298 — — 303 Impairment losses — — 185 — — 185 General and administrative 2 — — 12 — 14 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses 2 19 777 14 (1 ) 811 Operating Income (Loss) (2 ) 3 236 (13 ) — 224 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 128 10 — 66 (204 ) — Equity in earnings of unconsolidated affiliates — 9 21 30 — 60 Other income, net — — 3 — — 3 Interest expense — — (206 ) (66 ) — (272 ) Total other income (expense) 128 19 (182 ) 30 (204 ) (209 ) Net Income 126 22 54 17 (204 ) 15 Less: Net loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Net Income Attributable to NRG Yield LLC $ 126 $ 22 $ 55 $ 128 $ (205 ) $ 126 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 937 $ 10 $ — $ 968 Operating Costs and Expenses Cost of operations — 14 309 — — 323 Depreciation and amortization — 4 299 — — 303 Impairment losses — — 1 — — 1 General and administrative — — — 10 — 10 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 18 609 13 — 640 Operating Income (Loss) — 3 328 (3 ) — 328 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 157 (43 ) — 125 (239 ) — Equity in (losses) earnings of unconsolidated affiliates — (2 ) 8 25 — 31 Other income, net — — 3 — — 3 Loss on debt extinguishment — — (9 ) — — (9 ) Interest expense — — (206 ) (52 ) — (258 ) Total other income (expense), net 157 (45 ) (204 ) 98 (239 ) (233 ) Net Income (Loss) 157 (42 ) 124 95 (239 ) 95 Less: Net loss attributable to noncontrolling interests — — (2 ) (62 ) 2 (62 ) Net Income (Loss) Attributable to NRG Yield LLC $ 157 $ (42 ) $ 126 $ 157 $ (241 ) $ 157 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan51

Condensed Consolidating Financial Information CP Comprehensive Income Condensed Consolidating CP Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Condensed Statement of Comprehensive Income [Table Text Block]	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the year ended December 31, 2017 NRG Yield LLC (a) Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 137 $ 8 $ 102 $ 61 $ (246 ) $ 62 Other Comprehensive Income Unrealized gain on derivatives 17 1 16 17 (34 ) 17 Other comprehensive income 17 1 16 17 (34 ) 17 Comprehensive Income 154 9 118 78 (280 ) 79 Less: Comprehensive loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Comprehensive Income Attributable to NRG Yield LLC $ 154 $ 9 $ 123 $ 153 $ (285 ) $ 154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income $ 126 $ 22 $ 54 $ 17 $ (204 ) $ 15 Other Comprehensive Income Unrealized gain on derivatives 13 1 10 13 (24 ) 13 Other comprehensive income 13 1 10 13 (24 ) 13 Comprehensive Income 139 23 64 30 (228 ) 28 Less: Comprehensive loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Comprehensive Income Attributable to NRG Yield LLC $ 139 $ 23 $ 65 $ 141 $ (229 ) $ 139 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income (Loss) $ 157 $ (42 ) $ 124 $ 95 $ (239 ) $ 95 Other Comprehensive Loss Unrealized loss on derivatives (16 ) — (16 ) (17 ) 32 (17 ) Other comprehensive loss (16 ) — (16 ) (17 ) 32 (17 ) Comprehensive Income (Loss) 141 (42 ) 108 78 (207 ) 78 Less: Comprehensive loss attributable to noncontrolling interests — — (2 ) (63 ) 2 (63 ) Comprehensive Income (Loss) Attributable to NRG Yield LLC $ 141 $ (42 ) $ 110 $ 141 $ (209 ) $ 141 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan52

Condensed Consolidating Financial Information CP Balance Sheet Condensed Consolidating CP Balance Sheet (Tables)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Condensed Financial Information [Abstract]
Condensed Balance Sheet [Table Text Block]	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 22 $ — $ 124 $ — $ — $ 146 Restricted cash — — 168 — — 168 Accounts receivable — trade 1 2 92 1 — 96 Inventory — 1 38 — — 39 Notes receivable — current — — 13 — — 13 Prepayments and other current assets — — 18 1 — 19 Total current assets 23 3 453 2 — 481 Property, plant and equipment, net — 58 5,146 — — 5,204 Other Assets Investment in consolidated subsidiaries 1,823 460 — 3,177 (5,460 ) — Equity investments in affiliates — 233 577 368 — 1,178 Intangible assets, net — 55 1,173 — — 1,228 Other non-current assets — — 63 — — 63 Total other assets 1,823 748 1,813 3,545 (5,460 ) 2,469 Total Assets $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 306 $ — $ — $ 306 Accounts payable — trade — 2 25 — — 27 Accounts payable — affiliate — 5 27 16 — 48 Derivative instruments — — 17 — — 17 Accrued expenses and other current liabilities — 1 61 25 — 87 Total current liabilities — 8 436 41 — 485 Other Liabilities Long-term debt — external — — 4,025 896 — 4,921 Long-term debt — affiliate — — — 618 — 618 Derivative instruments — — 31 — — 31 Other non-current liabilities — — 84 7 — 91 Total non-current liabilities — — 4,140 1,521 — 5,661 Total Liabilities — 8 4,576 1,562 — 6,146 Commitments and Contingencies Members' Equity Contributed capital 1,897 863 2,871 2,097 (5,831 ) 1,897 Retained earnings (accumulated deficit) 17 (61 ) (21 ) (206 ) 288 17 Accumulated other comprehensive loss (68 ) (1 ) (71 ) (68 ) 140 (68 ) Noncontrolling interest — — 57 162 (57 ) 162 Total Members' Equity 1,846 801 2,836 1,985 (5,460 ) 2,008 Total Liabilities and Members’ Equity $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2016 NRG Yield LLC (a)(c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b)(c) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 211 $ — $ 110 $ — $ — $ 321 Restricted cash — — 176 — — 176 Accounts receivable — trade — 2 94 — — 96 Inventory — 2 37 — — 39 Notes receivable — current — — 16 — — 16 Prepayments and other current assets — — 21 1 — 22 Total current assets 211 4 454 1 — 670 Property, plant and equipment, net — 59 5,495 — — 5,554 Other Assets Investment in consolidated subsidiaries 1,927 527 — 3,272 (5,726 ) — Equity investments in affiliates — 171 600 381 — 1,152 Intangible assets, net — 56 1,247 — — 1,303 Other non-current assets — — 66 1 — 67 Total other assets 1,927 754 1,913 3,654 (5,726 ) 2,522 Total Assets $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b) (c) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 323 $ — $ — $ 323 Accounts payable — trade — 2 18 3 — 23 Accounts payable — affiliate — 7 15 18 — 40 Derivative instruments — — 33 — — 33 Accrued expenses and other current liabilities — 1 60 24 — 85 Total current liabilities — 10 449 45 — 504 Other Liabilities Long-term debt — external — — 4,289 839 — 5,128 Long-term debt — affiliate — — — 618 — 618 Accounts payable — affiliate — — 9 — — 9 Derivative instruments — — 46 — — 46 Other non-current liabilities — — 77 — — 77 Total non-current liabilities — — 4,421 1,457 — 5,878 Total Liabilities — 10 4,870 1,502 — 6,382 Commitments and Contingencies Members' Equity Contributed capital 2,179 874 2,972 2,155 (6,001 ) 2,179 Retained earnings (accumulated deficit) 44 (65 ) 43 (143 ) 165 44 Accumulated other comprehensive loss (85 ) (2 ) (87 ) (85 ) 174 (85 ) Noncontrolling interest — — 64 226 (64 ) 226 Total Members' Equity 2,138 807 2,992 2,153 (5,726 ) 2,364 Total Liabilities and Members’ Equity $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan53

Condensed Consolidating Financial Information CP Cash Flows Condensed Consolidating CP Cash Flows (Tables)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Information [Abstract]
Condensed Cash Flow Statement [Table Text Block]	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 58 $ 529 $ (71 ) $ 516 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (15 ) — — 15 — Acquisition of Drop Down Assets, net of cash acquired — — — (250 ) (250 ) Capital expenditures — (4 ) (27 ) — (31 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 10 14 23 47 Investments in unconsolidated affiliates — (64 ) (7 ) (2 ) (73 ) Other — — 7 — 7 Net Cash Provided by (Used in) Investing Activities (15 ) (58 ) 4 (214 ) (283 ) Cash Flows from Financing Activities Net contributions from noncontrolling interests — — 2 11 13 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (13 ) (7 ) (20 ) Transfer of funds under intercompany cash management arrangement (5 ) — (1 ) 6 — Proceeds from the issuance of Class C units 33 — — — 33 (Payments of) proceeds from distributions (202 ) — (220 ) 220 (202 ) Proceeds from the revolving credit facility — — — 55 55 Proceeds from issuance of long-term debt — — 41 — 41 Payments of debt issuance costs — — (4 ) — (4 ) Payments for long-term debt — external — — (332 ) — (332 ) Net Cash (Used in) Provided by Financing Activities (174 ) — (527 ) 285 (416 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (189 ) — 6 — (183 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 211 — 286 — 497 Cash, Cash Equivalents and Restricted Cash at End of Period $ 22 $ — $ 292 $ — $ 314 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2016 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated Net Cash Provided by (Used in) Operating Activities $ — $ 62 $ 554 $ (39 ) $ 577 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 325 — (21 ) (304 ) — Acquisition of Drop Down Assets — — — (77 ) (77 ) Capital expenditures — — (20 ) — (20 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 16 — 12 28 Investments in unconsolidated affiliates — (80 ) (3 ) — (83 ) Other — — 4 — 4 Net Cash Used in Investing Activities 325 (64 ) (23 ) (369 ) (131 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement 44 2 — (46 ) — Net contributions from noncontrolling interests — — — 5 5 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (174 ) (10 ) (184 ) (Payments of) proceeds from distributions (173 ) — (420 ) 420 (173 ) Proceeds from the revolving credit facility — — — 60 60 Payments for the revolving credit facility — — — (366 ) (366 ) Proceeds from the issuance of long-term debt - external — — 390 350 740 Payments of debt issuance costs — — (10 ) (5 ) (15 ) Payments for long-term debt — external — — (269 ) — (269 ) Net Cash Provided by (Used in) Financing Activities (129 ) 2 (483 ) 408 (202 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash 196 — 48 — 244 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 15 — 238 — 253 Cash, Cash Equivalents and Restricted Cash at End of Period $ 211 $ — $ 286 $ — $ 497 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2015 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 19 $ 423 $ (18 ) $ 424 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (464 ) — 285 179 — Acquisition of businesses, net of cash acquired — — — (37 ) (37 ) Acquisition of Drop Down Assets, net of cash acquired — — — (698 ) (698 ) Capital expenditures — — (29 ) — (29 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — — — 42 42 Investments in unconsolidated affiliates — (28 ) — — (374 ) (402 ) Other — — 9 — 9 Net Cash (Used in) Provided by Investing Activities (464 ) (28 ) 282 (888 ) (1,098 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (309 ) 9 — 300 — Net contributions from noncontrolling interests — — — 122 122 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (79 ) — (79 ) Proceeds from the issuance of Class C units 599 — — — 599 (Payments of) proceeds from distributions (139 ) — (392 ) 392 (139 ) Proceeds from the revolving credit facility — — — 551 551 Payments for the revolving credit facility — — — (245 ) (245 ) Proceeds from issuance of long-term debt — external — — 6 — 6 Proceeds from issuance of long-term debt — affiliate — — — 281 281 Payments for long-term debt — external — — (241 ) (494 ) (735 ) Payment of debt issuance costs — — (6 ) (1 ) (7 ) Net Cash Provided by (Used in) Financing Activities 151 9 (712 ) 906 354 Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (313 ) — (7 ) — (320 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 328 — 245 — 573 Cash, Cash Equivalents and Restricted Cash at End of Period $ 15 $ — $ 238 $ — $ 253 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan54

Condensed Consolidating Financial Information PP Income Statement Condensed Consolidating PP Income Statement (Tables)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Statements, Captions [Line Items]
Condensed Income Statement [Table Text Block]	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 988 $ 1 $ (1 ) $ 1,009 Operating Costs and Expenses — Cost of operations — 14 312 1 (1 ) 326 Depreciation and amortization — 5 329 — — 334 Impairment losses — — 44 — — 44 General and administrative — — — 19 — 19 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 19 685 23 (1 ) 726 Operating (Loss) Income — 2 303 (22 ) — 283 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 136 (16 ) — 126 (246 ) — Equity in earnings of unconsolidated affiliates — 22 21 28 — 71 Other income, net 1 — 3 — — 4 Loss on debt extinguishment — — (3 ) — — (3 ) Interest expense — — (222 ) (71 ) — (293 ) Total other income (expense), net 137 6 (201 ) 83 (246 ) (221 ) Net Income 137 8 102 61 (246 ) 62 Less: Net loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Net Income Attributable to NRG Yield LLC $ 137 $ 8 $ 107 $ 136 $ (251 ) $ 137 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 22 $ 1,013 $ 1 $ (1 ) $ 1,035 Operating Costs and Expenses Cost of operations — 14 294 1 (1 ) 308 Depreciation and amortization — 5 298 — — 303 Impairment losses — — 185 — — 185 General and administrative 2 — — 12 — 14 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses 2 19 777 14 (1 ) 811 Operating Income (Loss) (2 ) 3 236 (13 ) — 224 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 128 10 — 66 (204 ) — Equity in earnings of unconsolidated affiliates — 9 21 30 — 60 Other income, net — — 3 — — 3 Interest expense — — (206 ) (66 ) — (272 ) Total other income (expense) 128 19 (182 ) 30 (204 ) (209 ) Net Income 126 22 54 17 (204 ) 15 Less: Net loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Net Income Attributable to NRG Yield LLC $ 126 $ 22 $ 55 $ 128 $ (205 ) $ 126 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 937 $ 10 $ — $ 968 Operating Costs and Expenses Cost of operations — 14 309 — — 323 Depreciation and amortization — 4 299 — — 303 Impairment losses — — 1 — — 1 General and administrative — — — 10 — 10 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 18 609 13 — 640 Operating Income (Loss) — 3 328 (3 ) — 328 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 157 (43 ) — 125 (239 ) — Equity in (losses) earnings of unconsolidated affiliates — (2 ) 8 25 — 31 Other income, net — — 3 — — 3 Loss on debt extinguishment — — (9 ) — — (9 ) Interest expense — — (206 ) (52 ) — (258 ) Total other income (expense), net 157 (45 ) (204 ) 98 (239 ) (233 ) Net Income (Loss) 157 (42 ) 124 95 (239 ) 95 Less: Net loss attributable to noncontrolling interests — — (2 ) (62 ) 2 (62 ) Net Income (Loss) Attributable to NRG Yield LLC $ 157 $ (42 ) $ 126 $ 157 $ (241 ) $ 157 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan55

Condensed Consolidating Financial Information PP Comprehensive Income Condensed Consolidating PP Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Information [Abstract]
Condensed Statement of Comprehensive Income [Table Text Block]	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the year ended December 31, 2017 NRG Yield LLC (a) Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 137 $ 8 $ 102 $ 61 $ (246 ) $ 62 Other Comprehensive Income Unrealized gain on derivatives 17 1 16 17 (34 ) 17 Other comprehensive income 17 1 16 17 (34 ) 17 Comprehensive Income 154 9 118 78 (280 ) 79 Less: Comprehensive loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Comprehensive Income Attributable to NRG Yield LLC $ 154 $ 9 $ 123 $ 153 $ (285 ) $ 154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income $ 126 $ 22 $ 54 $ 17 $ (204 ) $ 15 Other Comprehensive Income Unrealized gain on derivatives 13 1 10 13 (24 ) 13 Other comprehensive income 13 1 10 13 (24 ) 13 Comprehensive Income 139 23 64 30 (228 ) 28 Less: Comprehensive loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Comprehensive Income Attributable to NRG Yield LLC $ 139 $ 23 $ 65 $ 141 $ (229 ) $ 139 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income (Loss) $ 157 $ (42 ) $ 124 $ 95 $ (239 ) $ 95 Other Comprehensive Loss Unrealized loss on derivatives (16 ) — (16 ) (17 ) 32 (17 ) Other comprehensive loss (16 ) — (16 ) (17 ) 32 (17 ) Comprehensive Income (Loss) 141 (42 ) 108 78 (207 ) 78 Less: Comprehensive loss attributable to noncontrolling interests — — (2 ) (63 ) 2 (63 ) Comprehensive Income (Loss) Attributable to NRG Yield LLC $ 141 $ (42 ) $ 110 $ 141 $ (209 ) $ 141 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan56

Condensed Consolidating Financial Information PP Balance Sheet Condensed Consolidating PP Balance Sheet (Tables)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Condensed Financial Information [Abstract]
Condensed Balance Sheet [Table Text Block]	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 22 $ — $ 124 $ — $ — $ 146 Restricted cash — — 168 — — 168 Accounts receivable — trade 1 2 92 1 — 96 Inventory — 1 38 — — 39 Notes receivable — current — — 13 — — 13 Prepayments and other current assets — — 18 1 — 19 Total current assets 23 3 453 2 — 481 Property, plant and equipment, net — 58 5,146 — — 5,204 Other Assets Investment in consolidated subsidiaries 1,823 460 — 3,177 (5,460 ) — Equity investments in affiliates — 233 577 368 — 1,178 Intangible assets, net — 55 1,173 — — 1,228 Other non-current assets — — 63 — — 63 Total other assets 1,823 748 1,813 3,545 (5,460 ) 2,469 Total Assets $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC Eliminations (b) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 306 $ — $ — $ 306 Accounts payable — trade — 2 25 — — 27 Accounts payable — affiliate — 5 27 16 — 48 Derivative instruments — — 17 — — 17 Accrued expenses and other current liabilities — 1 61 25 — 87 Total current liabilities — 8 436 41 — 485 Other Liabilities Long-term debt — external — — 4,025 896 — 4,921 Long-term debt — affiliate — — — 618 — 618 Derivative instruments — — 31 — — 31 Other non-current liabilities — — 84 7 — 91 Total non-current liabilities — — 4,140 1,521 — 5,661 Total Liabilities — 8 4,576 1,562 — 6,146 Commitments and Contingencies Members' Equity Contributed capital 1,897 863 2,871 2,097 (5,831 ) 1,897 Retained earnings (accumulated deficit) 17 (61 ) (21 ) (206 ) 288 17 Accumulated other comprehensive loss (68 ) (1 ) (71 ) (68 ) 140 (68 ) Noncontrolling interest — — 57 162 (57 ) 162 Total Members' Equity 1,846 801 2,836 1,985 (5,460 ) 2,008 Total Liabilities and Members’ Equity $ 1,846 $ 809 $ 7,412 $ 3,547 $ (5,460 ) $ 8,154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2016 NRG Yield LLC (a)(c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b)(c) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 211 $ — $ 110 $ — $ — $ 321 Restricted cash — — 176 — — 176 Accounts receivable — trade — 2 94 — — 96 Inventory — 2 37 — — 39 Notes receivable — current — — 16 — — 16 Prepayments and other current assets — — 21 1 — 22 Total current assets 211 4 454 1 — 670 Property, plant and equipment, net — 59 5,495 — — 5,554 Other Assets Investment in consolidated subsidiaries 1,927 527 — 3,272 (5,726 ) — Equity investments in affiliates — 171 600 381 — 1,152 Intangible assets, net — 56 1,247 — — 1,303 Other non-current assets — — 66 1 — 67 Total other assets 1,927 754 1,913 3,654 (5,726 ) 2,522 Total Assets $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business . NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (c) Eliminations (b) (c) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 323 $ — $ — $ 323 Accounts payable — trade — 2 18 3 — 23 Accounts payable — affiliate — 7 15 18 — 40 Derivative instruments — — 33 — — 33 Accrued expenses and other current liabilities — 1 60 24 — 85 Total current liabilities — 10 449 45 — 504 Other Liabilities Long-term debt — external — — 4,289 839 — 5,128 Long-term debt — affiliate — — — 618 — 618 Accounts payable — affiliate — — 9 — — 9 Derivative instruments — — 46 — — 46 Other non-current liabilities — — 77 — — 77 Total non-current liabilities — — 4,421 1,457 — 5,878 Total Liabilities — 10 4,870 1,502 — 6,382 Commitments and Contingencies Members' Equity Contributed capital 2,179 874 2,972 2,155 (6,001 ) 2,179 Retained earnings (accumulated deficit) 44 (65 ) 43 (143 ) 165 44 Accumulated other comprehensive loss (85 ) (2 ) (87 ) (85 ) 174 (85 ) Noncontrolling interest — — 64 226 (64 ) 226 Total Members' Equity 2,138 807 2,992 2,153 (5,726 ) 2,364 Total Liabilities and Members’ Equity $ 2,138 $ 817 $ 7,862 $ 3,655 $ (5,726 ) $ 8,746 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan57

Condensed Consolidating Financial Information PP Cash Flows Condensed Consolidating PP Cash Flows (Tables)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Financial Information [Abstract]
Condensed Cash Flow Statement [Table Text Block]	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 58 $ 529 $ (71 ) $ 516 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (15 ) — — 15 — Acquisition of Drop Down Assets, net of cash acquired — — — (250 ) (250 ) Capital expenditures — (4 ) (27 ) — (31 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 10 14 23 47 Investments in unconsolidated affiliates — (64 ) (7 ) (2 ) (73 ) Other — — 7 — 7 Net Cash Provided by (Used in) Investing Activities (15 ) (58 ) 4 (214 ) (283 ) Cash Flows from Financing Activities Net contributions from noncontrolling interests — — 2 11 13 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (13 ) (7 ) (20 ) Transfer of funds under intercompany cash management arrangement (5 ) — (1 ) 6 — Proceeds from the issuance of Class C units 33 — — — 33 (Payments of) proceeds from distributions (202 ) — (220 ) 220 (202 ) Proceeds from the revolving credit facility — — — 55 55 Proceeds from issuance of long-term debt — — 41 — 41 Payments of debt issuance costs — — (4 ) — (4 ) Payments for long-term debt — external — — (332 ) — (332 ) Net Cash (Used in) Provided by Financing Activities (174 ) — (527 ) 285 (416 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (189 ) — 6 — (183 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 211 — 286 — 497 Cash, Cash Equivalents and Restricted Cash at End of Period $ 22 $ — $ 292 $ — $ 314 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2016 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated Net Cash Provided by (Used in) Operating Activities $ — $ 62 $ 554 $ (39 ) $ 577 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 325 — (21 ) (304 ) — Acquisition of Drop Down Assets — — — (77 ) (77 ) Capital expenditures — — (20 ) — (20 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 16 — 12 28 Investments in unconsolidated affiliates — (80 ) (3 ) — (83 ) Other — — 4 — 4 Net Cash Used in Investing Activities 325 (64 ) (23 ) (369 ) (131 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement 44 2 — (46 ) — Net contributions from noncontrolling interests — — — 5 5 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (174 ) (10 ) (184 ) (Payments of) proceeds from distributions (173 ) — (420 ) 420 (173 ) Proceeds from the revolving credit facility — — — 60 60 Payments for the revolving credit facility — — — (366 ) (366 ) Proceeds from the issuance of long-term debt - external — — 390 350 740 Payments of debt issuance costs — — (10 ) (5 ) (15 ) Payments for long-term debt — external — — (269 ) — (269 ) Net Cash Provided by (Used in) Financing Activities (129 ) 2 (483 ) 408 (202 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash 196 — 48 — 244 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 15 — 238 — 253 Cash, Cash Equivalents and Restricted Cash at End of Period $ 211 $ — $ 286 $ — $ 497 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2015 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 19 $ 423 $ (18 ) $ 424 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (464 ) — 285 179 — Acquisition of businesses, net of cash acquired — — — (37 ) (37 ) Acquisition of Drop Down Assets, net of cash acquired — — — (698 ) (698 ) Capital expenditures — — (29 ) — (29 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — — — 42 42 Investments in unconsolidated affiliates — (28 ) — — (374 ) (402 ) Other — — 9 — 9 Net Cash (Used in) Provided by Investing Activities (464 ) (28 ) 282 (888 ) (1,098 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (309 ) 9 — 300 — Net contributions from noncontrolling interests — — — 122 122 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (79 ) — (79 ) Proceeds from the issuance of Class C units 599 — — — 599 (Payments of) proceeds from distributions (139 ) — (392 ) 392 (139 ) Proceeds from the revolving credit facility — — — 551 551 Payments for the revolving credit facility — — — (245 ) (245 ) Proceeds from issuance of long-term debt — external — — 6 — 6 Proceeds from issuance of long-term debt — affiliate — — — 281 281 Payments for long-term debt — external — — (241 ) (494 ) (735 ) Payment of debt issuance costs — — (6 ) (1 ) (7 ) Net Cash Provided by (Used in) Financing Activities 151 9 (712 ) 906 354 Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (313 ) — (7 ) — (320 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 328 — 245 — 573 Cash, Cash Equivalents and Restricted Cash at End of Period $ 15 $ — $ 238 $ — $ 253 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan58

Condensed Consolidating Financial Information PP2 Income Statement (Tables)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Condensed Income Statement [Table Text Block]	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 988 $ 1 $ (1 ) $ 1,009 Operating Costs and Expenses — Cost of operations — 14 312 1 (1 ) 326 Depreciation and amortization — 5 329 — — 334 Impairment losses — — 44 — — 44 General and administrative — — — 19 — 19 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 19 685 23 (1 ) 726 Operating (Loss) Income — 2 303 (22 ) — 283 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 136 (16 ) — 126 (246 ) — Equity in earnings of unconsolidated affiliates — 22 21 28 — 71 Other income, net 1 — 3 — — 4 Loss on debt extinguishment — — (3 ) — — (3 ) Interest expense — — (222 ) (71 ) — (293 ) Total other income (expense), net 137 6 (201 ) 83 (246 ) (221 ) Net Income 137 8 102 61 (246 ) 62 Less: Net loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Net Income Attributable to NRG Yield LLC $ 137 $ 8 $ 107 $ 136 $ (251 ) $ 137 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 22 $ 1,013 $ 1 $ (1 ) $ 1,035 Operating Costs and Expenses Cost of operations — 14 294 1 (1 ) 308 Depreciation and amortization — 5 298 — — 303 Impairment losses — — 185 — — 185 General and administrative 2 — — 12 — 14 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses 2 19 777 14 (1 ) 811 Operating Income (Loss) (2 ) 3 236 (13 ) — 224 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 128 10 — 66 (204 ) — Equity in earnings of unconsolidated affiliates — 9 21 30 — 60 Other income, net — — 3 — — 3 Interest expense — — (206 ) (66 ) — (272 ) Total other income (expense) 128 19 (182 ) 30 (204 ) (209 ) Net Income 126 22 54 17 (204 ) 15 Less: Net loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Net Income Attributable to NRG Yield LLC $ 126 $ 22 $ 55 $ 128 $ (205 ) $ 126 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 21 $ 937 $ 10 $ — $ 968 Operating Costs and Expenses Cost of operations — 14 309 — — 323 Depreciation and amortization — 4 299 — — 303 Impairment losses — — 1 — — 1 General and administrative — — — 10 — 10 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 18 609 13 — 640 Operating Income (Loss) — 3 328 (3 ) — 328 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 157 (43 ) — 125 (239 ) — Equity in (losses) earnings of unconsolidated affiliates — (2 ) 8 25 — 31 Other income, net — — 3 — — 3 Loss on debt extinguishment — — (9 ) — — (9 ) Interest expense — — (206 ) (52 ) — (258 ) Total other income (expense), net 157 (45 ) (204 ) 98 (239 ) (233 ) Net Income (Loss) 157 (42 ) 124 95 (239 ) 95 Less: Net loss attributable to noncontrolling interests — — (2 ) (62 ) 2 (62 ) Net Income (Loss) Attributable to NRG Yield LLC $ 157 $ (42 ) $ 126 $ 157 $ (241 ) $ 157 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan59

