Clearway Energy (CWEN.A) 10-K 1 Mar 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Jan. 31, 2019	Jun. 30, 2016
Class of Stock [Line Items]
Entity Registrant Name	Clearway Energy LLC
Entity Central Index Key	1,637,757
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Amendment Flag	false
Entity Shell Company	false
Entity Emerging Growth Company	false
Entity Small Business	false
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Voluntary Filers	Yes
Entity Well-known Seasoned Issuer	No
Document Fiscal Year Focus	2,018
Entity Public Float			$ 0
Document Fiscal Period Focus	FY
Common Class A [Member]
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		34,599,645
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		73,323,463
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, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	[1]	Dec. 31, 2016
Operating Revenues
Total operating revenues	$ 229	$ 292	$ 307	$ 225	$ 231	$ 269	$ 288	$ 221	$ 1,053	$ 1,009		$ 1,035	[1]
Operating Costs and Expenses
Cost of operations									332	326		308	[1]
Depreciation and amortization									331	334		303	[1]
Impairment losses									0	44		185	[1],[2]
General and administrative									20	19		14	[1]
Acquisition-related transaction and integration costs									20	3		1
Development costs									3	0		0	[1]
Total operating costs and expenses									706	726		811	[1]
Operating Income	54	100	144	49	20	84	125	54	347	283		224	[1]
Other Income (Expense)
Equity in earnings of unconsolidated affiliates									74	71		60	[1],[2]
Other income, net									8	4		3	[1]
Loss on debt extinguishment									0	(3)		0	[1],[2]
Interest expense									(294)	(294)		(272)	[1]
Total other expense, net									(212)	(222)		(209)	[1]
Net Income	$ (37)	$ 64	$ 106	$ 2	$ (37)	$ 42	$ 56	$ 0	135	61	[3],[4]	15	[1],[3],[4]
Less: Net loss attributable to noncontrolling interests									(105)	(75)		(111)	[1]
Net Income Attributable to Clearway Energy LLC									$ 240	$ 136		$ 126	[1]
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	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, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	[2]	Dec. 31, 2016	[2]
Statement of Comprehensive Income [Abstract]
Net income	$ (37)	$ 64	$ 106	$ 2	$ (37)	$ 42	$ 56	$ 0	$ 135	$ 61	[1],[3]	$ 15	[1],[3]
Other Comprehensive Loss, net of tax
Unrealized (loss) gain on derivatives									24	17		13
Other comprehensive (loss) income									24	17		13
Comprehensive Income									159	78		28
Less: Comprehensive loss attributable to noncontrolling interests									105	75		111
Comprehensive Income Attributable to NRG Yield LLC									$ 264	$ 153		$ 139
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	[1]
Current Assets
Cash and cash equivalents	$ 407	$ 146
Restricted cash	176	168
Accounts receivable — trade	104	95
Accounts receivable — affiliates	5	1
Inventory	40	39
Notes receivable — current	0	13
Prepayments and other current assets	29	19
Total current assets	761	481
Property, plant and equipment, net	5,245	5,410
Other Assets
Equity investments in affiliates	1,172	1,178
Intangible assets, net	1,156	1,228
Derivative instruments	8	1
Other non-current assets	106	62
Total other assets	2,442	2,469
Total Assets	8,448	8,360
Current Liabilities
Current portion of long-term debt — external	314	339
Current portion of long-term debt — affiliate	215	0
Accounts payable — trade	45	46
Accounts payable — affiliate	20	49
Derivative instruments	4	18
Accrued interest expense	44	38
Accrued expenses and other current liabilities	57	49
Total current liabilities	699	539
Other Liabilities
Long-term debt — external	5,404	5,049
Long-term debt — affiliate	44	618
Derivative instruments	17	31
Other non-current liabilities	102	94
Total non-current liabilities	5,567	5,792
Total Liabilities	6,266	6,331
Commitments and Contingencies	0	0
Members' Equity
Contributed capital	1,940	1,919
Retained earnings	86	16
Accumulated other comprehensive loss	(44)	(68)
Noncontrolling interest	200	162
Total Members' Equity	2,182	2,029
Total Liabilities and Members’ Equity	$ 8,448	$ 8,360
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Consolidated Statements Of Cas

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Statement of Cash Flows [Abstract]
Net income	$ 135	$ 61	[1],[2],[3]	$ 15	[1],[2],[3]
Adjustments to reconcile net income to net cash provided by operating activities:
Equity in earnings of unconsolidated affiliates	(74)	(71)	[1]	(60)	[1],[4]
Distributions from unconsolidated affiliates	70	72		58	[4]
Depreciation and amortization	331	334		303	[4]
Amortization of financing costs	13	13		8	[4]
Amortization of intangibles and out-of-market contracts	70	70		76	[4]
Loss on debt extinguishment	0	3	[1]	0	[1],[4]
Impairment losses	0	44	[1]	185	[1],[4]
Changes in derivative instruments	(16)	(15)		(15)	[4]
(Gain) loss on disposal of asset components	0	16		6	[4]
Changes in prepaid and accrued capacity payments	0	(4)		(8)	[4]
Changes in other working capital	(37)	(6)		9	[4]
Net Cash Provided by Operating Activities	492	517		577	[4]
Cash Flows from Investing Activities
Acquisition of business	(11)	0		0	[4]
Acquisition of Drop Down Assets, net of cash acquired	(126)	(250)		(77)	[4]
Capital expenditures	(83)	(190)		(20)	[4]
Cash receipts from notes receivable	13	17		17	[4]
Return of investment from unconsolidated affiliates	45	47		28	[4]
Investments in unconsolidated affiliates	(34)	(73)		(83)	[4]
Other	11	7		4	[4]
Net Cash Used in Investing Activities	(185)	(442)		(131)	[4]
Cash Flows from Financing Activities
Net contributions from noncontrolling interests	106	13		5	[4]
Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets	0	(23)		(184)	[4]
Proceeds from the issuance of class C units	153	33		0	[4]
Payments of distributions	(253)	(202)		(173)	[4]
Proceeds from the revolving credit facility	35	55		60	[4]
Payments for the revolving credit facility	(90)	0		(366)	[4]
Proceeds from issuance of long-term debt — external	827	210		740	[4]
Payments of debt issuance costs	(14)	(12)		(15)	[4]
Payments for long-term debt — external	(443)	(332)		(269)	[4]
Payments for long-term debt — affiliate	(359)	0		0	[4]
Net Cash Used in Financing Activities	(38)	(258)		(202)	[4]
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	269	(183)		244	[4]
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	314	497	[4]	253	[4]
Cash, Cash Equivalents and Restricted Cash at End of Period	583	314		497	[4]
Supplemental Disclosures
Interest paid, net of amount capitalized	(292)	(297)		(271)	[4]
Non-cash investing and financing activities:
(Reductions) Additions to fixed assets for accrued capital expenditures	$ (15)	22		3	[4]
Non-cash contributions from CEG, NRG, net of distributions		$ 2		$ (90)	[4]
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Consolidated Statements of Memb

Consolidated Statements of Members' Equity - USD ($) $ in Millions		Total		Clearway Energy, Inc.	NRG	Contributed Capital	Contributed CapitalClearway Energy, Inc.	Contributed CapitalNRG	Retained Earnings	Retained EarningsClearway Energy, Inc.	Retained EarningsNRG	Accumulated Other Comprehensive Loss	Noncontrolling Interest
Balance, beginning of period at Dec. 31, 2015		$ 2,705				$ 2,364			$ 107			$ (98)	$ 332
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	[3]	15	[1],[2]						126				(111)
Unrealized gain on derivatives		13	[2]									13
Payment for Drop Down Asset		(77)				(77)
Distributions and returns of capital, net of contributions		(184)				(182)			(2)
Capital contributions, non-cash	[3]	90				99			(9)
Capital contributions from tax equity investors		5											5
Distributions paid, non-cash				$ (5)						$ (5)
Distributions paid				(92)	$ (81)					(92)	$ (81)
Balance, end of period at Dec. 31, 2016		2,389				2,204			44			(85)	226
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	[3]	61	[1],[2]						136				(75)
Unrealized gain on derivatives		17	[2]									17
Payment for Drop Down Asset		(250)				(250)
Drop Down Assets contingent consideration		(8)				(8)
Distributions and returns of capital, net of contributions	[3]	(21)				(21)
Distributions paid, net of contributions - non-cash	[3]	(2)				(8)			6
Capital contributions from tax equity investors		11											11
Proceeds from the issuance of Class C Common Stock		34				34
Distributions paid				(108)	(94)		$ (26)	$ (6)		(82)	(88)
Balance, end of period at Dec. 31, 2017		2,029	[4]			1,919			16			(68)	162
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		135							240				(105)
Unrealized gain on derivatives		24										24
Payment for Drop Down Asset		(52)				(52)
Distributions and returns of capital, net of contributions		(11)				(11)
Capital contributions from tax equity investors		106											106
Proceeds from the issuance of Class C Common Stock		153				153
Contributions from CEG, NRG, net of distributions, non-cash		36											37
Distributions paid				$ (130)	$ (108)		$ (68)			$ (62)	$ (108)
Balance, end of period at Dec. 31, 2018		$ 2,182				$ 1,940			$ 86			$ (44)	$ 200
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Nature of Business

Nature of Business	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business	Nature of Business Clearway Energy LLC (formerly NRG Yield LLC), together with its consolidated subsidiaries, or the Company, was formed by NRG as a Delaware limited liability company on March 5, 2013, to serve as the primary vehicle through which NRG owns, operates and acquires contracted renewable and conventional generation and thermal infrastructure assets. On August 31, 2018, NRG Energy, Inc., or NRG, transferred its full ownership interest in Clearway Energy, Inc. (formerly NRG Yield, Inc.) to Clearway Energy Group LLC, or CEG, the holder of NRG's renewable energy development and operations platform, and subsequently sold 100% of its interest in CEG to Global Infrastructure Partners III, or GIP, referred to hereinafter as the GIP Transaction. As a result of the GIP Transaction, GIP indirectly acquired a 45.2% economic interest in the Company and a 55% voting interest in the Clearway Energy, Inc. GIP is an independent fund manager that invests in infrastructure assets in energy and transport sectors. The Company is sponsored by GIP through GIP's portfolio company, Clearway Energy Group. The Company’s environmentally-sound asset portfolio includes over 5,272 MW of wind, solar and natural gas-fired power generation facilities, as well as district energy systems. Nearly all of these assets sell substantially all of their output pursuant to long-term offtake agreements with creditworthy counterparties. The weighted average remaining contract duration of these offtake agreements was approximately 15 years as of December 31, 2018 based on CAFD. The Company also owns thermal infrastructure assets with an aggregate steam and chilled water capacity of 1,385 net MWt and electric generation capacity of 133 net MW. These thermal infrastructure assets provide steam, hot and/or chilled water, and, in some instances, electricity to commercial businesses, universities, hospitals and governmental units in multiple locations, principally through long-term contracts or pursuant to rates regulated by state utility commissions. The Company consolidates the results of Clearway Energy LLC through its controlling interest, with CEG's interest shown as noncontrolling interest in the financial statements. The holders of Clearway Energy, Inc.'s outstanding shares of Class A and Class C common stock are entitled to dividends as declared. CEG receives its distributions from Clearway Energy LLC through its ownership of Clearway Energy LLC Class B and Class D units. As a result of the Clearway Energy, Inc. Class C common stock issuances during the year ended December 31, 2018 , Clearway Energy, Inc. currently owns 55.8% of the economic interests of the Company, with CEG retaining 44.2% of the economic interests of the Company. The following table represents the structure of the Company as of December 31, 2018 : On January 29, 2019, Pacific Gas and Electric, or PG&E, filed voluntary petitions for relief under Chapter 11 of the United States Bankruptcy Code. Certain subsidiaries of the Company , holding interests in 6 solar facilities totaling 480 MW and Marsh Landing with capacity of 720 MW, sell the output of their facilities to PG&E, under long-term PPAs. The Company consolidates three of the solar facilities and Marsh Landing and records its interest in the other solar facilities as equity method investments. The related subsidiaries of the Company have entered into financing agreements consisting of non-recourse project level debt and in certain cases, non-recourse holding company debt. The effect of the bankruptcy filing on the Company's operations is further described in Note 2, Summary of Significant Accounting Policies , Note 5, Investments Accounted for by the Equity Method and Variable Interest Entities , and Note 10, Long-Term Debt 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. For the complete listing of the company's generation assets, refer to Item 2 - Properties to this Form 10-K. Recast of the Historical Financial Statements Prior to the GIP Transaction on August 31, 2018, the Company completed several acquisitions of Drop Down Assets from NRG, which were accounted for as transfer of entities under common control, and are further described in Note 3, Business Acquisitions . The accounting guidance for transfers of entities under common control requires retrospective combination of the entities for all periods presented as if the combinations had 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). Transition Services Agreement As a result of the GIP Transaction, the Company entered into a Transition Services Agreement with NRG, or the NRG TSA, pursuant to which NRG or certain of its affiliates began providing transitional services to the Company following the consummation of the GIP Transaction, in exchange for the payment of a fee in respect of such services. The agreement is effective until the earlier of June 30, 2019 or the date that all services are terminated by the Company. The Company may extend the term on a month-by-month basis no later than March 31, 2020 for a fixed monthly fee provided for in the agreement. Expenses related to the NRG TSA are recorded in general and administrative expenses in the consolidated statements of operations.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
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, and Restricted Cash 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 $109 million and $124 million as of December 31, 2018 and 2017 , respectively. 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, 2018 2017 2016 (In millions) Cash and cash equivalents $ 407 $ 146 $ 321 Restricted cash 176 168 176 Cash, cash equivalents and restricted cash shown in the statement of cash flows 583 314 497 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. As of December 31, 2018 , these restricted funds comprised of $84 million designated to fund operating expenses, approximately $26 million designated for current debt service payments, and $32 million restricted for reserves including debt service, performance obligations and other reserves, as well as capital expenditures. The remaining $34 million is held in distribution reserve accounts, of which $31 million related to subsidiaries affected by the PG&E Bankruptcy as discussed further below and may not be distributed during the pendency of the bankruptcy. On January 29, 2019, PG&E filed for reorganization under Chapter 11 of the U.S. Bankruptcy Code. The Company has non-recourse project-level debt related to each of its subsidiaries that sell their output to PG&E under long-term PPAs. The PG&E bankruptcy filing is an event of default under the related financing agreements. As of December 31, 2018, all project level cash balances for these subsidiaries were classified as restricted cash. 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, 2018 and 2017 . 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. 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. Development costs include project development costs, which are expensed in the preliminary stages of a project and capitalized when the project is deemed to be commercially viable. Commercial viability is determined by one or a series of actions including, among others, Board of Director approval pursuant to a formal project plan that subjects the Company to significant future obligations that can only be discharged by the use of a Company asset. When a project is available for operations, capitalized interest and capitalized project development costs are reclassified to property, plant and equipment and depreciated on a straightline basis over the estimated useful life of the project's related assets. Capitalized costs are charged to expense if a project is abandoned or management otherwise determines the costs to be unrecoverable. 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. 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. 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. 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 Revenue from Contracts with Customers On January 1, 2018, the Company adopted the guidance in ASC 606, Revenue from Contracts with Customers, or Topic 606, using the modified retrospective method applied to contracts which were not completed as of the adoption date, with no adjustment required to the financial statements upon adoption. Following the adoption of the new standard, the Company’s revenue recognition of its contracts with customers remains materially consistent with its historical practice. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. The Company's policies with respect to its various revenue streams are detailed below. In general, the Company applies the invoicing practical expedient to recognize revenue for the revenue streams detailed below, except in circumstances where the invoiced amount does not represent the value transferred to the customer. Thermal Revenues Steam and chilled water revenue is recognized as the Company transfers the product to the customer, 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. For thermal contracts, the Company’s performance obligation to deliver steam and chilled water is satisfied over time and revenue is recognized based on the invoiced amount. 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. As contracts for steam and chilled water are long-term contracts, the Company has performance obligations under these contracts that have not yet been satisfied. These performance obligations have transaction prices that are both fixed and variable, and that vary based on the contract duration, customer type, inception date and other contract-specific factors. For the fixed price contracts, the Company cannot accurately estimate the amount of its unsatisfied performance obligations as it will vary based on customer usage, which will depend on factors such as weather and customer activity. Power Purchase Agreements, or PPAs The majority of the Company’s revenues are obtained through PPAs or other contractual agreements. Energy, capacity and where applicable, renewable attributes, from the majority of the Company’s renewable energy assets and certain conventional energy plants is sold through long-term PPAs and tolling agreements to a single counterparty, which is often a utility or commercial customer. The majority of these PPAs are accounted for as leases. 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, 2018 , 2017 and 2016 was $583 million , $559 million and $583 million , respectively. These balances include intercompany revenue for Elbow Creek of $6 million for the eight months ended August 31, 2018 and $8 million for each of the years ended December 31, 2017 and 2016 , as further discussed in Note 13 Related Party Transactions . Renewable Energy Credits, or RECs As stated above, renewable energy credits, or RECs, are usually sold through long-term PPAs. Revenue from the sale of self-generated RECs is recognized when the related energy is generated and simultaneously delivered even in cases where there is a certification lag as it has been deemed to be perfunctory. In a bundled contract to sell energy, capacity and/or self-generated RECs, all performance obligations are deemed to be delivered at the same time and hence, timing of recognition of revenue for all performance obligations is the same and occurs over time. In such cases, it is often unnecessary to allocate transaction price to multiple performance obligations. Sale of Emission Allowances The Company records its bank of emission allowances as part of intangible assets. From time to time, management may authorize the transfer of emission allowances in excess of usage from the Company's emission bank to intangible assets held-for-sale for trading purposes. The Company records the sale of emission allowances on a net basis within operating revenue in the Company's consolidated statements of operations. Disaggregated Revenues The following tables represent the Company’s disaggregation of revenue from contracts with customers for the year ended December 31, 2018 , along with the reportable segment for each category: Year ended December 31, 2018 (In millions) Conventional Generation Renewables Thermal Corporate Total Energy revenue (a) $ 5 $ 572 $ 4 — $ 581 Capacity revenue (a) 337 — 166 — 503 Other revenues — 16 26 (3 ) 39 Contract amortization (5 ) (62 ) (3 ) — (70 ) Total operating revenue 337 526 193 (3 ) 1,053 Less: Lease revenue (342 ) (534 ) (2 ) — (878 ) Less: Contract amortization 5 62 3 — 70 Total revenue from contracts with customers $ — $ 54 $ 194 (3 ) $ 245 (a) The following amounts of energy and capacity revenue relate to leases and are accounted for under ASC 840: Conventional Generation Renewables Thermal Total Energy Revenue $ 5 $ 534 $ 2 $ 541 Capacity Revenue 337 — — 337 342 534 2 878 Contract Amortization Assets and liabilities recognized from power sales agreements assumed through acquisitions related to the sale of electric capacity and energy in future periods for which the fair value has been determined to be significantly less (more) than market are amortized to revenue over the term of each underlying contract based on actual generation and/or contracted volumes or on a straight-line basis, where applicable. Contract Balances The following table reflects the contract assets and liabilities included on the Company’s balance sheet as of December 31, 2018 : (In millions) December 31, 2018 December 31, 2017 Accounts receivable, net - Contracts with customers $ 35 $ 28 Accounts receivable, net - Leases 69 67 Total accounts receivable, net $ 104 $ 95 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 interest rate instruments used to mitigate variability in earnings due to fluctuations in interest rates, power purchase or sale contracts used to mitigate variability in earnings due to fluctuations in market prices and fuels purchase contracts used to control customer reimbursable fuel cost. On an ongoing basis, the Company qualitatively assesses the effectiveness of its 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 cash flows of hedged items. If necessary, the Company will perform an analyses to measure the statistical correlation between the derivative and the associated hedged item determine the effectiveness of such a contract designated as a hedge. The Company will discontinue hedge accounting if it is determined that the hedge is no longer effective. 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. See Item 1A, Risk Factors, Risks related to the PG&E Bankruptcy for a discussion on the Company’s dependence on major customers . 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, 2018 and 2017 , along with the additions and accretion related to the Company's ARO obligations for the year ended December 31, 2018 : (In millions) Balance as of December 31, 2017 $ 58 Revisions in estimates for current obligations/Additions 5 Accretion — expense 4 Balance as of December 31, 2018 $ 67 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. Recent Accounting Developments - Adopted in 2019 ASU 2016-02 — In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), or Topic 842, as amended, 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 adopted the standard effective January 1, 2019 using the modified retrospective transition method and will not restate prior periods for the impact of Topic 842. In addition, the Company elected certain of the permitted practical expedients, including the expedient that permits the Company to retain its existing lease assessment and classification. The company will not record a right-of-use asset and related lease liability for leases with an initial term of 12 months or less and will account for lease and non-lease components for specific asset classes as a single lease component. The Company's leases consist mainly of land leases for many operating asset locations, as well as leases of office space and office equipment. The Company estimates it will record lease liabilities of approximately $160 million to $170 million and right-of-use assets of approximately $155 million to $165 million , as of January 1, 2019, with an immaterial impact estimated to retained earnings. The actual amounts recorded may vary from this estimate as the Company completes its adoption of the guidance. Other than disclosed, the Company does not expect that there will be a material impact to the consolidated statements of operations, comprehensive income or consolidated cash flows as a result of adoption of this new guidance.

Business Acquisitions

Business Acquisitions	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Business Acquisition	Business Acquisitions 2018 Acquisitions UPMC Thermal Project Asset Acquisition — On June 19, 2018, upon reaching substantial completion, the Company acquired from NRG the UPMC Thermal Project for cash consideration of $84 million , subject to working capital adjustments. The Company had a payable of $4 million to NRG as of December 31,2018, $3 million of which was paid in January 2019 upon final completion of the project pursuant to the EPC agreement. The project adds 73 MWt of thermal equivalent capacity and 7.5 MW of emergency backup electrical capacity to the Company's portfolio. The transaction is reflected in the Company's Thermal segment. The acquisition was funded with the proceeds from the sale of the Series E Notes and Series F Notes, as further described in Note 7 , Long-term Debt . The assets transferred to the Company relate to interests under common control by NRG and were recorded at book value in accordance with ASC 805-50, Business Combinations - Related Issues . The difference between the purchase price and book value of the assets was recorded as a distribution to NRG and decreased the balance of contributed capital. The acquisition was determined to be an asset acquisition and not a business combination, therefore no recast of the historical financial information was deemed necessary. Central CA Fuel Cell 1, LLC — On April 18, 2018 , the Company acquired the Central CA Fuel Cell 1, LLC project in Tulare, California from FuelCell Energy Finance, Inc., for cash consideration of $11 million , subject to working capital adjustments. The project adds 2.8 MW of thermal capacity to the Company's portfolio, with a 20 -year PPA contract with the City of Tulare. The transaction is reflected in the Company's Thermal segment. Buckthorn Solar Drop Down Asset — On March 30, 2018, the Company acquired 100% of NRG's interests in Buckthorn Renewables, LLC, which owns a 154 MW construction-stage utility-scale solar generation project located in Texas, or the Buckthorn Solar Drop Down Asset, for cash consideration of approximately $42 million , subject to working capital adjustments. The Company also assumed non-recourse debt of $ 183 million and non-controlling interest of $19 million (as of acquisition date) attributable to the Class A member, as further described below. The Company converted $132 million of non-recourse debt to a term loan and the remainder of the outstanding debt was paid down with the contribution from the Class A member in the amount of $80 million upon the project reaching substantial completion in May 2018. The purchase price for the Buckthorn Solar Drop Down Asset was funded with cash on hand and borrowings from the Company's revolving credit facility. 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 Combinations - Related Issues . The difference between the cash paid and historical value of the entities' equity was recorded as a distribution to NRG and decreased the balance of contributed capital. Since 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 had been in effect since the inception of common control. Buckthorn Solar Portfolio, LLC, a wholly owned subsidiary of Buckthorn Renewables, LLC, is the Class B member in a tax equity partnership, Buckthorn Holdings, LLC, the owner of the Buckthorn Solar Drop Down Asset. The Class A member is a tax equity investor, or TE investor, who receives 99% of allocations of taxable income and other items through the six month anniversary of the placed in service date, at which time the allocations change to 67% through the last calendar year before the flip point, and then back to 99% through 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 5% for all the periods thereafter. Before the flip point, the TE investor would receive a priority distribution of distributable cash, as defined, plus a percentage of remaining distributable cash after the priority distribution subject to a percentage cap. The project sells power under a 25 -year PPA to the City of Georgetown, Texas, which commenced in July 2018. The following is a summary of net assets transferred in connection with the acquisition of the Buckthorn Solar Drop Down Asset as of March 31, 2018: (In millions) Assets: Current assets $ 20 Property, plant and equipment 212 Non-current assets 3 Total assets 235 Liabilities: Debt (Current and non-current) (a) 176 Other current and non-current liabilities 15 Total liabilities 191 Less: noncontrolling interest 19 Net assets acquired $ 25 (a) Net of $7 million of net debt issuance costs. The following table presents a summary of the Company's historical information for the year ended December 31, 2017, which combines the financial information for the Buckthorn Solar Drop Down Asset transferred in connection with the acquisition. Year ended December 31, 2017 As Previously Reported Buckthorn Solar Drop Down Asset As Currently Reported (In millions) Total operating revenues $ 1,009 $ — $ 1,009 Operating income 283 — 283 Net income 62 (1 ) 61 Net income attributable to Clearway Energy LLC 137 (1 ) 136 The Buckthorn Solar Drop Down Asset had no impact on the Company's consolidated statements of operations for the year end ended December 31, 2016. 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, 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. Since 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. August 2017 Drop Down Assets — On August 1, 2017, the Company acquired the remaining 25% interest in Wind TE Holdco, a portfolio of 12 wind projects, from NRG for total cash consideration of $44 million , including working capital adjustments. 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 . The Company originally acquired 75% of 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 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). 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. The Company paid cash consideration of $128 million , which includes $3 million of final net working capital adjustment received by the Company from NRG. 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 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 contributed capital. 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). 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 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 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.