Condensed Consolidating Financial Information PP2 Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Condensed Statement of Comprehensive Income [Table Text Block]	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the year ended December 31, 2017 NRG Yield LLC (a) Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 137 $ 8 $ 102 $ 61 $ (246 ) $ 62 Other Comprehensive Income Unrealized gain on derivatives 17 1 16 17 (34 ) 17 Other comprehensive income 17 1 16 17 (34 ) 17 Comprehensive Income 154 9 118 78 (280 ) 79 Less: Comprehensive loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Comprehensive Income Attributable to NRG Yield LLC $ 154 $ 9 $ 123 $ 153 $ (285 ) $ 154 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2016 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income $ 126 $ 22 $ 54 $ 17 $ (204 ) $ 15 Other Comprehensive Income Unrealized gain on derivatives 13 1 10 13 (24 ) 13 Other comprehensive income 13 1 10 13 (24 ) 13 Comprehensive Income 139 23 64 30 (228 ) 28 Less: Comprehensive loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Comprehensive Income Attributable to NRG Yield LLC $ 139 $ 23 $ 65 $ 141 $ (229 ) $ 139 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2015 NRG Yield LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) NRG Yield Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income (Loss) $ 157 $ (42 ) $ 124 $ 95 $ (239 ) $ 95 Other Comprehensive Loss Unrealized loss on derivatives (16 ) — (16 ) (17 ) 32 (17 ) Other comprehensive loss (16 ) — (16 ) (17 ) 32 (17 ) Comprehensive Income (Loss) 141 (42 ) 108 78 (207 ) 78 Less: Comprehensive loss attributable to noncontrolling interests — — (2 ) (63 ) 2 (63 ) Comprehensive Income (Loss) Attributable to NRG Yield LLC $ 141 $ (42 ) $ 110 $ 141 $ (209 ) $ 141 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) All significant intercompany transactions have been eliminated in consolidation. (c) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Condensed Consolidating Finan60

Condensed Consolidating Financial Information PP2 Cash Flows (Tables)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Cash Flows [Abstract]
Condensed Cash Flow Statement [Table Text Block]	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the year ended December 31, 2017 NRG Yield LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries NRG Yield Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 58 $ 529 $ (71 ) $ 516 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (15 ) — — 15 — Acquisition of Drop Down Assets, net of cash acquired — — — (250 ) (250 ) Capital expenditures — (4 ) (27 ) — (31 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 10 14 23 47 Investments in unconsolidated affiliates — (64 ) (7 ) (2 ) (73 ) Other — — 7 — 7 Net Cash Provided by (Used in) Investing Activities (15 ) (58 ) 4 (214 ) (283 ) Cash Flows from Financing Activities Net contributions from noncontrolling interests — — 2 11 13 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (13 ) (7 ) (20 ) Transfer of funds under intercompany cash management arrangement (5 ) — (1 ) 6 — Proceeds from the issuance of Class C units 33 — — — 33 (Payments of) proceeds from distributions (202 ) — (220 ) 220 (202 ) Proceeds from the revolving credit facility — — — 55 55 Proceeds from issuance of long-term debt — — 41 — 41 Payments of debt issuance costs — — (4 ) — (4 ) Payments for long-term debt — external — — (332 ) — (332 ) Net Cash (Used in) Provided by Financing Activities (174 ) — (527 ) 285 (416 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (189 ) — 6 — (183 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 211 — 286 — 497 Cash, Cash Equivalents and Restricted Cash at End of Period $ 22 $ — $ 292 $ — $ 314 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2016 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated Net Cash Provided by (Used in) Operating Activities $ — $ 62 $ 554 $ (39 ) $ 577 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 325 — (21 ) (304 ) — Acquisition of Drop Down Assets — — — (77 ) (77 ) Capital expenditures — — (20 ) — (20 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — 16 — 12 28 Investments in unconsolidated affiliates — (80 ) (3 ) — (83 ) Other — — 4 — 4 Net Cash Used in Investing Activities 325 (64 ) (23 ) (369 ) (131 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement 44 2 — (46 ) — Net contributions from noncontrolling interests — — — 5 5 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (174 ) (10 ) (184 ) (Payments of) proceeds from distributions (173 ) — (420 ) 420 (173 ) Proceeds from the revolving credit facility — — — 60 60 Payments for the revolving credit facility — — — (366 ) (366 ) Proceeds from the issuance of long-term debt - external — — 390 350 740 Payments of debt issuance costs — — (10 ) (5 ) (15 ) Payments for long-term debt — external — — (269 ) — (269 ) Net Cash Provided by (Used in) Financing Activities (129 ) 2 (483 ) 408 (202 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash 196 — 48 — 244 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 15 — 238 — 253 Cash, Cash Equivalents and Restricted Cash at End of Period $ 211 $ — $ 286 $ — $ 497 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .	NRG YIELD LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2015 NRG Yield LLC (a) (b) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) NRG Yield Operating LLC (Note Issuer) (b) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 19 $ 423 $ (18 ) $ 424 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (464 ) — 285 179 — Acquisition of businesses, net of cash acquired — — — (37 ) (37 ) Acquisition of Drop Down Assets, net of cash acquired — — — (698 ) (698 ) Capital expenditures — — (29 ) — (29 ) Cash receipts from notes receivable — — 17 — 17 Return of investment from unconsolidated affiliates — — — 42 42 Investments in unconsolidated affiliates — (28 ) — — (374 ) (402 ) Other — — 9 — 9 Net Cash (Used in) Provided by Investing Activities (464 ) (28 ) 282 (888 ) (1,098 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (309 ) 9 — 300 — Net contributions from noncontrolling interests — — — 122 122 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — — (79 ) — (79 ) Proceeds from the issuance of Class C units 599 — — — 599 (Payments of) proceeds from distributions (139 ) — (392 ) 392 (139 ) Proceeds from the revolving credit facility — — — 551 551 Payments for the revolving credit facility — — — (245 ) (245 ) Proceeds from issuance of long-term debt — external — — 6 — 6 Proceeds from issuance of long-term debt — affiliate — — — 281 281 Payments for long-term debt — external — — (241 ) (494 ) (735 ) Payment of debt issuance costs — — (6 ) (1 ) (7 ) Net Cash Provided by (Used in) Financing Activities 151 9 (712 ) 906 354 Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (313 ) — (7 ) — (320 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 328 — 245 — 573 Cash, Cash Equivalents and Restricted Cash at End of Period $ 15 $ — $ 238 $ — $ 253 (a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .

Nature of Business (Details)

Nature of Business (Details) - MW		12 Months Ended
		Dec. 31, 2017	Aug. 31, 2016	Nov. 02, 2015
Nature of Business
Power Generation Capacity, Megawatts	[1],[2]	5,241
Megawatts Thermal Equivalent, Available Under right-to-use Provisions		134
Power Generation Capacity, Megawatts, including portion attributable to noncontrolling interest		5,247
Distributed Solar
Nature of Business
Power Generation Capacity, Megawatts	[1]	52
Wind Farms [Member]
Nature of Business
Power Generation Capacity, Megawatts	[1]	2,200
Thermal [Member]
Nature of Business
Percentage of Ownership	[3]	100.00%
Power Generation Capacity, Megawatts	[1]	123
Steam and Chilled Water Capacity, Megawatts Thermal Equivalent	[1],[3]	1,319
NRG Energy Center Dover [Member]
Nature of Business
Percentage of Ownership		100.00%
Conventional Generation [Member]
Nature of Business
Power Generation Capacity, Megawatts	[1]	1,945
Utility-Scale Solar
Nature of Business
Power Generation Capacity, Megawatts	[1]	921
Spring Canyon [Member] | Wind Farms [Member]
Nature of Business
Power Generation Capacity, Megawatts attributed to noncontrolling interest		6
Thermal [Member] | Thermal [Member]
Nature of Business
Power Generation Capacity, Megawatts	[1]	20
NRG Yield LLC | NRG Yield, Inc. [Member]
Nature of Business
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest		44.90%
NRG Yield LLC | NRG
Nature of Business
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Voting Interest		55.10%
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest		55.10%
GenConn Middletown [Member] | Conventional Generation [Member]
Nature of Business
Equity Method Investment, Ownership Percentage		50.00%
Power Generation Capacity, Megawatts	[1]	95
GenConn Devon [Member] | Conventional Generation [Member]
Nature of Business
Equity Method Investment, Ownership Percentage		50.00%
Power Generation Capacity, Megawatts	[1]	95
Marsh Landing | Conventional Generation [Member]
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	720
El Segundo [Member] | Conventional Generation [Member]
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	550
Walnut Creek [Member] | Conventional Generation [Member]
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts		485
Agua Caliente [Member] | Utility-Scale Solar
Nature of Business
Percentage of Ownership		16.00%
Power Generation Capacity, Megawatts	[1]	46
Alpine [Member] | Utility-Scale Solar
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	66
Avenal [Member] | Utility-Scale Solar
Nature of Business
Equity Method Investment, Ownership Percentage		50.00%
Power Generation Capacity, Megawatts	[1]	23
Avra Valley [Member] | Utility-Scale Solar
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	26
NRG Solar Blythe LLC [Member] | Utility-Scale Solar
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	21
Borrego [Member] | Utility-Scale Solar
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	26
NRG Solar Roadrunner LLC [Member] | Utility-Scale Solar
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	20
CVSR [Member] | Utility-Scale Solar
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	250
RE Kansas South [Member] | Utility-Scale Solar
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	20
TA - High Desert LLC [Member] | Utility-Scale Solar
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	20
Utah Portfolio [Member] | Utility-Scale Solar
Nature of Business
Percentage of Ownership	[4],[5]	50.00%
Power Generation Capacity, Megawatts	[1],[4],[5]	265
Desert Sunlight [Member] | Utility-Scale Solar
Nature of Business
Percentage of Ownership		25.00%
AZ DG Solar Projects | Distributed Solar
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	9
PFMG DG Solar Projects | Distributed Solar
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	5
Alta I [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	150
Alta II [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	150
Alta III [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	150
Alta IV [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	102
Alta V [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	168
Alta X [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership	[4]	100.00%
Power Generation Capacity, Megawatts	[1],[4]	137
Alta XI [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership	[4]	100.00%
Power Generation Capacity, Megawatts	[1],[4]	90
South Trent | Wind Farms [Member]
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	101
Spanish Fork [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership	[4],[6]	100.00%
Power Generation Capacity, Megawatts	[1],[4],[6]	19
Laredo Ridge [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	80
Lookout [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership	[4],[6]	100.00%
Power Generation Capacity, Megawatts	[1],[4],[6]	38
Odin Wind Farm [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership	[4],[6]	99.90%
Power Generation Capacity, Megawatts	[1],[4],[6]	20
Taloga [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts		130
Pinnacle [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	55
San Juan Mesa Wind Project, LLC [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership	[4],[6]	75.00%
Power Generation Capacity, Megawatts	[1],[4],[6]	90
Sleeping Bear [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership	[4],[6]	100.00%
Power Generation Capacity, Megawatts	[1],[4],[6]	95
Buffalo Bear [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	19
Crosswinds [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership	[4],[6]	99.00%
Power Generation Capacity, Megawatts	[1],[4],[6]	21
Forward [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership	[4],[6]	100.00%
Power Generation Capacity, Megawatts	[1],[4],[6]	29
Goat Wind [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership	[4],[6]	100.00%
Power Generation Capacity, Megawatts	[1],[4],[6]	150
Elbow Creek [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership	[4],[6]	100.00%
Power Generation Capacity, Megawatts	[1],[4],[6]	122
Elkhorn Ridge Wind, LLC [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership	[4],[6]	66.70%
Power Generation Capacity, Megawatts	[1],[4],[6]	54
Hardin [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership	[4],[6]	99.00%
Power Generation Capacity, Megawatts	[1],[4],[6]	15
Spring Canyon II [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership	[4]	90.10%
Power Generation Capacity, Megawatts	[1],[4]	29
Spring Canyon III [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership	[4]	90.10%
Power Generation Capacity, Megawatts	[1],[4]	25
Wildorado [Member] | Wind Farms [Member]
Nature of Business
Percentage of Ownership	[4],[6]	100.00%
Power Generation Capacity, Megawatts	[1],[4],[6]	161
NRG Energy Center Dover [Member] | Thermal [Member]
Nature of Business
Power Generation Capacity, Megawatts	[1]	103
SPP Projects [Member] | Distributed Solar
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	25
Other DG Assets [Member] | Distributed Solar
Nature of Business
Percentage of Ownership		100.00%
Power Generation Capacity, Megawatts	[1]	13
CVSR [Member]
Nature of Business
Equity Method Investment, Ownership Percentage			48.95%
November 2015 Drop Down Assets [Member] | Wind Farms [Member]
Nature of Business
Power Generation Capacity, Megawatts				814
Pacific Gas and Electric [Member] | Desert Sunlight [Member] | Utility-Scale Solar
Nature of Business
Power Generation Capacity, Megawatts	[1]	75
Southern California Edison [Member] | Desert Sunlight [Member] | Utility-Scale Solar
Nature of Business
Power Generation Capacity, Megawatts	[1]	63
Common Class B [Member] | NRG Yield LLC
Nature of Business
Sale of Stock, Percentage of Ownership after Transaction		100.00%
Common Class A [Member] | NRG Yield LLC
Nature of Business
Sale of Stock, Percentage of Ownership after Transaction		100.00%
Unconsolidated Solar Partnerships [Member]
Nature of Business
Power Generation Capacity, Megawatts		247
[1]	(a) Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of December 31, 2017
[2]	(c) The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247.
[3]	(d)For thermal energy, net capacity represents MWt for steam or chilled water and excludes 134 MWt available under the right-to-use provisions contained in agreements between two of the Company's thermal facilities and certain of its customers.
[4]	(b) Projects are part of tax equity arrangements.
[5]	(e) Represents interests in Four Brothers Solar, LLC, Granite Mountain Holdings, LLC, and Iron Springs Holdings, LLC, all acquired as part of the March 2017 Drop Down Assets acquisition (ownership percentage is based upon cash to be distributed).
[6]	(f) Projects are part of NRG Wind TE Holdco portfolio.

Summary of Significant Accoun62

Summary of Significant Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015
Summary of Significant Accounting Policies [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification			$ 33
Noncontrolling interest		$ 162	226
Contributions from noncontrolling interest for Alta Wind X-X1 TE Holdco		11	5		$ 122
Noncontrolling interest acquired in Spring Canyon acquisition					74
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest		$ (75)	(111)	[1]	(63)	[1]
Dividends Payable, Date Declared		Feb. 15, 2018
Common Stock, Dividends, Per Share, Declared		$ 0.298
Dividends Payable, Date to be Paid		Mar. 15, 2018
Operating Leases, Income Statement, Contingent Revenue		$ 559	583		$ 443
Long-Term Debt, Current [Member]
Summary of Significant Accounting Policies [Line Items]
Restricted Cash and Cash Equivalents		25
Operating Expense [Member]
Summary of Significant Accounting Policies [Line Items]
Restricted Cash and Cash Equivalents		25
Cash Distribution [Member]
Summary of Significant Accounting Policies [Line Items]
Restricted Cash and Cash Equivalents		36
Reserves [Member]
Summary of Significant Accounting Policies [Line Items]
Restricted Cash and Cash Equivalents		82
Project Level Subsidiaries [Member]
Summary of Significant Accounting Policies [Line Items]
Other Cash Equivalents, at Carrying Value		$ 124	111
Elbow Creek [Member] | Wind Farms [Member]
Summary of Significant Accounting Policies [Line Items]
Percentage of Ownership	[2],[3]	100.00%
Elbow Creek [Member] | NRG [Member]
Summary of Significant Accounting Policies [Line Items]
Revenue from Related Parties		$ 8	$ 8
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(b) Projects are part of tax equity arrangements.
[3]	(f) Projects are part of NRG Wind TE Holdco portfolio.

Summary of Significant Accoun63

Summary of Significant Accounting Policies ARO (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligation	$ 55	$ 49
Asset Retirement Obligation, Revision of Estimate	2
Asset Retirement Obligation, Accretion Expense	$ 4

Summary of Significant Accoun64

Summary of Significant Accounting Policies Restricted Cash (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014	[2]
Cash and Cash Equivalents [Abstract]
Cash and Cash Equivalents, at Carrying Value	$ 146	$ 321	[1]	$ 110
Restricted Cash and Cash Equivalents, Current	168	176	[1]	143
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 314	$ 497	[2]	$ 253	[2]	$ 573
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Business Acquisitions Business

Business Acquisitions Business Acquisitions - CVSR (Details) - USD ($) $ in Millions		Sep. 02, 2016	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016		Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015		Sep. 01, 2016	Aug. 31, 2016
Business Acquisition [Line Items]
Long-term Debt			$ 5,899				$ 6,134					$ 5,899	$ 6,134
Current Assets			481				670	[1]				481	670	[1]
Property, Plant and Equipment, Net			5,204				5,554	[1]				5,204	5,554	[1]
Other Assets			2,469				2,522	[1]				2,469	2,522	[1]
Total Assets			8,154				8,746	[1]				8,154	8,746	[1]
Other Liabilities							(313)						(313)
Liabilities			6,146				6,382	[1]				6,146	6,382	[1]
Accumulated Other Comprehensive Income (Loss), Net of Tax			(68)				(85)	[1]				(68)	(85)	[1]
Debt Issuance Costs, Net			54				65					54	65
Business Combination, Acquisition Related Costs												3	1	[2]	$ 3	[2]
Members' Equity			2,008				2,364	[1]				2,008	2,364	[1]
Revenues			231	$ 269	$ 288	$ 221	235		$ 276	$ 287	$ 237	1,009	1,035	[2]	968	[2]
Operating Income (Loss)			19	85	124	55	(100)		120	130	74	283	224	[2]	328	[2]
Net Income (Loss)			(38)	41	59	0	(138)		68	80	5	62	15	[2],[3],[4]	95	[2],[3],[4]
CVSR [Member]
Business Acquisition [Line Items]
Equity Method Investment, Ownership Percentage																		48.95%
Business Acquisition, Percentage of Voting Interests Acquired																	51.05%
Payments to Acquire Businesses, Gross		$ 78.5
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt																	$ 496
Scenario, Previously Reported [Member]
Business Acquisition [Line Items]
Current Assets	[5]						656						656
Property, Plant and Equipment, Net	[5]						5,460						5,460
Other Assets	[5]						2,504						2,504
Total Assets	[5]						8,620						8,620
Other Liabilities	[5]						(309)						(309)
Liabilities	[5]						6,316						6,316
Revenues				265	284	218	232		272	283	234		1,021	[6]	953	[6]
Operating Income (Loss)				95	122	54	(99)		118	128	73		220	[6]	322	[6]
Net Income (Loss)				$ 52	$ 57	$ 1	(137)		$ 67	$ 79	$ 6		15	[6]	$ 93	[6]
CVSR Financing Agreement [Member]
Business Acquisition [Line Items]
Long-term Debt			746				771					746	771
CVSR Financing Agreement [Member] | CVSR [Member]
Business Acquisition [Line Items]
Long-term Debt																	771
CVSR Holdco due 2037 [Member]
Business Acquisition [Line Items]
Long-term Debt			$ 194				$ 199					$ 194	$ 199
CVSR Holdco due 2037 [Member] | CVSR [Member]
Business Acquisition [Line Items]
Long-term Debt																	$ 200
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[5]	(a) As previously reported in the May 9, 2017 Form 8-K filed in connection with the March 2017 Drop Down completed on March 27, 2017.
[6]	(a) As previously reported in the May 9, 2017 Form 8-K filed in connection with the March 2017 Drop Down completed on March 27, 2017

Business Acquisitions - Novembe

Business Acquisitions - November 2015 Drop Down (Details)		Feb. 19, 2016USD ($)	Dec. 31, 2017USD ($)MW	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)		Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Mar. 31, 2015USD ($)	Dec. 31, 2017USD ($)MW	Dec. 31, 2016USD ($)		Dec. 31, 2015USD ($)		Nov. 01, 2017USD ($)MW	Aug. 01, 2017USD ($)	Nov. 03, 2015USD ($)	Nov. 02, 2015USD ($)MW	Dec. 31, 2014USD ($)
Business Acquisition [Line Items]
Revenues			$ 231,000,000	$ 269,000,000	$ 288,000,000	$ 221,000,000	$ 235,000,000		$ 276,000,000	$ 287,000,000	$ 237,000,000		$ 1,009,000,000	$ 1,035,000,000	[1]	$ 968,000,000	[1]
Current Assets			481,000,000				670,000,000	[2]					481,000,000	670,000,000	[2]
Noncontrolling Interest, Increase from Business Combination																74,000,000
Other Assets			$ 2,469,000,000				2,522,000,000	[2]					$ 2,469,000,000	2,522,000,000	[2]
Power Generation Capacity, Megawatts | MW	[3],[4]		5,241										5,241
Property, Plant and Equipment, Net			$ 5,204,000,000				5,554,000,000	[2]					$ 5,204,000,000	5,554,000,000	[2]
Total Assets			8,154,000,000				8,746,000,000	[2]					8,154,000,000	8,746,000,000	[2]
Debt, Long-term and Short-term, Combined Amount							6,069,000,000							6,069,000,000
Long-term Debt			5,899,000,000				6,134,000,000						5,899,000,000	6,134,000,000
Other current and non-current liabilities							313,000,000							313,000,000
Liabilities			6,146,000,000				6,382,000,000	[2]					6,146,000,000	6,382,000,000	[2]
Operating Income (Loss)			19,000,000	85,000,000	124,000,000	55,000,000	(100,000,000)		120,000,000	130,000,000	74,000,000		283,000,000	224,000,000	[1]	328,000,000	[1]
Net Income (Loss)			(38,000,000)	41,000,000	59,000,000	0	(138,000,000)		68,000,000	80,000,000	5,000,000		62,000,000	15,000,000	[1],[5],[6]	95,000,000	[1],[5],[6]
Net Income (Loss) Attributable to Parent													137,000,000	126,000,000	[1]	157,000,000	[1]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest			2,008,000,000				2,364,000,000						2,008,000,000	2,364,000,000		2,705,000,000						$ 2,757,000,000
Liabilities and Equity			$ 8,154,000,000				8,746,000,000	[2]					$ 8,154,000,000	8,746,000,000	[2]
November 2017 Drop Down Assets [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets																		$ 7,000,000
Revenues														14,000,000		15,000,000
Current Assets							14,000,000							14,000,000
Business Acquisition, Consideration Transferred, Working Capital																		3,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment																		83,000,000
Other Assets							18,000,000							18,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets																		102,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities																		26,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net																		$ 76,000,000
Power Generation Capacity, Megawatts | MW																		38
Property, Plant and Equipment, Net							94,000,000							94,000,000
Total Assets							126,000,000							126,000,000
Debt, Long-term and Short-term, Combined Amount							62,000,000							62,000,000
Other current and non-current liabilities							4,000,000							4,000,000
Liabilities							66,000,000							66,000,000
Operating Income (Loss)														4,000,000		6,000,000
Net Income (Loss)														0		2,000,000
Net Income (Loss) Attributable to Parent												$ 3,000,000		0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest							60,000,000							60,000,000
August 2017 Drop Down Assets [Member]
Business Acquisition [Line Items]
Revenues														0		0
Business Acquisition, Consideration Transferred, Working Capital																			$ 3,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net																			$ 87,000,000
Operating Income (Loss)														0		0
Net Income (Loss)														0		0
Net Income (Loss) Attributable to Parent												10,000,000		(31,000,000)
November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt																				$ 193,000,000
Number of Facilities																					12
Payments to Acquire Businesses, Gross		$ 207,000,000
Financial Institutions [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Taxable Income Allocation, Pre-Flip																				99.00%
Taxable Income Allocation, Post-Flip																				8.53%
Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value																				$ 159,000,000
Pre-Flip Point [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Percentage of Cash Available for Distributions																				100.00%
Post-Flip Point [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Percentage of Cash Available for Distributions																				91.47%
Pre-determined Date Through Flip Point If Flip Has Not Occured [Member] | Financial Institutions [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Percentage of Cash Available for Distributions																				100.00%
Wind Farms [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW	[3]		2,200										2,200
Wind Farms [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW																					814
Scenario, Previously Reported [Member]
Business Acquisition [Line Items]
Revenues				265,000,000	284,000,000	218,000,000	232,000,000		272,000,000	283,000,000	234,000,000			1,021,000,000	[7]	953,000,000	[7]
Current Assets	[8]						656,000,000							656,000,000
Other Assets	[8]						2,504,000,000							2,504,000,000
Property, Plant and Equipment, Net	[8]						5,460,000,000							5,460,000,000
Total Assets	[8]						8,620,000,000							8,620,000,000
Debt, Long-term and Short-term, Combined Amount	[8]						6,007,000,000							6,007,000,000
Other current and non-current liabilities	[8]						309,000,000							309,000,000
Liabilities	[8]						6,316,000,000							6,316,000,000
Operating Income (Loss)				95,000,000	122,000,000	54,000,000	(99,000,000)		118,000,000	128,000,000	73,000,000			220,000,000	[7]	322,000,000	[7]
Net Income (Loss)				$ 52,000,000	$ 57,000,000	$ 1,000,000	(137,000,000)		$ 67,000,000	$ 79,000,000	$ 6,000,000			15,000,000	[7]	$ 93,000,000	[7]
Net Income (Loss) Attributable to Parent	[7]											$ 144,000,000		157,000,000
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest							$ 2,304,000,000	[8]						$ 2,304,000,000	[8]							$ 2,695,000,000	[9]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of December 31, 2017
[4]	(c) The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247.
[5]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[6]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[7]	(a) As previously reported in the May 9, 2017 Form 8-K filed in connection with the March 2017 Drop Down completed on March 27, 2017
[8]	(a) As previously reported in the May 9, 2017 Form 8-K filed in connection with the March 2017 Drop Down completed on March 27, 2017.
[9]	(a) As previously reported in the Company's consolidated financial statements for the year ended December 31, 2016, included in the Company's May 9, 2017 Form 8-K.

Business Acquisitions - Desert

Business Acquisitions - Desert Sunlight/Spring Canyon/Fuel Cell (Details)		Jun. 30, 2015	May 08, 2015	Apr. 30, 2015	Dec. 31, 2017USD ($)MW	Dec. 31, 2016USD ($)		Nov. 03, 2015	Nov. 02, 2015USD ($)MW	Jun. 29, 2015project	May 07, 2015
Business Acquisition [Line Items]
Long-term Debt | $					$ 5,899,000,000	$ 6,134,000,000
Pro-Rate Share of Debt Held by Unconsolidated Affiliates | $					777,000,000
Equity Method Investments | $					$ 1,178,000,000	$ 1,152,000,000	[1]
Power Generation Capacity, Megawatts	[2],[3]				5,241
November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Number of Facilities | $									12
Utility-Scale Solar [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts	[2]				921
Wind Farms [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts	[2]				2,200
Wind Farms [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts									814
Wind Farms [Member] | Spring Canyon [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired											90.10%
Wind Farms [Member] | Spring Canyon II [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts					32
Wind Farms [Member] | Spring Canyon III [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts					28
Thermal [Member]
Business Acquisition [Line Items]
Percentage of Ownership	[4]				100.00%
Power Generation Capacity, Megawatts	[2]				123
Desert Sunlight [Member]
Business Acquisition [Line Items]
Equity Method Investments | $					$ 272,000,000
Number of Facilities | project										2
Power Generation Capacity, Megawatts					550
UB Fuel Cell [Member] | Thermal [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts					1.4
Supply Commitment [Member] | Spring Canyon [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life			24 years
Supply Commitment [Member] | UB Fuel Cell [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life				12 years
Pacific Gas and Electric [Member] | Supply Commitment [Member] | Desert Sunlight [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		25 years
Southern California Edison [Member] | Supply Commitment [Member] | Desert Sunlight [Member]
Business Acquisition [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life		20 years
Financial Institutions [Member] | November 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Taxable Income Allocation, Pre-Flip								99.00%
Taxable Income Allocation, Post-Flip								8.53%
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of December 31, 2017
[3]	(c) The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247.
[4]	(d)For thermal energy, net capacity represents MWt for steam or chilled water and excludes 134 MWt available under the right-to-use provisions contained in agreements between two of the Company's thermal facilities and certain of its customers.

Business Acquisitions - January

Business Acquisitions - January 2015 Drop Downs (Details) $ in Millions		Jan. 02, 2015USD ($)	Dec. 31, 2017MW
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts	[1],[2]		5,241
January 2015 Drop Down Assets [Member]
Business Acquisition [Line Items]
Acquisition of businesses, net of cash acquired | $		$ (489)
Business Acquisition, Consideration Transferred, Working Capital | $		9
Business Combination, Consideration Transferred, Liabilities Incurred | $		737
Business Combination, Separately Recognized Transactions, Net Gains and Losses | $		$ 61
Conventional Generation [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts	[1]		1,945
Conventional Generation [Member] | Walnut Creek [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts			485
Wind Farms [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts	[1]		2,200
Wind Farms [Member] | Pinnacle [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts	[1]		55
Wind Farms [Member] | Buffalo Bear [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts	[1]		19
Wind Farms [Member] | Taloga [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts			130
Wind Farms [Member] | Laredo Ridge [Member]
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts	[1]		80
[1]	(a) Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of December 31, 2017
[2]	(c) The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247.

Business Acquisitions November

Business Acquisitions November 2017 Drop Down (Details) $ in Millions		Nov. 02, 2017USD ($)	Aug. 02, 2017USD ($)	Dec. 31, 2017USD ($)MW	Nov. 01, 2017USD ($)MW	Aug. 01, 2017USD ($)	Dec. 31, 2016USD ($)
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW	[1],[2]			5,241
Long-term Debt				$ 5,899			$ 6,134
Debt Issuance Costs, Net				54			$ 65
November 2017 Drop Down Assets [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred		$ 74
Power Generation Capacity, Megawatts | MW					38
Business Acquisition, Consideration Transferred, Working Capital					$ 3
Debt Issuance Costs, Net				3
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets					7
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment					83
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets					12
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets					102
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financial Liabilities	[3]				23
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other					3
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities					26
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net					76
August 2017 Drop Down Assets [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred			$ 44
Business Acquisition, Consideration Transferred, Working Capital						$ 3
Business Combination, Contingent Consideration, Liability				$ 8
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net						$ 87
August 2017 Drop Down Assets [Member]
Business Acquisition [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired						25.00%
November 2017 Drop Down Assets [Member]
Business Acquisition [Line Items]
Long-term Debt					$ 26
[1]	(a) Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of December 31, 2017
[2]	(c) The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247.
[3]	(a) Net of $3 million of net debt issuance costs.

Business Acquisitions Busines70

Business Acquisitions Business Acquisitions - March 2017 Drop Down (Details) $ in Millions		Nov. 02, 2017USD ($)	Mar. 27, 2017USD ($)MW	Sep. 02, 2016USD ($)	Dec. 31, 2017USD ($)MW	Nov. 01, 2017USD ($)MW	Dec. 31, 2016USD ($)		Aug. 31, 2016
Business Acquisition [Line Items]
Power Generation Capacity, Megawatts | MW	[1],[2]				5,241
Debt Issuance Costs, Net					$ 54		$ 65
Equity Method Investments					1,178		$ 1,152	[3]
November 2017 Drop Down Assets [Member]
Business Acquisition [Line Items]
Business Acquisition, Consideration Transferred, Working Capital						$ 3
Business Combination, Consideration Transferred		$ 74
Power Generation Capacity, Megawatts | MW						38
Debt Issuance Costs, Net					3
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets						$ 102
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financial Liabilities	[4]					23
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other						3
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities						26
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net						$ 76
Business Combination, Pro Forma Information, Revenue of Acquiree since Acquisition Date, Actual					$ 1
CVSR [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred				$ 6
Equity Method Investment, Ownership Percentage									48.95%
Business Combination, Separately Recognized Transactions, Net Gains and Losses				$ 112
Agua Caliente Borrower 2 [Member]
Business Acquisition [Line Items]
Remaining Power Purchase Agreement term			22 years
Non-Recourse Debt			$ 41
Power Generation Capacity, Megawatts | MW			46
Power Purchase Agreement Period			25 years
Equity Method Investment, Ownership Percentage					16.00%
Percentage of NRG's Ownership			31.00%
Equity Method Investments					$ 92
Utah Portfolio [Member]
Business Acquisition [Line Items]
Remaining Power Purchase Agreement term			20 years
Business Acquisition, Consideration Transferred, Working Capital			$ 106
Non-Recourse Debt			287
Percentage of Cash Available for Distributions					50.00%
March 2017 Drop Down Assets [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents			6
Business Acquisition, Consideration Transferred, Working Capital			2
Business Combination, Consideration Transferred			132
Business Combination, Separately Recognized Transactions, Net Gains and Losses			8
Debt Issuance Costs, Net			8
Equity Method Investments			456
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets			462
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financial Liabilities			320
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other			3
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities			323
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net			$ 139
NRG [Member] | Agua Caliente Borrower 2 [Member]
Business Acquisition [Line Items]
Percentage of Ownership			51.00%
NRG [Member] | Utah Portfolio [Member]
Business Acquisition [Line Items]
Percentage of Cash Available for Distributions	[5]				50.00%
Equity Method Investments	[5]				$ 345
[1]	(a) Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of December 31, 2017
[2]	(c) The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(a) Net of $3 million of net debt issuance costs.
[5]	(a) Economic interest based on cash to be distributed. Four Brothers Solar, LLC, Granite Mountain Holdings, LLC and Iron Springs Holdings, LLC are tax equity structures and VIEs. The related allocations are described below.

Property, Plant and Equipment71

Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Machinery and Equipment, Gross	$ 6,289	$ 6,339
Land and Land Improvements	166	167
Property, plant and equipment, gross	6,489	6,530
Under construction	34	24
Less accumulated depreciation	(1,285)	(976)
Property, Plant and Equipment, Net	5,204	5,554	[1]
Prepaid Long Term Service Agreement	$ 24	$ 20
Minimum [Member] | Support Equipment and Facilities [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	2 years
Maximum [Member] | Support Equipment and Facilities [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	45 years
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Equity Method Investments and72

Equity Method Investments and VIEs Equity Method Investments and VIEs - Summary Table (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Mar. 27, 2017	Dec. 31, 2016		Jun. 29, 2015
Schedule of Equity Method Investments [Line Items]
Equity investments in affiliates		$ 1,178		$ 1,152	[1]
Retained Earnings, Undistributed Earnings from Equity Method Investees		$ 57
Utah Portfolio [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of Cash Available for Distributions		50.00%
Business Acquisition, Consideration Transferred, Working Capital			$ 106
Desert Sunlight [Member]
Schedule of Equity Method Investments [Line Items]
Business Acquisition, Consideration Transferred, Working Capital						$ 171
Equity investments in affiliates		$ 272
GCE Holding LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	[2]	50.00%
Equity investments in affiliates	[2]	$ 102
Retained Earnings, Undistributed Earnings from Equity Method Investees				$ 51
Agua Caliente Borrower 2 [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		16.00%
Equity investments in affiliates		$ 92
Elkhorn Ridge Wind, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		66.70%
Equity investments in affiliates	[3]	$ 73
Percentage of Ownership	[3]	66.70%
San Juan Mesa Wind Project, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		75.00%
Equity investments in affiliates	[3]	$ 66
Percentage of Ownership	[3]	75.00%
NRG DGPV Holdco 1 [Member]
Schedule of Equity Method Investments [Line Items]
Equity investments in affiliates	[4]	$ 76
Percentage of Ownership	[4]	95.00%
NRG DGPV Holdco 2 [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of Ownership	[4]	95.00%
Payments to Acquire Interest in Subsidiaries and Affiliates	[4]	$ 61
NRG DGPV Holdco 3 [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of Ownership	[4]	99.00%
Payments to Acquire Interest in Subsidiaries and Affiliates	[4]	$ 39
NRG RPV Holdco [Member]
Schedule of Equity Method Investments [Line Items]
Equity investments in affiliates	[4]	$ 58
Percentage of Ownership	[4]	95.00%
Avenal [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		50.00%
Equity investments in affiliates		$ (6)
Utility-Scale Solar [Member] | Desert Sunlight [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage		25.00%
NRG [Member] | Utah Portfolio [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of Cash Available for Distributions	[5]	50.00%
Equity investments in affiliates	[5]	$ 345
NRG [Member] | Agua Caliente Borrower 2 [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of Ownership			51.00%
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(b) GenConn is a variable interest entity.
[3]	(c) San Juan Mesa and Elkhorn Ridge are part of the Wind TE Holdco tax equity structure, as described below. San Juan Mesa and Elkhorn Ridge are owned 75% and 66.7%, respectively, by Wind TE Holdco. The Company owns 100% of the Class B interests in Wind TE Holdco.
[4]	(d) Economic interest based on cash to be distributed. NRG DGPV Holdco 1 LLC, NRG DGPV Holdco 2 LLC, NRG DGPV Holdco 3 LLC and NRG RPV Holdco 1 LLC are tax equity structures and VIEs. The related allocations are described below.
[5]	(a) Economic interest based on cash to be distributed. Four Brothers Solar, LLC, Granite Mountain Holdings, LLC and Iron Springs Holdings, LLC are tax equity structures and VIEs. The related allocations are described below.

Equity Method Investments and73

Equity Method Investments and VIEs Equity Method Investments and VIEs - Entities that are not consolidated (Details) $ in Millions		Jun. 29, 2015USD ($)	Dec. 31, 2017USD ($)MW	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)		Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)MW	Dec. 31, 2016USD ($)		Dec. 31, 2015USD ($)		Mar. 27, 2017USD ($)
Schedule of Equity Method Investments [Line Items]
Revenues			$ 231	$ 269	$ 288	$ 221	$ 235		$ 276	$ 287	$ 237	$ 1,009	$ 1,035	[1]	$ 968	[1]
Pro-Rate Share of Debt Held by Unconsolidated Affiliates			$ 777									$ 777
Power Generation Capacity, Megawatts | MW	[2],[3]		5,241									5,241
Long-term Debt			$ 5,899				6,134					$ 5,899	6,134
Operating Income (Loss)			19	85	124	55	(100)		120	130	74	283	224	[1]	328	[1]
Net Income (Loss)			(38)	$ 41	$ 59	$ 0	(138)		$ 68	$ 80	$ 5	62	15	[1],[4],[5]	95	[1],[4],[5]
Current Assets			481				670	[6]				481	670	[6]
Current Liabilities			485				504	[6]				485	504	[6]
Total non-current liabilities			$ 5,661				5,878	[6]				$ 5,661	5,878	[6]
Avenal [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage			50.00%									50.00%
Desert Sunlight [Member]
Schedule of Equity Method Investments [Line Items]
Payments to Acquire Equity Method Investments		$ 285
Business Acquisition, Consideration Transferred, Working Capital		$ 171
Revenues												$ 207	211		206
Power Generation Capacity, Megawatts | MW			550									550
Operating Income (Loss)												$ 127	129		124
Net Income (Loss)												80	80		73
Current Assets			$ 133				281					133	281
Assets, Noncurrent			1,350				1,401					1,350	1,401
Current Liabilities			64				64					64	64
Total non-current liabilities			1,003				1,043					1,003	1,043
Utah Portfolio [Member]
Schedule of Equity Method Investments [Line Items]
Business Acquisition, Consideration Transferred, Working Capital																	$ 106
Revenues	[7]											75	13		0
Operating Income (Loss)	[7]											18	(6)		(1)
Net Income (Loss)	[7]											18	(6)		(1)
Current Assets	[7]		13				20					13	20
Assets, Noncurrent	[7]		1,090				1,105					1,090	1,105
Current Liabilities	[7]		5				14					5	14
Total non-current liabilities	[7]		$ 24				38					24	38
GCE Holding LLC [Member]
Schedule of Equity Method Investments [Line Items]
Revenues												$ 71	72		78
Equity Method Investment, Ownership Percentage	[8]		50.00%									50.00%
Operating Income (Loss)												$ 36	38		40
Net Income (Loss)												26	26		28
Current Assets			$ 38				36					38	36
Assets, Noncurrent			374				389					374	389
Current Liabilities			18				16					18	16
Total non-current liabilities			$ 189				196					$ 189	196
NRG DGPV Holdco 2 [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of Ownership	[9]		95.00%									95.00%
NRG DGPV Holdco [Member]
Schedule of Equity Method Investments [Line Items]
Revenues	[10]											$ 37	14		1
Operating Income (Loss)	[10]											7	2		0
Net Income (Loss)	[10]											(3)	0		0
Current Assets	[10]		$ 74				44					74	44
Assets, Noncurrent	[10]		671				562					671	562
Current Liabilities	[10]		83				112					83	112
Total non-current liabilities	[10]		216				23					216	23
Redeemable Noncontrolling Interest, Equity, Carrying Amount	[10]		$ 44				28					$ 44	28
NRG RPV Holdco [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of Ownership	[9]		95.00%									95.00%
Revenues												$ 16	13		4
Operating Income (Loss)												3	2		(6)
Net Income (Loss)												3	2		$ (6)
Current Assets			$ 3				15					3	15
Assets, Noncurrent			183				191					183	191
Current Liabilities			0				11					0	11
Total non-current liabilities			7				7					7	7
Redeemable Noncontrolling Interest, Equity, Carrying Amount			$ 16				$ 0					$ 16	$ 0
Capital Unit, Class B [Member] | Financial Institutions [Member] | Utah Portfolio [Member]
Schedule of Equity Method Investments [Line Items]
Taxable Income Allocation, Pre-Flip			99.00%									99.00%
Taxable Income Allocation, Post-Flip			50.00%									50.00%
Capital Unit, Class A [Member] | Utah Portfolio [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of Ownership			100.00%									100.00%
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of December 31, 2017
[3]	(c) The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247.
[4]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[5]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[6]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[7]	(a) Utah Solar Portfolio was acquired by NRG on November 2, 2016.
[8]	(b) GenConn is a variable interest entity.
[9]	(d) Economic interest based on cash to be distributed. NRG DGPV Holdco 1 LLC, NRG DGPV Holdco 2 LLC, NRG DGPV Holdco 3 LLC and NRG RPV Holdco 1 LLC are tax equity structures and VIEs. The related allocations are described below.
[10]	(b) Includes DGPV Holdco 1, DGPV Holdco 2 and DGPV Holdco 3

Equity Method Investments and74

Equity Method Investments and VIEs Equity Method Investments and VIEs - VIEs that are consolidated (Details)		12 Months Ended
		Dec. 31, 2017USD ($)MW	Dec. 31, 2016USD ($)		Dec. 31, 2015USD ($)	Aug. 01, 2017	Nov. 03, 2015	Nov. 02, 2015USD ($)MW	May 07, 2015
Variable Interest Entity [Line Items]
Equity Method Investments		$ 1,178,000,000	$ 1,152,000,000	[1]
Other Assets		$ 2,469,000,000	2,522,000,000	[1]
Power Generation Capacity, Megawatts | MW	[2],[3]	5,241
Proceeds from Noncontrolling Interests		$ 11,000,000	5,000,000		$ 122,000,000
Property, Plant and Equipment, Net		5,204,000,000	5,554,000,000	[1]
Total Assets		8,154,000,000	8,746,000,000	[1]
Liabilities		$ 6,146,000,000	$ 6,382,000,000	[1]
November 2015 Drop Down Assets [Member]
Variable Interest Entity [Line Items]
Number of Facilities								12
Wind Farms [Member]
Variable Interest Entity [Line Items]
Power Generation Capacity, Megawatts | MW	[2]	2,200
Wind Farms [Member] | November 2015 Drop Down Assets [Member]
Variable Interest Entity [Line Items]
Power Generation Capacity, Megawatts | MW								814
Wind Farms [Member] | Spring Canyon [Member]
Variable Interest Entity [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired									90.10%
Wind Farms [Member] | Spring Canyon II [Member]
Variable Interest Entity [Line Items]
Power Generation Capacity, Megawatts | MW		32
Wind Farms [Member] | Spring Canyon III [Member]
Variable Interest Entity [Line Items]
Power Generation Capacity, Megawatts | MW		28
Financial Institutions [Member] | November 2015 Drop Down Assets [Member]
Variable Interest Entity [Line Items]
Taxable Income Allocation, Pre-Flip							99.00%
Taxable Income Allocation, Post-Flip							8.53%
Pre-Flip Point [Member] | November 2015 Drop Down Assets [Member]
Variable Interest Entity [Line Items]
Percentage of Cash Available for Distributions							100.00%
Post-Flip Point [Member] | November 2015 Drop Down Assets [Member]
Variable Interest Entity [Line Items]
Percentage of Cash Available for Distributions							91.47%
Pre-determined Date Through Flip Point If Flip Has Not Occured [Member] | Financial Institutions [Member] | November 2015 Drop Down Assets [Member]
Variable Interest Entity [Line Items]
Percentage of Cash Available for Distributions							100.00%
November 2015 Drop Down Assets [Member]
Variable Interest Entity [Line Items]
Other Assets		$ 172,000,000
Property, Plant and Equipment, Net		376,000,000
Intangible Assets, Net (Excluding Goodwill)		2,000,000
Total Assets		550,000,000
Liabilities		197,000,000
Noncontrolling Interest in Variable Interest Entity		9,000,000
Net Assets		344,000,000
Alta X and XI TE Holdco [Member]
Variable Interest Entity [Line Items]
Other Assets		17,000,000
Property, Plant and Equipment, Net		436,000,000
Intangible Assets, Net (Excluding Goodwill)		262,000,000
Total Assets		715,000,000
Liabilities		9,000,000
Noncontrolling Interest in Variable Interest Entity		93,000,000
Net Assets		$ 613,000,000
Alta X and XI TE Holdco [Member] | Financial Institutions [Member]
Variable Interest Entity [Line Items]
Taxable Income Allocation, Pre-Flip		99.00%
Taxable Income Allocation, Post-Flip		5.00%
Alta X and XI TE Holdco [Member] | Post-Flip Point [Member]
Variable Interest Entity [Line Items]
Percentage of Cash Available for Distributions		97.12%
Alta X and XI TE Holdco [Member] | Pre-determined Date Through Flip Point If Flip Has Not Occured [Member] | Financial Institutions [Member]
Variable Interest Entity [Line Items]
Percentage of Cash Available for Distributions		100.00%
Alta X and XI TE Holdco [Member] | Second Year through Flip Point [Member]
Variable Interest Entity [Line Items]
Percentage of Cash Available for Distributions		94.34%
Spring Canyon [Member]
Variable Interest Entity [Line Items]
Other Assets		$ 2,000,000
Property, Plant and Equipment, Net		95,000,000
Intangible Assets, Net (Excluding Goodwill)		0
Total Assets		97,000,000
Liabilities		5,000,000
Noncontrolling Interest in Variable Interest Entity		60,000,000
Net Assets		$ 32,000,000
Spring Canyon [Member] | Pre-Flip Point [Member]
Variable Interest Entity [Line Items]
Percentage of Cash Available for Distributions		65.19%
Spring Canyon [Member] | Pre-Flip Point [Member] | Financial Institutions [Member]
Variable Interest Entity [Line Items]
Percentage of Cash Available for Distributions		34.81%
Spring Canyon [Member] | Post-Flip Point [Member]
Variable Interest Entity [Line Items]
Percentage of Cash Available for Distributions		95.00%
Spring Canyon [Member] | Post-Flip Point [Member] | Financial Institutions [Member]
Variable Interest Entity [Line Items]
Percentage of Cash Available for Distributions		5.00%
August 2017 Drop Down Assets [Member]
Variable Interest Entity [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired						25.00%
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of December 31, 2017
[3]	(c) The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247.

Equity Method Investments and75

Equity Method Investments and VIEs Equity Method Investments and VIEs - VIEs that are not consolidated (Details) $ in Millions		May 08, 2015	Dec. 31, 2017USD ($)generatingunitMW	Oct. 12, 2017USD ($)	Dec. 31, 2016USD ($)	[3]
Variable Interest Entity [Line Items]
Power Generation Capacity, Megawatts | MW	[1],[2]		5,241
Equity investments in affiliates			$ 1,178		$ 1,152
NRG DGPV Holdco 1 [Member]
Variable Interest Entity [Line Items]
Equity investments in affiliates	[4]		$ 76
NRG DGPV Holdco 1 [Member] | Tax Equity Financed Portfolio of Leases - Commercial PV 1 [Member]
Variable Interest Entity [Line Items]
Power Generation Capacity, Megawatts | MW			47
Remaining Lease Term		18 years
NRG DGPV Holdco 2 [Member]
Variable Interest Entity [Line Items]
Remaining Lease Term			21 years
Payments to Acquire Interest in Subsidiaries and Affiliates	[4]		$ 61
NRG DGPV Holdco 2 [Member] | Tax Equity Financed Portfolio of Leases - Commercial PV 1 [Member]
Variable Interest Entity [Line Items]
Power Generation Capacity, Megawatts | MW			113
NRG DGPV Holdco 3 [Member]
Variable Interest Entity [Line Items]
Power Generation Capacity, Megawatts | MW			43
Remaining Lease Term			20 years
Payments to Acquire Interest in Subsidiaries and Affiliates	[4]		$ 39
NRG DGPV Holdco [Member]
Variable Interest Entity [Line Items]
Equity investments in affiliates			176
NRG RPV Holdco [Member]
Variable Interest Entity [Line Items]
Equity investments in affiliates	[4]		$ 58
NRG RPV Holdco [Member] | Tax Equity Financed Portfolio of Leases [Member]
Variable Interest Entity [Line Items]
Number of Solar Leases in Portfolio | generatingunit			5,400
Power Generation Capacity, Megawatts | MW			30
NRG RPV Holdco [Member] | Existing Portfolio of Leases [Member]
Variable Interest Entity [Line Items]
Number of Solar Leases in Portfolio | generatingunit			2,200
Power Generation Capacity, Megawatts | MW			14
Remaining Lease Term			15 years
Maximum [Member] | NRG DGPV Holdco 1 [Member] | Tax Equity Financed Portfolio of Leases [Member]
Variable Interest Entity [Line Items]
Equity investments in affiliates			$ 100
Maximum [Member] | NRG DGPV Holdco 2 [Member] | Tax Equity Financed Portfolio of Leases [Member]
Variable Interest Entity [Line Items]
Equity investments in affiliates				$ 60
Maximum [Member] | NRG DGPV Holdco 3 [Member] | Tax Equity Financed Portfolio of Leases [Member]
Variable Interest Entity [Line Items]
Equity investments in affiliates			$ 50
Maximum [Member] | NRG RPV Holdco [Member] | Tax Equity Financed Portfolio of Leases [Member]
Variable Interest Entity [Line Items]
Remaining Lease Term			18 years
[1]	(a) Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of December 31, 2017
[2]	(c) The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(d) Economic interest based on cash to be distributed. NRG DGPV Holdco 1 LLC, NRG DGPV Holdco 2 LLC, NRG DGPV Holdco 3 LLC and NRG RPV Holdco 1 LLC are tax equity structures and VIEs. The related allocations are described below.