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment The Company’s major classes of property, plant, and equipment were as follows: December 31, 2018 December 31, 2017 Depreciable Lives (In millions) Facilities and equipment $ 6,638 $ 6,291 2 - 45 Years Land and improvements 171 166 Construction in progress (a) 26 238 Total property, plant and equipment 6,835 6,695 Accumulated depreciation (1,590 ) (1,285 ) Net property, plant and equipment $ 5,245 $ 5,410 (a) As of December 31, 2018 and 2017 , construction in progress includes $6 million and $24 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 year ended December 31, 2017, as further described in Note 9 , Asset Impairments .

Investments Accounted for by th

Investments Accounted for by the Equity Method and Variable Interest Entities	12 Months Ended
	Dec. 31, 2018
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, 2018 : Name Economic Interest Investment Balance (In millions) Utah Solar Portfolio (a) 50% $317 Desert Sunlight (e) 25% 264 GenConn (b) 50% 98 Agua Caliente Solar (e) 16% 90 Elkhorn Ridge (c) 66.7% 59 San Juan Mesa (c) 75% 57 DGPV Holdco 1 LLC (d) 95% 81 DGPV Holdco 2 LLC (d) 95% 63 DGPV Holdco 3 LLC (d) 99% 116 RPV Holdco 1 LLC (d) 95% 29 Avenal (e) 50% (2) $1,172 (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. DGPV Holdco 1 LLC, DGPV Holdco 2 LLC, DGPV Holdco 3 LLC and RPV Holdco 1 LLC are tax equity structures and VIEs. The related allocations are described below. (e) Entities that have PPAs with PG&E. On January 29, 2019, PG&E filed for bankruptcy under Chapter 11 of the U.S. Bankruptcy Code. The Company has non-recourse project-level debt, and in some cases holding company debt, related to each of its subsidiaries that sell their output to PG&E under long-term PPAs. The PG&E bankruptcy filing is an event of default under the related financing agreements, and as a result, the respective lenders under these arrangements may accelerate the repayment of these debt balances. In addition, the event of default may have an impact on the Company’s ability to distribute cash from the project-level cash accounts to the parent entities. The Company continues to operate the projects in the normal course of business and is currently in the process of negotiating forbearance agreements with the related lenders. As of December 31, 2018 and 2017 , the Company had $ 87 million and $ 57 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 $878 million as of December 31, 2018 . This included $432 million attributable to Desert Sunlight, Agua Caliente Solar, and Avenal, the unconsolidated affiliates that sell output to PG&E under long-term PPAs. The following tables present summarized financial information for the Company's significant equity method investments: Year Ended December 31, 2018 2017 2016 Income Statement Data: (In millions) GenConn Operating revenues $ 65 $ 71 $ 72 Operating income 32 36 38 Net income 22 26 26 Desert Sunlight Operating revenues 208 207 211 Operating income 129 127 129 Net income 84 80 80 DGPV entities (a) Operating revenues 69 37 14 Operating income 23 7 2 Net income (loss) 11 (3 ) — RPV Holdco Operating revenues 14 16 13 Operating income — 3 2 Net income — 3 2 Other (b) Operating revenues 249 247 193 Operating income 103 89 71 Net income $ 75 $ 56 $ 38 As of December 31, 2018 2017 Balance Sheet Data: (In millions) GenConn Current assets $ 43 $ 38 Non-current assets 358 374 Current liabilities 22 18 Non-current liabilities 182 189 Desert Sunlight Current assets 133 133 Non-current assets 1,298 1,350 Current liabilities 58 64 Non-current liabilities 962 1,003 DGPV entities (a) Current assets 79 74 Non-current assets 784 671 Current liabilities 84 83 Non-current liabilities 314 216 Redeemable Noncontrolling Interest — 44 RPV Holdco Current assets 2 3 Non-current assets 173 183 Current liabilities 1 — Non-current liabilities 8 7 Redeemable Noncontrolling Interest 26 16 Other (b) Current assets 148 139 Non-current assets 2,511 2,621 Current liabilities 58 60 Non-current liabilities $ 889 $ 932 (a) Includes DGPV Holdco 1, DGPV Holdco 2 and DGPV Holdco 3 (b) Includes Agua Caliente, Utah Solar Portfolio, Avenal, Elkhorn Ridge and San Juan Mesa Variable Interest Entities, or VIEs Entities that are Consolidated The Company has a controlling financial interest in certain entities which have been identified as VIEs under ASC 810, Consolidations, or ASC 810. These arrangements are primarily related to tax equity arrangements entered into with third parties in order to monetize certain tax credits associated with wind facilities and are further described below. Buckthorn Renewables, LLC — As described in Note 3 , Business Acquisitions , on March 30, 2018, the Company acquired 100% of NRG’s interest in a 154 MW construction-stage utility-scale solar generation project, Buckthorn Renewables, LLC, which owns 100% interest in Buckthorn Solar Portfolio, LLC, which in turn owns 100% of the Class B membership interests in Buckthorn Holdings, LLC. Buckthorn Holdings, LLC is a tax equity fund, which is a variable interest entity that is consolidated by Buckthorn Solar Portfolio, LLC. The Company is the primary beneficiary, through its position as managing member, and indirectly consolidates Buckthorn Holdings, LLC through Buckthorn Solar Portfolio, LLC. The Class A member is a tax equity investor who made its initial contribution of $19 million on March 30, 2018, which is reflected as noncontrolling interest on the Company’s consolidated balance sheet. The project achieved substantial completion in May 2018, at which time the remaining tax equity contributions of $80 million were funded. The Company utilizes the HLBV method to determine the net income or loss allocated to the tax equity investor noncontrolling interest. The Company recorded $55 million of loss attributable to noncontrolling interest in Buckthorn Renewables, LLC during the period ended December 31, 2018 . Wind TE Holdco — As of December 31, 2018, Wind TE Holdco was a VIE and the Company, as the holder of Class B shares and the primary beneficiary through its position as managing member consolidated Wind TE Holdco. The Class A shares of Wind TE Holdco were owned by a tax equity investor, who received 99% of allocations of taxable income and other items. On January 2, the Company bought out 100% of the Class A membership interests from the TE Investor, for cash consideration of $19 million . On August 30, 2018, Wind TE Holdco, entered into a partnership with Clearway Renew LLC, an indirect subsidiary of CEG, in order to facilitate the repowering of wind facilities of the two of its indirect subsidiaries, Elbow Creek Wind Project LLC and Wildorado Wind LLC. Wind TE Holdco contributed its interests in the two facilities and Clearway Renew LLC contributed a turbine supply agreement, including title to certain components that qualify for production tax credits. Clearway Renew LLC paid a total of $35 million to the service provider, which was recorded to other non current assets on the Company's consolidated balance sheets as of December 31, 2018. Wind TE Holdco is the managing member of Repowering Partnership LLC and consolidates the entity, which is a VIE. Clearway Renew LLC is entitled to allocations of 21% of income, which is reflected in Wind TE Holdco’s noncontrolling interests. 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 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, 2018 : (In millions) Wind TE Holdco Alta TE Holdco Spring Canyon Buckthorn Renewables, LLC Other current and non-current assets $ 215 $ 17 $ 2 $ 15 Property, plant and equipment 346 410 91 223 Intangible assets 2 249 — — Total assets 563 676 93 238 Current and non-current liabilities 210 9 4 Total liabilities 210 9 4 135 Noncontrolling interest 45 63 49 43 Net assets less noncontrolling interests $ 308 $ 604 $ 40 $ 60 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 on the last day of the calendar month on which the Class B member does not have an agreed upon adjusted capital account deficit, but not prior to the 10th day after the five year anniversary of the last project to achieve its placed in service date, 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. DGPV Holdco 1 LLC — The Company and CEG are parties to the 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 Clearway Energy Group LLC or its subsidiaries via intermediate funds. The Company owns approximately 52 MW of distributed solar capacity, based on cash to be distributed, with a weighted average contract life of 17 years . Under this partnership, the Company committed to fund up to $100 million of capital. DGPV Holdco 2 LLC — The Company and CEG are parties to the 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 Clearway Energy Group 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 20 years . Under this partnership, the Company committed to fund up to $60 million of capital. DGPV Holdco 3 LLC — The Company and CEG are parties to the DGPV Holdco 3 LLC partnership, 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 CEG. The Company owns approximately 59 MW of distributed solar capacity, based on cash to be distributed, with a weighted average contract life of approximately 21 years as of December 31, 2018 . In December 2018, the Company and CEG amended the DGPV Holdco 3 partnership agreement to increase the capital commitment of $50 million to $70 million . The Company had a $9 million payable due to DGPV Holdco 3 LLC as of December 31, 2018. 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 $260 million on a combined basis. RPV Holdco 1 LLC — The Company and CEG are parties to the 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 14 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 17 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,

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2018
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, 2018 As of December 31, 2017 Carrying Amount Fair Value Carrying Amount Fair Value (In millions) Assets: Notes receivable, including current portion $ — $ — $ 13 $ 13 Liabilities: Long-term debt, including current portion — affiliate 259 257 618 618 Long-term debt, including current portion — external $ 5,779 $ 5,681 $ 5,450 $ 5,466 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, 2018 and 2017 : As of December 31, 2018 As of December 31, 2017 Level 2 Level 3 Level 2 Level 3 (In millions) Long-term debt, including current portion $ 1,358 $ 4,580 $ 870 $ 5,214 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, 2018 As of December 31, 2017 Fair Value (a) Fair Value (a) (In millions) Level 2 Level 2 Derivative assets: Commodity contracts (b) $ — $ 1 Interest rate contracts 11 1 Total assets $ 11 $ 2 Derivative liabilities: Commodity contracts (b) $ — 1 Interest rate contracts 21 48 Total liabilities $ 21 $ 49 (a) There were no derivative assets or liabilities classified as Level 1 or 3 as of December 31, 2018 and 2017 . (b) The fair value of commodities was not material as of December 31, 2018 . 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 the Company'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 its own 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, 2018 , the credit reserve was no t material. 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, 2018 , credit risk exposure to these counterparties attributable to the Company's ownership interests was approximately $2.3 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. As previously described, on January 29, 2019, PG&E filed for reorganization under Chapter 11 of the U.S. Bankruptcy Code. Certain subsidiaries of the Company sell the output of their facilities to PG&E under long-term PPAs, including interests in 6 solar facilities totaling 480 MW and Marsh Landing with a capacity of 720 MW. The Company consolidates three of the solar facilities and Marsh Landing and records its interest in the other solar facilities as equity method investments. The Company had $17 million in accounts receivable for its consolidated projects as of December 31, 2018. All of these amounts were collected in January 2019.

Accounting for Derivative Instr

Accounting for Derivative Instruments and Hedging Activities	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
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, 2018 , 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, 2018 , these contracts were not designated as cash flow or fair value hedges. Also, as of December 31, 2018 , 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 purchase agreements through 2043 , 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, 2018 , the Company had interest rate derivative instruments on non-recourse debt extending through 2041 , 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, 2018 and 2017 : Total Volume December 31, 2018 December 31, 2017 Commodity Units (In millions) Natural Gas MMBtu 1 2 Interest Dollars $ 1,862 $ 2,050 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, 2018 December 31, 2017 December 31, 2018 December 31, 2017 (In millions) Derivatives Designated as Cash Flow Hedges: Interest rate contracts current $ 2 $ — $ 1 $ 4 Interest rate contracts long-term 3 1 6 9 Total Derivatives Designated as Cash Flow Hedges 5 1 7 13 Derivatives Not Designated as Cash Flow Hedges : Interest rate contracts current 1 — 3 13 Interest rate contracts long-term 5 — 11 22 Commodity contracts current (b) — 1 — 1 Total Derivatives Not Designated as Cash Flow Hedges 6 1 14 36 Total Derivatives $ 11 $ 2 $ 21 $ 49 (a) Derivative Asset balances classified as current are included within the prepayments and other current assets line item of the Consolidated Balance Sheet. (b) The fair value of commodities was not material as of December 31, 2018 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, 2018 and 2017 , there was no outstanding collateral paid or received. As of December 31, 2018 , the commodity balances were not material. 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, 2018 Gross Amounts of Recognized Assets/Liabilities Derivative Instruments Net Amount Interest rate contracts: Derivative assets $ 11 $ (1 ) $ 10 Derivative liabilities (21 ) 1 (20 ) Total interest rate contracts (10 ) — (10 ) Total derivative instruments $ (10 ) $ — $ (10 ) 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 (48 ) 1 (47 ) Total interest rate contracts (47 ) — (47 ) Total derivative instruments $ (47 ) $ — $ (47 ) 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, 2018 2017 2016 (In millions) Accumulated OCL beginning balance $ (69 ) $ (86 ) $ (99 ) Reclassified from accumulated OCL to income due to realization of previously deferred amounts 15 17 17 Mark-to-market of cash flow hedge accounting contracts 9 — (4 ) Accumulated OCL ending balance (45 ) (69 ) (86 ) Accumulated OCL attributable to noncontrolling interests (1 ) (1 ) (1 ) Accumulated OCL attributable to Clearway Energy LLC $ (44 ) $ (68 ) $ (85 ) Losses expected to be realized from OCL during the next 12 months $ 9 Amounts reclassified from accumulated OCL into income are recorded to interest expense. 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, 2018 , 2017 and 2016 the impact to the consolidated statements of income was a gain of $15 million , gain of $6 million and a loss of $2 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. See Note 6 , Fair Value of Financial Instruments , for a discussion regarding concentration of credit risk.

Intangible Assets

Intangible Assets	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	Intangible Assets Intangible Assets — The Company's intangible assets as of December 31, 2018 and 2017 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 Energy Center Phoenix and 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 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. • Other — Consists of a) 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, and b) development rights related to certain solar businesses acquired in 2010 and 2011. The following tables summarize the components of intangible assets subject to amortization: Year ended December 31, 2018 PPAs Leasehold Rights Customer Customer Contracts Emission Allowances Other Total (In millions) December 31, 2018 $ 1,280 $ 86 $ 66 $ 15 $ 9 $ 8 $ 1,464 Less accumulated amortization (269 ) (18 ) (7 ) (9 ) (2 ) (3 ) (308 ) Net carrying amount $ 1,011 $ 68 $ 59 $ 6 $ 7 $ 5 $ 1,156 Year ended December 31, 2017 PPAs Leasehold Rights Customer Customer Contracts Emission Allowances Other Total (In millions) January 1, 2017 $ 1,286 $ 86 $ 66 $ 15 $ 9 $ 9 $ 1,471 Asset Impairments (a) (6 ) — — — — — (6 ) December 31, 2017 1,280 86 66 15 9 9 1,465 Less accumulated amortization (205 ) (13 ) (5 ) (8 ) (3 ) (3 ) (237 ) Net carrying amount $ 1,075 $ 73 $ 61 $ 7 $ 6 $ 6 $ 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 . The Company recorded amortization expense of $71 million during the years ended December 31, 2018 , 2017 and 2016 . Of these amounts, $70 million for the years ended December 31, 2018 , 2017 and 2016 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 2023 . 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, 2018 , accumulated amortization of out-of-market contracts was $4 million and amortization expense was $1 million for each of the years ended December 31, 2018 and 2017 .

Asset Impairments

Asset Impairments	12 Months Ended
	Dec. 31, 2018
Asset Impairments [Abstract]
Asset Impairments	Asset Impairments During the fourth quarter of 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, 2018 . 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 quarter of 2016, NRG recorded impairment losses of approximately $2 million 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.

Long-term Debt

Long-term Debt	12 Months Ended
	Dec. 31, 2018
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, 2018 December 31, 2017 Interest rate % (a) Letters of Credit Outstanding at December 31, 2018 (In millions, except rates) Long-term debt - affiliate, due 2019 $ 215 $ 337 3.580 Long-term debt - affiliate, due 2020 44 281 3.325 2024 Senior Notes 500 500 5.375 2025 Senior Notes 600 — 5.750 2026 Senior Notes 350 350 5.000 Clearway Energy LLC and Clearway Energy Operating LLC Revolving Credit Facility, due 2019 (b) — 55 L+1.75 41 Project-level debt: Agua Caliente Borrower 2, due 2038 (c) 39 41 5.430 17 Alpine, due 2022 (c) 127 135 L+1.750 16 Alta Wind I - V lease financing arrangements, due 2034 and 2035 886 926 5.696 - 7.015 44 Buckthorn Solar, due 2025 132 169 L+1.750 26 CVSR, due 2037 (c) 720 746 2.339 - 3.775 — CVSR Holdco Notes, due 2037 (c) 188 194 4.680 13 El Segundo Energy Center, due 2023 352 400 L+1.75 - L+2.375 138 Energy Center Minneapolis Series C, D, E, F, G, H Notes, due 2025-2037 328 208 various — Laredo Ridge, due 2028 89 95 L+1.875 10 Kansas South, due 2030 (c) 26 29 L+2.00 2 Marsh Landing, due 2023 (c) 263 318 L+2.125 60 South Trent Wind, due 2020 50 53 L+1.625 Tapestry, due 2021 151 162 L+1.625 20 Utah Solar Portfolio, due 2022 267 278 various 13 Viento, due 2023 146 163 L+2.00 26 Walnut Creek, due 2023 222 267 L+1.75 74 Other 343 361 various 24 Subtotal project-level debt 4,329 4,545 Total debt 6,038 6,068 Less current maturities (529 ) (339 ) Less net debt issuance costs (61 ) (62 ) Total long-term debt $ 5,448 $ 5,667 (a) As of December 31, 2018 , L+ equals 3 month LIBOR plus x%, except for Viento, due 2023 and Kansas South, due 2030, where L + equals 6 month LIBOR plus 2.00% and Utah Solar Portfolio, where L+equals 1 month LIBOR plus x%. (b) Applicable rate is determined by the borrower leverage ratio, as defined in the credit agreement. (c) On January 29, 2019, PG&E filed for bankruptcy under Chapter 11 of the U.S. Bankruptcy Code. The Company has non-recourse project-level debt, and in some cases holding company debt, related to each of its subsidiaries that sell their output to PG&E under long-term PPAs. The PG&E bankruptcy filing is an event of default under the related financing agreements, and as a result, the respective lenders under these arrangements may accelerate the repayment of these debt balances. In addition, the event of default may have an impact on the Company’s ability to distribute cash from the project-level cash accounts to the parent entities. The Company continues to operate the projects in the normal course of business and is currently in the process of negotiating forbearance agreements with the related lenders. 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, 2018 , the Company was in compliance with all of the required covenants. Clearway Energy LLC and Clearway Energy 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. On April 30, 2018, the Company closed on the refinancing of the revolving credit facility, which extended the maturity of the facility to April 28, 2023, and decreased the Company's overall cost of borrowing from L+ 2.50% to L+ 1.75% . The applicable rate is determined by the borrower leverage ratio, as defined in the credit agreement, and was L+ 1.75% as of December 31, 2018. The facility will continue to be used for general corporate purposes including financing of future acquisitions and posting letters of credit. On October 9, 2018, the Company terminated certain letters of credit relating to certain project PPAs in exchange for a one-time payment, which reduced the outstanding letters of credit under the revolving credit facility. As of December 31, 2018 , there were no outstanding borrowings under the revolving credit facility and the Company had $41 million of letters of credit outstanding. Bridge Credit Agreement On August 31, 2018, the Company entered into a senior unsecured 364-day bridge credit agreement, or the Bridge Credit Agreement, which provided total borrowings of up to a maximum amount of $1.5 billion at a rate per annum equal to LIBOR or a base rate plus an applicable margin equal to 3.00% in the case of LIBOR loans and 2.00% in the case of base rate loans. In October 2018, the Company reduced the lenders' commitments under the bridge agreement from $1.5 billion to $867.5 million following the offering of the 2025 Senior Notes and the convertible notes tender offer results, each described below. On October 31, 2018, the Company terminated the Bridge Credit Agreement. 2025 Senior Notes On October 1, 2018, Clearway Energy Operating LLC issued $600 million of senior unsecured notes, or the 2025 Senior Notes. The 2025 Senior Notes bear interest at 5.750% and mature on October 15, 2025. Interest on the 2025 Senior Notes is payable semi-annually on April 15 and October 15 of each year, and interest payments will commence on April 15, 2019. The 2025 Senior Notes are unsecured obligations of Clearway Energy Operating LLC and are guaranteed by Clearway Energy LLC and by certain of Clearway Energy Operating LLC's wholly owned current and future subsidiaries. The proceeds from the 2025 Senior Notes were partially used to repay the 2019 Convertible Notes. 2019 Convertible Notes Open Market Repurchases In August 2018, the Company repurchased an aggregate principal amount of $16 million of the 2019 Convertible Notes in open market transactions. The repurchases were funded through a partial repayment of the intercompany note between Clearway Energy Operating LLC and Clearway Energy, Inc., which was reduced by $16 million . In January 2019, the Company repurchased an additional aggregate principal amount of $50 million of the 2019 Convertible Notes in open market transactions. The repurchase was funded through a partial repayment of the intercompany note between Clearway Energy Operating LLC and Clearway Energy, Inc., which was reduced by $50 million . 2019 Convertible Notes and 2020 Convertible Notes Tender Offer On September 10, 2018, pursuant to the 2019 Convertible Notes and the 2020 Convertible Notes indentures, Clearway Energy, Inc. delivered to the holders of the 2019 Convertible Notes and the 2020 Convertible Notes a fundamental change notice and offer to repurchase any and all of the 2019 Convertible Notes and 2020 Convertible Notes for cash at a price equal to 100% of the principal amount of the Convertible Notes plus any accrued and unpaid interest. The tender offer expired on October 9, 2018. An aggregate principal amount of $109 million of the 2019 Convertible Notes and $243 million of the 2020 Convertible Notes were tendered on or prior to the expiration date and accepted by the Company for purchase. After the expiration of the tender offer, $216 million aggregate principal amount of the intercompany note due 2019 remained outstanding and $44 million aggregate principal amount of the intercompany note due 2020 remained outstanding as of December 31, 2018. The 2019 Convertible Notes matured on February 1, 2019 and Clearway Energy, Inc. paid off the remaining balance of an aggregate principal amount of $170 million , which was funded through the payment of the remaining balance of the intercompany note due 2019 between Clearway Energy Operating LLC and Clearway Energy, Inc.. Project - level Debt Energy Center Minneapolis Series E, F, G, H Notes On June 19, 2018, Energy Center Minneapolis LLC, a subsidiary of the Company, entered into an amended and restated Thermal note purchase and private shelf agreement under which it authorized the issuance of the Series E Notes, Series F Notes, Series G Notes, and Series H Notes, as further described in the table below: (In millions) Amount Interest Rate Energy Center Minneapolis Series E Notes, due 2033 $ 70 4.80 % Energy Center Minneapolis Series F Notes, due 2033 10 4.60 % Energy Center Minneapolis Series G Notes, due 2035 83 5.90 % Energy Center Minneapolis Series H Notes, due 2037 40 4.83 % Total proceeds $ 203 Repayment of Energy Center Minneapolis Series C Notes, due 2025 (83 ) 5.95 % Net borrowings $ 120 The proceeds from the sale of the Series E Notes and the Series F Notes were utilized to finance the acquisition of the UPMC Thermal Project as described in Note 3 , Business Acquisitions . The Series G Notes were used to refinance the Series C Notes as noted above in the table. The Series H Notes were used to make a dividend to Clearway Energy Operating LLC. The amended and restated Thermal note purchase and private shelf agreement also established a private shelf facility for the future issuance of notes in the amount of $40 million . Buckthorn Solar Drop Down Asset Debt As part of the Buckthorn Solar Drop Down Asset acquisition, as further described in Note 3 , Business Acquisitions , the Company assumed non-recourse debt of $183 million relating to Buckthorn Solar Portfolio, LLC as of the date of the acquisition, March 30, 2018. The assumed debt consisted of a construction loan and an Investment Tax Credits, or ITC, bridge loan, both at an interest rate of LIBOR plus 1.75% . On May 31, 2018, $132 million of non-recourse debt was converted to a term loan with an expected maturity of May 2025, and the remainder of the non-recourse debt was repaid with the final contribution from the Class A member in the amount of $80 million upon the project reaching substantial completion in May 2018. Buckthorn Solar entered into a series of fixed for floating interest rate swaps that would fix the interest rate for a minimum of 80% of the outstanding notional amount. All interest rate swap payments by Buckthorn Solar and its counterparties are made quarterly and LIBOR is determined in advance of each interest period. 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 held $39 million of the Agua Caliente Holdco debt as of December 31, 2018. 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 held $267 million of the Utah Solar Portfolio debt as of December 31, 2018. 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, 2018 : % of Principal Fixed Interest Rate Floating Interest Rate Notional Amount at December 31, 2018 (In millions) Effective Date Maturity Date Alpine 85 % various 3-Month LIBOR $ 108 various various Avra Valley 87 % 2.333 % 3-Month LIBOR 44 November 30, 2012 November 30, 2030 AWAM 100 % 2.47 % 3-Month LIBOR 16 May 22, 2013 May 15, 2031 Blythe 75 % 3.563 % 3-Month LIBOR 12 June 25, 2010 June 25, 2028 Borrego 75 % 1.125 % 3-Month LIBOR 3 April 3, 2013 June 30, 2020 Buckthorn Solar 83 % various 3-Month LIBOR 109 February 28, 2018 December 31, 2041 El Segundo 85 % various 3-Month LIBOR 299 various various Kansas South 75 % 2.368 % 6-Month LIBOR 20 June 28, 2013 December 31, 2030 Laredo Ridge 80 % 2.31 % 3-Month LIBOR 71 March 31, 2011 March 31, 2026 Marsh Landing 94 % 3.244 % 3-Month LIBOR 246 June 28, 2013 June 30, 2023 Roadrunner 75 % 4.313 % 3-Month LIBOR 24 September 30, 2011 December 31, 2029 South Trent 75 % 3.265 % 3-Month LIBOR 37 June 15, 2010 June 14, 2020 South Trent 75 % 4.95 % 3-Month LIBOR 21 June 30, 2020 June 14, 2028 Tapestry 90 % 2.21 % 3-Month LIBOR 136 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 214 various September 30, 2036 Viento Funding II 91 % various 6-Month LIBOR 134 various various Viento Funding II 90 % 4.985 % 6-Month LIBOR 65 July 11, 2023 June 30, 2028 Walnut Creek Energy 90 % various 3-Month LIBOR 200 June 28, 2013 May 31, 2023 WCEP Holdings 100 % 4.003 % 3-Month LIBOR 43 June 28, 2013 May 31, 2023 Total $ 1,862 Annual Maturities Annual payments based on the maturities of the Company's debt, for the years ending after December 31, 2018 , are as follows: (In millions) 2019 $ 529 2020 405 2021 447 2022 646 2023 389 Thereafter 3,622 Total $ 6,038

Members' Equity

Members' Equity	12 Months Ended
	Dec. 31, 2018
Members' Equity [Abstract]
Members' Equity	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, 2018 : Fourth Quarter 2018 Third Quarter 2018 Second Quarter 2018 First Quarter 2018 Distributions per Class A and Class B units $ 0.331 $ 0.320 $ 0.309 $ 0.298 Distributions per Class C and Class D units $ 0.331 $ 0.320 $ 0.309 $ 0.298 On February 12, 2019 , the Company declared a quarterly distribution on its Class A, Class B, Class C and Class D units of $0.20 per share payable on March 15, 2019 . During 2018 , 2017 , and 2016 , 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 members’ equity as changes in the contributed capital balance.