Equity Method Investments and76

Equity Method Investments and VIEs Equity Method Investments and VIEs (Details) $ in Millions		Mar. 27, 2017	Dec. 31, 2017USD ($)MW	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)		Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)MW	Dec. 31, 2016USD ($)		Dec. 31, 2015USD ($)
Schedule of Equity Method Investments [Line Items]
Current Assets			$ 481				$ 670	[1]				$ 481	$ 670	[1]
Revenues			$ 231	$ 269	$ 288	$ 221	235		$ 276	$ 287	$ 237	$ 1,009	1,035	[2]	$ 968	[2]
Power Generation Capacity, Megawatts | MW	[3],[4]		5,241									5,241
Operating Income (Loss)			$ 19	85	124	55	(100)		120	130	74	$ 283	224	[2]	328	[2]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest			(38)	$ 41	$ 59	$ 0	(138)		$ 68	$ 80	$ 5	62	15	[2],[5],[6]	95	[2],[5],[6]
Current Liabilities			485				504	[1]				485	504	[1]
Liabilities, Noncurrent			5,661				5,878	[1]				5,661	5,878	[1]
Utah Portfolio [Member]
Schedule of Equity Method Investments [Line Items]
Current Assets	[7]		$ 13				20					13	20
Revenues	[7]											$ 75	13		0
Remaining Power Purchase Agreement term		20 years
Percentage of Cash Available for Distributions			50.00%									50.00%
Operating Income (Loss)	[7]											$ 18	(6)		(1)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	[7]											18	(6)		(1)
Assets, Noncurrent	[7]		$ 1,090				1,105					1,090	1,105
Current Liabilities	[7]		5				14					5	14
Liabilities, Noncurrent	[7]		24				38					24	38
NRG DGPV Holdco [Member]
Schedule of Equity Method Investments [Line Items]
Current Assets	[8]		74				44					74	44
Revenues	[8]											37	14		1
Operating Income (Loss)	[8]											7	2		0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	[8]											(3)	0		0
Assets, Noncurrent	[8]		671				562					671	562
Current Liabilities	[8]		83				112					83	112
Liabilities, Noncurrent	[8]		216				23					216	23
Redeemable Noncontrolling Interest, Equity, Carrying Amount	[8]		44				28					44	28
NRG RPV Holdco [Member]
Schedule of Equity Method Investments [Line Items]
Current Assets			$ 3				15					3	15
Revenues												$ 16	13		4
Percentage of Ownership	[9]		95.00%									95.00%
Operating Income (Loss)												$ 3	2		(6)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest												3	2		$ (6)
Assets, Noncurrent			$ 183				191					183	191
Current Liabilities			0				11					0	11
Liabilities, Noncurrent			7				7					7	7
Redeemable Noncontrolling Interest, Equity, Carrying Amount			$ 16				$ 0					$ 16	$ 0
NRG [Member] | Utah Portfolio [Member]
Schedule of Equity Method Investments [Line Items]
Percentage of Cash Available for Distributions	[10]		50.00%									50.00%
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of December 31, 2017
[4]	(c) The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247.
[5]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[6]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[7]	(a) Utah Solar Portfolio was acquired by NRG on November 2, 2016.
[8]	(b) Includes DGPV Holdco 1, DGPV Holdco 2 and DGPV Holdco 3
[9]	(d) Economic interest based on cash to be distributed. NRG DGPV Holdco 1 LLC, NRG DGPV Holdco 2 LLC, NRG DGPV Holdco 3 LLC and NRG RPV Holdco 1 LLC are tax equity structures and VIEs. The related allocations are described below.
[10]	(a) Economic interest based on cash to be distributed. Four Brothers Solar, LLC, Granite Mountain Holdings, LLC and Iron Springs Holdings, LLC are tax equity structures and VIEs. The related allocations are described below.

Fair Value of Financial Instr77

Fair Value of Financial Instruments Fair Value of Financial Instruments - Balance Sheet Grouping (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt — affiliate	$ 618	$ 618	[1]
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financing Receivable, Net	13	30
Long-term Debt and Capital Lease Obligations, Including Current Maturities	5,281	5,516
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Financing Receivable, Net	13	30
Long-term debt — affiliate	618	608
Long-term Debt and Capital Lease Obligations, Including Current Maturities	5,297	5,500
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt and Capital Lease Obligations, Including Current Maturities	870	833
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt and Capital Lease Obligations, Including Current Maturities	$ 5,045	$ 5,275
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Fair Value of Financial Instr78

Fair Value of Financial Instruments Fair Value of Financial Instruments - Recurring Fair Value (Details) - USD ($)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	$ 2,000,000	$ 3,000,000
Derivative Liability, Fair Value, Gross Liability		48,000,000	79,000,000
Fair Value Assets, Measured on Recurring Basis, Valuation Techniques, Impact of Credit Reserve to Fair Value		1,000,000
Concentration Risk, Credit Risk, Financial Instrument, Maximum Exposure		2,700,000,000
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset	[2]		1,000,000
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset	[2]	2,000,000	2,000,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability, Fair Value, Gross Liability	[2]	48,000,000	79,000,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net		0	0
Commodity Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset		1,000,000	2,000,000
Derivative Liability, Fair Value, Gross Liability		1,000,000	1,000,000
Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset	[2]		1,000,000
Derivative Liability, Fair Value, Gross Liability	[2]		0
Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset	[2]	1,000,000	1,000,000
Derivative Liability, Fair Value, Gross Liability	[2]	1,000,000	1,000,000
Interest Rate Contract [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset		1,000,000	1,000,000
Derivative Liability, Fair Value, Gross Liability		47,000,000	78,000,000
Interest Rate Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset	[2]		0
Derivative Liability, Fair Value, Gross Liability	[2]		0
Interest Rate Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset	[2]	1,000,000	1,000,000
Derivative Liability, Fair Value, Gross Liability	[2]	$ 47,000,000	$ 78,000,000
[1]	(a) Derivative Asset balances classified as current are included within the prepayments and other current assets line item of the Consolidated Balance Sheet. Derivative Asset balances classified as long-term are included within the other non-current assets line item of the Consolidated Balance Sheet.
[2]	(a) There were no derivative assets or liabilities classified Level 1 as of December 31, 2017. There were no derivative assets or liabilities classified Level 3 as of December 31, 2017 and 2016.

Fair Value of Financial Instr79

Fair Value of Financial Instruments Fair Value of Financial Instruments - Credit Risk and Derivative FV Measurements (Details) - USD ($)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	$ 2,000,000	$ 3,000,000
Fair Value Assets, Measured on Recurring Basis, Valuation Techniques, Impact of Credit Reserve to Fair Value		1,000,000
Concentration Risk, Credit Risk, Financial Instrument, Maximum Exposure		$ 2,700,000,000
Estimated Counterparty Credit Risk Exposure to Certain Counterparties, Period		5 years
Derivative Liability, Fair Value, Gross Liability		$ 48,000,000	79,000,000
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset	[2]		1,000,000
Fair Value, Inputs, Level 1 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net		0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Asset, Fair Value, Gross Asset	[2]	2,000,000	2,000,000
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability, Fair Value, Gross Liability	[2]	48,000,000	79,000,000
Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net		$ 0	$ 0
[1]	(a) Derivative Asset balances classified as current are included within the prepayments and other current assets line item of the Consolidated Balance Sheet. Derivative Asset balances classified as long-term are included within the other non-current assets line item of the Consolidated Balance Sheet.
[2]	(a) There were no derivative assets or liabilities classified Level 1 as of December 31, 2017. There were no derivative assets or liabilities classified Level 3 as of December 31, 2017 and 2016.

Accounting for Derivative Ins80

Accounting for Derivative Instruments and Hedging Activities - FV of Derivatives (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount		$ 1,940
Derivative Asset, Fair Value, Gross Asset	[1]	2	$ 3
Derivative Liability, Fair Value, Gross Liability		48	79
Derivative, Collateral, Right to Reclaim Cash		0	0
Derivative, Collateral, Obligation to Return Cash		0	0
Fair Value of Gross Derivative Assets/(Liabilities), Net		(46)	(76)
Derivative Asset Fair Value Gross Liability Net Of Derivative Liability Fair Value Gross Asset		0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral Net Of Derivative Liability, Fair Value, Amount Offset Against Collateral		(46)	(76)
United States of America, Dollars | Interest [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount		1,940	2,090
MMbtu [Member] | Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount		2	3
Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		1	2
Derivative Liability, Fair Value, Gross Liability		1	1
Derivative Asset, Fair Value, Gross Liability		0	0
Derivative Asset		1	2
Derivative Liability, Fair Value, Gross Asset		0	0
Derivative Liability		1	1
Fair Value of Gross Derivative Assets/(Liabilities), Net		0	1
Derivative Asset Fair Value Gross Liability Net Of Derivative Liability Fair Value Gross Asset		0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral Net Of Derivative Liability, Fair Value, Amount Offset Against Collateral		0	1
Interest Rate Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		1	1
Derivative Liability, Fair Value, Gross Liability		47	78
Derivative Asset, Fair Value, Gross Liability		1	1
Derivative Asset		0	0
Derivative Liability, Fair Value, Gross Asset		1	1
Derivative Liability		46	77
Fair Value of Gross Derivative Assets/(Liabilities), Net		(46)	(77)
Derivative Asset Fair Value Gross Liability Net Of Derivative Liability Fair Value Gross Asset		0	0
Derivative Asset, Fair Value, Amount Offset Against Collateral Net Of Derivative Liability, Fair Value, Amount Offset Against Collateral		(46)	(77)
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	1	1
Derivative Liability, Fair Value, Gross Liability		13	65
Designated as Hedging Instrument [Member] | Interest Rate Contract Current [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	0	0
Derivative Liability, Fair Value, Gross Liability		4	26
Designated as Hedging Instrument [Member] | Interest Rate Contract Non Current [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	1	1
Derivative Liability, Fair Value, Gross Liability		9	39
Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	1	2
Derivative Liability, Fair Value, Gross Liability		35	14
Not Designated as Hedging Instrument [Member] | Interest Rate Contract Current [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	0	0
Derivative Liability, Fair Value, Gross Liability		12	6
Not Designated as Hedging Instrument [Member] | Interest Rate Contract Non Current [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	0	0
Derivative Liability, Fair Value, Gross Liability		22	7
Not Designated as Hedging Instrument [Member] | Commodity Contract Current [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	1	2
Derivative Liability, Fair Value, Gross Liability		$ 1	$ 1
[1]	(a) Derivative Asset balances classified as current are included within the prepayments and other current assets line item of the Consolidated Balance Sheet. Derivative Asset balances classified as long-term are included within the other non-current assets line item of the Consolidated Balance Sheet.

Accounting for Derivative Ins81

Accounting for Derivative Instruments and Hedging Activities - AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Sep. 30, 2016	Dec. 31, 2014
Derivative [Line Items]
Derivative, Collateral, Right to Reclaim Cash	$ 0	$ 0
Derivative, Collateral, Obligation to Return Cash	0	0
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	(69)	(86)	$ (99)		$ (82)
Reclassified from accumulated OCL to income due to realization of previously deferred amounts	17	17
Mark-to-market of cash flow hedge accounting contracts	0	$ (4)	(34)
Losses expected to be realized from OCL during the next 12 months	15
Reclassification out of Accumulated Other Comprehensive Income [Member]
Derivative [Line Items]
Reclassified from accumulated OCL to income due to realization of previously deferred amounts			17
Noncontrolling Interest [Member]
Derivative [Line Items]
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	(1)		(1)	$ (1)
Successor [Member]
Derivative [Line Items]
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	$ (68)		$ (98)	$ (85)

Accounting for Derivative Ins82

Accounting for Derivative Instruments and Hedging Activities - Impact on Statement of Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives	$ 17	$ 13	$ (17)
Interest Rate Contract [Member] | Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives	$ 7	$ 2	(17)
Commodity Contract [Member] | Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives			$ 2

Intangible Assets Intangible 83

Intangible Assets Intangible Assets - (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months		$ 71
Contra Revenue Intangibles Amortization		70	$ 70		$ 55
Amortization of Intangible Assets		71	71		56
Finite-Lived Intangible Assets, Gross		1,465	1,471		1,477
Impairment of Intangible Assets, Finite-lived	[1]	6
Finite-Lived Intangible Assets, Other Changes			(6)
Finite-Lived Intangible Assets, Accumulated Amortization		237	168
Intangible assets, net		1,228	1,303	[2]
Finite-Lived Intangible Assets, Amortization Expense, Year Two		71
Finite-Lived Intangible Assets, Amortization Expense, Year Three		71
Finite-Lived Intangible Assets, Amortization Expense, Year Four		71
Finite-Lived Intangible Assets, Amortization Expense, Year Five		$ 71
Finite-Lived Intangible Asset, Useful Life		20 years
Accumulated Amortization of Out of Market Contracts		$ 4
Emission Allowances [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		9	9		15
Impairment of Intangible Assets, Finite-lived	[1]	0
Finite-Lived Intangible Assets, Other Changes			(6)
Finite-Lived Intangible Assets, Accumulated Amortization		3	2
Intangible assets, net		6	7
Developed Technology Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		3	3		3
Impairment of Intangible Assets, Finite-lived	[1]	0
Finite-Lived Intangible Assets, Other Changes			0
Finite-Lived Intangible Assets, Accumulated Amortization		1	1
Intangible assets, net		2	2
Customer Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		15	15		15
Impairment of Intangible Assets, Finite-lived	[1]	0
Finite-Lived Intangible Assets, Other Changes			0
Finite-Lived Intangible Assets, Accumulated Amortization		8	7
Intangible assets, net		7	8
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		66	66		66
Impairment of Intangible Assets, Finite-lived	[1]	0
Finite-Lived Intangible Assets, Other Changes			0
Finite-Lived Intangible Assets, Accumulated Amortization		5	4
Intangible assets, net		61	62
Supply Commitment Arrangement [Domain]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		1,280	1,286		1,286
Impairment of Intangible Assets, Finite-lived	[1]	6
Finite-Lived Intangible Assets, Other Changes			0
Finite-Lived Intangible Assets, Accumulated Amortization		205	143
Intangible assets, net		1,075	1,143
Leasehold Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		86	86		86
Impairment of Intangible Assets, Finite-lived	[1]	0
Finite-Lived Intangible Assets, Other Changes			0
Finite-Lived Intangible Assets, Accumulated Amortization		13	9
Intangible assets, net		73	77
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross		6	6		$ 6
Impairment of Intangible Assets, Finite-lived	[1]	0
Finite-Lived Intangible Assets, Other Changes			0
Finite-Lived Intangible Assets, Accumulated Amortization		2	2
Intangible assets, net		4	4
Out of Market Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization		1	$ 1
NRG Solar Blythe LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Out of Market Contracts		7
Spring Canyon [Member]
Finite-Lived Intangible Assets [Line Items]
Out of Market Contracts		$ 3
Finite-Lived Intangible Asset, Useful Life		25 years
Alta Wind XI [Member]
Finite-Lived Intangible Assets [Line Items]
Out of Market Contracts		$ 5
[1]	(a) $6 million of asset impairments relate to one of the November 2017 Drop Down Assets that was recorded by NRG during the quarter ended September 30, 2017, as further described in Note 9, Asset Impairments.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Asset Impairments Asset Impai84

Asset Impairments Asset Impairments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment losses	$ 44	$ 185	[1],[2]	$ 1	[1],[2]
Elbow Creek [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment losses	26	117
Goat Wind [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment losses		60
Forward [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment losses	5	6
November 2017 Drop Down Assets [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment losses	13	$ 2		$ 1
Property, Plant and Equipment [Member] | November 2017 Drop Down Assets [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment losses	8
Finite-Lived Intangible Assets [Member] | November 2017 Drop Down Assets [Member]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment losses	$ 5
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Long-term Debt - Debt Table (De

Long-term Debt - Debt Table (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016		Nov. 01, 2017	Mar. 27, 2017	Feb. 17, 2017	Oct. 31, 2016	Jul. 15, 2016
Debt Instrument [Line Items]
Long-term debt — affiliate		$ 618		$ 618	[1]
Long-term Debt		5,899		6,134
Current portion of long-term debt — external		306		323	[1]
Long-term Debt, Excluding Current Maturities		5,539		5,746
5.375% Senior Notes due in 2024 [Member]
Debt Instrument [Line Items]
Senior Notes		$ 500		500
Debt Instrument, Interest Rate, Stated Percentage	[2]	5.375%
5.00% Senior Notes due in 2026 [Member]
Debt Instrument [Line Items]
Senior Notes		$ 350		350
Debt Instrument, Interest Rate, Stated Percentage	[2]	5.00%
Intercompany Credit Agreement due 2019 [Member]
Debt Instrument [Line Items]
Long-term debt — affiliate		$ 337		337
Debt Instrument, Interest Rate, Stated Percentage	[2]	3.58%
Intercompany Credit Agreement due 2020 [Member]
Debt Instrument [Line Items]
Long-term debt — affiliate		$ 281		281
Debt Instrument, Interest Rate, Stated Percentage	[2]	3.325%
NRG Yield Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term Debt	[3]	$ 55		0
Debt Instrument, Description of Variable Rate Basis	[2]	1 month LIBOR
Debt Instrument, Basis Spread on Variable Rate	[2]	2.50%
Agua Caliente Borrower 2 [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 41		0
Debt Instrument, Interest Rate, Stated Percentage	[2]	5.43%
West Holdings Credit Agreement [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 400		443
Marsh Landing Term Loan Facility [Member]
Debt Instrument [Line Items]
Long-term Debt		318		370
Walnut Creek Energy, LLC, due in 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 267		310
Debt Instrument, Description of Variable Rate Basis	[2]	1 month LIBOR
Debt Instrument, Basis Spread on Variable Rate	[2]	1.625%
Tapestry Wind LLC due in 2021 [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 162		172
Debt Instrument, Description of Variable Rate Basis	[2]	3-Month LIBOR
Debt Instrument, Basis Spread on Variable Rate	[2]	1.625%
Utah Solar Portfolio, due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 278		287			$ 287
Debt Instrument, Description of Variable Rate Basis	[2]	1 month LIBOR
Debt Instrument, Basis Spread on Variable Rate	[2]	2.625%
NRG Energy Center Minneapolis LLC Senior Secured Notes [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 83		96
Debt Instrument, Interest Rate, Stated Percentage	[2]	5.95%
NRG Energy Center Minneapolis Series D Notes [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 125		125
Debt Instrument, Interest Rate, Stated Percentage		3.55%	[2]						3.55%
Laredo Ridge Wind, LLC, due in 2026 [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 95		100
Debt Instrument, Description of Variable Rate Basis	[2]	3-Month LIBOR
Debt Instrument, Basis Spread on Variable Rate	[2]	1.875%
Other Debt [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 443		505
Letters of Credit Outstanding, Amount		38
Viento Funding II, Inc., due in 2023 [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 163		178
Debt Instrument, Description of Variable Rate Basis	[2]	3-Month LIBOR
Debt Instrument, Basis Spread on Variable Rate	[2]	2.75%
Project [Domain]
Debt Instrument [Line Items]
Long-term Debt		$ 4,376		$ 4,666
Marsh Landing Tranche B due 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis	[2]	3-Month LIBOR
Debt Instrument, Basis Spread on Variable Rate		1.875%	[2]
Alpine Financing Agreement, due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 135		$ 145
Debt Instrument, Description of Variable Rate Basis	[2]	3-Month LIBOR
Alta Wind I-V, lease financing arrangement, due 2034 and 2035 [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 926		965
CVSR Financing Agreement [Member]
Debt Instrument [Line Items]
Long-term Debt		746		771
Debt Instrument, Interest Rate, Stated Percentage										4.68%
CVSR Holdco due 2037 [Member]
Debt Instrument [Line Items]
Long-term Debt		$ 194		$ 199
Debt Instrument, Interest Rate, Stated Percentage	[2]	4.68%
November 2017 Drop Down Assets [Member]
Debt Instrument [Line Items]
Long-term Debt						$ 26
Debt Instrument, Interest Rate, Stated Percentage		4.69%
Agua Caliente Borrower 1, due 2038 [Member]
Debt Instrument [Line Items]
Long-term Debt								$ 130
Letter of Credit [Member] | NRG Yield Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount	[3]	$ 74
Letter of Credit [Member] | Agua Caliente Borrower 2 [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		17
Letter of Credit [Member] | West Holdings Credit Agreement [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		102
Letter of Credit [Member] | Marsh Landing Term Loan Facility [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		22
Letter of Credit [Member] | Walnut Creek Energy, LLC, due in 2023 [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		41
Letter of Credit [Member] | Tapestry Wind LLC due in 2021 [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		20
Letter of Credit [Member] | Utah Solar Portfolio, due 2022 [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		13
Letter of Credit [Member] | NRG Energy Center Minneapolis LLC Senior Secured Notes [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		0
Letter of Credit [Member] | NRG Energy Center Minneapolis Series D Notes [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		0
Letter of Credit [Member] | Laredo Ridge Wind, LLC, due in 2026 [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		10
Letter of Credit [Member] | Viento Funding II, Inc., due in 2023 [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		27
Letter of Credit [Member] | Alpine Financing Agreement, due 2022 [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		16
Letter of Credit [Member] | Alta Wind I-V, lease financing arrangement, due 2034 and 2035 [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		119
Letter of Credit [Member] | CVSR Financing Agreement [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		0
Letter of Credit [Member] | CVSR Holdco due 2037 [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		$ 13
Minimum [Member] | West Holdings Credit Agreement [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis	[2]	1 month LIBOR
Debt Instrument, Basis Spread on Variable Rate
Minimum [Member] | West Holdings Credit Agreement due 2023 Tranche A [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	[2]	1.625%
Minimum [Member] | West Holdings Credit Agreement due 2023 Tranche B [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	[2]	2.25%
Minimum [Member] | Alpine Financing Agreement [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	[2]	1.75%
Minimum [Member] | Alpine [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate
Minimum [Member] | CVSR Financing Agreement [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	[2]	2.339%
Minimum [Member] | Alta Wind I - V Lease financing arrangement [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	[2]	5.696%
Maximum [Member] | West Holdings Credit Agreement [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate
Maximum [Member] | Alpine Financing Agreement [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate
Maximum [Member] | Alpine [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate
Maximum [Member] | CVSR Financing Agreement [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	[2]	3.775%
Maximum [Member] | Alta Wind I - V Lease financing arrangement [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	[2]	7.015%
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) As of December 31, 2017, L+ equals 3 month LIBOR plus x%, except for Viento, due 2023, where L + equals 6 month LIBOR plus 3.00%.
[3]	(b) Applicable rate is determined by the borrower leverage ratio, as defined in the credit agreement.

Long-term Debt - Corporate Debt

Long-term Debt - Corporate Debt (Details)		Aug. 18, 2016USD ($)	Jul. 15, 2016USD ($)	Jun. 30, 2015	May 15, 2015	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Jun. 29, 2015USD ($)$ / shares	Mar. 31, 2014USD ($)	Feb. 11, 2014USD ($)$ / shares
Debt Instrument [Line Items]
Long-term Debt						$ 5,899,000,000	$ 6,134,000,000
Intercompany Credit Agreement due 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	[1]					3.325%
3.25% Convertible Notes due 2020 [Member]
Debt Instrument [Line Items]
Convertible Debt								$ 288,000,000
Debt Instrument, Interest Rate, Stated Percentage						3.25%
Debt Instrument, Convertible, Conversion Price | $ / shares								$ 27.50
Debt Instrument, Convertible, Conversion Ratio				36.3636
Debt Instrument, Face Amount								$ 1,000
3.5% Convertible Notes due 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage						3.50%
Long-term Debt									$ 345,000,000
Debt Instrument, Convertible, Conversion Ratio					42.9644
Convertible Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Convertible, Conversion Price | $ / shares										$ 46.55
Debt Instrument, Face Amount										$ 1,000
Intercompany Credit Agreement due 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	[1]					3.58%
NRG Yield Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	[1]					2.50%
Long-term Debt	[2]					$ 55,000,000	0
Proceeds from Issuance of Debt						55,000,000
CVSR Financing Agreement [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage			4.68%
Long-term Debt						$ 746,000,000	$ 771,000,000
Proceeds from Issuance of Debt			$ 200,000,000
Proceeds from Debt, Net of Issuance Costs			$ 97,500,000
5.00% Senior Notes due in 2026 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	[1]					5.00%
Proceeds from Issuance of Unsecured Debt		$ 350,000,000
Letter of Credit [Member] | NRG Yield Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount	[2]					$ 74,000,000
Letter of Credit [Member] | CVSR Financing Agreement [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount						$ 0
[1]	(a) As of December 31, 2017, L+ equals 3 month LIBOR plus x%, except for Viento, due 2023, where L + equals 6 month LIBOR plus 3.00%.
[2]	(b) Applicable rate is determined by the borrower leverage ratio, as defined in the credit agreement.

Long-term Debt Long-Term Debt T

Long-term Debt Long-Term Debt Thermal/CVSR (Details) - USD ($) $ in Millions		Oct. 31, 2016	Jul. 15, 2016	Dec. 31, 2017		Mar. 16, 2017	Dec. 31, 2016	Sep. 01, 2016
Debt Instrument [Line Items]
Long-term Debt				$ 5,899			$ 6,134
NRG Energy Center Minneapolis Series D Notes [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt		$ 125
Debt Instrument, Interest Rate, Stated Percentage		3.55%		3.55%	[1]
Long-term Debt				$ 125			125
NRG Energy Center Minneapolis Series F Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		4.80%		4.60%
Line of Credit Facility, Maximum Borrowing Capacity		$ 70		$ 80
Credit Facility, Maximum Borrowing Capacity, Amendment						$ 10
CVSR Financing Agreement [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt			$ 200
Debt Instrument, Interest Rate, Stated Percentage			4.68%
Proceeds from Debt, Net of Issuance Costs			$ 97.5
Long-term Debt				$ 746			771
CVSR Holdco due 2037 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	[1]			4.68%
Long-term Debt				$ 194			$ 199
CVSR [Member]
Debt Instrument [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired								51.05%
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt								$ 496
CVSR [Member] | CVSR Financing Agreement [Member]
Debt Instrument [Line Items]
Long-term Debt								771
CVSR [Member] | CVSR Holdco due 2037 [Member]
Debt Instrument [Line Items]
Long-term Debt								$ 200
[1]	(a) As of December 31, 2017, L+ equals 3 month LIBOR plus x%, except for Viento, due 2023, where L + equals 6 month LIBOR plus 3.00%.