Segment Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
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 and includes eliminating entries. 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, 2018 , 2017 and 2016 : 2018 2017 2016 Customer Conventional (%) Renewables (%) Conventional (%) Renewables (%) Conventional (%) Renewables (%) SCE 20% 20% 21% 20% 21% 21% PG&E 12% 11% 12% 11% 12% 11% Year ended December 31, 2018 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues (a) $ 337 $ 526 $ 193 $ (3 ) $ 1,053 Cost of operations (a) 62 146 127 (3 ) 332 Depreciation and amortization 101 207 23 — 331 General and administrative — — 1 19 20 Acquisition-related transaction and integration costs — — — 20 20 Development costs — — 2 1 3 Operating income (loss) 174 173 40 (40 ) 347 Equity in earnings of unconsolidated affiliates 11 63 — — 74 Other income, net 1 4 1 2 8 Interest expense (51 ) (154 ) (12 ) (77 ) (294 ) Net Income (Loss) 135 86 29 (115 ) 135 Less: Net loss attributable to noncontrolling interests — (104 ) — (1 ) (105 ) Net Income (Loss) Attributable to Clearway Energy LLC $ 135 $ 190 $ 29 $ (114 ) $ 240 Balance Sheet Equity investment in affiliates $ 98 $ 1,074 $ — $ — $ 1,172 Capital expenditures (a) 14 26 28 — 68 Total Assets $ 1,788 $ 5,836 $ 516 $ 308 $ 8,448 (a) Inter-segment revenues and cost of operations include operations and maintenance fee revenue and related costs recorded in the Renewables segment. (b) Includes accruals. 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 ) (164 ) (10 ) (71 ) (294 ) Net Income (Loss) 120 8 25 (92 ) 61 Less: Net loss attributable to noncontrolling interests — (75 ) — — (75 ) Net Income (Loss) Attributable to Clearway Energy LLC $ 120 $ 83 $ 25 $ (92 ) $ 136 Balance Sheet Equity investments in affiliates $ 102 $ 1,076 $ — $ — $ 1,178 Capital expenditures (a) 15 181 16 — 212 Total Assets $ 1,897 $ 6,017 $ 422 $ 24 $ 8,360 (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 Less: Net loss attributable to noncontrolling interests — (111 ) — — (111 ) Net Income (Loss) Attributable to Clearway Energy LLC $ 153 $ 25 $ 29 $ (81 ) $ 126

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2018
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Related Party Transactions with CEG entities Administrative Services Agreements by and between the Company and Clearway Renewable Operation & Maintenance LLC (formerly NRG Renew Operation & Maintenance LLC) Various wholly-owned subsidiaries of the Company in the Renewables segment are party to administrative services agreements with Clearway Renewable Operation & Maintenance LLC (formerly NRG Renew Operation & Maintenance LLC), or RENOM, a wholly-owned subsidiary of CEG, which provides Operation and Maintenance, O&M, services to these subsidiaries. The Company incurred total expenses for these services of $30 million , $23 million and $13 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. There was a balance of $6 million and $5 million due to RENOM as of December 31, 2018 and 2017 , respectively. CEG Master Services Agreements Following the consummation of the GIP Transaction, Clearway Energy, Inc. along with Clearway Energy LLC and Clearway Energy Operating LLC entered into Master Services Agreements with CEG, pursuant to which CEG and certain of its affiliates or third party service providers began providing certain services to the Company, including operational and administrative services, which include human resources, information systems, external affairs, accounting, procurement and risk management services, and the Company began providing certain services to CEG, including accounting, internal audit, tax and treasury services, in exchange for the payment of fees in respect of such services. Amounts due to CEG or its subsidiaries are recorded as accounts payable - affiliate and amounts due to the Company from CEG and subsidiaries are recorded as accounts receivable - affiliate on the Company's consolidated balance sheet. Related Party Transactions with NRG entities prior to the GIP Transaction The following transactions relate to the period prior to sale of NRG's interest in CEG to GIP on August 31, 2018 and therefore were considered to be related party transactions for all the periods prior to August 31, 2018: 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 eight months ended August 31, 2018, Elbow Creek and Dover, collectively, generated revenues of $8 million . For the years ended December 31, 2017 and 2016 , Elbow Creek and Dover, collectively, generated revenues of $12 million and $13 million , respectively. Energy Marketing Services Agreement by and between Thermal entities and NRG Power Marketing Energy Center Dover LLC, Energy Center Minneapolis, Energy Center Phoenix LLC, and 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. For the eight months ended August 31, 2018, the Thermal entities purchased $7 million of natural gas from NRG Power Marketing. The Thermal entities purchased a total of $9 million of natural gas during each of the years ended December 31, 2017 and 2016 . 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 these agreements was $27 million for the eight months ended August 31, 2018. The fees incurred under this agreement were $39 million and $36 million for the years ended December 31, 2017 and 2016 , respectively. O&M Services Agreements by and between GenConn and NRG GenConn incurs fees under two O&M agreements with wholly-owned subsidiaries of NRG. For the eight months ended August 31, 2018, the aggregate fees incurred under the agreements were $4 million . The fees incurred under the agreements were $5 million during each of the years ended December 31, 2017 and 2016 . Administrative Services Agreement by and between Marsh Landing and NRG West Coast LLC Marsh Landing is a party to an administrative services agreement with NRG West Coast LLC, a wholly owned subsidiary of NRG. The Company reimbursed costs under this agreement of $11 million for the eight months ended August 31, 2018. The Company reimbursed costs under this agreement of approximately $15 million and $14 million for the years ended December 31, 2017 and 2016 , respectively. Project Administrative Services Agreement by and between ESEC and NRG West Coast LLC During 2018, ESEC, NRG West Coast LLC and NRG Power Marketing LLC, or PML, entered into confirmation agreements under the Project Administration Services Agreement between ESEC and NRG West Coast LLC, whereby PML purchased California Carbon Allowances which ESEC could subsequently purchase for the purposes of ESEC’s compliance with the California Cap-and-Trade Program. ESEC reimbursed costs under these agreements of $11 million for the eight months ended August 31, 2018. Management Services Agreement by and between the Company and NRG Prior to the GIP Transaction, NRG provided 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. Costs incurred under this agreement were $7 million for the eight months ended August 31, 2018. Costs incurred under this agreement were approximately $10 million during each of the years ended December 31, 2017 and 2016 , respectively. The costs incurred under the Management Services Agreement included certain direct expenses incurred by NRG on behalf of the Company in addition to the base management fee. On August 31, 2018, in connection with the consummation of the GIP Transaction, the Company entered into a Termination Agreement with Clearway Energy LLC, Clearway Energy Operating LLC and NRG terminating the Management Services Agreement, dated as of July 22, 2013, by and among the Company, Clearway Energy LLC, Clearway Energy Operating LLC and NRG. Subsequent to the GIP Transaction, the Company entered into a Transition Services Agreement with NRG, or the NRG TSA, pursuant to which NRG or certain of its affiliates began providing transitional services to the Company following the consummation of the GIP Transaction, in exchange for the payment of a fee in respect of such services. Expenses related to the NRG TSA are recorded in acquisition-related transaction and integration costs in the consolidated statements of operations. EPC Agreement by and between ECP and NRG NRG Business Services LLC, a subsidiary of NRG, and Energy Center Pittsburgh LLC, or ECP, a wholly owned subsidiary of the Company, entered into an EPC agreement for the construction of a 73 MWt district energy system for ECP 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. On June 19, 2018, as discussed in Note 3 , Business Acquisitions , ECP purchased the UPMC Thermal Project assets from NRG Business Services LLC for cash consideration of $84 million , subject to working capital adjustments. The Company paid an additional $3 million to NRG upon final completion of the project in January 2019 pursuant to the EPC agreement.

Commitments and Contingencies (

Commitments and Contingencies (Notes)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	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 $18 million , $17 million and $15 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. Future minimum lease commitments under operating leases for the years ending after December 31, 2018 are as follows: (In millions) 2019 $ 13 2020 13 2021 13 2022 13 2023 12 Thereafter 207 Total $ 271 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, 2018 , 2017 and 2016 , the Company purchased $39 million , $34 million and $32 million , respectively, under such arrangements. As further described in Note 13 Related Party Transactions , these purchases include intercompany transactions through August 31, 2018 between certain Thermal entities and NRG Power Marketing under the Energy Marketing Services Agreements in the amount of $7 million for the eight months ended August 31, 2018 and $9 million during each of the years ended December 31, 2017 and 2016 . As of December 31, 2018 , the Company's commitments under such outstanding agreements are estimated as follows: Period (In millions) 2019 $ 11 2020 3 2021 3 2022 3 2023 3 Thereafter 13 Total $ 36 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. Nebraska Public Power District Litigation On January 11, 2019, Nebraska Public Power District, or NPPD, sent written notice to certain of the Company’s subsidiaries which own the Laredo Ridge and Elkhorn Ridge wind projects alleging an event of default under each of the power purchase agreements between NPPD and the projects. NPPD alleges that Company moved forward with certain transactions without obtaining the consent of NPPD. NPPD threatened to terminate the applicable power purchase agreements by February 11, 2019 if the alleged default was not cured. The Company filed a motion for a temporary restraining order and preliminary injunction in the U.S. District Court for the District of Nebraska relating to the Laredo Ridge project, and a similar motion in the District Court of Knox County, Nebraska for the Elkhorn Ridge project, to enjoin NPPD from taking any actions related to the power purchase agreements. On February 19, 2019, the U.S. District Court in the Laredo Ridge matter approved a stipulation between the parties to provide for an injunction preventing NPPD from terminating the PPA pending disposition of the litigation. On February 26, 2019, the Knox County District Court approved a similar stipulation relating to the Elkhorn Ridge project. The Company believes the allegations of NPPD are meritless and the Company is vigorously defending its rights under the power purchase agreements.

Unaudited Quarterly Financial D

Unaudited Quarterly Financial Data	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Unaudited Quarterly Data	Unaudited Quarterly Data Below is summarized unaudited quarterly financial data for the periods ending December 31, 2018 and 2017 . The Company's historical financial results for the four quarters of 2017 were recast to include the results of the Buckthorn Solar Drop Down Asset acquisition, which took place on March 30, 2018, and is further described in Note 3 , Business Acquisitions . The Company originally recast its historical quarterly financial statements to include the result of the Buckthorn Drop Down Asset acquisition in its Form 10-Q for the period ended September 30, 2018. Additionally, the quarterly results for the period ended December 31, 2017, as presented below in the table, were recast to include the quarterly operating results of the Buckthorn Solar Drop Down Asset for the period ending December 31, 2017. Quarter Ended December 31, September 30, June 30, March 31, 2018 (In millions) Operating Revenues $ 229 $ 292 $ 307 $ 225 Operating Income 54 100 144 49 Net (Loss) Income (37 ) 64 106 2 Quarter Ended December 31, September 30, June 30, March 31, 2017 (In millions) Operating Revenues $ 231 $ 269 $ 288 $ 221 Operating Income 20 84 125 54 Net (Loss) Income (37 ) (a) 42 56 — (a) The Company reported Net loss of $38 million for the quarter ending December 31, 2017, as previously reported in the Note 17 , Unaudited Quarterly Financial Data of its Form 2017 10-K. The recast results in the table above include $1 million of Net Income attributable to the Buckthorn Solar Drop Down Asset acquisition.

Condensed Consolidating Financi

Condensed Consolidating Financial Information	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Condensed Financial Information Disclosure [Abstract]
Condensed Consolidating Financial Information	Condensed Consolidating Financial Information As of December 31, 2018 , Clearway Energy Operating LLC had outstanding $500 million of the 2024 Senior Notes, $600 million of the 2025 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, 2018 : Alta Wind 1-5 Holding Company, LLC Alta Wind Company, LLC Central CA Fuel Cell 1, LLC Clearway Energy LLC Clearway Energy Operating LLC Clearway Solar Star LLC DGPV Holding LLC ECP Uptown Campus Holdings LLC Energy Center Caguas Holdings LLC Fuel Cell Holdings LLC Portfolio Solar I, LLC RPV Holding LLC Solar Flagstaff One LLC Solar Iguana LLC Solar Las Vegas MB 1 LLC Solar Tabernacle LLC South Trent Holdings LLC SPP Asset Holdings, LLC SPP Fund II Holdings, LLC SPP Fund II, LLC SPP Fund II-B, LLC SPP Fund III, LLC Thermal Canada Infrastructure Holdings LLC Thermal Infrastructure Development Holdings LLC UB Fuel Cell, LLC Clearway Energy 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 Clearway Energy 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 Clearway Energy Operating LLC. However, there may be restrictions for certain non-guarantor subsidiaries. On January 29, 2019, PG&E filed for bankruptcy under Chapter 11 of the U.S. Bankruptcy Code. PG&E is one of the Company's largest customers, representing approximately 23% of the Company's consolidated operating revenues during the year ended December 31, 2018 and 16% of total accounts receivable as of December 31, 2018, of which all has been collected as of January 31, 2019. The PG&E bankruptcy filing is an event of default under the related financing agreements which caused uncertainty around the timing of when certain project-level cash distributions will be available to the Company. As of December 31, 2018, all project level cash balances for these subsidiaries were classified as restricted cash. None of the subsidiaries affected by the PG&E bankruptcy are guarantors of the Senior Notes as of December 31, 2018. The following condensed consolidating financial information presents the financial information of Clearway Energy LLC, Clearway Energy 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, Clearway Energy LLC consists of parent company operations. Guarantor subsidiaries and non-guarantor subsidiaries of Clearway Energy 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 Buckthorn Solar Drop Down Asset on March 30, 2018. 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. The Company also completed the UPMC Thermal Project Asset Acquisition on June 19, 2018, which was an asset acquisition. The assets transferred to the Company relate to interests under common control by NRG and were recorded at book value in accordance with ASC 805-50, Business Combinations - Related Issues . The difference between the purchase price and book value of the assets was recorded as a distribution to NRG and decreased the balance of contributed capital. The acquisition was determined to be an asset acquisition and not a business combination, therefore no recast of the historical financial information was deemed necessary. During the first six months of 2018, the Company added certain subsidiaries to the list of guarantors under the Senior Notes indentures, and as a result, the Company recast the historical financial statements to allow for the comparability between the reported periods as required by GAAP. 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 Clearway Energy LLC’s subsidiaries exceed 25 percent of the consolidated net assets of Clearway Energy LLC. These statements should be read in conjunction with the consolidated statements and notes thereto of Clearway Energy LLC. For a discussion of Clearway Energy LLC's long-term debt, see Note 10 , Long-term Debt . For a discussion of Clearway Energy LLC's commitments and contingencies, see Note 14 , Commitments and Contingencies . For a discussion of Clearway Energy LLC's distributions to Clearway Energy, Inc., NRG Energy, (and subsequent to August 31, 2018, CEG), see Note 11 , Members' Equity . In addition, Clearway Energy LLC’s cash and cash equivalents represents corporate cash held in overnight investment accounts and is used for general corporate purposes for Clearway LLC and Clearway Operating LLC. CLEARWAY ENERGY LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2018 Clearway Energy LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries Clearway Energy Operating LLC (Senior Notes Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 11 $ 1,042 $ 3 $ (3 ) $ 1,053 Operating Costs and Expenses — Cost of operations — 3 329 3 (3 ) 332 Depreciation and amortization — 6 325 — — 331 General and administrative — — — 20 — 20 Acquisition-related transaction and integration costs — — — 20 — 20 Development costs — — — 3 — 3 Total operating costs and expenses — 9 654 46 (3 ) 706 Operating Income (Loss) — 2 388 (43 ) — 347 Other Income (Expense) Equity in earnings of consolidated affiliates 237 — — 224 (461 ) — Equity in earnings of unconsolidated affiliates — 43 3 28 — 74 Other income, net 3 — 5 — — 8 Interest expense — — (217 ) (77 ) — (294 ) Total other income (expense), net 240 43 (209 ) 175 (461 ) (212 ) Net Income 240 45 179 132 (461 ) 135 Less: Net loss attributable to noncontrolling interests — — (69 ) (105 ) 69 (105 ) Net Income Attributable to Clearway Energy LLC $ 240 $ 45 $ 248 $ 237 $ (530 ) $ 240 (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. CLEARWAY ENERGY LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2018 Clearway Energy LLC (a) Guarantor Subsidiaries Non-Guarantor Subsidiaries Clearway Energy Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 240 $ 45 $ 179 $ 132 $ (461 ) $ 135 Other Comprehensive Income Unrealized gain on derivatives 24 1 20 24 (45 ) 24 Other comprehensive income 24 1 20 24 (45 ) 24 Comprehensive Income 264 46 199 156 (506 ) 159 Less: Comprehensive loss attributable to noncontrolling interests — — (69 ) (105 ) 69 (105 ) Comprehensive Income Attributable to Clearway Energy LLC $ 264 $ 46 $ 268 $ 261 $ (575 ) $ 264 (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. LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2018 Clearway Energy LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries Clearway Energy Operating LLC Eliminations (b) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 298 $ — $ 109 $ — $ — $ 407 Restricted cash — — 176 — — 176 Accounts receivable — trade — 1 103 — — 104 Accounts receivable — affiliates 8 — — 11 (14 ) 5 Inventory — — 40 40 Prepayments and other current assets 27 2 — 29 Total current assets 306 1 455 13 (14 ) 761 Property, plant and equipment, net — 65 5,180 — — 5,245 Other Assets Investment in consolidated subsidiaries 1,676 417 — 3,250 (5,343 ) — Equity investments in affiliates — 289 522 361 — 1,172 Intangible assets, net — 11 1,145 — — 1,156 Derivative instruments — — 8 — — 8 Other non-current assets — — 103 3 — 106 Total other assets 1,676 717 1,778 3,614 (5,343 ) 2,442 Total Assets $ 1,982 $ 783 $ 7,413 $ 3,627 $ (5,357 ) $ 8,448 (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. CLEARWAY ENERGY LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2018 Clearway Energy LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries Clearway Energy Operating LLC Eliminations (b) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 314 $ — $ — $ 314 Current portion of long-term debt — affiliate — — — 215 — 215 Accounts payable — trade — 1 36 8 — 45 Accounts payable — affiliate — — 23 11 (14 ) 20 Derivative instruments — — 4 — — 4 Accrued interest expense — — 17 27 — 44 Accrued expenses and other current liabilities — — 53 4 — 57 Total current liabilities — 1 447 265 (14 ) 699 Other Liabilities Long-term debt — external — — 3,970 1,434 — 5,404 Long-term debt — affiliate — — — 44 — 44 Derivative instruments — — 17 — — 17 Other non-current liabilities — 2 92 8 — 102 Total non-current liabilities — 2 4,079 1,486 — 5,567 Total Liabilities — 3 4,526 1,751 (14 ) 6,266 Commitments and Contingencies Members' Equity Contributed capital 1,940 804 2,708 1,930 (5,442 ) 1,940 Retained earnings (accumulated deficit) 86 (24 ) 108 (210 ) 126 86 Accumulated other comprehensive loss (44 ) — (51 ) (44 ) 95 (44 ) Noncontrolling interest — — 122 200 (122 ) 200 Total Members' Equity 1,982 780 2,887 1,876 (5,343 ) 2,182 Total Liabilities and Members’ Equity $ 1,982 $ 783 $ 7,413 $ 3,627 $ (5,357 ) $ 8,448 (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. LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2018 Clearway Energy LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries Clearway Energy Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 23 $ 550 $ (81 ) $ 492 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 361 — — (361 ) — Acquisition of business, net of cash acquired — — — (11 ) (11 ) Acquisition of Drop Down Assets, net of cash acquired — — — (126 ) (126 ) Capital expenditures — — (83 ) — (83 ) Cash receipts from notes receivable — — 13 — 13 Return of investment from unconsolidated affiliates — 11 20 14 45 Investments in unconsolidated affiliates — (34 ) — — (34 ) Other — — 11 — 11 Net Cash Provided by (Used in) Investing Activities 361 (23 ) (39 ) (484 ) (185 ) Cash Flows from Financing Activities Net contributions from noncontrolling interests — — 97 9 106 Transfer of funds under intercompany cash management arrangement — — 4 (4 ) — Proceeds from the issuance of Class C units 153 — — — 153 (Payments of) proceeds from distributions (238 ) — (400 ) 385 (253 ) Proceeds from the revolving credit facility — — — 35 35 Payments for the revolving credit facility — — — (90 ) (90 ) Payments of debt issuance costs — — (3 ) (11 ) (14 ) Proceeds from issuance of long-term debt — — 227 600 827 Payments for long-term debt — external — — (443 ) — (443 ) Payments for long-term debt — affiliate — — — (359 ) (359 ) Net Cash (Used in) Provided by Financing Activities (85 ) — (518 ) 565 (38 ) Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash 276 — (7 ) — 269 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 22 — 292 — 314 Cash, Cash Equivalents and Restricted Cash at End of Period $ 298 $ — $ 285 $ — $ 583 (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. LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2017 Clearway Energy LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) Clearway Energy Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 10 $ 999 $ 1 $ (1 ) $ 1,009 Operating Costs and Expenses Cost of operations — 2 324 1 (1 ) 326 Depreciation and amortization — 6 328 — — 334 Impairment losses — 12 32 — — 44 General and administrative — — — 19 — 19 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 20 684 23 (1 ) 726 Operating Income (Loss) — (10 ) 315 (22 ) — 283 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 135 (16 ) — 125 (244 ) — Equity in earnings of unconsolidated affiliates — 22 21 28 — 71 Loss on debt extinguishment — (3 ) — — — (3 ) Other income, net 1 — 3 — — 4 Interest expense — 1 (224 ) (71 ) — (294 ) Total other income (expense) 136 4 (200 ) 82 (244 ) (222 ) Net Income (Loss) 136 (6 ) 115 60 (244 ) 61 Less: Net loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Net Income (Loss) Attributable to Clearway Energy LLC $ 136 $ (6 ) $ 120 $ 135 $ (249 ) $ 136 (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 . LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2017 Clearway Energy LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) Clearway Energy Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income (Loss) $ 136 $ (6 ) $ 115 $ 60 $ (244 ) $ 61 Other Comprehensive Income Unrealized gain on derivatives 17 1 16 17 (34 ) 17 Other comprehensive income 17 1 16 17 (34 ) 17 Comprehensive Income (Loss) 153 (5 ) 131 77 (278 ) 78 Less: Comprehensive loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Comprehensive Income (Loss) Attributable to Clearway Energy LLC $ 153 $ (5 ) $ 136 $ 152 $ (283 ) $ 153 (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 . LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2017 Clearway Energy LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) Clearway Energy Operating LLC (c) Eliminations (b)(c) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 22 $ — $ 124 $ — $ — $ 146 Restricted cash — — 168 — — 168 Accounts receivable — trade — 1 93 1 — 95 Accounts receivable — affiliates 1 — — — — 1 Inventory — — 39 — — 39 Notes receivable — current — — 13 — — 13 Prepayments and other current assets — — 18 1 — 19 Total current assets 23 1 455 2 — 481 Property, plant and equipment, net — 59 5,351 — — 5,410 Other Assets Investment in consolidated subsidiaries 1,844 460 — 3,198 (5,502 ) — Equity investments in affiliates — 233 577 368 — 1,178 Intangible assets, net — 12 1,216 — — 1,228 Derivative instruments — — 1 — — 1 Other non-current assets — — 62 — — 62 Total other assets 1,844 705 1,856 3,566 (5,502 ) 2,469 Total Assets $ 1,867 $ 765 $ 7,662 $ 3,568 $ (5,502 ) $ 8,360 (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 . CLEARWAY ENERGY LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2017 Clearway Energy LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) Clearway Energy Operating LLC (c) Eliminations (b) (c) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 339 $ — $ — $ 339 Accounts payable — trade — — 46 — — 46 Accounts payable — affiliate — — 33 16 — 49 Derivative instruments — — 18 — — 18 Accrued interest expense — — 16 22 — 38 Accrued expenses and other current liabilities 46 3 49 Total current liabilities — — 498 41 — 539 Other Liabilities Long-term debt — external — — 4,153 896 — 5,049 Long-term debt — affiliate — — — 618 — 618 Derivative instruments — — 31 — — 31 Other non-current liabilities — 2 85 7 — 94 Total non-current liabilities — 2 4,269 1,521 — 5,792 Total Liabilities — 2 4,767 1,562 — 6,331 Commitments and Contingencies Members' Equity Contributed capital 1,919 822 2,934 2,119 (5,875 ) 1,919 Retained earnings (accumulated deficit) 16 (58 ) (25 ) (207 ) 290 16 Accumulated other comprehensive loss (68 ) (1 ) (71 ) (68 ) 140 (68 ) Noncontrolling interest — — 57 162 (57 ) 162 Total Members' Equity 1,867 763 2,895 2,006 (5,502 ) 2,029 Total Liabilities and Members’ Equity $ 1,867 $ 765 $ 7,662 $ 3,568 $ (5,502 ) $ 8,360 (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 . LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2017 Clearway Energy LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) Clearway Energy Operating LLC (Note Issuer) Consolidated Net Cash Provided by (Used in) Operating Activities $ — $ 51 $ 537 $ (71 ) $ 517 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (15 ) — — 15 — Acquisition of Drop Down Assets — — — (250 ) (250 ) Capital expenditures — — (190 ) — (190 ) 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 Used in Investing Activities (15 ) (54 ) (159 ) (214 ) (442 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (5 ) — (1 ) 6 — Net contributions from noncontrolling interests — — 2 11 13 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — 30 (46 ) (7 ) (23 ) 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 the issuance of long-term debt - external — — 210 — 210 Payments of debt issuance costs — — (12 ) — (12 ) Payments for long-term debt — external — (36 ) (296 ) — (332 ) Net Cash Provided by (Used in) Financing Activities (174 ) (6 ) (363 ) 285 (258 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (189 ) (9 ) 15 — (183 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 211 9 277 — 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. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .	LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2016 Clearway Energy LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries Clearway Energy Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 10 $ 1,025 $ 1 $ (1 ) $ 1,035 Operating Costs and Expenses Cost of operations — 3 305 1 (1 ) 308 Depreciation and amortization — 5 298 — — 303 Impairment losses — 2 183 — — 185 General and administrative 2 — — 12 — 14 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses 2 10 786 14 (1 ) 811 Operating (Loss) Income (2 ) — 239 (13 ) — 224 Other Income (Expense) Equity in earnings of consolidated affiliates 128 10 — 66 (204 ) — Equity in (losses) earnings of unconsolidated affiliates — 9 21 30 — 60 Other income, net — — 3 — — 3 Interest expense — (2 ) (204 ) (66 ) — (272 ) Total other income (expense), net 128 17 (180 ) 30 (204 ) (209 ) Net Income 126 17 59 17 (204 ) 15 Less: Net loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Net Income Attributable to Clearway Energy LLC $ 126 $ 17 $ 60 $ 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. LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2016 Clearway Energy LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries Clearway Energy Operating LLC (Senior Notes Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 126 $ 17 $ 59 $ 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 18 69 30 (228 ) 28 Less: Comprehensive loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Comprehensive Income Attributable to Clearway Energy LLC $ 139 $ 18 $ 70 $ 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. LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2016 Clearway Energy LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries Clearway Energy Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 67 $ 549 $ (39 ) $ 577 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 325 — (21 ) (304 ) — Acquisition of Drop Down Assets, net of cash acquired — — — (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) Provided by 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 — (3 ) (171 ) (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 issuance of long-term debt — external — — 390 350 740 Payments for long-term debt — external — (3 ) (266 ) — (269 ) Payment of debt issuance costs — — (10 ) (5 ) (15 ) Net Cash (Used in) Provided by Financing Activities (129 ) (4 ) (477 ) 408 (202 ) Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash 196 (1 ) 49 — 244 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 15 10 228 — 253 Cash, Cash Equivalents and Restricted Cash at End of Period $ 211 $ 9 $ 277 $ — $ 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.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Basis of Presentation	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.
Principles of Consolidation	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.
Restricted Cash	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.
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, 2018 and 2017 .
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. 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.
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.
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.
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.
Income Taxes	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	Revenue from Contracts with Customers On January 1, 2018, the Company adopted the guidance in ASC 606, Revenue from Contracts with Customers, or Topic 606, using the modified retrospective method applied to contracts which were not completed as of the adoption date, with no adjustment required to the financial statements upon adoption. Following the adoption of the new standard, the Company’s revenue recognition of its contracts with customers remains materially consistent with its historical practice. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. The Company's policies with respect to its various revenue streams are detailed below. In general, the Company applies the invoicing practical expedient to recognize revenue for the revenue streams detailed below, except in circumstances where the invoiced amount does not represent the value transferred to the customer. Thermal Revenues Steam and chilled water revenue is recognized as the Company transfers the product to the customer, 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. For thermal contracts, the Company’s performance obligation to deliver steam and chilled water is satisfied over time and revenue is recognized based on the invoiced amount. 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. As contracts for steam and chilled water are long-term contracts, the Company has performance obligations under these contracts that have not yet been satisfied. These performance obligations have transaction prices that are both fixed and variable, and that vary based on the contract duration, customer type, inception date and other contract-specific factors. For the fixed price contracts, the Company cannot accurately estimate the amount of its unsatisfied performance obligations as it will vary based on customer usage, which will depend on factors such as weather and customer activity. Power Purchase Agreements, or PPAs The majority of the Company’s revenues are obtained through PPAs or other contractual agreements. Energy, capacity and where applicable, renewable attributes, from the majority of the Company’s renewable energy assets and certain conventional energy plants is sold through long-term PPAs and tolling agreements to a single counterparty, which is often a utility or commercial customer. The majority of these PPAs are accounted for as leases. 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, 2018 , 2017 and 2016 was $583 million , $559 million and $583 million , respectively. These balances include intercompany revenue for Elbow Creek of $6 million for the eight months ended August 31, 2018 and $8 million for each of the years ended December 31, 2017 and 2016 , as further discussed in Note 13 Related Party Transactions . Renewable Energy Credits, or RECs As stated above, renewable energy credits, or RECs, are usually sold through long-term PPAs. Revenue from the sale of self-generated RECs is recognized when the related energy is generated and simultaneously delivered even in cases where there is a certification lag as it has been deemed to be perfunctory. In a bundled contract to sell energy, capacity and/or self-generated RECs, all performance obligations are deemed to be delivered at the same time and hence, timing of recognition of revenue for all performance obligations is the same and occurs over time. In such cases, it is often unnecessary to allocate transaction price to multiple performance obligations. Sale of Emission Allowances The Company records its bank of emission allowances as part of intangible assets. From time to time, management may authorize the transfer of emission allowances in excess of usage from the Company's emission bank to intangible assets held-for-sale for trading purposes. The Company records the sale of emission allowances on a net basis within operating revenue in the Company's consolidated statements of operations. Disaggregated Revenues The following tables represent the Company’s disaggregation of revenue from contracts with customers for the year ended December 31, 2018 , along with the reportable segment for each category: Year ended December 31, 2018 (In millions) Conventional Generation Renewables Thermal Corporate Total Energy revenue (a) $ 5 $ 572 $ 4 — $ 581 Capacity revenue (a) 337 — 166 — 503 Other revenues — 16 26 (3 ) 39 Contract amortization (5 ) (62 ) (3 ) — (70 ) Total operating revenue 337 526 193 (3 ) 1,053 Less: Lease revenue (342 ) (534 ) (2 ) — (878 ) Less: Contract amortization 5 62 3 — 70 Total revenue from contracts with customers $ — $ 54 $ 194 (3 ) $ 245 (a) The following amounts of energy and capacity revenue relate to leases and are accounted for under ASC 840: Conventional Generation Renewables Thermal Total Energy Revenue $ 5 $ 534 $ 2 $ 541 Capacity Revenue 337 — — 337 342 534 2 878 Contract Amortization Assets and liabilities recognized from power sales agreements assumed through acquisitions related to the sale of electric capacity and energy in future periods for which the fair value has been determined to be significantly less (more) than market are amortized to revenue over the term of each underlying contract based on actual generation and/or contracted volumes or on a straight-line basis, where applicable. Contract Balances The following table reflects the contract assets and liabilities included on the Company’s balance sheet as of December 31, 2018 : (In millions) December 31, 2018 December 31, 2017 Accounts receivable, net - Contracts with customers $ 35 $ 28 Accounts receivable, net - Leases 69 67 Total accounts receivable, net $ 104 $ 95
Derivatives 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 interest rate instruments used to mitigate variability in earnings due to fluctuations in interest rates, power purchase or sale contracts used to mitigate variability in earnings due to fluctuations in market prices and fuels purchase contracts used to control customer reimbursable fuel cost. On an ongoing basis, the Company qualitatively assesses the effectiveness of its 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 cash flows of hedged items. If necessary, the Company will perform an analyses to measure the statistical correlation between the derivative and the associated hedged item determine the effectiveness of such a contract designated as a hedge. The Company will discontinue hedge accounting if it is determined that the hedge is no longer effective. 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. See Item 1A, Risk Factors, Risks related to the PG&E Bankruptcy for a discussion on the Company’s dependence on major customers .
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.
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.
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 Investments	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.
Pension Benefits	.
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.
Recent Accounting Developments	ASU 2016-02 — In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), or Topic 842, as amended, 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 adopted the standard effective January 1, 2019 using the modified retrospective transition method and will not restate prior periods for the impact of Topic 842. In addition, the Company elected certain of the permitted practical expedients, including the expedient that permits the Company to retain its existing lease assessment and classification. The company will not record a right-of-use asset and related lease liability for leases with an initial term of 12 months or less and will account for lease and non-lease components for specific asset classes as a single lease component. The Company's leases consist mainly of land leases for many operating asset locations, as well as leases of office space and office equipment. The Company estimates it will record lease liabilities of approximately $160 million to $170 million and right-of-use assets of approximately $155 million to $165 million , as of January 1, 2019, with an immaterial impact estimated to retained earnings. The actual amounts recorded may vary from this estimate as the Company completes its adoption of the guidance. Other than disclosed, the Company does not expect that there will be a material impact to the consolidated statements of operations, comprehensive income or consolidated cash flows as a result of adoption of this new guidance.