Long-term Debt Long-Term Debt A

Long-term Debt Long-Term Debt Avenal/Alta (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term Debt		$ 5,899	$ 6,134
NRG Yield Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis	[1]	1 month LIBOR
Debt Instrument, Basis Spread on Variable Rate	[1]	2.50%
Long-term Debt	[2]	$ 55	$ 0
Avenal [Member]
Debt Instrument [Line Items]
Equity Method Investment, Ownership Percentage		50.00%
Utility-Scale Solar [Member] | Avenal [Member]
Debt Instrument [Line Items]
Equity Method Investment, Ownership Percentage		50.00%
[1]	(a) As of December 31, 2017, L+ equals 3 month LIBOR plus x%, except for Viento, due 2023, where L + equals 6 month LIBOR plus 3.00%.
[2]	(b) Applicable rate is determined by the borrower leverage ratio, as defined in the credit agreement.

Long-term Debt Long-Term Debt S

Long-term Debt Long-Term Debt Swaps/Maturities (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Mar. 27, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Next Twelve Months		$ 306
Derivative, Notional Amount		1,940
Long-term Debt, Maturities, Repayments of Principal in Year Two		714
Long-term Debt, Maturities, Repayments of Principal in Year Three		650
Long-term Debt, Maturities, Repayments of Principal in Year Four		455
Long-term Debt, Maturities, Repayments of Principal in Year Five		653
Long-term Debt, Maturities, Repayments of Principal after Year Five		3,121
Long-term Debt		$ 5,899		$ 6,134
Utah Solar Portfolio, due 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis	[1]	1 month LIBOR
Long-term Debt		$ 278	$ 287	287
Viento Funding II, Inc., due in 2023 [Member]
Debt Instrument [Line Items]
Debt Instrument, Description of Variable Rate Basis	[1]	3-Month LIBOR
Long-term Debt		$ 163		$ 178
Interest Rate Swap [Member] | Alta Wind Asset Management, due 2031 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		100.00%
Derivative, Fixed Interest Rate		2.47%
Debt Instrument, Description of Variable Rate Basis		3-Month LIBOR
Derivative, Notional Amount		$ 17
Interest Rate Swap [Member] | Utah Solar Portfolio, due 2022 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		80.00%
Debt Instrument, Description of Variable Rate Basis		1-Month LIBOR
Derivative, Notional Amount		$ 223
Interest Rate Swap [Member] | Viento Funding II, Inc., due in 2023 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		90.00%
Debt Instrument, Description of Variable Rate Basis		6-Month LIBOR
Derivative, Notional Amount		$ 148
Interest Rate Swap [Member] | Walnut Creek [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		75.00%
Debt Instrument, Description of Variable Rate Basis		3-Month LIBOR
Derivative, Notional Amount		$ 239
Interest Rate Swap [Member] | WCEP Holdings, LLC, due in 2023 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		90.00%
Derivative, Fixed Interest Rate		4.003%
Debt Instrument, Description of Variable Rate Basis		3-Month LIBOR
Derivative, Notional Amount		$ 45
Interest Rate Swap [Member] | Maturity - June 30, 2028 [Member] | Viento Funding II, Inc., due in 2023 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		90.00%
Derivative, Fixed Interest Rate		4.985%
Debt Instrument, Description of Variable Rate Basis		6-Month LIBOR
Derivative, Notional Amount		$ 65
NRG Solar Alpine LLC [Member] | Interest Rate Swap [Member] | Maturity - December 31, 2029 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		85.00%
Debt Instrument, Description of Variable Rate Basis		3-Month LIBOR
Derivative, Notional Amount		$ 115
NRG Solar Avra Valley [Member] | Interest Rate Swap [Member] | Maturity - November 30, 2030 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		85.00%
Derivative, Fixed Interest Rate		2.333%
Debt Instrument, Description of Variable Rate Basis		3-Month LIBOR
Derivative, Notional Amount		$ 46
NRG Solar Blythe LLC [Member] | Interest Rate Swap [Member] | Maturity - June 25, 2028 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		75.00%
Derivative, Fixed Interest Rate		3.563%
Debt Instrument, Description of Variable Rate Basis		3-Month LIBOR
Derivative, Notional Amount		$ 13
Borrego [Member] | Interest Rate Swap [Member] | Maturity - December 31, 2029 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		75.00%
Derivative, Fixed Interest Rate		1.125%
Debt Instrument, Description of Variable Rate Basis		3-Month LIBOR
Derivative, Notional Amount		$ 5
NRG West Holdings LLC [Member] | Interest Rate Swap [Member] | Maturity - June 30, 2023 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		75.00%
Debt Instrument, Description of Variable Rate Basis		3-Month LIBOR
Derivative, Notional Amount		$ 340
Kansas South [Member] | Interest Rate Swap [Member] | Maturity - June 30, 2023 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		75.00%
Derivative, Fixed Interest Rate		2.368%
Debt Instrument, Description of Variable Rate Basis		6-Month LIBOR
Derivative, Notional Amount		$ 21
Laredo Ridge [Member] | Interest Rate Swap [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		75.00%
Derivative, Fixed Interest Rate		2.31%
Debt Instrument, Description of Variable Rate Basis		3-Month LIBOR
Derivative, Notional Amount		$ 75
Marsh Landing [Member] | Interest Rate Swap [Member] | Maturity - June 30, 2023 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		75.00%
Derivative, Fixed Interest Rate		3.244%
Debt Instrument, Description of Variable Rate Basis		3-Month LIBOR
Derivative, Notional Amount		$ 295
NRG Solar Roadrunner LLC [Member] | Interest Rate Swap [Member] | Maturity - December 31, 2029 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		75.00%
Derivative, Fixed Interest Rate		4.313%
Debt Instrument, Description of Variable Rate Basis		3-Month LIBOR
Derivative, Notional Amount		$ 26
South Trent Wind LLC [Member] | Interest Rate Swap [Member] | Maturity - June14, 2020 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		75.00%
Derivative, Fixed Interest Rate		3.265%
Debt Instrument, Description of Variable Rate Basis		3-Month LIBOR
Derivative, Notional Amount		$ 40
South Trent Wind LLC [Member] | Interest Rate Swap [Member] | Maturity - June 14, 2028 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		75.00%
Derivative, Fixed Interest Rate		4.95%
Debt Instrument, Description of Variable Rate Basis		3-Month LIBOR
Derivative, Notional Amount		$ 21
Tapestry Wind [Member] | Interest Rate Swap [Member] | Maturity - December 21, 2021 [Member] [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		75.00%
Derivative, Fixed Interest Rate		2.21%
Debt Instrument, Description of Variable Rate Basis		3-Month LIBOR
Derivative, Notional Amount		$ 146
Tapestry Wind [Member] | Interest Rate Swap [Member] | Maturity - December 21, 2029 [Member]
Debt Instrument [Line Items]
Percentage of Debt Hedged by Interest Rate Derivatives		50.00%
Derivative, Fixed Interest Rate		3.57%
Debt Instrument, Description of Variable Rate Basis		3-Month LIBOR
Derivative, Notional Amount		$ 60
[1]	(a) As of December 31, 2017, L+ equals 3 month LIBOR plus x%, except for Viento, due 2023, where L + equals 6 month LIBOR plus 3.00%.

Long-term Debt March Drop Down

Long-term Debt March Drop Down (Details) - USD ($) $ in Millions		2 Months Ended	12 Months Ended
		Dec. 31, 2016	Dec. 31, 2017	Mar. 27, 2017	Nov. 02, 2016
Debt Instrument [Line Items]
Long-term Debt		$ 6,134	$ 5,899
Utah Solar Portfolio, due 2022 [Member]
Debt Instrument [Line Items]
Long-term Debt		287	$ 278	$ 287
Debt Instrument, Basis Spread on Variable Rate	[1]		2.625%
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt					$ 222
Proceeds from Issuance of Debt		$ 65
[1]	(a) As of December 31, 2017, L+ equals 3 month LIBOR plus x%, except for Viento, due 2023, where L + equals 6 month LIBOR plus 3.00%.

Long-term Debt Long Term Debt N

Long-term Debt Long Term Debt November 2017 Drop Down (Details)	Dec. 31, 2017
November 2017 Drop Down Assets [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	8.00%

Members' Equity (Details)

Members' Equity (Details) - USD ($) $ / shares in Units, $ in Millions	Sep. 02, 2016	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2017
Schedule of Capitalization, Equity [Line Items]
Distribution Made to Limited Liability Company (LLC) Member, Distributions Paid, Per Unit		$ 0.288
Dividends Payable, Date Declared						Feb. 15, 2018
Common Stock, Dividends, Per Share, Declared						$ 0.298
Dividends Payable, Date to be Paid						Mar. 15, 2018
CVSR [Member]
Schedule of Capitalization, Equity [Line Items]
Business Combination, Separately Recognized Transactions, Net Gains and Losses	$ 112
Common Class B [Member]
Schedule of Capitalization, Equity [Line Items]
Distribution Made to Limited Liability Company (LLC) Member, Distributions Paid, Per Unit			$ 0.28	$ 0.27	$ 0.26
Common Class D [Member]
Schedule of Capitalization, Equity [Line Items]
Distribution Made to Limited Liability Company (LLC) Member, Distributions Paid, Per Unit					$ 0.26

Segment Reporting (Details)

Segment Reporting (Details) - USD ($) $ in Millions	3 Months Ended										5 Months Ended	12 Months Ended
	Dec. 31, 2017		Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016		Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2013	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Segment Reporting
Total operating revenues	$ 231		$ 269	$ 288	$ 221	$ 235		$ 276	$ 287	$ 237		$ 1,009		$ 1,035	[1]	$ 968	[1]
Cost of operations												326		308		323
Depreciation and amortization												334		303	[1]	303	[1]
Impairment losses												44		185	[1],[2]	1	[1],[2]
General and administrative												19		14	[1]	10	[1]
Acquisition-related transaction and integration costs												3		1	[1]	3	[1]
Operating Income	19		85	124	55	(100)		120	130	74		283		224	[1]	328	[1]
Equity in earnings of unconsolidated affiliates												71		60	[1],[2]	31	[1],[2]
Other income, net												4		3	[1]	3	[1]
Loss on debt extinguishment												(3)		0	[1],[2]	(9)	[1],[2]
Interest expense												(293)		(272)	[1]	(258)	[1]
Income Before Income Taxes														15		95
Net Income	(38)		$ 41	$ 59	$ 0	(138)		$ 68	$ 80	$ 5		62		15	[1],[3],[4]	95	[1],[3],[4]
Equity Method Investments	1,178					1,152	[5]					1,178		1,152	[5]
Total Assets	8,154					8,746	[5]					8,154		8,746	[5]
Capital Expenditures	35	[6]				23	[7]					35	[6]	23	[7]
Conventional Generation [Member]
Segment Reporting
Total operating revenues												336		333		336
Cost of operations												77		66		59
Depreciation and amortization												103		80		81
Impairment losses												0		0		0
General and administrative												0		0		0
Acquisition-related transaction and integration costs												0		0		0
Operating Income												156		187		196
Equity in earnings of unconsolidated affiliates												12		13		14
Other income, net												1		1		1
Loss on debt extinguishment												0				(7)
Interest expense												(49)		(48)		(48)
Income Before Income Taxes														153		156
Net Income												120
Equity Method Investments	102					106						102		106
Total Assets	1,897					1,993						1,897		1,993
Capital Expenditures	15	[6]				7	[7]					15	[6]	7	[7]
Corporate
Segment Reporting
Total operating revenues												0		0		0
Cost of operations												0		0		0
Depreciation and amortization												0		0		0
Impairment losses												0		0		0
General and administrative												19		14		10
Acquisition-related transaction and integration costs												3		1		3
Operating Income												(22)		(15)		(13)
Equity in earnings of unconsolidated affiliates												0		0		0
Other income, net												1		0		0
Loss on debt extinguishment												0				0
Interest expense												(71)		(66)		(52)
Income Before Income Taxes														(81)		(65)
Net Income												(92)
Equity Method Investments						0								0
Total Assets	24					213						24		213
Capital Expenditures	0	[6]				0	[7]					0	[6]	0	[7]
Thermal [Member]
Segment Reporting
Total operating revenues												172		170		174
Cost of operations												116		114		126
Depreciation and amortization												21		20		19
Impairment losses												0		0		0
General and administrative												0		0		0
Acquisition-related transaction and integration costs												0		0		0
Operating Income												35		36		29
Equity in earnings of unconsolidated affiliates												0		0		0
Other income, net												0		0		0
Loss on debt extinguishment												0				0
Interest expense												(10)		(7)		(7)
Income Before Income Taxes														29		22
Net Income												25
Equity Method Investments	0					0						0		0
Total Assets	422					426						422		426
Capital Expenditures	16	[6]				14	[7]					16	[6]	14	[7]
Renewables
Segment Reporting
Total operating revenues												501		532		458
Cost of operations												133		128		138
Depreciation and amortization												210		203		203
Impairment losses												44		185		1
General and administrative												0		0		0
Acquisition-related transaction and integration costs												0		0		0
Operating Income												114		16		116
Equity in earnings of unconsolidated affiliates												59		47		17
Other income, net												2		2		2
Loss on debt extinguishment												(3)				(2)
Interest expense												(163)		(151)		(151)
Income Before Income Taxes														(86)		$ (18)
Net Income												9
Equity Method Investments	1,076					1,046						1,076		1,046
Total Assets	5,811					6,114						5,811		6,114
Capital Expenditures	$ 4	[6]				$ 2	[7]					$ 4	[6]	$ 2	[7]
Affiliated Entity [Member]
Segment Reporting
General and administrative											$ 8
Southern California Edison [Member] | Conventional Generation [Member]
Segment Reporting
Customer's Percentage of Total Revenue												21.00%		21.00%		22.00%
Southern California Edison [Member] | Renewables
Segment Reporting
Customer's Percentage of Total Revenue												20.00%		21.00%		17.00%
PG&E [Member] | Conventional Generation [Member]
Segment Reporting
Customer's Percentage of Total Revenue												12.00%		12.00%		12.00%
PG&E [Member] | Renewables
Segment Reporting
Customer's Percentage of Total Revenue												11.00%		11.00%		12.00%
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[5]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[6]	(a) Includes accruals.
[7]	(a) Includes accruals.

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($)	2 Months Ended	5 Months Ended	12 Months Ended
	Feb. 28, 2018	Dec. 31, 2013	Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015		Jan. 05, 2017	Oct. 31, 2016
Related Party Transaction [Line Items]
General and administrative			$ 19,000,000	$ 14,000,000	[1]	$ 10,000,000	[1]
Due to Affiliate, Current			48,000,000	40,000,000	[2]
Due to Affiliate, Noncurrent			618,000,000	618,000,000	[2]
NRG Repowering Holdings LLC [Member]
Related Party Transaction [Line Items]
Cost of Natural Gas Purchases			9,000,000	9
Affiliated Entity [Member]
Related Party Transaction [Line Items]
General and administrative		$ 8,000,000
NRG RENOM [Member]
Related Party Transaction [Line Items]
Due to Affiliate			5,000,000	5
Related Party Transaction, Expenses from Transactions with Related Party			23,000,000	13,000,000		7,000,000
NRG Wind TE Holdco [Member] | NRG [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties						16,000,000
NRG Yield [Member] | NRG [Member]
Related Party Transaction [Line Items]
Management Services Fee, Increase				1,000,000
General and administrative			10,000,000	10
NRG Yield [Member] | NRG [Member] | Scenario, Plan [Member]
Related Party Transaction [Line Items]
Management Services Fee, Annual			8,500,000
NRG Yield, Inc. [Member] | NRG [Member]
Related Party Transaction [Line Items]
Due to Affiliate			4,000,000
Marsh Landing [Member] | NRG [Member]
Related Party Transaction [Line Items]
Due to Affiliate			1,000,000	1
Related Party Transaction, Expenses from Transactions with Related Party			15,000,000	14,000,000		13,000,000
Elbow Creek [Member] | NRG [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties			8,000,000	8,000,000
NECP [Member] | NRG [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Amount to be Paid Upon Completion of Project								$ 88,000,000	$ 79,000,000
Operations and Maintenance services [Member] | NRG [Member]
Related Party Transaction [Line Items]
Due to Affiliate			13,000,000	22,000,000
Related Party Transaction, Expenses from Transactions with Related Party			39,000,000	36,000,000		$ 36
Operations and Maintenance services [Member] | GCE Holding LLC [Member] | NRG [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party			$ 5,000,000	$ 5
Subsequent Event [Member] | Operations and Maintenance services [Member] | NRG [Member]
Related Party Transaction [Line Items]
Repayments of Accounts Payable, Affiliate	$ 5,000,000
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Related Party Transactions O&M

Related Party Transactions O&M Thermal (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015
Related Party Transaction [Line Items]
General and administrative	$ 19	$ 14	[1]	$ 10	[1]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Related Party Transactions O&96

Related Party Transactions O&M GenConn (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
NRG [Member] | Operations and Maintenance services [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	$ 39,000,000	$ 36,000,000	$ 36
GCE Holding LLC [Member] | NRG [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party			$ 4,000,000
GCE Holding LLC [Member] | NRG [Member] | Operations and Maintenance services [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	$ 5,000,000	$ 5

Related Party Transactions NRG

Related Party Transactions NRG and Dover (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
NRG Repowering Holdings LLC [Member]
Related Party Transaction [Line Items]
Cost of Natural Gas Purchases	$ 9,000,000	$ 9
coal, gas purchases		9,000,000	$ 13,000,000
NRG Energy Center Dover [Member] | NRG [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	$ 4,000,000	$ 5,000,000

Commitments and Contingencies98

Commitments and Contingencies (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Long-term Purchase Commitment [Line Items]
Purchase Obligation, Due in Next Twelve Months	$ 11,000,000
Utilities Operating Expense, Purchased Power under Long-term Contracts	34,000,000	$ 32,000,000	$ 40,000,000
Unrecorded Unconditional Purchase Obligation, Due within Two Years	5,000,000
Unrecorded Unconditional Purchase Obligation, Due within Three Years	3,000,000
Unrecorded Unconditional Purchase Obligation, Due within Four Years	3,000,000
Unrecorded Unconditional Purchase Obligation, Due within Five Years	3,000,000
Unrecorded Unconditional Purchase Obligation, Due after Five Years	16,000,000
Purchase Obligation	41,000,000
Operating Leases, Future Minimum Payments Due	209,000,000
Operating Leases, Future Minimum Payments Due, Next Twelve Months	9,000,000
Operating Leases, Rent Expense	17,000,000	15,000,000	10,000,000
Operating Leases, Future Minimum Payments, Due in Two Years	9,000,000
Operating Leases, Future Minimum Payments, Due in Three Years	9,000,000
Operating Leases, Future Minimum Payments, Due in Four Years	9,000,000
Operating Leases, Future Minimum Payments, Due in Five Years	9,000,000
Operating Leases, Future Minimum Payments, Due Thereafter	151,000,000
NRG Repowering Holdings LLC [Member]
Long-term Purchase Commitment [Line Items]
Cost of Natural Gas Purchases	$ 9,000,000	9
coal, gas purchases		$ 9,000,000	$ 13,000,000

Unaudited Quarterly Financial99

Unaudited Quarterly Financial Data (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015
Total operating revenues	$ 231	$ 269	$ 288	$ 221	$ 235	$ 276	$ 287	$ 237	$ 1,009	$ 1,035	[1]	$ 968	[1]
Operating Income (Loss)	19	85	124	55	(100)	120	130	74	283	224	[1]	328	[1]
Net Income (Loss)	$ (38)	41	59	0	(138)	68	80	5	$ 62	15	[1],[2],[3]	95	[1],[2],[3]
Scenario, Previously Reported [Member]
Total operating revenues		265	284	218	232	272	283	234		1,021	[4]	953	[4]
Operating Income (Loss)		95	122	54	(99)	118	128	73		220	[4]	322	[4]
Net Income (Loss)		52	57	1	(137)	67	79	6		$ 15	[4]	$ 93	[4]
Operating Revenues [Member]
Quarterly Financial Information, Quarterly Charges and Credits, Amount Reconciling to Previously Reported Results		4	4	3	3	4	4	3
Operating Income (Loss) [Member]
Quarterly Financial Information, Quarterly Charges and Credits, Amount Reconciling to Previously Reported Results		(10)	2	1	(1)	2	2	1
Net Income (Loss) [Member]
Quarterly Financial Information, Quarterly Charges and Credits, Amount Reconciling to Previously Reported Results		$ (11)	$ 2	$ (1)	$ (1)	$ 1	$ 1	$ (1)
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(a) As previously reported in the May 9, 2017 Form 8-K filed in connection with the March 2017 Drop Down completed on March 27, 2017

Condensed Consolidating Fina100

Condensed Consolidating Financial Information Condensed Consolidating Financial Information Condensed Consolidating Financial Information (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
5.375% Senior Notes due in 2024 [Member]
Senior Notes	$ 500	$ 500
5.00% Senior Notes due in 2026 [Member]
Senior Notes	$ 350	$ 350

Condensed Consolidating Fina101

Condensed Consolidating Financial Information CP Income Statement (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Condensed Income Statements, Captions [Line Items]
Total operating revenues	$ 231	$ 269	$ 288	$ 221	$ 235	$ 276	$ 287	$ 237	$ 1,009		$ 1,035	[1]	$ 968	[1]
Operating Costs and Expenses [Abstract]
Cost of operations									326		308	[1]	323	[1]
Depreciation and amortization									334		303	[1]	303	[1]
Impairment losses									44		185	[1],[2]	1	[1],[2]
General and administrative									19		14	[1]	10	[1]
Acquisition-related transaction and integration costs									3		1	[1]	3	[1]
Total operating costs and expenses									726		811	[1]	640	[1]
Operating Income	19	85	124	55	(100)	120	130	74	283		224	[1]	328	[1]
Costs and Expenses [Abstract]
Equity in earnings (losses) of consolidated affiliates									0		0		0
Equity in earnings of unconsolidated affiliates									71		60	[1],[2]	31	[1],[2]
Other income, net									4		3	[1]	3	[1]
Loss on debt extinguishment									(3)		0	[1],[2]	(9)	[1],[2]
Interest expense									(293)		(272)	[1]	(258)	[1]
Total other income (expense), net									(221)		(209)	[1]	(233)	[1]
Net Income	$ (38)	$ 41	$ 59	$ 0	$ (138)	$ 68	$ 80	$ 5	62		15	[1],[3],[4]	95	[1],[3],[4]
Net Income (Loss) Attributable to NRG Yield LLC									137		126	[1]	157	[1]
Net (Loss) Income Attributable to Noncontrolling Interest									(75)		(111)	[1]	(62)	[1]
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues									21		22		21	[5],[6]
Operating Costs and Expenses [Abstract]
Cost of operations									14		14		14
Depreciation and amortization									5		5		4
Impairment losses									0		0		0
General and administrative									0		0		0
Acquisition-related transaction and integration costs									0		0		0
Total operating costs and expenses									19		19		18
Operating Income									2		3		3
Costs and Expenses [Abstract]
Equity in earnings (losses) of consolidated affiliates									(16)		10		(43)
Equity in earnings of unconsolidated affiliates									22		9		(2)
Other income, net									0		0		0
Loss on debt extinguishment									0				0
Interest expense									0		0		0
Total other income (expense), net									6		19		(45)
Net Income									8		22		(42)
Net Income (Loss) Attributable to NRG Yield LLC									8		22		(42)
Net (Loss) Income Attributable to Noncontrolling Interest									0		0		0
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues									988		1,013	[7]	937	[6]
Operating Costs and Expenses [Abstract]
Cost of operations									312		294	[7]	309	[6]
Depreciation and amortization									329		298	[7]	299	[6]
Impairment losses									44		185	[7]	1	[6]
General and administrative									0		0	[7]	0	[6]
Acquisition-related transaction and integration costs									0		0	[7]	0	[6]
Total operating costs and expenses									685		777	[7]	609	[6]
Operating Income									303		236	[7]	328	[6]
Costs and Expenses [Abstract]
Equity in earnings (losses) of consolidated affiliates									0		0	[7]	0	[6]
Equity in earnings of unconsolidated affiliates									21		21	[7]	8	[6]
Other income, net									3		3	[7]	3	[6]
Loss on debt extinguishment									(3)				(9)	[6]
Interest expense									(222)		(206)	[7]	(206)	[6]
Total other income (expense), net									(201)		(182)	[7]	(204)	[6]
Net Income									102		54	[7],[8]	124	[6]
Net Income (Loss) Attributable to NRG Yield LLC									107		55	[7]	126	[6]
Net (Loss) Income Attributable to Noncontrolling Interest									(5)		(1)	[7]	(2)	[6]
NRG Yield LLC [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues									0	[9]	0	[7],[10]	0	[5],[7]
Operating Costs and Expenses [Abstract]
Cost of operations									0	[9]	0	[7],[10]	0	[5],[6]
Depreciation and amortization									0	[9]	0	[7],[10]	0	[5],[6]
Impairment losses									0	[9]	0	[7],[10]	0	[5],[6]
General and administrative									0	[9]	2	[7],[10]	0	[5],[6]
Acquisition-related transaction and integration costs									0	[9]	0	[7],[10]	0	[5],[6]
Total operating costs and expenses									0	[9]	2	[7],[10]	0	[5],[6]
Operating Income									0	[9]	(2)	[7],[10]	0	[5],[6]
Costs and Expenses [Abstract]
Equity in earnings (losses) of consolidated affiliates									136	[11]	128	[7],[10]	157	[5],[6]
Equity in earnings of unconsolidated affiliates									0	[11]	0	[7],[10]	0	[5],[6]
Other income, net									1	[11]	0	[7],[10]	0	[5],[6]
Loss on debt extinguishment									0	[11]			0	[5],[6]
Interest expense									0	[11]	0	[7],[10]	0	[5],[6]
Total other income (expense), net									137	[11]	128	[7],[10]	157	[5],[6]
Net Income									137	[11]	126	[7],[8],[10],[12]	157	[13],[14]
Net Income (Loss) Attributable to NRG Yield LLC									137	[9]	126	[7],[10]	157	[5],[6]
Net (Loss) Income Attributable to Noncontrolling Interest									0	[9]	0	[7],[10]	0	[5],[6]
NRG Yield Operating LLC [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues									1		1	[7]	10	[6]
Operating Costs and Expenses [Abstract]
Cost of operations									1		1	[7]	0	[6]
Depreciation and amortization									0		0	[7]	0	[6]
Impairment losses									0		0	[7]	0	[6]
General and administrative									19		12	[7]	10	[6]
Acquisition-related transaction and integration costs									3		1	[7]	3	[6]
Total operating costs and expenses									23		14	[7]	13	[6]
Operating Income									(22)		(13)	[7]	(3)	[6]
Costs and Expenses [Abstract]
Equity in earnings (losses) of consolidated affiliates									126		66	[7]	125	[6]
Equity in earnings of unconsolidated affiliates									28		30	[7]	25	[6]
Other income, net									0		0	[7]	0	[6]
Loss on debt extinguishment									0				0	[6]
Interest expense									(71)		(66)	[7]	(52)	[6]
Total other income (expense), net									83		30	[7]	98	[6]
Net Income									61		17	[7],[8]	95	[6]
Net Income (Loss) Attributable to NRG Yield LLC									136		128	[7]	157	[6]
Net (Loss) Income Attributable to Noncontrolling Interest									(75)		(111)	[7]	(62)	[6]
Consolidation, Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues									(1)	[15]	(1)	[7],[16]	0	[6],[17]
Operating Costs and Expenses [Abstract]
Cost of operations									(1)	[15]	(1)	[7],[16]	0	[6],[17]
Depreciation and amortization									0	[15]	0	[7],[16]	0	[6],[17]
Impairment losses									0	[15]	0	[7],[16]	0	[6],[17]
General and administrative									0	[15]	0	[7],[16]	0	[6],[17]
Acquisition-related transaction and integration costs									0	[15]	0	[7],[16]	0	[6],[17]
Total operating costs and expenses									(1)	[15]	(1)	[7],[16]	0	[6],[17]
Operating Income									0	[15]	0	[7],[16]	0	[6],[17]
Costs and Expenses [Abstract]
Equity in earnings (losses) of consolidated affiliates									(246)	[15]	(204)	[7],[16]	(239)	[6],[17]
Equity in earnings of unconsolidated affiliates									0	[15]	0	[7],[16]	0	[6],[17]
Other income, net									0	[15]	0	[7],[16]	0	[6],[17]
Loss on debt extinguishment									0	[15]			0	[6],[17]
Interest expense									0	[15]	0	[7],[16]	0	[6],[17]
Total other income (expense), net									(246)	[15]	(204)	[7],[16]	(239)	[6],[17]
Net Income									(246)	[15]	(204)	[7],[8],[16],[18]	(239)	[14],[19]
Net Income (Loss) Attributable to NRG Yield LLC									(251)	[15]	(205)	[7],[16]	(241)	[6],[17]
Net (Loss) Income Attributable to Noncontrolling Interest									$ 5	[15]	$ 1	[7],[16]	$ 2	[6],[17]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[5]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[6]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[7]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[8]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[9]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[10]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[11]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[12]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[13]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[14]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[15]	(b) All significant intercompany transactions have been eliminated in consolidation.
[16]	(b) All significant intercompany transactions have been eliminated in consolidation.
[17]	(b) All significant intercompany transactions have been eliminated in consolidation.
[18]	(b) All significant intercompany transactions have been eliminated in consolidation.
[19]	(b) All significant intercompany transactions have been eliminated in consolidation.

Condensed Consolidating Fina102

Condensed Consolidating Financial Information CP Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)	$ (38)	$ 41	$ 59	$ 0	$ (138)	$ 68	$ 80	$ 5	$ 62		$ 15	[1],[2],[3]	$ 95	[1],[2],[3]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax									17		13	[2]	(17)	[2]
Other comprehensive (loss) income									17		13	[2]	(17)	[2]
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest									79		28	[2]	78	[2]
Less: Comprehensive (loss) income attributable to noncontrolling interests									(75)		(111)	[2]	(63)	[2]
Comprehensive Income Attributable to NRG Yield LLC									154		139	[2]	141	[2]
Guarantor Subsidiaries [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)									8		22		(42)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax									1		1		0
Other comprehensive (loss) income									1		1		0
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest									9		23		(42)
Less: Comprehensive (loss) income attributable to noncontrolling interests									0		0		0
Comprehensive Income Attributable to NRG Yield LLC									9		23		(42)
Non-Guarantor Subsidiaries [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)									102		54	[4],[5]	124	[6]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax									16		10	[5]	(16)	[7]
Other comprehensive (loss) income									16		10	[5]	(16)	[7]
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest									118		64	[5]	108	[7]
Less: Comprehensive (loss) income attributable to noncontrolling interests									(5)		(1)	[5]	(2)	[7]
Comprehensive Income Attributable to NRG Yield LLC									123		65	[5]	110	[7]
NRG Yield LLC [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)									137	[8]	126	[4],[5],[9],[10]	157	[7],[11]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax									17	[12]	13	[5],[10]	(16)	[7],[11]
Other comprehensive (loss) income									17	[12]	13	[5],[10]	(16)	[7],[11]
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest									154	[12]	139	[5],[10]	141	[7],[11]
Less: Comprehensive (loss) income attributable to noncontrolling interests									0	[12]	0	[5],[10]	0	[7],[11]
Comprehensive Income Attributable to NRG Yield LLC									154	[12]	139	[5],[10]	141	[7],[11]
NRG Yield Operating LLC [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)									61		17	[4],[5]	95	[6]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax									17		13	[5]	(17)	[7]
Other comprehensive (loss) income									17		13	[5]	(17)	[7]
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest									78		30	[5]	78	[7]
Less: Comprehensive (loss) income attributable to noncontrolling interests									(75)		(111)	[5]	(63)	[7]
Comprehensive Income Attributable to NRG Yield LLC									153		141	[5]	141	[7]
Noncontrolling Interest [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)									(75)		(111)	[3]	(62)	[3]
Consolidation, Eliminations [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)									(246)	[13]	(204)	[4],[5],[14],[15]	(239)	[7],[16]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax									(34)	[17]	(24)	[5],[15]	32	[7],[16]
Other comprehensive (loss) income									(34)	[17]	(24)	[5],[15]	32	[7],[16]
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest									(280)	[17]	(228)	[5],[15]	(207)	[7],[16]
Less: Comprehensive (loss) income attributable to noncontrolling interests									5	[17]	1	[5],[15]	2	[7],[16]
Comprehensive Income Attributable to NRG Yield LLC									$ (285)	[17]	$ (229)	[5],[15]	$ (209)	[7],[16]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[5]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[6]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[7]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[8]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[9]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[10]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[11]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[12]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[13]	(b) All significant intercompany transactions have been eliminated in consolidation.
[14]	(b) All significant intercompany transactions have been eliminated in consolidation.
[15]	(b) All significant intercompany transactions have been eliminated in consolidation.
[16]	(b) All significant intercompany transactions have been eliminated in consolidation.
[17]	(b) All significant intercompany transactions have been eliminated in consolidation.

Condensed Consolidating Fina103

Condensed Consolidating Financial Information CP Balance Sheet (Details) - USD ($) $ in Millions		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		$ 146		$ 321	[1]	$ 110
Restricted cash		168		176	[1]	$ 143
Accounts receivable — trade		96		96	[1]
Inventory		39		39	[1]
Notes receivable		13		16	[1]
Prepayments and other current assets		19		22	[1]
Total current assets		481		670	[1]
Property, Plant and Equipment, Net		5,204		5,554	[1]
Investment in consolidated subsidiaries		0		0
Equity investments in affiliates		1,178		1,152	[1]
Intangible assets, net		1,228		1,303	[1]
Other non-current assets		63		67	[1]
Total other assets		2,469		2,522	[1]
Total Assets		8,154		8,746	[1]
Current portion of long-term debt — external		306		323	[1]
Accounts payable — trade		27		23	[1]
Accounts payable — affiliate		48		40	[1]
Derivative instruments		17		33	[1]
Accrued expenses and other current liabilities		87		85	[1]
Total current liabilities		485		504	[1]
Other Liabilities
Long-term debt — external		4,921		5,128	[1]
Long-term debt — affiliate		618		618	[1]
Due to Related Parties, Noncurrent		0		9	[1]
Derivative instruments		31		46	[1]
Other non-current liabilities		91		77
Total non-current liabilities		5,661		5,878	[1]
Total Liabilities		6,146		6,382	[1]
Contributed capital		1,897		2,179	[1]
Retained earnings		17		44	[1]
Accumulated other comprehensive loss		(68)		(85)	[1]
Stockholders' Equity Attributable to Noncontrolling Interest		162		226
Total Members' Equity		2,008		2,364	[1]
Total Liabilities and Members’ Equity		8,154		8,746	[1]
Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		0		0
Restricted cash		0		0
Accounts receivable — trade		2		2
Inventory		1		2
Notes receivable		0		0
Prepayments and other current assets		0		0
Total current assets		3		4
Property, Plant and Equipment, Net		58		59
Investment in consolidated subsidiaries		460		527
Equity investments in affiliates		233		171
Intangible assets, net		55		56
Other non-current assets		0		0
Total other assets		748		754
Total Assets		809		817
Current portion of long-term debt — external		0		0
Accounts payable — trade		2		2
Accounts payable — affiliate		5		7
Derivative instruments		0		0
Accrued expenses and other current liabilities		1		1
Total current liabilities		8		10
Other Liabilities
Long-term debt — external		0		0
Long-term debt — affiliate		0		0
Due to Related Parties, Noncurrent				0
Derivative instruments		0		0
Other non-current liabilities		0		0
Total non-current liabilities		0		0
Total Liabilities		8		10
Contributed capital		863		874
Retained earnings		(61)		(65)
Accumulated other comprehensive loss		(1)		(2)
Stockholders' Equity Attributable to Noncontrolling Interest		0		0
Total Members' Equity		801		807
Total Liabilities and Members’ Equity		809		817
Non-Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		124		110	[2]
Restricted cash		168		176	[2]
Accounts receivable — trade		92		94	[2]
Inventory		38		37	[2]
Notes receivable		13		16	[2]
Prepayments and other current assets		18		21	[2]
Total current assets		453		454	[2]
Property, Plant and Equipment, Net		5,146		5,495	[2]
Investment in consolidated subsidiaries		0		0	[2]
Equity investments in affiliates		577		600	[2]
Intangible assets, net		1,173		1,247	[2]
Other non-current assets		63		66	[2]
Total other assets		1,813		1,913	[2]
Total Assets		7,412		7,862	[2]
Current portion of long-term debt — external		306		323	[3]
Accounts payable — trade		25		18	[3]
Accounts payable — affiliate		27		15	[3]
Derivative instruments		17		33	[3]
Accrued expenses and other current liabilities		61		60	[3]
Total current liabilities		436		449	[3]
Other Liabilities
Long-term debt — external		4,025		4,289	[3]
Long-term debt — affiliate		0		0	[3]
Due to Related Parties, Noncurrent	[3]			9
Derivative instruments		31		46	[3]
Other non-current liabilities		84		77	[3]
Total non-current liabilities		4,140		4,421	[3]
Total Liabilities		4,576		4,870	[3]
Contributed capital		2,871		2,972	[3]
Retained earnings		(21)		43	[3]
Accumulated other comprehensive loss		(71)		(87)	[3]
Stockholders' Equity Attributable to Noncontrolling Interest		57		64	[3]
Total Members' Equity		2,836		2,992	[3]
Total Liabilities and Members’ Equity		7,412		7,862	[3]
NRG Yield LLC [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		22	[4]	211	[2],[5]
Restricted cash		0	[4]	0	[2],[5]
Accounts receivable — trade		1	[4]	0	[2],[5]
Inventory		0	[4]	0	[2],[5]
Notes receivable		0	[4]	0	[2],[5]
Prepayments and other current assets		0	[4]	0	[2],[5]
Total current assets		23	[4]	211	[2],[5]
Property, Plant and Equipment, Net		0	[4]	0	[2],[5]
Investment in consolidated subsidiaries		1,823	[4]	1,927	[2],[5]
Equity investments in affiliates		0	[4]	0	[2],[5]
Intangible assets, net		0	[4]	0	[2],[5]
Other non-current assets		0	[4]	0	[2],[5]
Total other assets		1,823	[4]	1,927	[2],[5]
Total Assets		1,846	[4]	2,138	[2],[5]
Current portion of long-term debt — external		0	[6]	0	[3],[7]
Accounts payable — trade		0	[6]	0	[3],[7]
Accounts payable — affiliate		0	[6]	0	[3],[7]
Derivative instruments		0	[6]	0	[3],[7]
Accrued expenses and other current liabilities		0	[6]	0	[3],[7]
Total current liabilities		0	[6]	0	[3],[7]
Other Liabilities
Long-term debt — external		0	[6]	0	[3],[7]
Long-term debt — affiliate		0	[6]	0	[3],[7]
Due to Related Parties, Noncurrent	[3],[7]			0
Derivative instruments		0	[6]	0	[3],[7]
Other non-current liabilities		0	[6]	0	[3],[7]
Total non-current liabilities		0	[6]	0	[3],[7]
Total Liabilities		0	[6]	0	[3],[7]
Contributed capital		1,897	[6]	2,179	[3],[7]
Retained earnings		17	[6]	44	[3],[7]
Accumulated other comprehensive loss		(68)	[6]	(85)	[3],[7]
Stockholders' Equity Attributable to Noncontrolling Interest		0	[6]	0	[3],[7]
Total Members' Equity		1,846	[6]	2,138	[3],[7]
Total Liabilities and Members’ Equity		1,846	[6]	2,138	[3],[7]
NRG Yield Operating LLC [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		0		0	[2]
Restricted cash		0		0	[2]
Accounts receivable — trade		1		0	[2]
Inventory		0		0	[2]
Notes receivable		0		0	[2]
Prepayments and other current assets		1		1	[2]
Total current assets		2		1	[2]
Property, Plant and Equipment, Net		0		0	[2]
Investment in consolidated subsidiaries		3,177		3,272	[2]
Equity investments in affiliates		368		381	[2]
Intangible assets, net		0		0	[2]
Other non-current assets		0		1	[2]
Total other assets		3,545		3,654	[2]
Total Assets		3,547		3,655	[2]
Current portion of long-term debt — external		0		0	[3]
Accounts payable — trade		0		3	[3]
Accounts payable — affiliate		16		18	[3]
Derivative instruments		0		0	[3]
Accrued expenses and other current liabilities		25		24	[3]
Total current liabilities		41		45	[3]
Other Liabilities
Long-term debt — external		896		839	[3]
Long-term debt — affiliate		618		618	[3]
Due to Related Parties, Noncurrent	[3]			0
Derivative instruments		0		0	[3]
Other non-current liabilities		7		0	[3]
Total non-current liabilities		1,521		1,457	[3]
Total Liabilities		1,562		1,502	[3]
Contributed capital		2,097		2,155	[3]
Retained earnings		(206)		(143)	[3]
Accumulated other comprehensive loss		(68)		(85)	[3]
Stockholders' Equity Attributable to Noncontrolling Interest		162		226	[3]
Total Members' Equity		1,985		2,153	[3]
Total Liabilities and Members’ Equity		3,547		3,655	[3]
Consolidation, Eliminations [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		0	[8]	0	[2],[9]
Restricted cash		0	[8]	0	[2],[9]
Accounts receivable — trade		0	[8]	0	[2],[9]
Inventory		0	[8]	0	[2],[9]
Notes receivable		0	[8]	0	[2],[9]
Prepayments and other current assets		0	[8]	0	[2],[9]
Total current assets		0	[8]	0	[2],[9]
Property, Plant and Equipment, Net		0	[8]	0	[2],[9]
Investment in consolidated subsidiaries		(5,460)	[8]	(5,726)	[2],[9]
Equity investments in affiliates		0	[8]	0	[2],[9]
Intangible assets, net		0	[8]	0	[2],[9]
Other non-current assets		0	[8]	0	[2],[9]
Total other assets		(5,460)	[8]	(5,726)	[2],[9]
Total Assets		(5,460)	[8]	(5,726)	[2],[9]
Current portion of long-term debt — external		0	[10]	0	[3],[11]
Accounts payable — trade		0	[10]	0	[3],[11]
Accounts payable — affiliate		0	[10]	0	[3],[11]
Derivative instruments		0	[10]	0	[3],[11]
Accrued expenses and other current liabilities		0	[10]	0	[3],[11]
Total current liabilities		0	[10]	0	[3],[11]
Other Liabilities
Long-term debt — external		0	[10]	0	[3],[11]
Long-term debt — affiliate		0	[10]	0	[3],[11]
Due to Related Parties, Noncurrent	[3],[11]			0
Derivative instruments		0	[10]	0	[3],[11]
Other non-current liabilities		0	[10]	0	[3],[11]
Total non-current liabilities		0	[10]	0	[3],[11]
Total Liabilities		0	[10]	0	[3],[11]
Contributed capital		(5,831)	[10]	(6,001)	[3],[11]
Retained earnings		288	[10]	165	[3],[11]
Accumulated other comprehensive loss		140	[10]	174	[3],[11]
Stockholders' Equity Attributable to Noncontrolling Interest		(57)	[10]	(64)	[3],[11]
Total Members' Equity		(5,460)	[10]	(5,726)	[3],[11]
Total Liabilities and Members’ Equity		$ (5,460)	[10]	$ (5,726)	[3],[11]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[5]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[6]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[7]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[8]	(b) All significant intercompany transactions have been eliminated in consolidation.
[9]	(b) All significant intercompany transactions have been eliminated in consolidation.
[10]	(b) All significant intercompany transactions have been eliminated in consolidation.
[11]	(b) All significant intercompany transactions have been eliminated in consolidation.

Condensed Consolidating Fina104

Condensed Consolidating Financial Information CP Cash Flows (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities		$ 516		$ 577	[1]	$ 424	[1]
Intercompany transactions between Yield LLC and subsidiaries		0		0		0
Acquisition of businesses, net of cash acquired		0		0	[1]	37	[1]
Acquisition of Drop Down Assets, net of cash acquired		(250)		(77)	[1]	(698)	[1]
Capital expenditures		(31)		(20)	[1]	(29)	[1]
Cash receipts from notes receivable		17		17	[1]	17	[1]
Return of investment from unconsolidated affiliates		47		28	[1]	42	[1]
Investments in unconsolidated affiliates		(73)		(83)	[1]	(402)	[1]
Other		7		4	[1]	9	[1]
Net Cash Used in Investing Activities		(283)		(131)	[1]	(1,098)	[1]
Payments of Capital Distribution		(20)		(184)	[1]	(79)	[1]
Transfer of funds under intercompany cash management arrangement		0		0		0
Net contributions from noncontrolling interests		13		5	[1]	122	[1]
Proceeds from the issuance of Class C units		33		0	[1]	599	[1]
Payments of (Proceeds from) distributions		(202)		(173)		(139)
Proceeds from the revolving credit facility		55		60	[1]	551	[1]
Repayments of Lines of Credit		0		(366)	[1]	(245)	[1]
Proceeds from issuance of long-term debt — external		41		740	[1]	6	[1]
Proceeds from issuance of long-term debt — affiliate		0		0	[1]	281	[1]
Payments of debt issuance costs		(4)		(15)	[1]	(7)	[1]
Payments for long-term debt — external		(332)		(269)	[1]	(735)	[1]
Net Cash (Used in) Provided by Financing Activities		(416)		(202)	[1]	354	[1]
Cash and cash equivalents		146		321	[2]	110
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect		(183)		244		(320)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		314		497	[1]	253	[1]	$ 573	[1]
Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities		58		62		19
Intercompany transactions between Yield LLC and subsidiaries		0		0		0
Acquisition of businesses, net of cash acquired						0
Acquisition of Drop Down Assets, net of cash acquired		0				0
Capital expenditures		(4)		0		0
Cash receipts from notes receivable		0		0		0
Return of investment from unconsolidated affiliates		10		16		0
Investments in unconsolidated affiliates		(64)		(80)		(28)
Other		0		0		0
Net Cash Used in Investing Activities		(58)		(64)		(28)
Payments of Capital Distribution		0		0		0
Transfer of funds under intercompany cash management arrangement		0		2		9
Net contributions from noncontrolling interests		0
Proceeds from the issuance of Class C units		0				0
Payments of (Proceeds from) distributions		0		0		0
Proceeds from the revolving credit facility		0		0
Repayments of Lines of Credit				0		0
Proceeds from issuance of long-term debt — external		0		0		0
Proceeds from issuance of long-term debt — affiliate						0
Payments of debt issuance costs		0		0
Payments for long-term debt — external		0		0
Net Cash (Used in) Provided by Financing Activities		0		2		9
Cash and cash equivalents		0		0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect		0		0		0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		0		0		0		0
Non-Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities		529		554	[3]	423	[4]
Intercompany transactions between Yield LLC and subsidiaries		0		(21)	[3]	285	[4]
Acquisition of businesses, net of cash acquired	[4]					0
Acquisition of Drop Down Assets, net of cash acquired		0				0	[4]
Capital expenditures		(27)		(20)	[3]	(29)	[4]
Cash receipts from notes receivable		17		17	[3]	17	[4]
Return of investment from unconsolidated affiliates		14		0	[3]	0	[4]
Investments in unconsolidated affiliates		(7)		(3)	[3]	0	[4]
Other		7		4	[3]	9	[4]
Net Cash Used in Investing Activities		4		(23)	[3]	282	[4]
Payments of Capital Distribution		(13)		(174)	[3]	(79)	[4]
Transfer of funds under intercompany cash management arrangement		(1)		0	[3]	0	[4]
Net contributions from noncontrolling interests		2
Proceeds from the issuance of Class C units		0				0	[4]
Payments of (Proceeds from) distributions		(220)		(420)	[3]	(392)	[4]
Proceeds from the revolving credit facility		0		0	[3]
Repayments of Lines of Credit	[3]			0		0
Proceeds from issuance of long-term debt — external		41		390	[3]	6	[4]
Proceeds from issuance of long-term debt — affiliate	[4]					0
Payments of debt issuance costs		(4)		(10)	[3]
Payments for long-term debt — external		(332)		(269)	[3]
Net Cash (Used in) Provided by Financing Activities		(527)		(483)	[3]	(712)	[4]
Cash and cash equivalents		124		110	[5]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect		6		48	[3]	(7)	[4]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		292		286	[3]	238	[3],[4]	245	[4]
NRG Yield LLC [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities		0	[6]	0	[3],[7]	0	[4],[8]
Intercompany transactions between Yield LLC and subsidiaries		(15)	[6]	325	[3],[7]	(464)	[4],[8]
Acquisition of businesses, net of cash acquired	[4],[8]					0
Acquisition of Drop Down Assets, net of cash acquired		0	[6]			0	[4],[8]
Capital expenditures		0	[6]	0	[3],[7]	0	[4],[8]
Cash receipts from notes receivable		0	[6]	0	[3],[7]	0	[4],[8]
Return of investment from unconsolidated affiliates		0	[6]	0	[3],[7]	0	[4],[8]
Investments in unconsolidated affiliates		0	[6]	0	[3],[7]	0	[4],[8]
Other		0	[6]	0	[3],[7]	0	[4],[8]
Net Cash Used in Investing Activities		(15)	[6]	325	[3],[7]	(464)	[4],[8]
Payments of Capital Distribution		0	[6]	0	[3],[7]	0	[4],[8]
Transfer of funds under intercompany cash management arrangement		(5)	[6]	44	[3],[7]	(309)	[4],[8]
Net contributions from noncontrolling interests	[6]	0
Proceeds from the issuance of Class C units		33	[6]			599	[4],[8]
Payments of (Proceeds from) distributions		(202)	[6]	(173)	[3],[7]	(139)	[4],[8]
Proceeds from the revolving credit facility		0	[6]	0	[3],[7]
Repayments of Lines of Credit				0	[3],[7]	0	[4],[8]
Proceeds from issuance of long-term debt — external		0	[6]	0	[3],[7]	0	[4],[8]
Proceeds from issuance of long-term debt — affiliate	[4],[8]					0
Payments of debt issuance costs		0	[6]	0	[3],[7]
Payments for long-term debt — external		0	[6]	0	[3],[7]
Net Cash (Used in) Provided by Financing Activities		(174)	[6]	(129)	[3],[7]	151	[4],[8]
Cash and cash equivalents		22	[9]	211	[5],[10]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect		(189)	[6]	196	[3],[7]	(313)	[4],[8]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		22	[6]	211	[3],[6],[7]	15	[3],[4],[7],[8]	328	[4],[8]
NRG Yield Operating LLC [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities		(71)		(39)	[3]	(18)	[4]
Intercompany transactions between Yield LLC and subsidiaries		15		(304)	[3]	179	[4]
Acquisition of businesses, net of cash acquired	[4]					37
Acquisition of Drop Down Assets, net of cash acquired		(250)		(77)	[3]	(698)	[4]
Capital expenditures		0		0	[3]	0	[4]
Cash receipts from notes receivable		0		0	[3]	0	[4]
Return of investment from unconsolidated affiliates		23		12	[3]	42	[4]
Investments in unconsolidated affiliates		(2)		0	[3]	(374)	[4]
Other		0		0	[3]	0	[4]
Net Cash Used in Investing Activities		(214)		(369)	[3]	(888)	[4]
Payments of Capital Distribution		(7)		(10)	[3]	0	[4]
Transfer of funds under intercompany cash management arrangement		6		(46)	[3]	300	[4]
Net contributions from noncontrolling interests		11
Proceeds from the issuance of Class C units		0				0	[4]
Payments of (Proceeds from) distributions		220		420	[3]	392	[4]
Proceeds from the revolving credit facility		55		60	[3]
Repayments of Lines of Credit	[3]			(366)		(245)
Proceeds from issuance of long-term debt — external		0		350	[3]	0	[4]
Proceeds from issuance of long-term debt — affiliate	[4]					281
Payments of debt issuance costs		0		(5)	[3]
Payments for long-term debt — external		0		0	[3]
Net Cash (Used in) Provided by Financing Activities		285		408	[3]	906	[4]
Cash and cash equivalents		0		0	[5]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect		0		0	[3]	0	[4]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		0		0	[3]	$ 0	[3],[4]	$ 0	[4]
Consolidation, Eliminations [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Cash and cash equivalents		$ 0	[11]	$ 0	[5],[12]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[5]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[6]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[7]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[8]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[9]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[10]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[11]	(b) All significant intercompany transactions have been eliminated in consolidation.
[12]	(b) All significant intercompany transactions have been eliminated in consolidation.