Nature of Business (Tables)

Nature of Business (Tables)	12 Months Ended
	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Company Organization Chart	The following table represents the structure of the Company as of December 31, 2018 :

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Schedule of Cash and Cash Equivalents	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, 2018 2017 2016 (In millions) Cash and cash equivalents $ 407 $ 146 $ 321 Restricted cash 176 168 176 Cash, cash equivalents and restricted cash shown in the statement of cash flows 583 314 497
Restrictions on Cash and Cash Equivalents	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, 2018 2017 2016 (In millions) Cash and cash equivalents $ 407 $ 146 $ 321 Restricted cash 176 168 176 Cash, cash equivalents and restricted cash shown in the statement of cash flows 583 314 497
Disaggregation of Revenue	The following tables represent the Company’s disaggregation of revenue from contracts with customers for the year ended December 31, 2018 , along with the reportable segment for each category: Year ended December 31, 2018 (In millions) Conventional Generation Renewables Thermal Corporate Total Energy revenue (a) $ 5 $ 572 $ 4 — $ 581 Capacity revenue (a) 337 — 166 — 503 Other revenues — 16 26 (3 ) 39 Contract amortization (5 ) (62 ) (3 ) — (70 ) Total operating revenue 337 526 193 (3 ) 1,053 Less: Lease revenue (342 ) (534 ) (2 ) — (878 ) Less: Contract amortization 5 62 3 — 70 Total revenue from contracts with customers $ — $ 54 $ 194 (3 ) $ 245 (a) The following amounts of energy and capacity revenue relate to leases and are accounted for under ASC 840: Conventional Generation Renewables Thermal Total Energy Revenue $ 5 $ 534 $ 2 $ 541 Capacity Revenue 337 — — 337 342 534 2 878
Schedule of Contract Balances	The following table reflects the contract assets and liabilities included on the Company’s balance sheet as of December 31, 2018 : (In millions) December 31, 2018 December 31, 2017 Accounts receivable, net - Contracts with customers $ 35 $ 28 Accounts receivable, net - Leases 69 67 Total accounts receivable, net $ 104 $ 95
Schedule of Change in Asset Retirement Obligation	The following table represents the balance of ARO obligations as of December 31, 2018 and 2017 , along with the additions and accretion related to the Company's ARO obligations for the year ended December 31, 2018 : (In millions) Balance as of December 31, 2017 $ 58 Revisions in estimates for current obligations/Additions 5 Accretion — expense 4 Balance as of December 31, 2018 $ 67

Business Acquisitions (Tables)

Business Acquisitions (Tables)	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Summary of Net Assets Transferred in Connection with the Acquisition	The following is a summary of net assets transferred in connection with the acquisition of the Buckthorn Solar Drop Down Asset as of March 31, 2018: (In millions) Assets: Current assets $ 20 Property, plant and equipment 212 Non-current assets 3 Total assets 235 Liabilities: Debt (Current and non-current) (a) 176 Other current and non-current liabilities 15 Total liabilities 191 Less: noncontrolling interest 19 Net assets acquired $ 25 (a) Net of $7 million of net debt issuance costs. The following table presents a summary of the Company's historical information for the year ended December 31, 2017, which combines the financial information for the Buckthorn Solar Drop Down Asset transferred in connection with the acquisition. Year ended December 31, 2017 As Previously Reported Buckthorn Solar Drop Down Asset As Currently Reported (In millions) Total operating revenues $ 1,009 $ — $ 1,009 Operating income 283 — 283 Net income 62 (1 ) 61 Net income attributable to Clearway Energy LLC 137 (1 ) 136

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
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, 2018 December 31, 2017 Depreciable Lives (In millions) Facilities and equipment $ 6,638 $ 6,291 2 - 45 Years Land and improvements 171 166 Construction in progress (a) 26 238 Total property, plant and equipment 6,835 6,695 Accumulated depreciation (1,590 ) (1,285 ) Net property, plant and equipment $ 5,245 $ 5,410 (a) As of December 31, 2018 and 2017 , construction in progress includes $6 million and $24 million of capital expenditures that relate to prepaid long-term service agreements in the Conventional segment, respectively.

Investments Accounted for by _2

Investments Accounted for by the Equity Method and Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2018
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	The following tables present summarized financial information for the Company's significant equity method investments: Year Ended December 31, 2018 2017 2016 Income Statement Data: (In millions) GenConn Operating revenues $ 65 $ 71 $ 72 Operating income 32 36 38 Net income 22 26 26 Desert Sunlight Operating revenues 208 207 211 Operating income 129 127 129 Net income 84 80 80 DGPV entities (a) Operating revenues 69 37 14 Operating income 23 7 2 Net income (loss) 11 (3 ) — RPV Holdco Operating revenues 14 16 13 Operating income — 3 2 Net income — 3 2 Other (b) Operating revenues 249 247 193 Operating income 103 89 71 Net income $ 75 $ 56 $ 38 As of December 31, 2018 2017 Balance Sheet Data: (In millions) GenConn Current assets $ 43 $ 38 Non-current assets 358 374 Current liabilities 22 18 Non-current liabilities 182 189 Desert Sunlight Current assets 133 133 Non-current assets 1,298 1,350 Current liabilities 58 64 Non-current liabilities 962 1,003 DGPV entities (a) Current assets 79 74 Non-current assets 784 671 Current liabilities 84 83 Non-current liabilities 314 216 Redeemable Noncontrolling Interest — 44 RPV Holdco Current assets 2 3 Non-current assets 173 183 Current liabilities 1 — Non-current liabilities 8 7 Redeemable Noncontrolling Interest 26 16 Other (b) Current assets 148 139 Non-current assets 2,511 2,621 Current liabilities 58 60 Non-current liabilities $ 889 $ 932 (a) Includes DGPV Holdco 1, DGPV Holdco 2 and DGPV Holdco 3 The following table summarizes the Company's equity method investments as of December 31, 2018 : Name Economic Interest Investment Balance (In millions) Utah Solar Portfolio (a) 50% $317 Desert Sunlight (e) 25% 264 GenConn (b) 50% 98 Agua Caliente Solar (e) 16% 90 Elkhorn Ridge (c) 66.7% 59 San Juan Mesa (c) 75% 57 DGPV Holdco 1 LLC (d) 95% 81 DGPV Holdco 2 LLC (d) 95% 63 DGPV Holdco 3 LLC (d) 99% 116 RPV Holdco 1 LLC (d) 95% 29 Avenal (e) 50% (2) $1,172 (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. DGPV Holdco 1 LLC, DGPV Holdco 2 LLC, DGPV Holdco 3 LLC and RPV Holdco 1 LLC are tax equity structures and VIEs. The related allocations are described below. (e) Entities that have PPAs with PG&E. On January 29, 2019, PG&E filed for bankruptcy under Chapter 11 of the U.S. Bankruptcy Code. The Company has non-recourse project-level debt, and in some cases holding company debt, related to each of its subsidiaries that sell their output to PG&E under long-term PPAs. The PG&E bankruptcy filing is an event of default under the related financing agreements, and as a result, the respective lenders under these arrangements may accelerate the repayment of these debt balances. In addition, the event of default may have an impact on the Company’s ability to distribute cash from the project-level cash accounts to the parent entities. The Company continues to operate the projects in the normal course of business and is currently in the process of negotiating forbearance agreements with the related lenders.
Schedule of Variable Interest Entities	Summarized financial information for the Company's consolidated VIEs consisted of the following as of December 31, 2018 : (In millions) Wind TE Holdco Alta TE Holdco Spring Canyon Buckthorn Renewables, LLC Other current and non-current assets $ 215 $ 17 $ 2 $ 15 Property, plant and equipment 346 410 91 223 Intangible assets 2 249 — — Total assets 563 676 93 238 Current and non-current liabilities 210 9 4 Total liabilities 210 9 4 135 Noncontrolling interest 45 63 49 43 Net assets less noncontrolling interests $ 308 $ 604 $ 40 $ 60

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value, by Balance Sheet Grouping	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, 2018 As of December 31, 2017 Carrying Amount Fair Value Carrying Amount Fair Value (In millions) Assets: Notes receivable, including current portion $ — $ — $ 13 $ 13 Liabilities: Long-term debt, including current portion — affiliate 259 257 618 618 Long-term debt, including current portion — external $ 5,779 $ 5,681 $ 5,450 $ 5,466
Fair Value Hierarchy of Long-term Debt	The following table presents the level within the fair value hierarchy for long-term debt, including current portion as of December 31, 2018 and 2017 : As of December 31, 2018 As of December 31, 2017 Level 2 Level 3 Level 2 Level 3 (In millions) Long-term debt, including current portion $ 1,358 $ 4,580 $ 870 $ 5,214
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	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, 2018 As of December 31, 2017 Fair Value (a) Fair Value (a) (In millions) Level 2 Level 2 Derivative assets: Commodity contracts (b) $ — $ 1 Interest rate contracts 11 1 Total assets $ 11 $ 2 Derivative liabilities: Commodity contracts (b) $ — 1 Interest rate contracts 21 48 Total liabilities $ 21 $ 49 (a) There were no derivative assets or liabilities classified as Level 1 or 3 as of December 31, 2018 and 2017 .

Accounting for Derivative Ins_2

Accounting for Derivative Instruments and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Notional Amounts of Outstanding	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, 2018 and 2017 : Total Volume December 31, 2018 December 31, 2017 Commodity Units (In millions) Natural Gas MMBtu 1 2 Interest Dollars $ 1,862 $ 2,050
Schedule of 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, 2018 December 31, 2017 December 31, 2018 December 31, 2017 (In millions) Derivatives Designated as Cash Flow Hedges: Interest rate contracts current $ 2 $ — $ 1 $ 4 Interest rate contracts long-term 3 1 6 9 Total Derivatives Designated as Cash Flow Hedges 5 1 7 13 Derivatives Not Designated as Cash Flow Hedges : Interest rate contracts current 1 — 3 13 Interest rate contracts long-term 5 — 11 22 Commodity contracts current (b) — 1 — 1 Total Derivatives Not Designated as Cash Flow Hedges 6 1 14 36 Total Derivatives $ 11 $ 2 $ 21 $ 49 (a) Derivative Asset balances classified as current are included within the prepayments and other current assets line item of the Consolidated Balance Sheet. (b) The fair value of commodities was not material as of December 31, 2018
Schedule of Offsetting of Derivatives	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, 2018 Gross Amounts of Recognized Assets/Liabilities Derivative Instruments Net Amount Interest rate contracts: Derivative assets $ 11 $ (1 ) $ 10 Derivative liabilities (21 ) 1 (20 ) Total interest rate contracts (10 ) — (10 ) Total derivative instruments $ (10 ) $ — $ (10 ) 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 (48 ) 1 (47 ) Total interest rate contracts (47 ) — (47 ) Total derivative instruments $ (47 ) $ — $ (47 )
Schedule of Cash Flow Hedges Included in Accumulated Other Comprehensive Income (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, 2018 2017 2016 (In millions) Accumulated OCL beginning balance $ (69 ) $ (86 ) $ (99 ) Reclassified from accumulated OCL to income due to realization of previously deferred amounts 15 17 17 Mark-to-market of cash flow hedge accounting contracts 9 — (4 ) Accumulated OCL ending balance (45 ) (69 ) (86 ) Accumulated OCL attributable to noncontrolling interests (1 ) (1 ) (1 ) Accumulated OCL attributable to Clearway Energy LLC $ (44 ) $ (68 ) $ (85 ) Losses expected to be realized from OCL during the next 12 months $ 9

Intangible Assets Intangible As

Intangible Assets Intangible Assets - (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	The following tables summarize the components of intangible assets subject to amortization: Year ended December 31, 2018 PPAs Leasehold Rights Customer Customer Contracts Emission Allowances Other Total (In millions) December 31, 2018 $ 1,280 $ 86 $ 66 $ 15 $ 9 $ 8 $ 1,464 Less accumulated amortization (269 ) (18 ) (7 ) (9 ) (2 ) (3 ) (308 ) Net carrying amount $ 1,011 $ 68 $ 59 $ 6 $ 7 $ 5 $ 1,156 Year ended December 31, 2017 PPAs Leasehold Rights Customer Customer Contracts Emission Allowances Other Total (In millions) January 1, 2017 $ 1,286 $ 86 $ 66 $ 15 $ 9 $ 9 $ 1,471 Asset Impairments (a) (6 ) — — — — — (6 ) December 31, 2017 1,280 86 66 15 9 9 1,465 Less accumulated amortization (205 ) (13 ) (5 ) (8 ) (3 ) (3 ) (237 ) Net carrying amount $ 1,075 $ 73 $ 61 $ 7 $ 6 $ 6 $ 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 .

Long-term Debt (Tables)

Long-term Debt (Tables)	12 Months Ended
	Dec. 31, 2018
Debt Disclosure [Abstract]
Schedule of Long-Term Debt	The Company's borrowings, including short term and long term portions consisted of the following: December 31, 2018 December 31, 2017 Interest rate % (a) Letters of Credit Outstanding at December 31, 2018 (In millions, except rates) Long-term debt - affiliate, due 2019 $ 215 $ 337 3.580 Long-term debt - affiliate, due 2020 44 281 3.325 2024 Senior Notes 500 500 5.375 2025 Senior Notes 600 — 5.750 2026 Senior Notes 350 350 5.000 Clearway Energy LLC and Clearway Energy Operating LLC Revolving Credit Facility, due 2019 (b) — 55 L+1.75 41 Project-level debt: Agua Caliente Borrower 2, due 2038 (c) 39 41 5.430 17 Alpine, due 2022 (c) 127 135 L+1.750 16 Alta Wind I - V lease financing arrangements, due 2034 and 2035 886 926 5.696 - 7.015 44 Buckthorn Solar, due 2025 132 169 L+1.750 26 CVSR, due 2037 (c) 720 746 2.339 - 3.775 — CVSR Holdco Notes, due 2037 (c) 188 194 4.680 13 El Segundo Energy Center, due 2023 352 400 L+1.75 - L+2.375 138 Energy Center Minneapolis Series C, D, E, F, G, H Notes, due 2025-2037 328 208 various — Laredo Ridge, due 2028 89 95 L+1.875 10 Kansas South, due 2030 (c) 26 29 L+2.00 2 Marsh Landing, due 2023 (c) 263 318 L+2.125 60 South Trent Wind, due 2020 50 53 L+1.625 Tapestry, due 2021 151 162 L+1.625 20 Utah Solar Portfolio, due 2022 267 278 various 13 Viento, due 2023 146 163 L+2.00 26 Walnut Creek, due 2023 222 267 L+1.75 74 Other 343 361 various 24 Subtotal project-level debt 4,329 4,545 Total debt 6,038 6,068 Less current maturities (529 ) (339 ) Less net debt issuance costs (61 ) (62 ) Total long-term debt $ 5,448 $ 5,667 (a) As of December 31, 2018 , L+ equals 3 month LIBOR plus x%, except for Viento, due 2023 and Kansas South, due 2030, where L + equals 6 month LIBOR plus 2.00% and Utah Solar Portfolio, where L+equals 1 month LIBOR plus x%. (b) Applicable rate is determined by the borrower leverage ratio, as defined in the credit agreement. (c) On January 29, 2019, PG&E filed for bankruptcy under Chapter 11 of the U.S. Bankruptcy Code. The Company has non-recourse project-level debt, and in some cases holding company debt, related to each of its subsidiaries that sell their output to PG&E under long-term PPAs. The PG&E bankruptcy filing is an event of default under the related financing agreements, and as a result, the respective lenders under these arrangements may accelerate the repayment of these debt balances. In addition, the event of default may have an impact on the Company’s ability to distribute cash from the project-level cash accounts to the parent entities. The Company continues to operate the projects in the normal course of business and is currently in the process of negotiating forbearance agreements with the related lenders.
Schedule of Derivative Instruments	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, 2018 : % of Principal Fixed Interest Rate Floating Interest Rate Notional Amount at December 31, 2018 (In millions) Effective Date Maturity Date Alpine 85 % various 3-Month LIBOR $ 108 various various Avra Valley 87 % 2.333 % 3-Month LIBOR 44 November 30, 2012 November 30, 2030 AWAM 100 % 2.47 % 3-Month LIBOR 16 May 22, 2013 May 15, 2031 Blythe 75 % 3.563 % 3-Month LIBOR 12 June 25, 2010 June 25, 2028 Borrego 75 % 1.125 % 3-Month LIBOR 3 April 3, 2013 June 30, 2020 Buckthorn Solar 83 % various 3-Month LIBOR 109 February 28, 2018 December 31, 2041 El Segundo 85 % various 3-Month LIBOR 299 various various Kansas South 75 % 2.368 % 6-Month LIBOR 20 June 28, 2013 December 31, 2030 Laredo Ridge 80 % 2.31 % 3-Month LIBOR 71 March 31, 2011 March 31, 2026 Marsh Landing 94 % 3.244 % 3-Month LIBOR 246 June 28, 2013 June 30, 2023 Roadrunner 75 % 4.313 % 3-Month LIBOR 24 September 30, 2011 December 31, 2029 South Trent 75 % 3.265 % 3-Month LIBOR 37 June 15, 2010 June 14, 2020 South Trent 75 % 4.95 % 3-Month LIBOR 21 June 30, 2020 June 14, 2028 Tapestry 90 % 2.21 % 3-Month LIBOR 136 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 214 various September 30, 2036 Viento Funding II 91 % various 6-Month LIBOR 134 various various Viento Funding II 90 % 4.985 % 6-Month LIBOR 65 July 11, 2023 June 30, 2028 Walnut Creek Energy 90 % various 3-Month LIBOR 200 June 28, 2013 May 31, 2023 WCEP Holdings 100 % 4.003 % 3-Month LIBOR 43 June 28, 2013 May 31, 2023 Total $ 1,862
Schedule of Maturities of Long-term Debt	Annual Maturities Annual payments based on the maturities of the Company's debt, for the years ending after December 31, 2018 , are as follows: (In millions) 2019 $ 529 2020 405 2021 447 2022 646 2023 389 Thereafter 3,622 Total $ 6,038

Members' Equity (Tables)

Members' Equity (Tables)	12 Months Ended
	Dec. 31, 2018
Members' Equity [Abstract]
Schedule of Dividends Paid	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, 2018 : Fourth Quarter 2018 Third Quarter 2018 Second Quarter 2018 First Quarter 2018 Distributions per Class A and Class B units $ 0.331 $ 0.320 $ 0.309 $ 0.298 Distributions per Class C and Class D units $ 0.331 $ 0.320 $ 0.309 $ 0.298

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting [Abstract]
Schedule of Revenue by Major Customers by Reporting Segments	The Company generated more than 10% of its revenues from the following customers for the years ended December 31, 2018 , 2017 and 2016 : 2018 2017 2016 Customer Conventional (%) Renewables (%) Conventional (%) Renewables (%) Conventional (%) Renewables (%) SCE 20% 20% 21% 20% 21% 21% PG&E 12% 11% 12% 11% 12% 11%
Schedule of Segment Reporting Information, by Segment	Year ended December 31, 2018 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues (a) $ 337 $ 526 $ 193 $ (3 ) $ 1,053 Cost of operations (a) 62 146 127 (3 ) 332 Depreciation and amortization 101 207 23 — 331 General and administrative — — 1 19 20 Acquisition-related transaction and integration costs — — — 20 20 Development costs — — 2 1 3 Operating income (loss) 174 173 40 (40 ) 347 Equity in earnings of unconsolidated affiliates 11 63 — — 74 Other income, net 1 4 1 2 8 Interest expense (51 ) (154 ) (12 ) (77 ) (294 ) Net Income (Loss) 135 86 29 (115 ) 135 Less: Net loss attributable to noncontrolling interests — (104 ) — (1 ) (105 ) Net Income (Loss) Attributable to Clearway Energy LLC $ 135 $ 190 $ 29 $ (114 ) $ 240 Balance Sheet Equity investment in affiliates $ 98 $ 1,074 $ — $ — $ 1,172 Capital expenditures (a) 14 26 28 — 68 Total Assets $ 1,788 $ 5,836 $ 516 $ 308 $ 8,448 (a) Inter-segment revenues and cost of operations include operations and maintenance fee revenue and related costs recorded in the Renewables segment. (b) Includes accruals. 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 ) (164 ) (10 ) (71 ) (294 ) Net Income (Loss) 120 8 25 (92 ) 61 Less: Net loss attributable to noncontrolling interests — (75 ) — — (75 ) Net Income (Loss) Attributable to Clearway Energy LLC $ 120 $ 83 $ 25 $ (92 ) $ 136 Balance Sheet Equity investments in affiliates $ 102 $ 1,076 $ — $ — $ 1,178 Capital expenditures (a) 15 181 16 — 212 Total Assets $ 1,897 $ 6,017 $ 422 $ 24 $ 8,360 (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 Less: Net loss attributable to noncontrolling interests — (111 ) — — (111 ) Net Income (Loss) Attributable to Clearway Energy LLC $ 153 $ 25 $ 29 $ (81 ) $ 126	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 Less: Net loss attributable to noncontrolling interests — (111 ) — — (111 ) Net Income (Loss) Attributable to Clearway Energy LLC $ 153 $ 25 $ 29 $ (81 ) $ 126

Commitments and Contingencies_2

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Long-term Purchase Commitment	As of December 31, 2018 , the Company's commitments under such outstanding agreements are estimated as follows: Period (In millions) 2019 $ 11 2020 3 2021 3 2022 3 2023 3 Thereafter 13 Total $ 36

Unaudited Quarterly Financial_2

Unaudited Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Schedule of Unaudited Quarterly Data	Quarter Ended December 31, September 30, June 30, March 31, 2018 (In millions) Operating Revenues $ 229 $ 292 $ 307 $ 225 Operating Income 54 100 144 49 Net (Loss) Income (37 ) 64 106 2 Quarter Ended December 31, September 30, June 30, March 31, 2017 (In millions) Operating Revenues $ 231 $ 269 $ 288 $ 221 Operating Income 20 84 125 54 Net (Loss) Income (37 ) (a) 42 56 — (a) The Company reported Net loss of $38 million for the quarter ending December 31, 2017, as previously reported in the Note 17 , Unaudited Quarterly Financial Data of its Form 2017 10-K. The recast results in the table above include $1 million of Net Income attributable to the Buckthorn Solar Drop Down Asset acquisition.

Condensed Consolidating Finan_2

Condensed Consolidating Financial Information (Tables)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Condensed Financial Information Disclosure [Abstract]
Condensed Income Statement	CLEARWAY ENERGY LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2018 Clearway Energy LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries Clearway Energy Operating LLC (Senior Notes Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 11 $ 1,042 $ 3 $ (3 ) $ 1,053 Operating Costs and Expenses — Cost of operations — 3 329 3 (3 ) 332 Depreciation and amortization — 6 325 — — 331 General and administrative — — — 20 — 20 Acquisition-related transaction and integration costs — — — 20 — 20 Development costs — — — 3 — 3 Total operating costs and expenses — 9 654 46 (3 ) 706 Operating Income (Loss) — 2 388 (43 ) — 347 Other Income (Expense) Equity in earnings of consolidated affiliates 237 — — 224 (461 ) — Equity in earnings of unconsolidated affiliates — 43 3 28 — 74 Other income, net 3 — 5 — — 8 Interest expense — — (217 ) (77 ) — (294 ) Total other income (expense), net 240 43 (209 ) 175 (461 ) (212 ) Net Income 240 45 179 132 (461 ) 135 Less: Net loss attributable to noncontrolling interests — — (69 ) (105 ) 69 (105 ) Net Income Attributable to Clearway Energy LLC $ 240 $ 45 $ 248 $ 237 $ (530 ) $ 240 (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. LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2017 Clearway Energy LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) Clearway Energy Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 10 $ 999 $ 1 $ (1 ) $ 1,009 Operating Costs and Expenses Cost of operations — 2 324 1 (1 ) 326 Depreciation and amortization — 6 328 — — 334 Impairment losses — 12 32 — — 44 General and administrative — — — 19 — 19 Acquisition-related transaction and integration costs — — — 3 — 3 Total operating costs and expenses — 20 684 23 (1 ) 726 Operating Income (Loss) — (10 ) 315 (22 ) — 283 Other Income (Expense) Equity in earnings (losses) of consolidated affiliates 135 (16 ) — 125 (244 ) — Equity in earnings of unconsolidated affiliates — 22 21 28 — 71 Loss on debt extinguishment — (3 ) — — — (3 ) Other income, net 1 — 3 — — 4 Interest expense — 1 (224 ) (71 ) — (294 ) Total other income (expense) 136 4 (200 ) 82 (244 ) (222 ) Net Income (Loss) 136 (6 ) 115 60 (244 ) 61 Less: Net loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Net Income (Loss) Attributable to Clearway Energy LLC $ 136 $ (6 ) $ 120 $ 135 $ (249 ) $ 136 (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 .	LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF OPERATIONS For the Year Ended December 31, 2016 Clearway Energy LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries Clearway Energy Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Operating Revenues Total operating revenues $ — $ 10 $ 1,025 $ 1 $ (1 ) $ 1,035 Operating Costs and Expenses Cost of operations — 3 305 1 (1 ) 308 Depreciation and amortization — 5 298 — — 303 Impairment losses — 2 183 — — 185 General and administrative 2 — — 12 — 14 Acquisition-related transaction and integration costs — — — 1 — 1 Total operating costs and expenses 2 10 786 14 (1 ) 811 Operating (Loss) Income (2 ) — 239 (13 ) — 224 Other Income (Expense) Equity in earnings of consolidated affiliates 128 10 — 66 (204 ) — Equity in (losses) earnings of unconsolidated affiliates — 9 21 30 — 60 Other income, net — — 3 — — 3 Interest expense — (2 ) (204 ) (66 ) — (272 ) Total other income (expense), net 128 17 (180 ) 30 (204 ) (209 ) Net Income 126 17 59 17 (204 ) 15 Less: Net loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Net Income Attributable to Clearway Energy LLC $ 126 $ 17 $ 60 $ 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.
Condensed Statement of Comprehensive Income	CLEARWAY ENERGY LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2018 Clearway Energy LLC (a) Guarantor Subsidiaries Non-Guarantor Subsidiaries Clearway Energy Operating LLC (Note Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 240 $ 45 $ 179 $ 132 $ (461 ) $ 135 Other Comprehensive Income Unrealized gain on derivatives 24 1 20 24 (45 ) 24 Other comprehensive income 24 1 20 24 (45 ) 24 Comprehensive Income 264 46 199 156 (506 ) 159 Less: Comprehensive loss attributable to noncontrolling interests — — (69 ) (105 ) 69 (105 ) Comprehensive Income Attributable to Clearway Energy LLC $ 264 $ 46 $ 268 $ 261 $ (575 ) $ 264 (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. LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2017 Clearway Energy LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) Clearway Energy Operating LLC (Note Issuer) (c) Eliminations (b) (c) Consolidated (In millions) Net Income (Loss) $ 136 $ (6 ) $ 115 $ 60 $ (244 ) $ 61 Other Comprehensive Income Unrealized gain on derivatives 17 1 16 17 (34 ) 17 Other comprehensive income 17 1 16 17 (34 ) 17 Comprehensive Income (Loss) 153 (5 ) 131 77 (278 ) 78 Less: Comprehensive loss attributable to noncontrolling interests — — (5 ) (75 ) 5 (75 ) Comprehensive Income (Loss) Attributable to Clearway Energy LLC $ 153 $ (5 ) $ 136 $ 152 $ (283 ) $ 153 (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 .	LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF COMPREHENSIVE INCOME For the Year Ended December 31, 2016 Clearway Energy LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries Clearway Energy Operating LLC (Senior Notes Issuer) Eliminations (b) Consolidated (In millions) Net Income $ 126 $ 17 $ 59 $ 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 18 69 30 (228 ) 28 Less: Comprehensive loss attributable to noncontrolling interests — — (1 ) (111 ) 1 (111 ) Comprehensive Income Attributable to Clearway Energy LLC $ 139 $ 18 $ 70 $ 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.
Condensed Balance Sheet	LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2018 Clearway Energy LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries Clearway Energy Operating LLC Eliminations (b) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 298 $ — $ 109 $ — $ — $ 407 Restricted cash — — 176 — — 176 Accounts receivable — trade — 1 103 — — 104 Accounts receivable — affiliates 8 — — 11 (14 ) 5 Inventory — — 40 40 Prepayments and other current assets 27 2 — 29 Total current assets 306 1 455 13 (14 ) 761 Property, plant and equipment, net — 65 5,180 — — 5,245 Other Assets Investment in consolidated subsidiaries 1,676 417 — 3,250 (5,343 ) — Equity investments in affiliates — 289 522 361 — 1,172 Intangible assets, net — 11 1,145 — — 1,156 Derivative instruments — — 8 — — 8 Other non-current assets — — 103 3 — 106 Total other assets 1,676 717 1,778 3,614 (5,343 ) 2,442 Total Assets $ 1,982 $ 783 $ 7,413 $ 3,627 $ (5,357 ) $ 8,448 (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. CLEARWAY ENERGY LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2018 Clearway Energy LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries Clearway Energy Operating LLC Eliminations (b) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 314 $ — $ — $ 314 Current portion of long-term debt — affiliate — — — 215 — 215 Accounts payable — trade — 1 36 8 — 45 Accounts payable — affiliate — — 23 11 (14 ) 20 Derivative instruments — — 4 — — 4 Accrued interest expense — — 17 27 — 44 Accrued expenses and other current liabilities — — 53 4 — 57 Total current liabilities — 1 447 265 (14 ) 699 Other Liabilities Long-term debt — external — — 3,970 1,434 — 5,404 Long-term debt — affiliate — — — 44 — 44 Derivative instruments — — 17 — — 17 Other non-current liabilities — 2 92 8 — 102 Total non-current liabilities — 2 4,079 1,486 — 5,567 Total Liabilities — 3 4,526 1,751 (14 ) 6,266 Commitments and Contingencies Members' Equity Contributed capital 1,940 804 2,708 1,930 (5,442 ) 1,940 Retained earnings (accumulated deficit) 86 (24 ) 108 (210 ) 126 86 Accumulated other comprehensive loss (44 ) — (51 ) (44 ) 95 (44 ) Noncontrolling interest — — 122 200 (122 ) 200 Total Members' Equity 1,982 780 2,887 1,876 (5,343 ) 2,182 Total Liabilities and Members’ Equity $ 1,982 $ 783 $ 7,413 $ 3,627 $ (5,357 ) $ 8,448 (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. LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS December 31, 2017 Clearway Energy LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) Clearway Energy Operating LLC (c) Eliminations (b)(c) Consolidated ASSETS (In millions) Current Assets Cash and cash equivalents $ 22 $ — $ 124 $ — $ — $ 146 Restricted cash — — 168 — — 168 Accounts receivable — trade — 1 93 1 — 95 Accounts receivable — affiliates 1 — — — — 1 Inventory — — 39 — — 39 Notes receivable — current — — 13 — — 13 Prepayments and other current assets — — 18 1 — 19 Total current assets 23 1 455 2 — 481 Property, plant and equipment, net — 59 5,351 — — 5,410 Other Assets Investment in consolidated subsidiaries 1,844 460 — 3,198 (5,502 ) — Equity investments in affiliates — 233 577 368 — 1,178 Intangible assets, net — 12 1,216 — — 1,228 Derivative instruments — — 1 — — 1 Other non-current assets — — 62 — — 62 Total other assets 1,844 705 1,856 3,566 (5,502 ) 2,469 Total Assets $ 1,867 $ 765 $ 7,662 $ 3,568 $ (5,502 ) $ 8,360 (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 . CLEARWAY ENERGY LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEETS (Continued) December 31, 2017 Clearway Energy LLC (a) (c) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (c) Clearway Energy Operating LLC (c) Eliminations (b) (c) Consolidated LIABILITIES AND MEMBERS' EQUITY (In millions) Current Liabilities Current portion of long-term debt — external $ — $ — $ 339 $ — $ — $ 339 Accounts payable — trade — — 46 — — 46 Accounts payable — affiliate — — 33 16 — 49 Derivative instruments — — 18 — — 18 Accrued interest expense — — 16 22 — 38 Accrued expenses and other current liabilities 46 3 49 Total current liabilities — — 498 41 — 539 Other Liabilities Long-term debt — external — — 4,153 896 — 5,049 Long-term debt — affiliate — — — 618 — 618 Derivative instruments — — 31 — — 31 Other non-current liabilities — 2 85 7 — 94 Total non-current liabilities — 2 4,269 1,521 — 5,792 Total Liabilities — 2 4,767 1,562 — 6,331 Commitments and Contingencies Members' Equity Contributed capital 1,919 822 2,934 2,119 (5,875 ) 1,919 Retained earnings (accumulated deficit) 16 (58 ) (25 ) (207 ) 290 16 Accumulated other comprehensive loss (68 ) (1 ) (71 ) (68 ) 140 (68 ) Noncontrolling interest — — 57 162 (57 ) 162 Total Members' Equity 1,867 763 2,895 2,006 (5,502 ) 2,029 Total Liabilities and Members’ Equity $ 1,867 $ 765 $ 7,662 $ 3,568 $ (5,502 ) $ 8,360 (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 Cash Flow Statement	LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2018 Clearway Energy LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries Clearway Energy Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 23 $ 550 $ (81 ) $ 492 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 361 — — (361 ) — Acquisition of business, net of cash acquired — — — (11 ) (11 ) Acquisition of Drop Down Assets, net of cash acquired — — — (126 ) (126 ) Capital expenditures — — (83 ) — (83 ) Cash receipts from notes receivable — — 13 — 13 Return of investment from unconsolidated affiliates — 11 20 14 45 Investments in unconsolidated affiliates — (34 ) — — (34 ) Other — — 11 — 11 Net Cash Provided by (Used in) Investing Activities 361 (23 ) (39 ) (484 ) (185 ) Cash Flows from Financing Activities Net contributions from noncontrolling interests — — 97 9 106 Transfer of funds under intercompany cash management arrangement — — 4 (4 ) — Proceeds from the issuance of Class C units 153 — — — 153 (Payments of) proceeds from distributions (238 ) — (400 ) 385 (253 ) Proceeds from the revolving credit facility — — — 35 35 Payments for the revolving credit facility — — — (90 ) (90 ) Payments of debt issuance costs — — (3 ) (11 ) (14 ) Proceeds from issuance of long-term debt — — 227 600 827 Payments for long-term debt — external — — (443 ) — (443 ) Payments for long-term debt — affiliate — — — (359 ) (359 ) Net Cash (Used in) Provided by Financing Activities (85 ) — (518 ) 565 (38 ) Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash 276 — (7 ) — 269 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 22 — 292 — 314 Cash, Cash Equivalents and Restricted Cash at End of Period $ 298 $ — $ 285 $ — $ 583 (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. LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2017 Clearway Energy LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries (b) Clearway Energy Operating LLC (Note Issuer) Consolidated Net Cash Provided by (Used in) Operating Activities $ — $ 51 $ 537 $ (71 ) $ 517 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries (15 ) — — 15 — Acquisition of Drop Down Assets — — — (250 ) (250 ) Capital expenditures — — (190 ) — (190 ) 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 Used in Investing Activities (15 ) (54 ) (159 ) (214 ) (442 ) Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (5 ) — (1 ) 6 — Net contributions from noncontrolling interests — — 2 11 13 Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets — 30 (46 ) (7 ) (23 ) 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 the issuance of long-term debt - external — — 210 — 210 Payments of debt issuance costs — — (12 ) — (12 ) Payments for long-term debt — external — (36 ) (296 ) — (332 ) Net Cash Provided by (Used in) Financing Activities (174 ) (6 ) (363 ) 285 (258 ) Net (Decrease) Increase in Cash, Cash Equivalents and Restricted Cash (189 ) (9 ) 15 — (183 ) Cash, Cash Equivalents and Restricted Cash at Beginning of Period 211 9 277 — 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. (b) Retrospectively adjusted as discussed in Note 1, Nature of Business .	LLC AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENTS OF CASH FLOWS For the Year Ended December 31, 2016 Clearway Energy LLC (a) Other Guarantor Subsidiaries Non-Guarantor Subsidiaries Clearway Energy Operating LLC (Note Issuer) Consolidated (In millions) Net Cash Provided by (Used in) Operating Activities $ — $ 67 $ 549 $ (39 ) $ 577 Cash Flows from Investing Activities Changes in investments in consolidated subsidiaries 325 — (21 ) (304 ) — Acquisition of Drop Down Assets, net of cash acquired — — — (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) Provided by 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 — (3 ) (171 ) (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 issuance of long-term debt — external — — 390 350 740 Payments for long-term debt — external — (3 ) (266 ) — (269 ) Payment of debt issuance costs — — (10 ) (5 ) (15 ) Net Cash (Used in) Provided by Financing Activities (129 ) (4 ) (477 ) 408 (202 ) Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash 196 (1 ) 49 — 244 Cash, Cash Equivalents and Restricted Cash at Beginning of Period 15 10 228 — 253 Cash, Cash Equivalents and Restricted Cash at End of Period $ 211 $ 9 $ 277 $ — $ 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.