Condensed Consolidating Fina105

Condensed Consolidating Financial Information PP Income Statement (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Condensed Income Statements, Captions [Line Items]
Total operating revenues	$ 231	$ 269	$ 288	$ 221	$ 235	$ 276	$ 287	$ 237	$ 1,009		$ 1,035	[1]	$ 968	[1]
Operating Costs and Expenses [Abstract]
Cost of operations									326		308	[1]	323	[1]
Depreciation and amortization									334		303	[1]	303	[1]
Impairment losses									44		185	[1],[2]	1	[1],[2]
General and administrative									19		14	[1]	10	[1]
Acquisition-related transaction and integration costs									3		1	[1]	3	[1]
Total operating costs and expenses									726		811	[1]	640	[1]
Operating Income	19	85	124	55	(100)	120	130	74	283		224	[1]	328	[1]
Equity in earnings (losses) of consolidated affiliates									0		0		0
Equity in earnings of unconsolidated affiliates									71		60	[1],[2]	31	[1],[2]
Loss on debt extinguishment									(3)		0	[1],[2]	(9)	[1],[2]
Other income, net									4		3	[1]	3	[1]
Interest expense									(293)		(272)	[1]	(258)	[1]
Total other income (expense), net									(221)		(209)	[1]	(233)	[1]
Net Income	$ (38)	$ 41	$ 59	$ 0	$ (138)	$ 68	$ 80	$ 5	62		15	[1],[3],[4]	95	[1],[3],[4]
Net Income (Loss) Attributable to Noncontrolling Interest									(75)		(111)	[1]	(62)	[1]
Net Income (Loss) Attributable to NRG Yield LLC									137		126	[1]	157	[1]
Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues									21		22		21	[5],[6]
Operating Costs and Expenses [Abstract]
Cost of operations									14		14		14
Depreciation and amortization									5		5		4
Impairment losses									0		0		0
General and administrative									0		0		0
Acquisition-related transaction and integration costs									0		0		0
Total operating costs and expenses									19		19		18
Operating Income									2		3		3
Equity in earnings (losses) of consolidated affiliates									(16)		10		(43)
Equity in earnings of unconsolidated affiliates									22		9		(2)
Loss on debt extinguishment									0				0
Other income, net									0		0		0
Interest expense									0		0		0
Total other income (expense), net									6		19		(45)
Net Income									8		22		(42)
Net Income (Loss) Attributable to Noncontrolling Interest									0		0		0
Net Income (Loss) Attributable to NRG Yield LLC									8		22		(42)
Non-Guarantor Subsidiaries [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues									988		1,013	[7]	937	[6]
Operating Costs and Expenses [Abstract]
Cost of operations									312		294	[7]	309	[6]
Depreciation and amortization									329		298	[7]	299	[6]
Impairment losses									44		185	[7]	1	[6]
General and administrative									0		0	[7]	0	[6]
Acquisition-related transaction and integration costs									0		0	[7]	0	[6]
Total operating costs and expenses									685		777	[7]	609	[6]
Operating Income									303		236	[7]	328	[6]
Equity in earnings (losses) of consolidated affiliates									0		0	[7]	0	[6]
Equity in earnings of unconsolidated affiliates									21		21	[7]	8	[6]
Loss on debt extinguishment									(3)				(9)	[6]
Other income, net									3		3	[7]	3	[6]
Interest expense									(222)		(206)	[7]	(206)	[6]
Total other income (expense), net									(201)		(182)	[7]	(204)	[6]
Net Income									102		54	[7],[8]	124	[6]
Net Income (Loss) Attributable to Noncontrolling Interest									(5)		(1)	[7]	(2)	[6]
Net Income (Loss) Attributable to NRG Yield LLC									107		55	[7]	126	[6]
NRG Yield LLC [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues									0	[9]	0	[7],[10]	0	[5],[7]
Operating Costs and Expenses [Abstract]
Cost of operations									0	[9]	0	[7],[10]	0	[5],[6]
Depreciation and amortization									0	[9]	0	[7],[10]	0	[5],[6]
Impairment losses									0	[9]	0	[7],[10]	0	[5],[6]
General and administrative									0	[9]	2	[7],[10]	0	[5],[6]
Acquisition-related transaction and integration costs									0	[9]	0	[7],[10]	0	[5],[6]
Total operating costs and expenses									0	[9]	2	[7],[10]	0	[5],[6]
Operating Income									0	[9]	(2)	[7],[10]	0	[5],[6]
Equity in earnings (losses) of consolidated affiliates									136	[11]	128	[7],[10]	157	[5],[6]
Equity in earnings of unconsolidated affiliates									0	[11]	0	[7],[10]	0	[5],[6]
Loss on debt extinguishment									0	[11]			0	[5],[6]
Other income, net									1	[11]	0	[7],[10]	0	[5],[6]
Interest expense									0	[11]	0	[7],[10]	0	[5],[6]
Total other income (expense), net									137	[11]	128	[7],[10]	157	[5],[6]
Net Income									137	[11]	126	[7],[8],[10],[12]	157	[13],[14]
Net Income (Loss) Attributable to Noncontrolling Interest									0	[9]	0	[7],[10]	0	[5],[6]
Net Income (Loss) Attributable to NRG Yield LLC									137	[9]	126	[7],[10]	157	[5],[6]
NRG Yield Operating LLC [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues									1		1	[7]	10	[6]
Operating Costs and Expenses [Abstract]
Cost of operations									1		1	[7]	0	[6]
Depreciation and amortization									0		0	[7]	0	[6]
Impairment losses									0		0	[7]	0	[6]
General and administrative									19		12	[7]	10	[6]
Acquisition-related transaction and integration costs									3		1	[7]	3	[6]
Total operating costs and expenses									23		14	[7]	13	[6]
Operating Income									(22)		(13)	[7]	(3)	[6]
Equity in earnings (losses) of consolidated affiliates									126		66	[7]	125	[6]
Equity in earnings of unconsolidated affiliates									28		30	[7]	25	[6]
Loss on debt extinguishment									0				0	[6]
Other income, net									0		0	[7]	0	[6]
Interest expense									(71)		(66)	[7]	(52)	[6]
Total other income (expense), net									83		30	[7]	98	[6]
Net Income									61		17	[7],[8]	95	[6]
Net Income (Loss) Attributable to Noncontrolling Interest									(75)		(111)	[7]	(62)	[6]
Net Income (Loss) Attributable to NRG Yield LLC									136		128	[7]	157	[6]
Consolidation, Eliminations [Member]
Condensed Income Statements, Captions [Line Items]
Total operating revenues									(1)	[15]	(1)	[7],[16]	0	[6],[17]
Operating Costs and Expenses [Abstract]
Cost of operations									(1)	[15]	(1)	[7],[16]	0	[6],[17]
Depreciation and amortization									0	[15]	0	[7],[16]	0	[6],[17]
Impairment losses									0	[15]	0	[7],[16]	0	[6],[17]
General and administrative									0	[15]	0	[7],[16]	0	[6],[17]
Acquisition-related transaction and integration costs									0	[15]	0	[7],[16]	0	[6],[17]
Total operating costs and expenses									(1)	[15]	(1)	[7],[16]	0	[6],[17]
Operating Income									0	[15]	0	[7],[16]	0	[6],[17]
Equity in earnings (losses) of consolidated affiliates									(246)	[15]	(204)	[7],[16]	(239)	[6],[17]
Equity in earnings of unconsolidated affiliates									0	[15]	0	[7],[16]	0	[6],[17]
Loss on debt extinguishment									0	[15]			0	[6],[17]
Other income, net									0	[15]	0	[7],[16]	0	[6],[17]
Interest expense									0	[15]	0	[7],[16]	0	[6],[17]
Total other income (expense), net									(246)	[15]	(204)	[7],[16]	(239)	[6],[17]
Net Income									(246)	[15]	(204)	[7],[8],[16],[18]	(239)	[14],[19]
Net Income (Loss) Attributable to Noncontrolling Interest									5	[15]	1	[7],[16]	2	[6],[17]
Net Income (Loss) Attributable to NRG Yield LLC									$ (251)	[15]	$ (205)	[7],[16]	$ (241)	[6],[17]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[5]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[6]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[7]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[8]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[9]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[10]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[11]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[12]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[13]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[14]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[15]	(b) All significant intercompany transactions have been eliminated in consolidation.
[16]	(b) All significant intercompany transactions have been eliminated in consolidation.
[17]	(b) All significant intercompany transactions have been eliminated in consolidation.
[18]	(b) All significant intercompany transactions have been eliminated in consolidation.
[19]	(b) All significant intercompany transactions have been eliminated in consolidation.

Condensed Consolidating Fina106

Condensed Consolidating Financial Information PP Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)	$ (38)	$ 41	$ 59	$ 0	$ (138)	$ 68	$ 80	$ 5	$ 62		$ 15	[1],[2],[3]	$ 95	[1],[2],[3]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax									17		13	[2]	(17)	[2]
Other comprehensive (loss) income									17		13	[2]	(17)	[2]
Comprehensive Income									79		28	[2]	78	[2]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest									(75)		(111)	[2]	(63)	[2]
Comprehensive Income Attributable to NRG Yield LLC									154		139	[2]	141	[2]
Guarantor Subsidiaries [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)									8		22		(42)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax									1		1		0
Other comprehensive (loss) income									1		1		0
Comprehensive Income									9		23		(42)
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest									0		0		0
Comprehensive Income Attributable to NRG Yield LLC									9		23		(42)
Non-Guarantor Subsidiaries [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)									102		54	[4],[5]	124	[6]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax									16		10	[5]	(16)	[7]
Other comprehensive (loss) income									16		10	[5]	(16)	[7]
Comprehensive Income									118		64	[5]	108	[7]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest									(5)		(1)	[5]	(2)	[7]
Comprehensive Income Attributable to NRG Yield LLC									123		65	[5]	110	[7]
NRG Yield LLC [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)									137	[8]	126	[4],[5],[9],[10]	157	[7],[11]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax									17	[12]	13	[5],[10]	(16)	[7],[11]
Other comprehensive (loss) income									17	[12]	13	[5],[10]	(16)	[7],[11]
Comprehensive Income									154	[12]	139	[5],[10]	141	[7],[11]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest									0	[12]	0	[5],[10]	0	[7],[11]
Comprehensive Income Attributable to NRG Yield LLC									154	[12]	139	[5],[10]	141	[7],[11]
NRG Yield Operating LLC [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)									61		17	[4],[5]	95	[6]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax									17		13	[5]	(17)	[7]
Other comprehensive (loss) income									17		13	[5]	(17)	[7]
Comprehensive Income									78		30	[5]	78	[7]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest									(75)		(111)	[5]	(63)	[7]
Comprehensive Income Attributable to NRG Yield LLC									153		141	[5]	141	[7]
Consolidation, Eliminations [Member]
Condensed Statement of Income Captions [Line Items]
Net Income (Loss)									(246)	[13]	(204)	[4],[5],[14],[15]	(239)	[7],[16]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax									(34)	[17]	(24)	[5],[15]	32	[7],[16]
Other comprehensive (loss) income									(34)	[17]	(24)	[5],[15]	32	[7],[16]
Comprehensive Income									(280)	[17]	(228)	[5],[15]	(207)	[7],[16]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest									5	[17]	1	[5],[15]	2	[7],[16]
Comprehensive Income Attributable to NRG Yield LLC									$ (285)	[17]	$ (229)	[5],[15]	$ (209)	[7],[16]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[5]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[6]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[7]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[8]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[9]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[10]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[11]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[12]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[13]	(b) All significant intercompany transactions have been eliminated in consolidation.
[14]	(b) All significant intercompany transactions have been eliminated in consolidation.
[15]	(b) All significant intercompany transactions have been eliminated in consolidation.
[16]	(b) All significant intercompany transactions have been eliminated in consolidation.
[17]	(b) All significant intercompany transactions have been eliminated in consolidation.

Condensed Consolidating Fina107

Condensed Consolidating Financial Information PP Balance Sheet (Details) - USD ($) $ in Millions		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		$ 146		$ 321	[1]	$ 110
Restricted cash		168		176	[1]	$ 143
Accounts receivable — trade		96		96	[1]
Inventory		39		39	[1]
Notes receivable		13		16	[1]
Prepayments and other current assets		19		22	[1]
Total current assets		481		670	[1]
Property, Plant and Equipment, Net		5,204		5,554	[1]
Investment in consolidated subsidiaries		0		0
Equity investments in affiliates		1,178		1,152	[1]
Intangible assets, net		1,228		1,303	[1]
Other non-current assets		63		67	[1]
Total other assets		2,469		2,522	[1]
Total Assets		8,154		8,746	[1]
Current portion of long-term debt — external		306		323	[1]
Accounts payable — trade		27		23	[1]
Accounts payable — affiliate		48		40	[1]
Derivative instruments		17		33	[1]
Accrued expenses and other current liabilities		87		85	[1]
Total current liabilities		485		504	[1]
Other Liabilities
Long-term debt — external		4,921		5,128	[1]
Long-term debt — affiliate		618		618	[1]
Due to Related Parties, Noncurrent		0		9	[1]
Derivative instruments		31		46	[1]
Other non-current liabilities		91		77
Total non-current liabilities		5,661		5,878	[1]
Total Liabilities		6,146		6,382	[1]
Contributed capital		1,897		2,179	[1]
Retained earnings		17		44	[1]
Accumulated other comprehensive loss		(68)		(85)	[1]
Stockholders' Equity Attributable to Noncontrolling Interest		162		226
Total Members' Equity		2,008		2,364	[1]
Total Liabilities and Members’ Equity		8,154		8,746	[1]
Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		0		0
Restricted cash		0		0
Accounts receivable — trade		2		2
Inventory		1		2
Notes receivable		0		0
Prepayments and other current assets		0		0
Total current assets		3		4
Property, Plant and Equipment, Net		58		59
Investment in consolidated subsidiaries		460		527
Equity investments in affiliates		233		171
Intangible assets, net		55		56
Other non-current assets		0		0
Total other assets		748		754
Total Assets		809		817
Current portion of long-term debt — external		0		0
Accounts payable — trade		2		2
Accounts payable — affiliate		5		7
Derivative instruments		0		0
Accrued expenses and other current liabilities		1		1
Total current liabilities		8		10
Other Liabilities
Long-term debt — external		0		0
Long-term debt — affiliate		0		0
Due to Related Parties, Noncurrent				0
Derivative instruments		0		0
Other non-current liabilities		0		0
Total non-current liabilities		0		0
Total Liabilities		8		10
Contributed capital		863		874
Retained earnings		(61)		(65)
Accumulated other comprehensive loss		(1)		(2)
Stockholders' Equity Attributable to Noncontrolling Interest		0		0
Total Members' Equity		801		807
Total Liabilities and Members’ Equity		809		817
Non-Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		124		110	[2]
Restricted cash		168		176	[2]
Accounts receivable — trade		92		94	[2]
Inventory		38		37	[2]
Notes receivable		13		16	[2]
Prepayments and other current assets		18		21	[2]
Total current assets		453		454	[2]
Property, Plant and Equipment, Net		5,146		5,495	[2]
Investment in consolidated subsidiaries		0		0	[2]
Equity investments in affiliates		577		600	[2]
Intangible assets, net		1,173		1,247	[2]
Other non-current assets		63		66	[2]
Total other assets		1,813		1,913	[2]
Total Assets		7,412		7,862	[2]
Current portion of long-term debt — external		306		323	[3]
Accounts payable — trade		25		18	[3]
Accounts payable — affiliate		27		15	[3]
Derivative instruments		17		33	[3]
Accrued expenses and other current liabilities		61		60	[3]
Total current liabilities		436		449	[3]
Other Liabilities
Long-term debt — external		4,025		4,289	[3]
Long-term debt — affiliate		0		0	[3]
Due to Related Parties, Noncurrent	[3]			9
Derivative instruments		31		46	[3]
Other non-current liabilities		84		77	[3]
Total non-current liabilities		4,140		4,421	[3]
Total Liabilities		4,576		4,870	[3]
Contributed capital		2,871		2,972	[3]
Retained earnings		(21)		43	[3]
Accumulated other comprehensive loss		(71)		(87)	[3]
Stockholders' Equity Attributable to Noncontrolling Interest		57		64	[3]
Total Members' Equity		2,836		2,992	[3]
Total Liabilities and Members’ Equity		7,412		7,862	[3]
NRG Yield LLC [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		22	[4]	211	[2],[5]
Restricted cash		0	[4]	0	[2],[5]
Accounts receivable — trade		1	[4]	0	[2],[5]
Inventory		0	[4]	0	[2],[5]
Notes receivable		0	[4]	0	[2],[5]
Prepayments and other current assets		0	[4]	0	[2],[5]
Total current assets		23	[4]	211	[2],[5]
Property, Plant and Equipment, Net		0	[4]	0	[2],[5]
Investment in consolidated subsidiaries		1,823	[4]	1,927	[2],[5]
Equity investments in affiliates		0	[4]	0	[2],[5]
Intangible assets, net		0	[4]	0	[2],[5]
Other non-current assets		0	[4]	0	[2],[5]
Total other assets		1,823	[4]	1,927	[2],[5]
Total Assets		1,846	[4]	2,138	[2],[5]
Current portion of long-term debt — external		0	[6]	0	[3],[7]
Accounts payable — trade		0	[6]	0	[3],[7]
Accounts payable — affiliate		0	[6]	0	[3],[7]
Derivative instruments		0	[6]	0	[3],[7]
Accrued expenses and other current liabilities		0	[6]	0	[3],[7]
Total current liabilities		0	[6]	0	[3],[7]
Other Liabilities
Long-term debt — external		0	[6]	0	[3],[7]
Long-term debt — affiliate		0	[6]	0	[3],[7]
Due to Related Parties, Noncurrent	[3],[7]			0
Derivative instruments		0	[6]	0	[3],[7]
Other non-current liabilities		0	[6]	0	[3],[7]
Total non-current liabilities		0	[6]	0	[3],[7]
Total Liabilities		0	[6]	0	[3],[7]
Contributed capital		1,897	[6]	2,179	[3],[7]
Retained earnings		17	[6]	44	[3],[7]
Accumulated other comprehensive loss		(68)	[6]	(85)	[3],[7]
Stockholders' Equity Attributable to Noncontrolling Interest		0	[6]	0	[3],[7]
Total Members' Equity		1,846	[6]	2,138	[3],[7]
Total Liabilities and Members’ Equity		1,846	[6]	2,138	[3],[7]
NRG Yield Operating LLC [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		0		0	[2]
Restricted cash		0		0	[2]
Accounts receivable — trade		1		0	[2]
Inventory		0		0	[2]
Notes receivable		0		0	[2]
Prepayments and other current assets		1		1	[2]
Total current assets		2		1	[2]
Property, Plant and Equipment, Net		0		0	[2]
Investment in consolidated subsidiaries		3,177		3,272	[2]
Equity investments in affiliates		368		381	[2]
Intangible assets, net		0		0	[2]
Other non-current assets		0		1	[2]
Total other assets		3,545		3,654	[2]
Total Assets		3,547		3,655	[2]
Current portion of long-term debt — external		0		0	[3]
Accounts payable — trade		0		3	[3]
Accounts payable — affiliate		16		18	[3]
Derivative instruments		0		0	[3]
Accrued expenses and other current liabilities		25		24	[3]
Total current liabilities		41		45	[3]
Other Liabilities
Long-term debt — external		896		839	[3]
Long-term debt — affiliate		618		618	[3]
Due to Related Parties, Noncurrent	[3]			0
Derivative instruments		0		0	[3]
Other non-current liabilities		7		0	[3]
Total non-current liabilities		1,521		1,457	[3]
Total Liabilities		1,562		1,502	[3]
Contributed capital		2,097		2,155	[3]
Retained earnings		(206)		(143)	[3]
Accumulated other comprehensive loss		(68)		(85)	[3]
Stockholders' Equity Attributable to Noncontrolling Interest		162		226	[3]
Total Members' Equity		1,985		2,153	[3]
Total Liabilities and Members’ Equity		3,547		3,655	[3]
Consolidation, Eliminations [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		0	[8]	0	[2],[9]
Restricted cash		0	[8]	0	[2],[9]
Accounts receivable — trade		0	[8]	0	[2],[9]
Inventory		0	[8]	0	[2],[9]
Notes receivable		0	[8]	0	[2],[9]
Prepayments and other current assets		0	[8]	0	[2],[9]
Total current assets		0	[8]	0	[2],[9]
Property, Plant and Equipment, Net		0	[8]	0	[2],[9]
Investment in consolidated subsidiaries		(5,460)	[8]	(5,726)	[2],[9]
Equity investments in affiliates		0	[8]	0	[2],[9]
Intangible assets, net		0	[8]	0	[2],[9]
Other non-current assets		0	[8]	0	[2],[9]
Total other assets		(5,460)	[8]	(5,726)	[2],[9]
Total Assets		(5,460)	[8]	(5,726)	[2],[9]
Current portion of long-term debt — external		0	[10]	0	[3],[11]
Accounts payable — trade		0	[10]	0	[3],[11]
Accounts payable — affiliate		0	[10]	0	[3],[11]
Derivative instruments		0	[10]	0	[3],[11]
Accrued expenses and other current liabilities		0	[10]	0	[3],[11]
Total current liabilities		0	[10]	0	[3],[11]
Other Liabilities
Long-term debt — external		0	[10]	0	[3],[11]
Long-term debt — affiliate		0	[10]	0	[3],[11]
Due to Related Parties, Noncurrent	[3],[11]			0
Derivative instruments		0	[10]	0	[3],[11]
Other non-current liabilities		0	[10]	0	[3],[11]
Total non-current liabilities		0	[10]	0	[3],[11]
Total Liabilities		0	[10]	0	[3],[11]
Contributed capital		(5,831)	[10]	(6,001)	[3],[11]
Retained earnings		288	[10]	165	[3],[11]
Accumulated other comprehensive loss		140	[10]	174	[3],[11]
Stockholders' Equity Attributable to Noncontrolling Interest		(57)	[10]	(64)	[3],[11]
Total Members' Equity		(5,460)	[10]	(5,726)	[3],[11]
Total Liabilities and Members’ Equity		$ (5,460)	[10]	$ (5,726)	[3],[11]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[5]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[6]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[7]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[8]	(b) All significant intercompany transactions have been eliminated in consolidation.
[9]	(b) All significant intercompany transactions have been eliminated in consolidation.
[10]	(b) All significant intercompany transactions have been eliminated in consolidation.
[11]	(b) All significant intercompany transactions have been eliminated in consolidation.