Nature of Business - Narrative

Nature of Business - Narrative (Details) - MW	12 Months Ended
	Dec. 31, 2018	Aug. 31, 2018
Nature of Business
Weighted average remaining PPA term	15 years
Thermal
Nature of Business
Power generation capacity, megawatts	133
Steam and chilled water capacity, megawatts	1,385
Conventional Generation, Utility-Scale Solar, Distributed Solar, and Wind
Nature of Business
Power generation capacity, megawatts	5,272
Clearway Energy LLC | Shareholders
Nature of Business
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Voting Interest	45.00%
Ownership percentage	55.80%
Clearway Energy LLC | GIP
Nature of Business
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Voting Interest	55.00%
Ownership percentage	44.20%
Clearway Energy LLC | CEG
Nature of Business
Ownership percentage	44.20%
Clearway Energy LLC | Clearway Energy, Inc.
Nature of Business
Ownership percentage	55.80%
NRG | Clearway Energy, Inc.
Nature of Business
Ownership percentage sold		100.00%
Clearway Energy, Inc. | GIP
Nature of Business
Economic ownership interest		55.00%
Clearway Energy LLC | GIP
Nature of Business
Economic ownership interest		45.20%

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Cash and Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015	[2]
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 407	$ 146	[1]	$ 321
Restricted cash	176	168		176
Cash, cash equivalents and restricted cash shown in the statement of cash flows	583	314		$ 497	[2]	$ 253
Project Level Subsidiaries
Cash and Cash Equivalents [Line Items]
Other cash and cash equivalents	109	$ 124
Operating Funds
Cash and Cash Equivalents [Line Items]
Restricted cash	84
Long-Term Debt, Current
Cash and Cash Equivalents [Line Items]
Restricted cash	26
Debt Service Obligations
Cash and Cash Equivalents [Line Items]
Restricted cash	32
Cash Distribution
Cash and Cash Equivalents [Line Items]
Restricted cash	34
Subsidiaries Affected By Bankruptcy
Cash and Cash Equivalents [Line Items]
Restricted cash	$ 31
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

- Revenue Narrative (Details)

- Revenue Narrative (Details) - USD ($) $ in Millions	8 Months Ended	12 Months Ended
	Aug. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Summary of Significant Accounting Policies [Line Items]
Contingent rental income		$ 583	$ 559	$ 583
NRG
Summary of Significant Accounting Policies [Line Items]
Revenue from related parties	$ 8		12	$ 13
Elbow Creek | NRG
Summary of Significant Accounting Policies [Line Items]
Revenue from related parties	$ 6		$ 8

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Disaggregated Revenues (Details) - USD ($)

3 Months Ended

12 Months Ended

Dec. 31, 2018

Sep. 30, 2018

Jun. 30, 2018

Mar. 31, 2018

Dec. 31, 2017

Sep. 30, 2017

Jun. 30, 2017

Mar. 31, 2017

Dec. 31, 2018

Dec. 31, 2017

Dec. 31, 2016

Disaggregation of Revenue [Line Items]

Revenues

$ 229,000,000

$ 292,000,000

$ 307,000,000

$ 225,000,000

$ 231,000,000

$ 269,000,000

$ 288,000,000

$ 221,000,000

$ 1,053,000,000

$ 1,009,000,000

[1]

$ 1,035,000,000

[1]

Less: Contract amortization

(70,000,000)

Less: Lease revenue

878,000,000

Total revenue from contracts with customers

245,000,000

Energy Revenue

Disaggregation of Revenue [Line Items]

Revenues

581,000,000

Less: Lease revenue

541,000,000

Capacity Revenue

Disaggregation of Revenue [Line Items]

Revenues

503,000,000

Less: Lease revenue

337,000,000

Other Revenues

Disaggregation of Revenue [Line Items]

Revenues

39,000,000

Conventional

Disaggregation of Revenue [Line Items]

Revenues

337,000,000

336,000,000

333,000,000

Less: Lease revenue

342,000,000

Conventional | Energy Revenue

Disaggregation of Revenue [Line Items]

Less: Lease revenue

5,000,000

Conventional | Capacity Revenue

Disaggregation of Revenue [Line Items]

Less: Lease revenue

337,000,000

Renewables

Disaggregation of Revenue [Line Items]

Revenues

526,000,000

501,000,000

532,000,000

Less: Lease revenue

534,000,000

Renewables | Energy Revenue

Disaggregation of Revenue [Line Items]

Less: Lease revenue

534,000,000

Renewables | Capacity Revenue

Disaggregation of Revenue [Line Items]

Less: Lease revenue

0

Thermal

Disaggregation of Revenue [Line Items]

Revenues

193,000,000

$ 172,000,000

$ 170,000,000

Less: Lease revenue

2,000,000

Thermal | Energy Revenue

Disaggregation of Revenue [Line Items]

Less: Lease revenue

2,000,000

Thermal | Capacity Revenue

Disaggregation of Revenue [Line Items]

Less: Lease revenue

0

Operating Segments | Conventional

Disaggregation of Revenue [Line Items]

Revenues

337,000,000

Less: Contract amortization

(5,000,000)

Less: Lease revenue

342,000,000

Total revenue from contracts with customers

0

Operating Segments | Conventional | Energy Revenue

Disaggregation of Revenue [Line Items]

Revenues

5,000,000

Operating Segments | Conventional | Capacity Revenue

Disaggregation of Revenue [Line Items]

Revenues

337,000,000

Operating Segments | Conventional | Other Revenues

Disaggregation of Revenue [Line Items]

Revenues

0

Operating Segments | Renewables

Disaggregation of Revenue [Line Items]

Revenues

526,000,000

Less: Contract amortization

(62,000,000)

Less: Lease revenue

534,000,000

Total revenue from contracts with customers

54,000,000

Operating Segments | Renewables | Energy Revenue

Disaggregation of Revenue [Line Items]

Revenues

572,000,000

Operating Segments | Renewables | Capacity Revenue

Disaggregation of Revenue [Line Items]

Revenues

0

Operating Segments | Renewables | Other Revenues

Disaggregation of Revenue [Line Items]

Revenues

16,000,000

Operating Segments | Thermal

Disaggregation of Revenue [Line Items]

Revenues

193,000,000

Less: Contract amortization

(3,000,000)

Less: Lease revenue

2,000,000

Total revenue from contracts with customers

194,000,000

Operating Segments | Thermal | Energy Revenue

Disaggregation of Revenue [Line Items]

Revenues

4,000,000

Operating Segments | Thermal | Capacity Revenue

Disaggregation of Revenue [Line Items]

Revenues

166,000,000

Operating Segments | Thermal | Other Revenues

Disaggregation of Revenue [Line Items]

Revenues

26,000,000

Corporate

Disaggregation of Revenue [Line Items]

Revenues

(3,000,000)

Total revenue from contracts with customers

(3,000,000)

Corporate | Other Revenues

Disaggregation of Revenue [Line Items]

Revenues

$ (3,000,000)

[1]

Retrospectively adjusted as discussed in Note 1, Nature of Business.

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Lease Revenue (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Operating Leased Assets [Line Items]
Lease revenue	$ 878
Energy Revenue
Operating Leased Assets [Line Items]
Lease revenue	541
Capacity Revenue
Operating Leased Assets [Line Items]
Lease revenue	337
Conventional
Operating Leased Assets [Line Items]
Lease revenue	342
Conventional | Energy Revenue
Operating Leased Assets [Line Items]
Lease revenue	5
Conventional | Capacity Revenue
Operating Leased Assets [Line Items]
Lease revenue	337
Renewables
Operating Leased Assets [Line Items]
Lease revenue	534
Renewables | Energy Revenue
Operating Leased Assets [Line Items]
Lease revenue	534
Renewables | Capacity Revenue
Operating Leased Assets [Line Items]
Lease revenue	0
Thermal
Operating Leased Assets [Line Items]
Lease revenue	2
Thermal | Energy Revenue
Operating Leased Assets [Line Items]
Lease revenue	2
Thermal | Capacity Revenue
Operating Leased Assets [Line Items]
Lease revenue	$ 0

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Contract Balances (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Accounts receivable, net	$ 104	$ 95
Customer Contracts
Disaggregation of Revenue [Line Items]
Accounts receivable, net	35	28
Lease Agreements
Disaggregation of Revenue [Line Items]
Accounts receivable, net	$ 69	$ 67

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Asset Retirement Obligation (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance as of December 31, 2017	$ 58
Revisions in estimates for current obligations/Additions	5
Accretion — expense	4
Balance as of December 31, 2018	$ 67

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Leases (Details) - Scenario, Forecast - Accounting Standards Update 2016-02 - Subsequent Event $ in Millions	Jan. 01, 2019USD ($)
Minimum
Operating Leased Assets [Line Items]
Lease liability	$ 160
Right-of-Use Asset	155
Maximum
Operating Leased Assets [Line Items]
Lease liability	170
Right-of-Use Asset	$ 165

Business Acquisitions Business

Business Acquisitions Business Acquisitions - Narrative (Details)

Jun. 19, 2018USD ($)

May 31, 2018USD ($)

Apr. 18, 2018USD ($)MW

Mar. 31, 2018USD ($)

Nov. 02, 2017USD ($)

Aug. 02, 2017USD ($)

Mar. 27, 2017USD ($)MW

Sep. 02, 2016USD ($)

Jan. 31, 2019USD ($)

Dec. 31, 2018USD ($)MW

Mar. 30, 2018USD ($)MW

Dec. 31, 2017USD ($)

Nov. 01, 2017USD ($)MW

Aug. 01, 2017USD ($)

Sep. 01, 2016USD ($)

Aug. 31, 2016

Nov. 03, 2015USD ($)

Business Acquisition [Line Items]

Long-term Debt

$ 6,038,000,000

$ 6,068,000,000

Non-resource debt

$ 878,000,000

UPMC Thermal

Business Acquisition [Line Items]

Business combination consideration transferred

$ 84,000,000

Central CA Fuel Cell 1

Business Acquisition [Line Items]

Business combination consideration transferred

$ 11,000,000

Power generation capacity, megawatts | MW

2.8

Power purchase agreement period

20 years

Buckthorn Solar Drop Down Asset

Business Acquisition [Line Items]

Business combination consideration transferred

$ 42,000,000

Power generation capacity, megawatts | MW

154

Power purchase agreement period

25 years

Voting interest acquired

100.00%

Noncontrolling interest

19,000,000

Allocations of taxable income from tax equity investor

$ 0.99

Taxable income allocation pre-flip

67.00%

Taxable income allocation, post flip

99.00%

Allocations of investor change percent

5.00%

Net assets acquired

$ 25,000,000

CVSR

Business Acquisition [Line Items]

Business combination consideration transferred

$ 78,500,000

Voting interest acquired

51.05%

Equity method, ownership percentage

48.95%

Long-term debt

$ 496,000,000

Net Gains and Losses

112,000,000

Other comprehensive, tax

$ 6,000,000

November 2017 Drop Down Assets

Business Acquisition [Line Items]

Business combination consideration transferred

$ 74,000,000

Power generation capacity, megawatts | MW

38

Long-term Debt

$ 26,000,000

August 2017 Drop Down Assets

Business Acquisition [Line Items]

Business combination consideration transferred

$ 44,000,000

Voting interest acquired

25.00%

75.00%

Ownership percentage by noncontrolling owners

25.00%

Contingent consideration liability

$ 8,000,000

Net assets acquired

$ 87,000,000

Thermal

Business Acquisition [Line Items]

Steam and chilled water capacity, megawatts | MW

1,385

Power generation capacity, megawatts | MW

133

Buckthorn Solar Drop Down Asset

Business Acquisition [Line Items]

Proceeds from Noncontrolling Interests

$ 80,000,000

UPMC Thermal | Thermal

Business Acquisition [Line Items]

Steam and chilled water capacity, megawatts | MW

73

Power generation capacity, megawatts | MW

7.5

CVSR, due 2037

Business Acquisition [Line Items]

Long-term Debt

$ 720,000,000

746,000,000

CVSR, due 2037 | CVSR

Business Acquisition [Line Items]

Long-term Debt

771,000,000

Buckthorn Solar, due 2025

Business Acquisition [Line Items]

Long-term Debt

$ 132,000,000

132,000,000

169,000,000

Buckthorn Solar, due 2025 | Buckthorn Solar Drop Down Asset

Business Acquisition [Line Items]

Long-term Debt

$ 183,000,000

CVSR Holdco Notes, due 2037

Business Acquisition [Line Items]

Long-term Debt

188,000,000

$ 194,000,000

CVSR Holdco Notes, due 2037 | CVSR

Business Acquisition [Line Items]

Long-term Debt

$ 200,000,000

Subsequent Event | UPMC Thermal

Business Acquisition [Line Items]

Business combination consideration transferred

$ 3,000,000

March 2017 Drop Down Assets

Business Acquisition [Line Items]

Business combination consideration transferred

$ 128,000,000

Working capital

$ 3,000,000

Net Gains and Losses

$ 8,000,000

Agua Caliente Solar(e)

Business Acquisition [Line Items]

Power generation capacity, megawatts | MW

46

Power purchase agreement period

25 years

Percentage of NRG's Ownership

31.00%

Remaining power purchase agreement term

22 years

Equity method, ownership percentage

16.00%

Non-resource debt

$ 41,000,000

Agua Caliente Solar(e) | NRG

Business Acquisition [Line Items]

Percentage Ownership

51.00%

Utah Solar Portfolio

Business Acquisition [Line Items]

Remaining power purchase agreement term

20 years

Equity method, ownership percentage

50.00%

Working capital

$ 106,000,000

Non-resource debt

$ 287,000,000

Business Acquisitions - Assets

Business Acquisitions - Assets Acquired (Details) - USD ($) $ in Millions	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Liabilities:
Net debt issuance costs	$ 61		$ 62
Buckthorn Solar Drop Down Asset
Assets:
Current assets		$ 20
Property, plant and equipment		212
Non-current assets		3
Total assets		235
Liabilities:
Debt (Current and non-current)		176
Other current and non-current liabilities		15
Total liabilities		191
Less: noncontrolling interest		19
Net assets acquired		25
Net debt issuance costs		$ 7

Business Acquisitions - Histori

Business Acquisitions - Historical Information (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016	[1]
Business Acquisition [Line Items]
Revenues	$ 229	$ 292	$ 307	$ 225	$ 231	$ 269	$ 288	$ 221	$ 1,053	$ 1,009	[1]	$ 1,035
Operating Income	54	100	144	49	20	84	125	54	347	283	[1]	224
Net income	$ (37)	$ 64	$ 106	$ 2	(37)	$ 42	$ 56	$ 0	135	61	[1],[2],[3]	15	[2],[3]
Net Income Attributable to Clearway Energy LLC									$ 240	136	[1]	$ 126
Buckthorn Solar Drop Down Asset
Business Acquisition [Line Items]
Revenues										0
Operating Income										0
Net income					(1)					(1)
Net Income Attributable to Clearway Energy LLC										(1)
As Previously Reported
Business Acquisition [Line Items]
Revenues										1,009
Operating Income										283
Net income					$ (38)					62
Net Income Attributable to Clearway Energy LLC										$ 137
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Property, Plant and Equipment_2

Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 6,835	$ 6,695
Less accumulated depreciation	(1,590)	(1,285)
Property, plant and equipment, net	5,245	5,410	[1]
Prepaid long-term service agreement	6	24
Facilities and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	6,638	6,291
Land and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	171	166
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 26	$ 238
Minimum | Facilities and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	2 years
Maximum | Facilities and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	45 years
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Investments Accounted for by _3

Investments Accounted for by the Equity Method and Variable Interest Entities - Equity method investments (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2018	Dec. 31, 2017		Mar. 27, 2017
Schedule of Equity Method Investments [Line Items]
Equity investments in affiliates		$ 1,172	$ 1,178	[1]
Undistributed earnings from equity method investees		87	$ 57
Non-resource debt		$ 878
Utah Solar Portfolio
Schedule of Equity Method Investments [Line Items]
Equity method, ownership percentage		50.00%
Equity investments in affiliates		$ 317
Working capital		106
Non-resource debt					$ 287
PG&E
Schedule of Equity Method Investments [Line Items]
Non-resource debt		$ 432
Desert Sunlight
Schedule of Equity Method Investments [Line Items]
Equity method, ownership percentage		25.00%
Equity investments in affiliates		$ 264
Payments to acquire equity method investments	$ 285
Working capital	$ 171
GenConn
Schedule of Equity Method Investments [Line Items]
Equity method, ownership percentage		50.00%
Equity investments in affiliates		$ 98
Agua Caliente Solar(e)
Schedule of Equity Method Investments [Line Items]
Equity method, ownership percentage		16.00%
Equity investments in affiliates		$ 90
Non-resource debt					$ 41
Elkhorn Ridge
Schedule of Equity Method Investments [Line Items]
Equity method, ownership percentage		66.70%
Equity investments in affiliates		$ 59
San Juan Mesa
Schedule of Equity Method Investments [Line Items]
Equity method, ownership percentage		75.00%
Equity investments in affiliates		$ 57
DGPV Holdco 1
Schedule of Equity Method Investments [Line Items]
Equity method, ownership percentage		95.00%
Equity investments in affiliates		$ 81
NRG DGPV Holdco 2
Schedule of Equity Method Investments [Line Items]
Equity method, ownership percentage		95.00%
Equity investments in affiliates		$ 63
DGPV Holdco 3
Schedule of Equity Method Investments [Line Items]
Equity method, ownership percentage		99.00%
Equity investments in affiliates		$ 116
RPV Holdco
Schedule of Equity Method Investments [Line Items]
Equity method, ownership percentage		95.00%
Equity investments in affiliates		$ 29
Avenal
Schedule of Equity Method Investments [Line Items]
Equity method, ownership percentage		50.00%
Equity investments in affiliates		$ (2)
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Investments Accounted for by _4

Investments Accounted for by the Equity Method and Variable Interest Entities - Non-recourse project-level debt of unconsolidated affiliates (Details) - USD ($) $ in Millions	3 Months Ended									12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017		Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Revenues	$ 229	$ 292	$ 307	$ 225	$ 231		$ 269	$ 288	$ 221	$ 1,053	$ 1,009	[1]	$ 1,035	[1]
Operating Income	54	100	144	49	20		84	125	54	347	283	[1]	224	[1]
Net income	(37)	$ 64	$ 106	$ 2	(37)		$ 42	$ 56	$ 0	135	61	[1],[2],[3]	15	[1],[2],[3]
Current assets	761				481	[4]				761	481	[4]
Current liabilities	699				539	[4]				699	539	[4]
Non-current liabilities	5,567				5,792	[4]				5,567	5,792	[4]
GenConn
Schedule of Equity Method Investments [Line Items]
Revenues										65	71		72
Operating Income										32	36		38
Net income										22	26		26
Current assets	43				38					43	38
Non-current assets	358				374					358	374
Current liabilities	22				18					22	18
Non-current liabilities	182				189					182	189
Desert Sunlight
Schedule of Equity Method Investments [Line Items]
Revenues										208	207		211
Operating Income										129	127		129
Net income										84	80		80
Current assets	133				133					133	133
Non-current assets	1,298				1,350					1,298	1,350
Current liabilities	58				64					58	64
Non-current liabilities	962				1,003					962	1,003
NRG DGPV Holdco
Schedule of Equity Method Investments [Line Items]
Revenues										69	37		14
Operating Income										23	7		2
Net income										11	(3)		0
Current assets	79				74					79	74
Non-current assets	784				671					784	671
Current liabilities	84				83					84	83
Non-current liabilities	314				216					314	216
Redeemable Noncontrolling Interest	0				44					0	44
RPV Holdco
Schedule of Equity Method Investments [Line Items]
Revenues										14	16		13
Operating Income										0	3		2
Net income										0	3		2
Current assets	2				3					2	3
Non-current assets	173				183					173	183
Current liabilities	1				0					1	0
Non-current liabilities	8				7					8	7
Redeemable Noncontrolling Interest	26				16					26	16
Other
Schedule of Equity Method Investments [Line Items]
Revenues										249	247		193
Operating Income										103	89		71
Net income										75	56		$ 38
Current assets	148				139					148	139
Non-current assets	2,511				2,621					2,511	2,621
Current liabilities	58				60					58	60
Non-current liabilities	$ 889				$ 932					$ 889	$ 932
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Investments Accounted for by _5

Investments Accounted for by the Equity Method and Variable Interest Entities - Entities that are consolidated (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)MW	Dec. 31, 2017USD ($)		Dec. 31, 2016USD ($)	[1]	Aug. 31, 2018USD ($)
Variable Interest Entity [Line Items]
Less: Net loss attributable to noncontrolling interests	$ (105)	$ (75)	[1]	$ (111)
Other Assets	2,442	2,469	[2]
Property, plant and equipment, net	5,245	5,410	[2]
Intangible assets, net	1,156	1,228	[2]
Total Assets	8,448	8,360	[2]
Liabilities	$ 6,266	$ 6,331	[2]
Financial Institutions | November 2015 Drop Down Assets
Variable Interest Entity [Line Items]
Taxable income allocation pre-flip	99.00%
Voting interest acquired	100.00%
Business combination consideration transferred	$ 19
November 2015 Drop Down Assets
Variable Interest Entity [Line Items]
Other Assets	215
Property, plant and equipment, net	346
Intangible assets, net	2
Total Assets	563
Liabilities	210
Noncontrolling Interest in Variable Interest Entity	45
Net Assets	308
Alta X and XI TE Holdco
Variable Interest Entity [Line Items]
Other Assets	17
Property, plant and equipment, net	410
Intangible assets, net	249
Total Assets	676
Liabilities	9
Noncontrolling Interest in Variable Interest Entity	63
Net Assets	$ 604
Alta X and XI TE Holdco | Financial Institutions
Variable Interest Entity [Line Items]
Taxable income allocation pre-flip	99.00%
Taxable income allocation, post flip	5.00%
Spring Canyon
Variable Interest Entity [Line Items]
Ownership percentage by noncontrolling owners	9.90%
Other Assets	$ 2
Property, plant and equipment, net	91
Intangible assets, net	0
Total Assets	93
Liabilities	4
Noncontrolling Interest in Variable Interest Entity	49
Net Assets	40
Buckthorn Solar Drop Down Asset
Variable Interest Entity [Line Items]
Less: Net loss attributable to noncontrolling interests	(55)
Other Assets	15
Property, plant and equipment, net	223
Intangible assets, net	0
Total Assets	238
Liabilities	135
Noncontrolling Interest in Variable Interest Entity	43
Net Assets	$ 60
Clearway Energy LLC | Repowering Partnership LLC | CEG
Variable Interest Entity [Line Items]
Working capital						$ 35
Ownership percentage by noncontrolling owners	21.00%
Second Year through Flip Point | Alta X and XI TE Holdco
Variable Interest Entity [Line Items]
Percentage of cash available for distributions	94.34%
Post-Flip Point | Alta X and XI TE Holdco
Variable Interest Entity [Line Items]
Percentage of cash available for distributions	97.12%
Post-Flip Point | Spring Canyon
Variable Interest Entity [Line Items]
Percentage of cash available for distributions	95.00%
Post-Flip Point | Spring Canyon | Financial Institutions
Variable Interest Entity [Line Items]
Percentage of cash available for distributions	5.00%
Pre-determined Date Through Flip Point if Flip Has Not Occured | Alta X and XI TE Holdco | Financial Institutions
Variable Interest Entity [Line Items]
Percentage of cash available for distributions	100.00%
Pre-Flip Point | Spring Canyon
Variable Interest Entity [Line Items]
Percentage of cash available for distributions	65.19%
Pre-Flip Point | Spring Canyon | Financial Institutions
Variable Interest Entity [Line Items]
Percentage of cash available for distributions	34.81%
Wind | Spring Canyon
Variable Interest Entity [Line Items]
Voting interest acquired	90.10%
Wind | Spring Canyon II
Variable Interest Entity [Line Items]
Power generation capacity, megawatts | MW	32
Wind | Spring Canyon III
Variable Interest Entity [Line Items]
Power generation capacity, megawatts | MW	28
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Investments Accounted for by _6

Investments Accounted for by the Equity Method and Variable Interest Entities - VIEs that are not consolidated (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)generatingunitMW	Dec. 31, 2017USD ($)		Dec. 31, 2016USD ($)	[1]	Oct. 12, 2017USD ($)
Variable Interest Entity [Line Items]
Less: Net loss attributable to noncontrolling interests	$ (105)	$ (75)	[1]	$ (111)
Equity investments in affiliates	$ 1,172	$ 1,178	[2]
Utah Solar Portfolio
Variable Interest Entity [Line Items]
Percentage of cash available for distributions	50.00%
Equity investments in affiliates	$ 317
Utah Solar Portfolio | Capital Unit, Class A
Variable Interest Entity [Line Items]
Percentage Ownership	100.00%
DGPV Holdco 1
Variable Interest Entity [Line Items]
Power generation capacity, megawatts | MW	52
Equity investments in affiliates	$ 81
NRG DGPV Holdco 2
Variable Interest Entity [Line Items]
Remaining lease term	20 years
Equity investments in affiliates	$ 63
DGPV Holdco 3
Variable Interest Entity [Line Items]
Power generation capacity, megawatts | MW	59
Remaining lease term	21 years
Due to related parties	$ 9
Equity investments in affiliates	116
NRG DGPV Holdco
Variable Interest Entity [Line Items]
Equity investments in affiliates	260
RPV Holdco
Variable Interest Entity [Line Items]
Equity investments in affiliates	$ 29
Financial Institutions | Utah Solar Portfolio | Capital Unit, Class B
Variable Interest Entity [Line Items]
Taxable income allocation pre-flip	99.00%
Taxable income allocation, post flip	50.00%
Tax Equity Financed Portfolio of Leases - Commercial PV 1 | DGPV Holdco 1
Variable Interest Entity [Line Items]
Remaining lease term	17 years
Tax Equity Financed Portfolio of Leases - Commercial PV 1 | NRG DGPV Holdco 2
Variable Interest Entity [Line Items]
Power generation capacity, megawatts | MW	113
Tax Equity Financed Portfolio of Leases | RPV Holdco
Variable Interest Entity [Line Items]
Power generation capacity, megawatts | MW	30
Number of solar leases in portfolio | generatingunit	5,400
Existing Portfolio of Leases | RPV Holdco
Variable Interest Entity [Line Items]
Power generation capacity, megawatts | MW	14
Remaining lease term	14 years
Number of solar leases in portfolio | generatingunit	2,200
Maximum | Tax Equity Financed Portfolio of Leases | DGPV Holdco 1
Variable Interest Entity [Line Items]
Equity investments in affiliates	$ 100
Maximum | Tax Equity Financed Portfolio of Leases | NRG DGPV Holdco 2
Variable Interest Entity [Line Items]
Equity investments in affiliates						$ 60
Maximum | Tax Equity Financed Portfolio of Leases | DGPV Holdco 3
Variable Interest Entity [Line Items]
Equity investments in affiliates	$ 70
Maximum | Tax Equity Financed Portfolio of Leases | RPV Holdco
Variable Interest Entity [Line Items]
Remaining lease term	17 years
Minimum | Tax Equity Financed Portfolio of Leases | DGPV Holdco 3
Variable Interest Entity [Line Items]
Equity investments in affiliates	$ 50
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Balance Sheet Grouping and Debt (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt — affiliate	$ 44	$ 618	[1]
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, including current portion	0	13
Long-term debt — affiliate	259
Long-term debt, including current portion — external	5,779	5,450
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Notes receivable, including current portion	0	13
Long-term debt — affiliate	257	618
Long-term debt, including current portion — external	5,681	5,466
Level 2 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion — external	1,358	870
Level 3 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion — external	$ 4,580	$ 5,214
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Fair Value of Financial Instr_4