Condensed Consolidating Fina108

Condensed Consolidating Financial Information PP Cash Flows (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities		$ 516		$ 577	[1]	$ 424	[1]
Acquisition of businesses, net of cash acquired		0		0	[1]	37	[1]
Intercompany (Payments to) Receipts from Consolidated Subsidiaries		0		0		0
Acquisition of Drop Down Assets, net of cash acquired		250		77	[1]	698	[1]
Capital expenditures		(31)		(20)	[1]	(29)	[1]
Cash receipts from notes receivable		17		17	[1]	17	[1]
Return of investment from unconsolidated affiliates		47		28	[1]	42	[1]
Investments in unconsolidated affiliates		(73)		(83)	[1]	(402)	[1]
Other		7		4	[1]	9	[1]
Net Cash Used in Investing Activities		(283)		(131)	[1]	(1,098)	[1]
Proceeds from Noncontrolling Interests		11		5		122
Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets		(20)		(184)	[1]	(79)	[1]
Proceeds from the issuance of class C units		33		0	[1]	599	[1]
Transfer of funds under intercompany cash management arrangement		0		0		0
Payments of (Proceeds from) distributions		(202)		(173)		(139)
Proceeds from the revolving credit facility		55		60	[1]	551	[1]
Repayments of Lines of Credit		0		(366)	[1]	(245)	[1]
Proceeds from issuance of long-term debt — external		41		740	[1]	6	[1]
Payments for long-term debt — external						(735)
Proceeds from issuance of long-term debt — affiliate		0		0	[1]	281	[1]
Payment of debt issuance costs						(7)
Net Cash (Used in) Provided by Financing Activities		(416)		(202)	[1]	354	[1]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect		(183)		244		(320)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		314		497	[1]	253	[1]	$ 573	[1]
Payments of Debt Issuance Costs		4		15	[1]	7	[1]
Proceeds from (Repayments of) Lines of Credit						551
Repayments of Long-term Debt		332		269	[1]	735	[1]
Cash and Cash Equivalents, at Carrying Value		146		321	[2]	110
Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities		58		62		19
Acquisition of businesses, net of cash acquired						0
Intercompany (Payments to) Receipts from Consolidated Subsidiaries		0		0		0
Acquisition of Drop Down Assets, net of cash acquired		0				0
Capital expenditures		(4)		0		0
Cash receipts from notes receivable		0		0		0
Return of investment from unconsolidated affiliates		10		16		0
Investments in unconsolidated affiliates		(64)		(80)		(28)
Other		0		0		0
Net Cash Used in Investing Activities		(58)		(64)		(28)
Proceeds from Noncontrolling Interests				0		0
Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets		0		0		0
Proceeds from the issuance of class C units		0				0
Transfer of funds under intercompany cash management arrangement		0		2		9
Payments of (Proceeds from) distributions		0		0		0
Proceeds from the revolving credit facility		0		0
Repayments of Lines of Credit				0		0
Proceeds from issuance of long-term debt — external		0		0		0
Payments for long-term debt — external						0
Proceeds from issuance of long-term debt — affiliate						0
Payment of debt issuance costs						0
Net Cash (Used in) Provided by Financing Activities		0		2		9
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect		0		0		0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		0		0		0		0
Payments of Debt Issuance Costs		0		0
Proceeds from (Repayments of) Lines of Credit						0
Repayments of Long-term Debt		0		0
Cash and Cash Equivalents, at Carrying Value		0		0
Non-Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities		529		554	[3]	423	[4]
Acquisition of businesses, net of cash acquired	[4]					0
Intercompany (Payments to) Receipts from Consolidated Subsidiaries		0		(21)	[3]	285	[4]
Acquisition of Drop Down Assets, net of cash acquired		0				0	[4]
Capital expenditures		(27)		(20)	[3]	(29)	[4]
Cash receipts from notes receivable		17		17	[3]	17	[4]
Return of investment from unconsolidated affiliates		14		0	[3]	0	[4]
Investments in unconsolidated affiliates		(7)		(3)	[3]	0	[4]
Other		7		4	[3]	9	[4]
Net Cash Used in Investing Activities		4		(23)	[3]	282	[4]
Proceeds from Noncontrolling Interests				0	[3]	0	[4]
Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets		(13)		(174)	[3]	(79)	[4]
Proceeds from the issuance of class C units		0				0	[4]
Transfer of funds under intercompany cash management arrangement		(1)		0	[3]	0	[4]
Payments of (Proceeds from) distributions		(220)		(420)	[3]	(392)	[4]
Proceeds from the revolving credit facility		0		0	[3]
Repayments of Lines of Credit	[3]			0		0
Proceeds from issuance of long-term debt — external		41		390	[3]	6	[4]
Payments for long-term debt — external	[4]					(241)
Proceeds from issuance of long-term debt — affiliate	[4]					0
Payment of debt issuance costs	[4]					(6)
Net Cash (Used in) Provided by Financing Activities		(527)		(483)	[3]	(712)	[4]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect		6		48	[3]	(7)	[4]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		292		286	[3]	238	[3],[4]	245	[4]
Payments of Debt Issuance Costs		4		10	[3]
Proceeds from (Repayments of) Lines of Credit	[3]					0
Repayments of Long-term Debt		332		269	[3]
Cash and Cash Equivalents, at Carrying Value		124		110	[5]
NRG Yield LLC [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities		0	[6]	0	[3],[7]	0	[4],[8]
Acquisition of businesses, net of cash acquired	[4],[8]					0
Intercompany (Payments to) Receipts from Consolidated Subsidiaries		(15)	[6]	325	[3],[7]	(464)	[4],[8]
Acquisition of Drop Down Assets, net of cash acquired		0	[6]			0	[4],[8]
Capital expenditures		0	[6]	0	[3],[7]	0	[4],[8]
Cash receipts from notes receivable		0	[6]	0	[3],[7]	0	[4],[8]
Return of investment from unconsolidated affiliates		0	[6]	0	[3],[7]	0	[4],[8]
Investments in unconsolidated affiliates		0	[6]	0	[3],[7]	0	[4],[8]
Other		0	[6]	0	[3],[7]	0	[4],[8]
Net Cash Used in Investing Activities		(15)	[6]	325	[3],[7]	(464)	[4],[8]
Proceeds from Noncontrolling Interests				0	[3],[7]	0	[4],[8]
Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets		0	[6]	0	[3],[7]	0	[4],[8]
Proceeds from the issuance of class C units		33	[6]			599	[4],[8]
Transfer of funds under intercompany cash management arrangement		(5)	[6]	44	[3],[7]	(309)	[4],[8]
Payments of (Proceeds from) distributions		(202)	[6]	(173)	[3],[7]	(139)	[4],[8]
Proceeds from the revolving credit facility		0	[6]	0	[3],[7]
Repayments of Lines of Credit				0	[3],[7]	0	[4],[8]
Proceeds from issuance of long-term debt — external		0	[6]	0	[3],[7]	0	[4],[8]
Payments for long-term debt — external	[4],[8]					0
Proceeds from issuance of long-term debt — affiliate	[4],[8]					0
Payment of debt issuance costs	[4],[8]					0
Net Cash (Used in) Provided by Financing Activities		(174)	[6]	(129)	[3],[7]	151	[4],[8]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect		(189)	[6]	196	[3],[7]	(313)	[4],[8]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		22	[6]	211	[3],[6],[7]	15	[3],[4],[7],[8]	328	[4],[8]
Payments of Debt Issuance Costs		0	[6]	0	[3],[7]
Proceeds from (Repayments of) Lines of Credit	[4],[8]					0
Repayments of Long-term Debt		0	[6]	0	[3],[7]
Cash and Cash Equivalents, at Carrying Value		22	[9]	211	[5],[10]
NRG Yield Operating LLC [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities		(71)		(39)	[3]	(18)	[4]
Acquisition of businesses, net of cash acquired	[4]					37
Intercompany (Payments to) Receipts from Consolidated Subsidiaries		15		(304)	[3]	179	[4]
Acquisition of Drop Down Assets, net of cash acquired		250		77	[3]	698	[4]
Capital expenditures		0		0	[3]	0	[4]
Cash receipts from notes receivable		0		0	[3]	0	[4]
Return of investment from unconsolidated affiliates		23		12	[3]	42	[4]
Investments in unconsolidated affiliates		(2)		0	[3]	(374)	[4]
Other		0		0	[3]	0	[4]
Net Cash Used in Investing Activities		(214)		(369)	[3]	(888)	[4]
Proceeds from Noncontrolling Interests				5	[3]	122	[4]
Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets		(7)		(10)	[3]	0	[4]
Proceeds from the issuance of class C units		0				0	[4]
Transfer of funds under intercompany cash management arrangement		6		(46)	[3]	300	[4]
Payments of (Proceeds from) distributions		220		420	[3]	392	[4]
Proceeds from the revolving credit facility		55		60	[3]
Repayments of Lines of Credit	[3]			(366)		(245)
Proceeds from issuance of long-term debt — external		0		350	[3]	0	[4]
Payments for long-term debt — external	[4]					(494)
Proceeds from issuance of long-term debt — affiliate	[4]					281
Payment of debt issuance costs	[4]					(1)
Net Cash (Used in) Provided by Financing Activities		285		408	[3]	906	[4]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect		0		0	[3]	0	[4]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		0		0	[3]	0	[3],[4]	$ 0	[4]
Payments of Debt Issuance Costs		0		5	[3]
Proceeds from (Repayments of) Lines of Credit	[3]					$ 551
Repayments of Long-term Debt		0		0	[3]
Cash and Cash Equivalents, at Carrying Value		$ 0		0	[5]
Drop Down Assets [Member] | Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Acquisition of Drop Down Assets, net of cash acquired				0
Drop Down Assets [Member] | Non-Guarantor Subsidiaries [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Acquisition of Drop Down Assets, net of cash acquired	[3]			0
Drop Down Assets [Member] | NRG Yield LLC [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Acquisition of Drop Down Assets, net of cash acquired	[3],[7]			$ 0
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[5]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[6]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[7]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[8]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[9]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[10]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.

Condensed Consolidating Fina109

Condensed Consolidating Financial Information PP2 Income Statement (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Total operating revenues	$ 231	$ 269	$ 288	$ 221	$ 235	$ 276	$ 287	$ 237	$ 1,009		$ 1,035	[1]	$ 968	[1]
Cost of operations									326		308	[1]	323	[1]
Depreciation, Depletion and Amortization									334		303	[1]	303	[1]
Asset Impairment Charges									44		185	[1],[2]	1	[1],[2]
General and Administrative Expense									19		14	[1]	10	[1]
Business Combination, Acquisition Related Costs									3		1	[1]	3	[1]
Total operating costs and expenses									726		811	[1]	640	[1]
Operating Income	19	85	124	55	(100)	120	130	74	283		224	[1]	328	[1]
Equity in earnings (losses) of consolidated affiliates									0		0		0
Income (Loss) from Equity Method Investments									71		60	[1],[2]	31	[1],[2]
Other Nonoperating Income (Expense)									4		3	[1]	3	[1]
Loss on debt extinguishment									(3)		0	[1],[2]	(9)	[1],[2]
Interest expense									(293)		(272)	[1]	(258)	[1]
Total other income (expense), net									(221)		(209)	[1]	(233)	[1]
Income Before Income Taxes											15		95
Net Income	$ (38)	$ 41	$ 59	$ 0	$ (138)	$ 68	$ 80	$ 5	62		15	[1],[3],[4]	95	[1],[3],[4]
Net Income (Loss) Attributable to Noncontrolling Interest									(75)		(111)	[1]	(62)	[1]
Net Income (Loss) Attributable to NRG Yield LLC									137		126	[1]	157	[1]
Guarantor Subsidiaries [Member]
Total operating revenues									21		22		21	[5],[6]
Cost of operations									14		14		14
Depreciation, Depletion and Amortization									5		5		4
Asset Impairment Charges									0		0		0
General and Administrative Expense									0		0		0
Business Combination, Acquisition Related Costs									0		0		0
Total operating costs and expenses									19		19		18
Operating Income									2		3		3
Equity in earnings (losses) of consolidated affiliates									(16)		10		(43)
Income (Loss) from Equity Method Investments									22		9		(2)
Other Nonoperating Income (Expense)									0		0		0
Loss on debt extinguishment									0				0
Interest expense									0		0		0
Total other income (expense), net									6		19		(45)
Net Income									8		22		(42)
Net Income (Loss) Attributable to Noncontrolling Interest									0		0		0
Net Income (Loss) Attributable to NRG Yield LLC									8		22		(42)
Non-Guarantor Subsidiaries [Member]
Total operating revenues									988		1,013	[7]	937	[6]
Cost of operations									312		294	[7]	309	[6]
Depreciation, Depletion and Amortization									329		298	[7]	299	[6]
Asset Impairment Charges									44		185	[7]	1	[6]
General and Administrative Expense									0		0	[7]	0	[6]
Business Combination, Acquisition Related Costs									0		0	[7]	0	[6]
Total operating costs and expenses									685		777	[7]	609	[6]
Operating Income									303		236	[7]	328	[6]
Equity in earnings (losses) of consolidated affiliates									0		0	[7]	0	[6]
Income (Loss) from Equity Method Investments									21		21	[7]	8	[6]
Other Nonoperating Income (Expense)									3		3	[7]	3	[6]
Loss on debt extinguishment									(3)				(9)	[6]
Interest expense									(222)		(206)	[7]	(206)	[6]
Total other income (expense), net									(201)		(182)	[7]	(204)	[6]
Net Income									102		54	[7],[8]	124	[6]
Net Income (Loss) Attributable to Noncontrolling Interest									(5)		(1)	[7]	(2)	[6]
Net Income (Loss) Attributable to NRG Yield LLC									107		55	[7]	126	[6]
NRG Yield LLC [Member]
Total operating revenues									0	[9]	0	[7],[10]	0	[5],[7]
Cost of operations									0	[9]	0	[7],[10]	0	[5],[6]
Depreciation, Depletion and Amortization									0	[9]	0	[7],[10]	0	[5],[6]
Asset Impairment Charges									0	[9]	0	[7],[10]	0	[5],[6]
General and Administrative Expense									0	[9]	2	[7],[10]	0	[5],[6]
Business Combination, Acquisition Related Costs									0	[9]	0	[7],[10]	0	[5],[6]
Total operating costs and expenses									0	[9]	2	[7],[10]	0	[5],[6]
Operating Income									0	[9]	(2)	[7],[10]	0	[5],[6]
Equity in earnings (losses) of consolidated affiliates									136	[11]	128	[7],[10]	157	[5],[6]
Income (Loss) from Equity Method Investments									0	[11]	0	[7],[10]	0	[5],[6]
Other Nonoperating Income (Expense)									1	[11]	0	[7],[10]	0	[5],[6]
Loss on debt extinguishment									0	[11]			0	[5],[6]
Interest expense									0	[11]	0	[7],[10]	0	[5],[6]
Total other income (expense), net									137	[11]	128	[7],[10]	157	[5],[6]
Net Income									137	[11]	126	[7],[8],[10],[12]	157	[13],[14]
Net Income (Loss) Attributable to Noncontrolling Interest									0	[9]	0	[7],[10]	0	[5],[6]
Net Income (Loss) Attributable to NRG Yield LLC									137	[9]	126	[7],[10]	157	[5],[6]
NRG Yield Operating LLC [Member]
Total operating revenues									1		1	[7]	10	[6]
Cost of operations									1		1	[7]	0	[6]
Depreciation, Depletion and Amortization									0		0	[7]	0	[6]
Asset Impairment Charges									0		0	[7]	0	[6]
General and Administrative Expense									19		12	[7]	10	[6]
Business Combination, Acquisition Related Costs									3		1	[7]	3	[6]
Total operating costs and expenses									23		14	[7]	13	[6]
Operating Income									(22)		(13)	[7]	(3)	[6]
Equity in earnings (losses) of consolidated affiliates									126		66	[7]	125	[6]
Income (Loss) from Equity Method Investments									28		30	[7]	25	[6]
Other Nonoperating Income (Expense)									0		0	[7]	0	[6]
Loss on debt extinguishment									0				0	[6]
Interest expense									(71)		(66)	[7]	(52)	[6]
Total other income (expense), net									83		30	[7]	98	[6]
Net Income									61		17	[7],[8]	95	[6]
Net Income (Loss) Attributable to Noncontrolling Interest									(75)		(111)	[7]	(62)	[6]
Net Income (Loss) Attributable to NRG Yield LLC									136		128	[7]	157	[6]
Consolidation, Eliminations [Member]
Total operating revenues									(1)	[15]	(1)	[7],[16]	0	[6],[17]
Cost of operations									(1)	[15]	(1)	[7],[16]	0	[6],[17]
Depreciation, Depletion and Amortization									0	[15]	0	[7],[16]	0	[6],[17]
Asset Impairment Charges									0	[15]	0	[7],[16]	0	[6],[17]
General and Administrative Expense									0	[15]	0	[7],[16]	0	[6],[17]
Business Combination, Acquisition Related Costs									0	[15]	0	[7],[16]	0	[6],[17]
Total operating costs and expenses									(1)	[15]	(1)	[7],[16]	0	[6],[17]
Operating Income									0	[15]	0	[7],[16]	0	[6],[17]
Equity in earnings (losses) of consolidated affiliates									(246)	[15]	(204)	[7],[16]	(239)	[6],[17]
Income (Loss) from Equity Method Investments									0	[15]	0	[7],[16]	0	[6],[17]
Other Nonoperating Income (Expense)									0	[15]	0	[7],[16]	0	[6],[17]
Loss on debt extinguishment									0	[15]			0	[6],[17]
Interest expense									0	[15]	0	[7],[16]	0	[6],[17]
Total other income (expense), net									(246)	[15]	(204)	[7],[16]	(239)	[6],[17]
Net Income									(246)	[15]	(204)	[7],[8],[16],[18]	(239)	[14],[19]
Net Income (Loss) Attributable to Noncontrolling Interest									5	[15]	1	[7],[16]	2	[6],[17]
Net Income (Loss) Attributable to NRG Yield LLC									$ (251)	[15]	$ (205)	[7],[16]	$ (241)	[6],[17]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[5]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[6]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[7]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[8]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[9]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[10]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[11]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[12]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[13]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[14]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[15]	(b) All significant intercompany transactions have been eliminated in consolidation.
[16]	(b) All significant intercompany transactions have been eliminated in consolidation.
[17]	(b) All significant intercompany transactions have been eliminated in consolidation.
[18]	(b) All significant intercompany transactions have been eliminated in consolidation.
[19]	(b) All significant intercompany transactions have been eliminated in consolidation.

Condensed Consolidating Fina110

Condensed Consolidating Financial Information PP2 Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Net Income (Loss)	$ (38)	$ 41	$ 59	$ 0	$ (138)	$ 68	$ 80	$ 5	$ 62		$ 15	[1],[2],[3]	$ 95	[1],[2],[3]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax									17		13	[2]	(17)	[2]
Other comprehensive (loss) income									17		13	[2]	(17)	[2]
Comprehensive Income									79		28	[2]	78	[2]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest									(75)		(111)	[2]	(63)	[2]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									154		139	[2]	141	[2]
Guarantor Subsidiaries [Member]
Net Income (Loss)									8		22		(42)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax									1		1		0
Other comprehensive (loss) income									1		1		0
Comprehensive Income									9		23		(42)
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest									0		0		0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									9		23		(42)
Non-Guarantor Subsidiaries [Member]
Net Income (Loss)									102		54	[4],[5]	124	[6]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax									16		10	[5]	(16)	[7]
Other comprehensive (loss) income									16		10	[5]	(16)	[7]
Comprehensive Income									118		64	[5]	108	[7]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest									(5)		(1)	[5]	(2)	[7]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									123		65	[5]	110	[7]
NRG Yield Operating LLC [Member]
Net Income (Loss)									61		17	[4],[5]	95	[6]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax									17		13	[5]	(17)	[7]
Other comprehensive (loss) income									17		13	[5]	(17)	[7]
Comprehensive Income									78		30	[5]	78	[7]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest									(75)		(111)	[5]	(63)	[7]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									153		141	[5]	141	[7]
NRG Yield LLC [Member]
Net Income (Loss)									137	[8]	126	[4],[5],[9],[10]	157	[7],[11]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax									17	[12]	13	[5],[10]	(16)	[7],[11]
Other comprehensive (loss) income									17	[12]	13	[5],[10]	(16)	[7],[11]
Comprehensive Income									154	[12]	139	[5],[10]	141	[7],[11]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest									0	[12]	0	[5],[10]	0	[7],[11]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									154	[12]	139	[5],[10]	141	[7],[11]
Consolidation, Eliminations [Member]
Net Income (Loss)									(246)	[13]	(204)	[4],[5],[14],[15]	(239)	[7],[16]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax									(34)	[17]	(24)	[5],[15]	32	[7],[16]
Other comprehensive (loss) income									(34)	[17]	(24)	[5],[15]	32	[7],[16]
Comprehensive Income									(280)	[17]	(228)	[5],[15]	(207)	[7],[16]
Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest									5	[17]	1	[5],[15]	2	[7],[16]
Comprehensive Income (Loss), Net of Tax, Attributable to Parent									$ (285)	[17]	$ (229)	[5],[15]	$ (209)	[7],[16]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[5]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[6]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[7]	(c) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[8]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[9]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[10]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[11]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[12]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[13]	(b) All significant intercompany transactions have been eliminated in consolidation.
[14]	(b) All significant intercompany transactions have been eliminated in consolidation.
[15]	(b) All significant intercompany transactions have been eliminated in consolidation.
[16]	(b) All significant intercompany transactions have been eliminated in consolidation.
[17]	(b) All significant intercompany transactions have been eliminated in consolidation.

Condensed Consolidating Fina111

Condensed Consolidating Financial Information PP2 Cash Flows (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015		Dec. 31, 2014
Net Cash Provided by Operating Activities		$ 516		$ 577	[1]	$ 424	[1]
Intercompany (Payments to) Receipts from Consolidated Subsidiaries		0		0		0
Acquisition of businesses, net of cash acquired		0		0	[1]	37	[1]
Acquisition of Drop Down Assets, net of cash acquired		(250)		(77)	[1]	(698)	[1]
Payments to Acquire Property, Plant, and Equipment		31		20	[1]	29	[1]
Increase (Decrease) in Notes Receivables		(17)		(17)	[1]	(17)	[1]
Return of investment from unconsolidated affiliates		47		28	[1]	42	[1]
Payments to Acquire Businesses and Interest in Affiliates		(73)		(83)	[1]	(402)	[1]
Payments for (Proceeds from) Other Investing Activities		(7)		(4)	[1]	(9)	[1]
Net Cash Used in Investing Activities		(283)		(131)	[1]	(1,098)	[1]
Proceeds from Payments to Intercompany Loans		0		0		0
Proceeds from Noncontrolling Interests		11		5		122
Proceeds from the issuance of class C units		33		0	[1]	599	[1]
Payments of Capital Distribution		20		184	[1]	79	[1]
Payments of (Proceeds from) distributions		202		173		139
Proceeds from (Repayments of) Lines of Credit						551
Repayments of Lines of Credit		0		(366)	[1]	(245)	[1]
Proceeds from Related Party Debt		0		0	[1]	(281)	[1]
Proceeds from Issuance of Long-term Debt		41		740	[1]	6	[1]
Proceeds from (Repayments of) Debt						(735)
Payments of Financing Costs						7
Net Cash (Used in) Provided by Financing Activities		(416)		(202)	[1]	354	[1]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect		(183)		244		(320)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		314		497	[1]	253	[1]	$ 573	[1]
Guarantor Subsidiaries [Member]
Net Cash Provided by Operating Activities		58		62		19
Intercompany (Payments to) Receipts from Consolidated Subsidiaries		0		0		0
Acquisition of businesses, net of cash acquired						0
Acquisition of Drop Down Assets, net of cash acquired		0				0
Payments to Acquire Property, Plant, and Equipment		4		0		0
Increase (Decrease) in Notes Receivables		0		0		0
Return of investment from unconsolidated affiliates		10		16		0
Payments to Acquire Businesses and Interest in Affiliates		(64)		(80)		(28)
Payments for (Proceeds from) Other Investing Activities		0		0		0
Net Cash Used in Investing Activities		(58)		(64)		(28)
Proceeds from Payments to Intercompany Loans		0		2		9
Proceeds from Noncontrolling Interests				0		0
Proceeds from the issuance of class C units		0				0
Payments of Capital Distribution		0		0		0
Payments of (Proceeds from) distributions		0		0		0
Proceeds from (Repayments of) Lines of Credit						0
Repayments of Lines of Credit				0		0
Proceeds from Related Party Debt						0
Proceeds from Issuance of Long-term Debt		0		0		0
Proceeds from (Repayments of) Debt						0
Payments of Financing Costs						0
Net Cash (Used in) Provided by Financing Activities		0		2		9
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect		0		0		0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		0		0		0		0
Non-Guarantor Subsidiaries [Member]
Net Cash Provided by Operating Activities		529		554	[2]	423	[3]
Intercompany (Payments to) Receipts from Consolidated Subsidiaries		0		(21)	[2]	285	[3]
Acquisition of businesses, net of cash acquired	[3]					0
Acquisition of Drop Down Assets, net of cash acquired		0				0	[3]
Payments to Acquire Property, Plant, and Equipment		27		20	[2]	29	[3]
Increase (Decrease) in Notes Receivables		(17)		(17)	[2]	(17)	[3]
Return of investment from unconsolidated affiliates		14		0	[2]	0	[3]
Payments to Acquire Businesses and Interest in Affiliates		(7)		(3)	[2]	0	[3]
Payments for (Proceeds from) Other Investing Activities		(7)		(4)	[2]	(9)	[3]
Net Cash Used in Investing Activities		4		(23)	[2]	282	[3]
Proceeds from Payments to Intercompany Loans		(1)		0	[2]	0	[3]
Proceeds from Noncontrolling Interests				0	[2]	0	[3]
Proceeds from the issuance of class C units		0				0	[3]
Payments of Capital Distribution		13		174	[2]	79	[3]
Payments of (Proceeds from) distributions		220		420	[2]	392	[3]
Proceeds from (Repayments of) Lines of Credit	[2]					0
Repayments of Lines of Credit	[2]			0		0
Proceeds from Related Party Debt	[3]					0
Proceeds from Issuance of Long-term Debt		41		390	[2]	6	[3]
Proceeds from (Repayments of) Debt	[3]					(241)
Payments of Financing Costs	[3]					6
Net Cash (Used in) Provided by Financing Activities		(527)		(483)	[2]	(712)	[3]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect		6		48	[2]	(7)	[3]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		292		286	[2]	238	[2],[3]	245	[3]
NRG Yield Operating LLC [Member]
Net Cash Provided by Operating Activities		(71)		(39)	[2]	(18)	[3]
Intercompany (Payments to) Receipts from Consolidated Subsidiaries		15		(304)	[2]	179	[3]
Acquisition of businesses, net of cash acquired	[3]					37
Acquisition of Drop Down Assets, net of cash acquired		(250)		(77)	[2]	(698)	[3]
Payments to Acquire Property, Plant, and Equipment		0		0	[2]	0	[3]
Increase (Decrease) in Notes Receivables		0		0	[2]	0	[3]
Return of investment from unconsolidated affiliates		23		12	[2]	42	[3]
Payments to Acquire Businesses and Interest in Affiliates		(2)		0	[2]	(374)	[3]
Payments for (Proceeds from) Other Investing Activities		0		0	[2]	0	[3]
Net Cash Used in Investing Activities		(214)		(369)	[2]	(888)	[3]
Proceeds from Payments to Intercompany Loans		6		(46)	[2]	300	[3]
Proceeds from Noncontrolling Interests				5	[2]	122	[3]
Proceeds from the issuance of class C units		0				0	[3]
Payments of Capital Distribution		7		10	[2]	0	[3]
Payments of (Proceeds from) distributions		(220)		(420)	[2]	(392)	[3]
Proceeds from (Repayments of) Lines of Credit	[2]					551
Repayments of Lines of Credit	[2]			(366)		(245)
Proceeds from Related Party Debt	[3]					(281)
Proceeds from Issuance of Long-term Debt		0		350	[2]	0	[3]
Proceeds from (Repayments of) Debt	[3]					(494)
Payments of Financing Costs	[3]					1
Net Cash (Used in) Provided by Financing Activities		285		408	[2]	906	[3]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect		0		0	[2]	0	[3]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		0		0	[2]	0	[2],[3]	0	[3]
NRG Yield LLC [Member]
Net Cash Provided by Operating Activities		0	[4]	0	[2],[5]	0	[3],[6]
Intercompany (Payments to) Receipts from Consolidated Subsidiaries		(15)	[4]	325	[2],[5]	(464)	[3],[6]
Acquisition of businesses, net of cash acquired	[3],[6]					0
Acquisition of Drop Down Assets, net of cash acquired		0	[4]			0	[3],[6]
Payments to Acquire Property, Plant, and Equipment		0	[4]	0	[2],[5]	0	[3],[6]
Increase (Decrease) in Notes Receivables		0	[4]	0	[2],[5]	0	[3],[6]
Return of investment from unconsolidated affiliates		0	[4]	0	[2],[5]	0	[3],[6]
Payments to Acquire Businesses and Interest in Affiliates		0	[4]	0	[2],[5]	0	[3],[6]
Payments for (Proceeds from) Other Investing Activities		0	[4]	0	[2],[5]	0	[3],[6]
Net Cash Used in Investing Activities		(15)	[4]	325	[2],[5]	(464)	[3],[6]
Proceeds from Payments to Intercompany Loans		(5)	[4]	44	[2],[5]	(309)	[3],[6]
Proceeds from Noncontrolling Interests				0	[2],[5]	0	[3],[6]
Proceeds from the issuance of class C units		33	[4]			599	[3],[6]
Payments of Capital Distribution		0	[4]	0	[2],[5]	0	[3],[6]
Payments of (Proceeds from) distributions		202	[4]	173	[2],[5]	139	[3],[6]
Proceeds from (Repayments of) Lines of Credit	[3],[6]					0
Repayments of Lines of Credit				0	[2],[5]	0	[3],[6]
Proceeds from Related Party Debt	[3],[6]					0
Proceeds from Issuance of Long-term Debt		0	[4]	0	[2],[5]	0	[3],[6]
Proceeds from (Repayments of) Debt	[3],[6]					0
Payments of Financing Costs	[3],[6]					0
Net Cash (Used in) Provided by Financing Activities		(174)	[4]	(129)	[2],[5]	151	[3],[6]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect		(189)	[4]	196	[2],[5]	(313)	[3],[6]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		$ 22	[4]	$ 211	[2],[4],[5]	$ 15	[2],[3],[5],[6]	$ 328	[3],[6]
[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	(b) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[5]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.
[6]	(a) Shown separately from the other guarantors in lieu of preparing Schedule I pursuant to the requirements of Rule 5-04(c) of Regulation S-X.