Fair Value of Financial Instruments - Recurring Fair Value (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	$ 11,000,000	$ 2,000,000
Derivative liabilities	21,000,000	49,000,000
Commodity contracts (b)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		1,000,000
Derivative liabilities		1,000,000
Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	11,000,000	1,000,000
Derivative liabilities	21,000,000	48,000,000
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	11,000,000	2,000,000
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets (liabilities)		0
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	21,000,000	49,000,000
Recurring | Level 2 | Commodity contracts (b)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	1,000,000
Derivative liabilities	0	1,000,000
Recurring | Level 2 | Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	11,000,000	1,000,000
Derivative liabilities	21,000,000	48,000,000
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets (liabilities)	$ 0	$ 0

Fair Value of Financial Instr_5

Fair Value of Financial Instruments - Credit Risk (Details)	12 Months Ended
	Dec. 31, 2018USD ($)facilityMW
Nature of Business [Line Items]
Impact of credit reserve to fair value	$ 0
Credit risk maximum exposure	$ 2,300,000,000
Credit risk period	5 years
PG&E
Nature of Business [Line Items]
Number of solar leases in portfolio | facility	6
Accounts Receivable, Related Parties	$ 17,000,000
PG&E | Solar Facilities
Nature of Business [Line Items]
Steam and chilled water capacity, megawatts | MW	480
PG&E | March Landing
Nature of Business [Line Items]
Steam and chilled water capacity, megawatts | MW	720

Accounting for Derivative Ins_3

Accounting for Derivative Instruments and Hedging Activities - Notional Amount and FV of Derivatives (Details) MMBTU in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)MMBTU	Dec. 31, 2017USD ($)MMBTU
Derivatives, Fair Value [Line Items]
Notional Amount at December 31, 2018 (In millions)	$ 1,862
Derivative assets	11	$ 2
Derivative liabilities	$ 21	$ 49
Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Derivative, Nonmonetary Notional Amount, Volume | MMBTU	1	2
Interest [Member]
Derivatives, Fair Value [Line Items]
Notional Amount at December 31, 2018 (In millions)	$ 1,862	$ 2,050
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative assets	5	1
Derivative liabilities	7	13
Designated as Hedging Instrument | Interest Rate Contract Current [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	2	0
Derivative liabilities	1	4
Designated as Hedging Instrument | Interest Rate Contract Non Current [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	3	1
Derivative liabilities	6	9
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative assets	6	1
Derivative liabilities	14	36
Not Designated as Hedging Instrument | Interest Rate Contract Current [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	1	0
Derivative liabilities	3	13
Not Designated as Hedging Instrument | Interest Rate Contract Non Current [Member]
Derivatives, Fair Value [Line Items]
Derivative assets	5	0
Derivative liabilities	11	22
Not Designated as Hedging Instrument | Commodity Contract Current [Member]
Derivatives, Fair Value [Line Items]
Derivative assets		1
Derivative liabilities	$ 0	$ 1

Accounting for Derivative Ins_4

Accounting for Derivative Instruments and Hedging Activities - Offsetting (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Offsetting Derivative Assets [Abstract]
Gross Amounts of Recognized Assets	$ 11	$ 2
Offsetting Derivative Liabilities [Abstract]
Gross Amounts of Recognized Liabilities	(21)	(49)
Gross Amounts of Recognized Assets/Liabilities	(10)	(47)
Derivative Instruments	0	0
Net Amount	(10)	(47)
Derivative, collateral, right to reclaim cash	0	0
Collateral, obligation to return cash	0	0
Commodity contracts (b)
Offsetting Derivative Assets [Abstract]
Gross Amounts of Recognized Assets		1
Derivative Instruments		0
Net Amount		1
Offsetting Derivative Liabilities [Abstract]
Gross Amounts of Recognized Liabilities		(1)
Derivative Instruments		0
Net Amount		(1)
Gross Amounts of Recognized Assets/Liabilities		0
Derivative Instruments		0
Net Amount		0
Interest rate contracts
Offsetting Derivative Assets [Abstract]
Gross Amounts of Recognized Assets	11	1
Derivative Instruments	(1)	(1)
Net Amount	10	0
Offsetting Derivative Liabilities [Abstract]
Gross Amounts of Recognized Liabilities	(21)	(48)
Derivative Instruments	1	1
Net Amount	(20)	(47)
Gross Amounts of Recognized Assets/Liabilities	(10)	(47)
Derivative Instruments	0	0
Net Amount	$ (10)	$ (47)

Accounting for Derivative Ins_5

Accounting for Derivative Instruments and Hedging Activities - AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated OCL beginning balance	$ (69)	$ (86)	$ (99)
Reclassified from accumulated OCL to income due to realization of previously deferred amounts	15	17
Mark-to-market of cash flow hedge accounting contracts	9	0	(4)
Accumulated OCL beginning balance	(45)	(69)	(86)
Losses expected to be realized from OCL during the next 12 months	9
Reclassification out of Accumulated Other Comprehensive Income [Member]
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Reclassified from accumulated OCL to income due to realization of previously deferred amounts			17
Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated OCL beginning balance	(1)	(1)
Accumulated OCL beginning balance	(1)	(1)	(1)
Parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated OCL beginning balance	(68)	(85)
Accumulated OCL beginning balance	$ (44)	$ (68)	$ (85)

Accounting for Derivative Ins_6

Accounting for Derivative Instruments and Hedging Activities - Impact on Statement of Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest rate contracts | Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized gain (loss) on derivatives	$ 15	$ 6	$ (2)

Intangible Assets Intangible _2

Intangible Assets Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Finite-lived Intangible Assets [Roll Forward]
Intangible assets, beginning balance	$ 1,465	$ 1,471
Asset Impairments		6
Intangible assets ending balance	1,464	1,465		$ 1,471
Less accumulated amortization	308	237
Net carrying amount	1,156	1,228	[1]
Amortization of intangible assets	71	71		71
Contra revenue intangibles amortization	70	70		70
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2,019	71
2,020	71
2,021	71
2,022	71
2,023	71
Accumulated amortization of out of market contracts	4
Out of Market Contracts
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Accumulated amortization of out of market contracts		4
Amortization	1	1
PPAs
Finite-lived Intangible Assets [Roll Forward]
Intangible assets, beginning balance	1,280	1,286
Intangible assets ending balance	1,280	1,280		1,286
Less accumulated amortization	269	205
Net carrying amount	1,011	1,075
Leasehold Rights
Finite-lived Intangible Assets [Roll Forward]
Intangible assets, beginning balance	86	86
Asset Impairments		0
Intangible assets ending balance	86	86		86
Less accumulated amortization	18	13
Net carrying amount	68	73
Customer Relationships
Finite-lived Intangible Assets [Roll Forward]
Intangible assets, beginning balance	66	66
Asset Impairments		0
Intangible assets ending balance	66	66		66
Less accumulated amortization	7	5
Net carrying amount	59	61
Customer Contracts
Finite-lived Intangible Assets [Roll Forward]
Intangible assets, beginning balance	15	15
Asset Impairments		0
Intangible assets ending balance	15	15		15
Less accumulated amortization	9	8
Net carrying amount	6	7
Emission Allowances
Finite-lived Intangible Assets [Roll Forward]
Intangible assets, beginning balance	9	9
Asset Impairments		0
Intangible assets ending balance	9	9		9
Less accumulated amortization	2	3
Net carrying amount	7	6
Other
Finite-lived Intangible Assets [Roll Forward]
Intangible assets, beginning balance	9	9
Asset Impairments		0
Intangible assets ending balance	8	9		$ 9
Less accumulated amortization	3	3
Net carrying amount	5	$ 6
Blythe
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Out of market contracts	$ 7
Intangible assets useful life	20 years
Spring Canyon
Finite-lived Intangible Assets [Roll Forward]
Net carrying amount	$ 0
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Out of market contracts	$ 3
Intangible assets useful life	25 years
Alta Wind XI
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Out of market contracts	$ 5
Intangible assets useful life	34 years
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Asset Impairments Asset Impairm

Asset Impairments Asset Impairments (Details) - USD ($) $ in Millions	3 Months Ended			12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Dec. 31, 2016	Dec. 31, 2018	Dec. 31, 2017	[1]	Dec. 31, 2016	[1],[2]
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment losses				$ 0	$ 44		$ 185
Elbow Creek
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment losses	$ 26		$ 117
Goat Wind
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment losses			60
Forward
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment losses	$ 5		6
November 2017 Drop Down Assets
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment losses		$ 13	$ 2
Property, Plant and Equipment | November 2017 Drop Down Assets
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment losses		8
Finite-Lived Intangible Assets | November 2017 Drop Down Assets
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment losses		$ 5
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

- Schedule of Borrowings (Detai

- Schedule of Borrowings (Details) - USD ($) $ in Millions

Oct. 02, 2018

Jun. 19, 2018

Apr. 30, 2018

Apr. 28, 2018

Mar. 27, 2017

Dec. 31, 2018

Oct. 10, 2018

Oct. 01, 2018

May 31, 2018

Dec. 31, 2017

Feb. 17, 2017

Debt Instrument [Line Items]

Long-term debt — affiliate

$ 44

$ 618

[1]

Long-term Debt

6,038

6,068

Less current maturities

(529)

(339)

Less net debt issuance costs

(61)

(62)

Total long-term debt

$ 5,448

5,667

Total proceeds

$ 203

Revolving Credit Facility due in 2019

Debt Instrument [Line Items]

Basis spread on variable rate

1.75%

Floating Interest Rate

3-Month LIBOR

Long-term debt - affiliate, due 2019

Debt Instrument [Line Items]

Long-term debt — affiliate

$ 215

$ 216

337

Interest rate stated rate

3.58%

Long-term debt - affiliate, due 2020

Debt Instrument [Line Items]

Long-term debt — affiliate

$ 44

$ 44

281

Interest rate stated rate

3.325%

2024 Senior Notes

Debt Instrument [Line Items]

Senior Notes

$ 500

500

Interest rate stated rate

5.375%

2025 Senior Notes

Debt Instrument [Line Items]

Senior Notes

$ 600

0

Interest rate stated rate

5.75%

5.75%

Total proceeds

$ 600

2026 Senior Notes

Debt Instrument [Line Items]

Senior Notes

$ 350

350

Interest rate stated rate

5.00%

Revolving Credit Facility

Debt Instrument [Line Items]

Long-term Debt

$ 0

55

Basis spread on variable rate

2.50%

1.75%

2.00%

Agua Caliente Borrower 2, due 2038

Debt Instrument [Line Items]

Long-term Debt

$ 39

41

$ 130

Interest rate stated rate

5.43%

5.43%

Alpine, due 2022

Debt Instrument [Line Items]

Long-term Debt

$ 127

135

Floating Interest Rate

3-Month LIBOR

Alta Wind I - V lease financing arrangements, due 2034 and 2035

Debt Instrument [Line Items]

Long-term Debt

$ 886

926

Buckthorn Solar, due 2025

Debt Instrument [Line Items]

Long-term Debt

$ 132

$ 132

169

Basis spread on variable rate

1.75%

Floating Interest Rate

3-Month LIBOR

CVSR, due 2037

Debt Instrument [Line Items]

Long-term Debt

$ 720

746

CVSR Holdco Notes, due 2037

Debt Instrument [Line Items]

Long-term Debt

$ 188

194

Interest rate stated rate

4.68%

El Segundo Energy Center, due 2023

Debt Instrument [Line Items]

Long-term Debt

$ 352

400

Energy Center Minneapolis Series C, D, E, F, G, H Notes, due 2025-2037

Debt Instrument [Line Items]

Long-term Debt

$ 328

208

Interest rate stated rate

5.95%

Energy Center Minneapolis Series D Notes, due 2031

Debt Instrument [Line Items]

Interest rate stated rate

0.00%

Laredo Ridge, due 2028

Debt Instrument [Line Items]

Long-term Debt

$ 89

95

Basis spread on variable rate

1.875%

Floating Interest Rate

3-Month LIBOR

Kansas South, due in 2030

Debt Instrument [Line Items]

Long-term Debt

$ 26

29

Basis spread on variable rate

2.00%

Floating Interest Rate

6-Month LIBOR

Marsh Landing Tranche B due 2023

Debt Instrument [Line Items]

Basis spread on variable rate

2.125%

Floating Interest Rate

3-Month LIBOR

Marsh Landing, due 2023

Debt Instrument [Line Items]

Long-term Debt

$ 263

318

South Trent Wind Due 2020

Debt Instrument [Line Items]

Long-term Debt

$ 50

53

Basis spread on variable rate

1.625%

Floating Interest Rate

3-Month LIBOR

Tapestry, due 2021

Debt Instrument [Line Items]

Long-term Debt

$ 151

162

Basis spread on variable rate

1.75%

Floating Interest Rate

3-Month LIBOR

Utah Solar Portfolio, due 2022

Debt Instrument [Line Items]

Long-term Debt

$ 287

$ 267

278

Interest rate stated rate

2.625%

Total proceeds

$ 65

Viento, due 2023

Debt Instrument [Line Items]

Long-term Debt

$ 146

163

Basis spread on variable rate

2.00%

Floating Interest Rate

6-Month LIBOR

Walnut Creek, due 2023

Debt Instrument [Line Items]

Long-term Debt

$ 222

267

Basis spread on variable rate

1.75%

Floating Interest Rate

3-Month LIBOR

Other

Debt Instrument [Line Items]

Long-term Debt

$ 343

361

Project Level Debt

Debt Instrument [Line Items]

Long-term Debt

4,329

$ 4,545

Letter of Credit | Revolving Credit Facility

Debt Instrument [Line Items]

Letters of credit outstanding

41

Letter of Credit | Agua Caliente Borrower 2, due 2038

Debt Instrument [Line Items]

Letters of credit outstanding

17

Letter of Credit | Alpine, due 2022

Debt Instrument [Line Items]

Letters of credit outstanding

16

Letter of Credit | Alta Wind I - V lease financing arrangements, due 2034 and 2035

Debt Instrument [Line Items]

Letters of credit outstanding

44

Letter of Credit | Buckthorn Solar, due 2025

Debt Instrument [Line Items]

Letters of credit outstanding

26

Letter of Credit | CVSR, due 2037

Debt Instrument [Line Items]

Letters of credit outstanding

0

Letter of Credit | CVSR Holdco Notes, due 2037

Debt Instrument [Line Items]

Letters of credit outstanding

13

Letter of Credit | El Segundo Energy Center, due 2023

Debt Instrument [Line Items]

Letters of credit outstanding

138

Letter of Credit | Energy Center Minneapolis Series C, D, E, F, G, H Notes, due 2025-2037

Debt Instrument [Line Items]

Letters of credit outstanding

0

Letter of Credit | Laredo Ridge, due 2028

Debt Instrument [Line Items]

Letters of credit outstanding

10

Letter of Credit | Kansas South, due in 2030

Debt Instrument [Line Items]

Letters of credit outstanding

2

Letter of Credit | Marsh Landing, due 2023

Debt Instrument [Line Items]

Letters of credit outstanding

60

Letter of Credit | Tapestry, due 2021

Debt Instrument [Line Items]

Letters of credit outstanding

20

Letter of Credit | Utah Solar Portfolio, due 2022

Debt Instrument [Line Items]

Letters of credit outstanding

13

Letter of Credit | Viento, due 2023

Debt Instrument [Line Items]

Letters of credit outstanding

26

Letter of Credit | Walnut Creek, due 2023

Debt Instrument [Line Items]

Letters of credit outstanding

74

Letter of Credit | Other

Debt Instrument [Line Items]

Letters of credit outstanding

$ 24

Minimum | Alpine, due 2022

Debt Instrument [Line Items]

Basis spread on variable rate

1.75%

Minimum | Alta Wind I - V Lease financing arrangement [Member]

Debt Instrument [Line Items]

Interest rate stated rate

5.696%

Minimum | CVSR, due 2037

Debt Instrument [Line Items]

Interest rate stated rate

2.339%

Minimum | West Holdings Credit Agreement

Debt Instrument [Line Items]

Floating Interest Rate

3-Month LIBOR

Minimum | West Holdings Credit Agreement due 2023 Tranche B

Debt Instrument [Line Items]

Basis spread on variable rate

2.375%

Minimum | West Holdings Credit Agreement due 2023 Tranche A

Debt Instrument [Line Items]

Basis spread on variable rate

1.75%

Maximum | Alta Wind I - V Lease financing arrangement [Member]

Debt Instrument [Line Items]

Interest rate stated rate

7.015%

Maximum | CVSR, due 2037

Debt Instrument [Line Items]

Interest rate stated rate

3.775%

[1]

Retrospectively adjusted as discussed in Note 1, Nature of Business.

Long-term Debt - Revolving Cred

Long-term Debt - Revolving Credit Facility (Details) - USD ($) $ in Millions	Apr. 30, 2018	Apr. 28, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	[1]	Feb. 01, 2019
Debt Instrument [Line Items]
Long-term Debt			$ 6,038	$ 6,068
Proceeds from the revolving credit facility			35	55	$ 60
Revolving Credit Facility
Debt Instrument [Line Items]
Long-term Debt			0	55
Line of credit fair value amount outstanding			$ 0
Basis spread on variable rate	2.50%	1.75%	2.00%
Proceeds from the revolving credit facility				$ 55
Leverage ratio			1.75%
Letter of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Letters of credit outstanding			$ 41
Subsequent Event | 3.5% Convertible Notes due 2019
Debt Instrument [Line Items]
Long-term Debt							$ 170
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Long-term Debt - Bridge Credit

Long-term Debt - Bridge Credit Facility (Details) - Bridge Loan - USD ($) $ in Millions	Aug. 31, 2018	Oct. 01, 2018
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 1,500	$ 867.5
Basis spread on LIBOR rate	3.00%
Basis spread on variable rate	2.00%

Long-term Debt - Senior Notes a

Long-term Debt - Senior Notes and Convertible Notes (Details) - USD ($) $ in Millions	Oct. 10, 2018	Oct. 02, 2018	Jun. 19, 2018	Jan. 31, 2019	Aug. 31, 2018	Dec. 31, 2018	Oct. 01, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Total proceeds			$ 203
Long-term debt — affiliate						$ 44		$ 618	[1]
2025 Senior Notes
Debt Instrument [Line Items]
Total proceeds		$ 600
Interest rate stated rate						5.75%	5.75%
3.5% Convertible Notes due 2019
Debt Instrument [Line Items]
Repayments of debt	$ 109				$ 16
3.25% Convertible Notes due 2020
Debt Instrument [Line Items]
Repayments of debt	243
Long-term debt - affiliate, due 2019
Debt Instrument [Line Items]
Interest rate stated rate						3.58%
Repayments of debt					$ 16
Long-term debt — affiliate	216					$ 215		337
Long-term debt - affiliate, due 2020
Debt Instrument [Line Items]
Interest rate stated rate						3.325%
Long-term debt — affiliate	$ 44					$ 44		$ 281
Subsequent Event | 3.5% Convertible Notes due 2019
Debt Instrument [Line Items]
Repayments of debt				$ 50
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Long-term Debt - Drop Down Asse

Long-term Debt - Drop Down Assets and Other (Details) - USD ($) $ in Millions	Jun. 19, 2018	May 31, 2018	Nov. 02, 2017	Mar. 27, 2017	Sep. 30, 2018	Dec. 31, 2018	Mar. 30, 2018	Dec. 31, 2017	Nov. 01, 2017	Feb. 17, 2017
Debt Instrument [Line Items]
Non-resource debt						$ 878
Long-term Debt						6,038		$ 6,068
Total proceeds	$ 203
Buckthorn Solar, due 2025
Debt Instrument [Line Items]
Long-term Debt		$ 132				$ 132		169
Repayments of debt		$ 80
Basis spread on variable rate						1.75%
Buckthorn Solar Drop Down Asset
Debt Instrument [Line Items]
Basis spread on variable rate					1.75%
Agua Caliente Solar(e)
Debt Instrument [Line Items]
Interest rate stated rate						5.43%				5.43%
Long-term Debt						$ 39		41		$ 130
Utah Solar Portfolio, due 2022
Debt Instrument [Line Items]
Interest rate stated rate				2.625%
Long-term Debt				$ 287		267		$ 278
Long-term debt				222
Total proceeds				$ 65
Thermal
Debt Instrument [Line Items]
Maximum borrowing capacity						$ 40
November 2017 Drop Down Assets
Debt Instrument [Line Items]
Interest rate stated rate									4.69%
Sale Leaseback Transaction, Imputed Interest Rate			8.00%
Long-term Debt									$ 26
Buckthorn Solar Drop Down Asset | Buckthorn Solar, due 2025
Debt Instrument [Line Items]
Long-term Debt							$ 183
Buckthorn Solar Drop Down Asset | Buckthorn Solar Drop Down Asset
Debt Instrument [Line Items]
Notional amount percent of required need coverage					80.00%

Long-term Debt - Energy Center

Long-term Debt - Energy Center Minneapolis Series E, F, G, H Notes (Details) $ in Millions	Jun. 19, 2018USD ($)
Debt Instrument [Line Items]
Total proceeds	$ 203
Net borrowings	$ 120
Energy Center Minneapolis Series E Notes, due 2033
Debt Instrument [Line Items]
Interest rate stated rate	4.80%
Total proceeds	$ 70
Energy Center Minneapolis Series F Notes, due 2033
Debt Instrument [Line Items]
Interest rate stated rate	4.60%
Total proceeds	$ 10
Energy Center Minneapolis Series G Notes, due 2035
Debt Instrument [Line Items]
Interest rate stated rate	5.90%
Total proceeds	$ 83
Energy Center Minneapolis Series H Notes, due 2037
Debt Instrument [Line Items]
Interest rate stated rate	4.83%
Total proceeds	$ 40
Energy Center Minneapolis Series C, D, E, F, G, H Notes, due 2025-2037
Debt Instrument [Line Items]
Interest rate stated rate	5.95%
Repayments of debt	$ (83)

Long-term Debt - Interest Rate

Long-term Debt - Interest Rate Swaps (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Debt Instrument [Line Items]
Notional Amount at December 31, 2018 (In millions)	$ 1,862
Interest Rate Swap | NRG Solar Alpine LLC
Debt Instrument [Line Items]
% of Principal	85.00%
Floating Interest Rate	3-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 108
Interest Rate Swap | El Segundo
Debt Instrument [Line Items]
% of Principal	85.00%
Floating Interest Rate	3-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 299
Interest Rate Swap | Viento Funding II
Debt Instrument [Line Items]
% of Principal	91.00%
Floating Interest Rate	6-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 134
Maturity - November 30, 2030 | Interest Rate Swap | Avra Valley
Debt Instrument [Line Items]
% of Principal	87.00%
Fixed Interest Rate	2.333%
Floating Interest Rate	3-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 44
Maturity - May 15, 2031 | Interest Rate Swap | AWAM
Debt Instrument [Line Items]
% of Principal	100.00%
Fixed Interest Rate	2.47%
Floating Interest Rate	3-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 16
Maturity - June 25, 2028 | Interest Rate Swap | Blythe
Debt Instrument [Line Items]
% of Principal	75.00%
Fixed Interest Rate	3.563%
Floating Interest Rate	3-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 12
Maturity - June 30, 2020 | Interest Rate Swap | Borrego
Debt Instrument [Line Items]
% of Principal	75.00%
Fixed Interest Rate	1.125%
Floating Interest Rate	3-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 3
Maturity - December 31, 2041 | Interest Rate Swap | Buckthorn Solar
Debt Instrument [Line Items]
% of Principal	83.00%
Floating Interest Rate	3-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 109
Maturity - December 31, 2030 | Interest Rate Swap | Kansas South
Debt Instrument [Line Items]
% of Principal	75.00%
Fixed Interest Rate	2.368%
Floating Interest Rate	6-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 20
Maturity - March 31, 2026 | Interest Rate Swap | Laredo Ridge
Debt Instrument [Line Items]
% of Principal	80.00%
Fixed Interest Rate	2.31%
Floating Interest Rate	3-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 71
Maturity - June 30, 2023 | Interest Rate Swap | Marsh Landing
Debt Instrument [Line Items]
% of Principal	94.00%
Fixed Interest Rate	3.244%
Floating Interest Rate	3-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 246
Maturity - December 31, 2029 | Interest Rate Swap | Roadrunner
Debt Instrument [Line Items]
% of Principal	75.00%
Fixed Interest Rate	4.313%
Floating Interest Rate	3-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 24
Maturity - December 31, 2029 | Interest Rate Swap | Tapestry Wind
Debt Instrument [Line Items]
% of Principal	50.00%
Fixed Interest Rate	3.57%
Floating Interest Rate	3-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 60
Maturity - June14, 2020 | Interest Rate Swap | South Trent
Debt Instrument [Line Items]
% of Principal	75.00%
Fixed Interest Rate	3.265%
Floating Interest Rate	3-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 37
Maturity - June 14, 2028 | Interest Rate Swap | South Trent
Debt Instrument [Line Items]
% of Principal	75.00%
Fixed Interest Rate	4.95%
Floating Interest Rate	3-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 21
Maturity - December 21, 2021 | Interest Rate Swap | Tapestry Wind
Debt Instrument [Line Items]
% of Principal	90.00%
Fixed Interest Rate	2.21%
Floating Interest Rate	3-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 136
Maturity - September 30, 2036 | Interest Rate Swap | Utah Solar Portfolio
Debt Instrument [Line Items]
% of Principal	80.00%
Floating Interest Rate	1-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 214
Maturity - June 30, 2028 | Interest Rate Swap | Viento Funding II
Debt Instrument [Line Items]
% of Principal	90.00%
Fixed Interest Rate	4.985%
Floating Interest Rate	6-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 65
Maturity - May 31, 2023 | Interest Rate Swap | Walnut Creek
Debt Instrument [Line Items]
% of Principal	90.00%
Floating Interest Rate	3-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 200
Maturity - May 31, 2023 | Interest Rate Swap | WCEP Holdings
Debt Instrument [Line Items]
% of Principal	100.00%
Fixed Interest Rate	4.003%
Floating Interest Rate	3-Month LIBOR
Notional Amount at December 31, 2018 (In millions)	$ 43

Long-term Debt - Maturities (De

Long-term Debt - Maturities (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Maturities of Long-term Debt [Abstract]
2,019	$ 529
2,020	405
2,021	447
2,022	646
2,023	389
Thereafter	3,622
Long-term Debt	$ 6,038	$ 6,068

Members' Equity (Details)

Members' Equity (Details) - $ / shares	Feb. 12, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2018
Class of Stock [Line Items]
Distributions paid (in dollars per share)		$ 0.331	$ 0.320	$ 0.309	$ 0.298
Dividends Payable, Date Declared						Feb. 12, 2019
Dividends date paid						Mar. 15, 2019
Subsequent Event
Class of Stock [Line Items]
Common stock dividends declared (in dollars per share)	$ 0.20

Segment Reporting (Details)

Segment Reporting (Details) - USD ($) $ in Millions	3 Months Ended									12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017		Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Segment Reporting
Total operating revenues	$ 229	$ 292	$ 307	$ 225	$ 231		$ 269	$ 288	$ 221	$ 1,053	$ 1,009	[1]	$ 1,035	[1]
Cost of operations										332	326	[1]	308	[1]
Depreciation and amortization										331	334	[1]	303	[1]
Impairment losses										0	44	[1]	185	[1],[2]
General and administrative										20	19	[1]	14	[1]
Acquisition-related transaction and integration costs										20	3	[1]	1
Development costs										3	0	[1]	0	[1]
Operating Income	54	100	144	49	20		84	125	54	347	283	[1]	224	[1]
Equity in earnings of unconsolidated affiliates										74	71	[1]	60	[1],[2]
Other income, net										8	4	[1]	3	[1]
Loss on debt extinguishment										0	(3)	[1]	0	[1],[2]
Interest expense										(294)	(294)	[1]	(272)	[1]
Net Income	(37)	$ 64	$ 106	$ 2	(37)		$ 42	$ 56	$ 0	135	61	[1],[3],[4]	15	[1],[3],[4]
Less: Net loss attributable to noncontrolling interests										(105)	(75)	[1]	(111)	[1]
Net Income Attributable to Clearway Energy LLC										240	136	[1]	126	[1]
Equity Method Investments	1,172				1,178	[5]				1,172	1,178	[5]
Total Assets	8,448				8,360	[5]				8,448	8,360	[5]
Capital Expenditures	68				212					68	212
Conventional
Segment Reporting
Total operating revenues										337	336		333
Cost of operations										62	77		66
Depreciation and amortization										101	103		80
Impairment losses											0		0
General and administrative										0	0		0
Acquisition-related transaction and integration costs										0	0		0
Development costs										0
Operating Income										174	156		187
Equity in earnings of unconsolidated affiliates										11	12		13
Other income, net										1	1		1
Interest expense										(51)	(49)		(48)
Net Income										135	120		153
Less: Net loss attributable to noncontrolling interests										0	0		0
Net Income Attributable to Clearway Energy LLC										135	120		153
Equity Method Investments	98				102					98	102
Total Assets	1,788				1,897					1,788	1,897
Capital Expenditures	14				15					14	15
Renewables
Segment Reporting
Total operating revenues										526	501		532
Cost of operations										146	133		128
Depreciation and amortization										207	210		203
Impairment losses											44		185
General and administrative										0	0		0
Acquisition-related transaction and integration costs										0	0		0
Development costs										0
Operating Income										173	114		16
Equity in earnings of unconsolidated affiliates										63	59		47
Other income, net										4	2		2
Interest expense										(154)	(164)		(151)
Net Income										86	8		(86)
Less: Net loss attributable to noncontrolling interests										(104)	(75)		(111)
Net Income Attributable to Clearway Energy LLC										190	83		25
Equity Method Investments	1,074				1,076					1,074	1,076
Total Assets	5,836				6,017					5,836	6,017
Capital Expenditures	26				181					26	181
Thermal
Segment Reporting
Total operating revenues										193	172		170
Cost of operations										127	116		114
Depreciation and amortization										23	21		20
Impairment losses											0		0
General and administrative										1	0		0
Acquisition-related transaction and integration costs										0	0		0
Development costs										2
Operating Income										40	35		36
Equity in earnings of unconsolidated affiliates										0	0		0
Other income, net										1	0		0
Interest expense										(12)	(10)		(7)
Net Income										29	25		29
Less: Net loss attributable to noncontrolling interests										0	0		0
Net Income Attributable to Clearway Energy LLC										29	25		29
Equity Method Investments	0				0					0	0
Total Assets	516				422					516	422
Capital Expenditures	28				16					28	16
Corporate
Segment Reporting
Total operating revenues										(3)	0		0
Cost of operations										(3)	0		0
Depreciation and amortization										0	0		0
Impairment losses											0		0
General and administrative										19	19		14
Acquisition-related transaction and integration costs										20	3		1
Development costs										1
Operating Income										(40)	(22)		(15)
Equity in earnings of unconsolidated affiliates										0	0		0
Other income, net										2	1		0
Interest expense										(77)	(71)		(66)
Net Income										(115)	(92)		(81)
Less: Net loss attributable to noncontrolling interests										(1)	0		0
Net Income Attributable to Clearway Energy LLC										(114)	(92)		$ (81)
Equity Method Investments					0						0
Total Assets	308				24					308	24
Capital Expenditures	$ 0				$ 0					$ 0	$ 0
SCE | Conventional
Segment Reporting
Customer's Percentage of Total Revenue										20.00%	21.00%		21.00%
SCE | Renewables
Segment Reporting
Customer's Percentage of Total Revenue										20.00%	20.00%		21.00%
PG&E | Conventional
Segment Reporting
Customer's Percentage of Total Revenue										12.00%	12.00%		12.00%
PG&E | Renewables
Segment Reporting
Customer's Percentage of Total Revenue										11.00%	11.00%		11.00%
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[5]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Related Party Transactions - Re

Related Party Transactions - Related Party Transactions with CEG entities (Details) - USD ($) $ in Millions	8 Months Ended	12 Months Ended
	Aug. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
RENOM
Related Party Transaction [Line Items]
Expenses from transactions with related party		$ 30	$ 23	$ 13
Due to related party		$ 6	$ 5
Management Service, Base | PML | NRG
Related Party Transaction [Line Items]
Total Emissions Credit Purchases	$ 11

Related Party Transactions - _2

Related Party Transactions - Related Party Transactions Prior (Details)	Jun. 19, 2018USD ($)	Jan. 31, 2019USD ($)	Aug. 31, 2018USD ($)	Dec. 31, 2018USD ($)kpphMWton	Dec. 31, 2017USD ($)		Dec. 31, 2016USD ($)
Related Party Transaction [Line Items]
General and administrative				$ 20,000,000	$ 19,000,000	[1]	$ 14,000,000	[1]
NRG
Related Party Transaction [Line Items]
Revenue from related parties			$ 8,000,000		12,000,000		13,000,000
NRG | Operations and Maintenance services
Related Party Transaction [Line Items]
Expenses from transactions with related party			27,000,000		39,000,000		36,000,000
Thermal | NRG
Related Party Transaction [Line Items]
Expenses from transactions with related party			7,000,000		9,000,000		9,000,000
GenConn | NRG | Operations and Maintenance services
Related Party Transaction [Line Items]
Expenses from transactions with related party			4,000,000		5,000,000		5
Marsh Landing | NRG
Related Party Transaction [Line Items]
Expenses from transactions with related party			11,000,000		15,000,000		14,000,000
NRG Yield | NRG
Related Party Transaction [Line Items]
General and administrative			$ 7,000,000		$ 10,000,000		$ 10
Thermal
Related Party Transaction [Line Items]
Steam and chilled water capacity, megawatts | MW				1,385
Power generation capacity, megawatts | MW				133
Thermal | UPMC Thermal
Related Party Transaction [Line Items]
Steam and chilled water capacity, megawatts | MW				73
Steam Energy | kpph				150
Chilled Water Capacity | ton				6,750
Power generation capacity, megawatts | MW				7.5
UPMC Thermal
Related Party Transaction [Line Items]
Related party transaction term	20 years
Business combination consideration transferred	$ 84,000,000
Subsequent Event | UPMC Thermal
Related Party Transaction [Line Items]
Business combination consideration transferred		$ 3,000,000
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Commitments and Contingencies_3

Commitments and Contingencies (Details) - USD ($) $ in Millions	8 Months Ended	12 Months Ended
	Aug. 31, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Rent expense		$ 18	$ 17	$ 15
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2,019		13
2,020		13
2,021		13
2,022		13
2,023		12
Thereafter		207
Total		271
Long-term Purchase Commitment [Line Items]
Purchased power under long-term contracts		39	34	32
Purchase Obligation, Fiscal Year Maturity [Abstract]
2,019		11
2,020		3
2,021		3
2,022		3
2,023		3
Thereafter		13
Total		$ 36
Thermal | NRG
Long-term Purchase Commitment [Line Items]
Expenses from transactions with related party	$ 7		$ 9	$ 9

Unaudited Quarterly Financial_3

Unaudited Quarterly Financial Data (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016	[1]
Condensed Financial Statements, Captions [Line Items]
Total operating revenues	$ 229	$ 292	$ 307	$ 225	$ 231	$ 269	$ 288	$ 221	$ 1,053	$ 1,009	[1]	$ 1,035
Operating Income	54	100	144	49	20	84	125	54	347	283	[1]	224
Net income	$ (37)	$ 64	$ 106	$ 2	(37)	$ 42	$ 56	$ 0	$ 135	61	[1],[2],[3]	$ 15	[2],[3]
As Previously Reported
Condensed Financial Statements, Captions [Line Items]
Total operating revenues										1,009
Operating Income										283
Net income					(38)					62
Buckthorn Solar Drop Down Asset
Condensed Financial Statements, Captions [Line Items]
Total operating revenues										0
Operating Income										0
Net income					$ (1)					$ (1)
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Condensed Consolidating Finan_3

Condensed Consolidating Financial Information Condensed Consolidating Financial Information (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
2024 Senior Notes
Senior Notes	$ 500	$ 500
2026 Senior Notes
Senior Notes	$ 350	$ 350

Condensed Consolidating Finan_4

Condensed Consolidating Financial Information Income Statement (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Operating Revenues
Total operating revenues	$ 229	$ 292	$ 307	$ 225	$ 231	$ 269	$ 288	$ 221	$ 1,053	$ 1,009	[1]	$ 1,035	[1]
Operating Costs and Expenses
Cost of operations									332	326	[1]	308	[1]
Depreciation and amortization									331	334	[1]	303	[1]
Impairment losses									0	44	[1]	185	[1],[2]
General and administrative									20	19	[1]	14	[1]
Acquisition-related transaction and integration costs									20	3	[1]	1
Development costs									3	0	[1]	0	[1]
Total operating costs and expenses									706	726	[1]	811	[1]
Operating Income	54	100	144	49	20	84	125	54	347	283	[1]	224	[1]
Other Income (Expense)
Equity in earnings (losses) of consolidated affiliates									0	0		0
Equity in earnings of unconsolidated affiliates									74	71	[1]	60	[1],[2]
Other income, net									8	4	[1]	3	[1]
Loss on debt extinguishment									0	(3)	[1]	0	[1],[2]
Interest expense									(294)	(294)	[1]	(272)	[1]
Total other expense, net									(212)	(222)	[1]	(209)	[1]
Net Income	$ (37)	$ 64	$ 106	$ 2	$ (37)	$ 42	$ 56	$ 0	135	61	[1],[3],[4]	15	[1],[3],[4]
Less: Net loss attributable to noncontrolling interests									(105)	(75)	[1]	(111)	[1]
Net Income Attributable to Clearway Energy LLC									240	136	[1]	126	[1]
Parent Company
Operating Revenues
Total operating revenues									0	0		0
Operating Costs and Expenses
Cost of operations									0	0		0
Depreciation and amortization									0	0		0
Impairment losses										0		0
General and administrative									0	0		2
Acquisition-related transaction and integration costs									0	0		0
Development costs									0
Total operating costs and expenses									0	0		2
Operating Income									0	0		(2)
Other Income (Expense)
Equity in earnings (losses) of consolidated affiliates									237	135		128
Equity in earnings of unconsolidated affiliates									0	0		0
Other income, net									3	1		0
Loss on debt extinguishment										0
Interest expense									0	0		0
Total other expense, net									240	136		128
Net Income									240	136		126
Less: Net loss attributable to noncontrolling interests									0	0		0
Net Income Attributable to Clearway Energy LLC									240	136		126
Guarantor Subsidiaries
Operating Revenues
Total operating revenues									11	10		10
Operating Costs and Expenses
Cost of operations									3	2		3
Depreciation and amortization									6	6		5
Impairment losses										12		2
General and administrative									0	0		0
Acquisition-related transaction and integration costs									0	0		0
Development costs									0
Total operating costs and expenses									9	20		10
Operating Income									2	(10)		0
Other Income (Expense)
Equity in earnings (losses) of consolidated affiliates									0	(16)		10
Equity in earnings of unconsolidated affiliates									43	22		9
Other income, net									0	0		0
Loss on debt extinguishment										(3)
Interest expense									0	1		(2)
Total other expense, net									43	4		17
Net Income									45	(6)		17
Less: Net loss attributable to noncontrolling interests									0	0		0
Net Income Attributable to Clearway Energy LLC									45	(6)		17
Non-Guarantor Subsidiaries
Operating Revenues
Total operating revenues									1,042	999		1,025
Operating Costs and Expenses
Cost of operations									329	324		305
Depreciation and amortization									325	328		298
Impairment losses										32		183
General and administrative									0	0		0
Acquisition-related transaction and integration costs									0	0		0
Development costs									0
Total operating costs and expenses									654	684		786
Operating Income									388	315		239
Other Income (Expense)
Equity in earnings (losses) of consolidated affiliates									0	0		0
Equity in earnings of unconsolidated affiliates									3	21		21
Other income, net									5	3		3
Loss on debt extinguishment										0
Interest expense									(217)	(224)		(204)
Total other expense, net									(209)	(200)		(180)
Net Income									179	115		59
Less: Net loss attributable to noncontrolling interests									(69)	(5)		(1)
Net Income Attributable to Clearway Energy LLC									248	120		60
Subsidiary Issuer
Operating Revenues
Total operating revenues									3	1		1
Operating Costs and Expenses
Cost of operations									3	1		1
Depreciation and amortization									0	0		0
Impairment losses										0		0
General and administrative									20	19		12
Acquisition-related transaction and integration costs									20	3		1
Development costs									3
Total operating costs and expenses									46	23		14
Operating Income									(43)	(22)		(13)
Other Income (Expense)
Equity in earnings (losses) of consolidated affiliates									224	125		66
Equity in earnings of unconsolidated affiliates									28	28		30
Other income, net									0	0		0
Loss on debt extinguishment										0
Interest expense									(77)	(71)		(66)
Total other expense, net									175	82		30
Net Income									132	60		17
Less: Net loss attributable to noncontrolling interests									(105)	(75)		(111)
Net Income Attributable to Clearway Energy LLC									237	135		128
Eliminations
Operating Revenues
Total operating revenues									(3)	(1)		(1)
Operating Costs and Expenses
Cost of operations									(3)	(1)		(1)
Depreciation and amortization									0	0		0
Impairment losses										0		0
General and administrative									0	0		0
Acquisition-related transaction and integration costs									0	0		0
Development costs									0
Total operating costs and expenses									(3)	(1)		(1)
Operating Income									0	0		0
Other Income (Expense)
Equity in earnings (losses) of consolidated affiliates									(461)	(244)		(204)
Equity in earnings of unconsolidated affiliates									0	0		0
Other income, net									0	0		0
Loss on debt extinguishment										0
Interest expense									0	0		0
Total other expense, net									(461)	(244)		(204)
Net Income									(461)	(244)		(204)
Less: Net loss attributable to noncontrolling interests									69	5		1
Net Income Attributable to Clearway Energy LLC									$ (530)	$ (249)		$ (205)
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[4]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Condensed Consolidating Finan_5

Condensed Consolidating Financial Information Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Condensed Statement of Income Captions [Line Items]
Net income	$ (37)	$ 64	$ 106	$ 2	$ (37)	$ 42	$ 56	$ 0	$ 135	$ 61	[1],[2],[3]	$ 15	[1],[2],[3]
Unrealized gain on derivatives									24	17	[2]	13	[2]
Other comprehensive (loss) income									24	17	[2]	13	[2]
Comprehensive Income									159	78	[2]	28	[2]
Less: Comprehensive (loss) income attributable to noncontrolling interests									(105)	(75)	[2]	(111)	[2]
Comprehensive Income Attributable to NRG Yield LLC									264	153	[2]	139	[2]
Eliminations
Condensed Statement of Income Captions [Line Items]
Net income									(461)	(244)		(204)
Unrealized gain on derivatives									(45)	(34)		(24)
Other comprehensive (loss) income									(45)	(34)		(24)
Comprehensive Income									(506)	(278)		(228)
Less: Comprehensive (loss) income attributable to noncontrolling interests									69	5		1
Comprehensive Income Attributable to NRG Yield LLC									(575)	(283)		(229)
Parent Company
Condensed Statement of Income Captions [Line Items]
Net income									240	136		126
Unrealized gain on derivatives									24	17		13
Other comprehensive (loss) income									24	17		13
Comprehensive Income									264	153		139
Less: Comprehensive (loss) income attributable to noncontrolling interests									0	0		0
Comprehensive Income Attributable to NRG Yield LLC									264	153		139
Guarantor Subsidiaries
Condensed Statement of Income Captions [Line Items]
Net income									45	(6)		17
Unrealized gain on derivatives									1	1		1
Other comprehensive (loss) income									1	1		1
Comprehensive Income									46	(5)		18
Less: Comprehensive (loss) income attributable to noncontrolling interests									0	0		0
Comprehensive Income Attributable to NRG Yield LLC									46	(5)		18
Non-Guarantor Subsidiaries
Condensed Statement of Income Captions [Line Items]
Net income									179	115		59
Unrealized gain on derivatives									20	16		10
Other comprehensive (loss) income									20	16		10
Comprehensive Income									199	131		69
Less: Comprehensive (loss) income attributable to noncontrolling interests									(69)	(5)		(1)
Comprehensive Income Attributable to NRG Yield LLC									268	136		70
Subsidiary Issuer
Condensed Statement of Income Captions [Line Items]
Net income									132	60		17
Unrealized gain on derivatives									24	17		13
Other comprehensive (loss) income									24	17		13
Comprehensive Income									156	77		30
Less: Comprehensive (loss) income attributable to noncontrolling interests									(105)	(75)		(111)
Comprehensive Income Attributable to NRG Yield LLC									$ 261	$ 152		$ 141
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	Retrospectively adjusted as discussed in Note 1, Nature of Business.
[3]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Condensed Consolidating Finan_6

Condensed Consolidating Financial Information Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Current Assets
Cash and cash equivalents	$ 407	$ 146	[1]	$ 321
Restricted cash	176	168	[1]
Accounts receivable — trade	104	95	[1]
Accounts receivable — affiliates	5	1	[1]
Inventory	40	39	[1]
Notes receivable — current	0	13	[1]
Prepayments and other current assets	29	19	[1]
Total current assets	761	481	[1]
Property, plant and equipment, net	5,245	5,410	[1]
Other Assets
Investment in consolidated subsidiaries	0	0
Equity investments in affiliates	1,172	1,178	[1]
Intangible assets, net	1,156	1,228	[1]
Derivative instruments	8	1	[1]
Other non-current assets	106	62	[1]
Total other assets	2,442	2,469	[1]
Total Assets	8,448	8,360	[1]
Current portion of long-term debt — external	314	339	[1]
Current portion of long-term debt — affiliate	215	0	[1]
Accounts payable — trade	45	46	[1]
Accounts payable — affiliate	20	49	[1]
Derivative instruments	4	18	[1]
Accrued interest expense	44	38	[1]
Accrued expenses and other current liabilities	57	49	[1]
Total current liabilities	699	539	[1]
Other Liabilities
Long-term debt — external	5,404	5,049	[1]
Long-term debt — affiliate	44	618	[1]
Derivative instruments	17	31	[1]
Other non-current liabilities	102	94	[1]
Total non-current liabilities	5,567	5,792	[1]
Total Liabilities	6,266	6,331	[1]
Contributed capital	1,940	1,919	[1]
Retained earnings	86	16	[1]
Accumulated other comprehensive loss	(44)	(68)	[1]
Noncontrolling interest	200	162	[1]
Total Members' Equity	2,182	2,029	[1]	$ 2,389	$ 2,705
Total Liabilities and Members’ Equity	8,448	8,360	[1]
Parent Company
Current Assets
Cash and cash equivalents	298	22
Restricted cash	0	0
Accounts receivable — trade	0	0
Accounts receivable — affiliates	8	1
Inventory	0	0
Notes receivable — current		0
Prepayments and other current assets		0
Total current assets	306	23
Property, plant and equipment, net	0	0
Other Assets
Investment in consolidated subsidiaries	1,676	1,844
Equity investments in affiliates	0	0
Intangible assets, net	0	0
Derivative instruments	0	0
Other non-current assets	0	0
Total other assets	1,676	1,844
Total Assets	1,982	1,867
Current portion of long-term debt — external	0	0
Accounts payable — trade	0	0
Accounts payable — affiliate	0	0
Derivative instruments	0	0
Accrued interest expense	0	0
Accrued expenses and other current liabilities	0
Total current liabilities	0	0
Other Liabilities
Long-term debt — external	0	0
Long-term debt — affiliate	0	0
Derivative instruments	0	0
Other non-current liabilities	0	0
Total non-current liabilities	0	0
Total Liabilities	0	0
Contributed capital	1,940	1,919
Retained earnings	86	16
Accumulated other comprehensive loss	(44)	(68)
Noncontrolling interest	0	0
Total Members' Equity	1,982	1,867
Total Liabilities and Members’ Equity	1,982	1,867
Guarantor Subsidiaries
Current Assets
Cash and cash equivalents	0	0
Restricted cash	0	0
Accounts receivable — trade	1	1
Accounts receivable — affiliates	0	0
Inventory	0	0
Notes receivable — current		0
Prepayments and other current assets		0
Total current assets	1	1
Property, plant and equipment, net	65	59
Other Assets
Investment in consolidated subsidiaries	417	460
Equity investments in affiliates	289	233
Intangible assets, net	11	12
Derivative instruments	0	0
Other non-current assets	0	0
Total other assets	717	705
Total Assets	783	765
Current portion of long-term debt — external	0	0
Current portion of long-term debt — affiliate	0
Accounts payable — trade	1	0
Accounts payable — affiliate	0	0
Derivative instruments	0	0
Accrued interest expense	0	0
Accrued expenses and other current liabilities	0
Total current liabilities	1	0
Other Liabilities
Long-term debt — external	0	0
Long-term debt — affiliate	0	0
Derivative instruments	0	0
Other non-current liabilities	2	2
Total non-current liabilities	2	2
Total Liabilities	3	2
Contributed capital	804	822
Retained earnings	(24)	(58)
Accumulated other comprehensive loss	0	(1)
Noncontrolling interest	0	0
Total Members' Equity	780	763
Total Liabilities and Members’ Equity	783	765
Non-Guarantor Subsidiaries
Current Assets
Cash and cash equivalents	109	124
Restricted cash	176	168
Accounts receivable — trade	103	93
Accounts receivable — affiliates	0	0
Inventory	40	39
Notes receivable — current		13
Prepayments and other current assets	27	18
Total current assets	455	455
Property, plant and equipment, net	5,180	5,351
Other Assets
Investment in consolidated subsidiaries	0	0
Equity investments in affiliates	522	577
Intangible assets, net	1,145	1,216
Derivative instruments	8	1
Other non-current assets	103	62
Total other assets	1,778	1,856
Total Assets	7,413	7,662
Current portion of long-term debt — external	314	339
Current portion of long-term debt — affiliate	0
Accounts payable — trade	36	46
Accounts payable — affiliate	23	33
Derivative instruments	4	18
Accrued interest expense	17	16
Accrued expenses and other current liabilities	53	46
Total current liabilities	447	498
Other Liabilities
Long-term debt — external	3,970	4,153
Long-term debt — affiliate	0	0
Derivative instruments	17	31
Other non-current liabilities	92	85
Total non-current liabilities	4,079	4,269
Total Liabilities	4,526	4,767
Contributed capital	2,708	2,934
Retained earnings	108	(25)
Accumulated other comprehensive loss	(51)	(71)
Noncontrolling interest	122	57
Total Members' Equity	2,887	2,895
Total Liabilities and Members’ Equity	7,413	7,662
Subsidiary Issuer
Current Assets
Cash and cash equivalents	0	0
Restricted cash	0	0
Accounts receivable — trade	0	1
Accounts receivable — affiliates	11	0
Inventory		0
Notes receivable — current		0
Prepayments and other current assets	2	1
Total current assets	13	2
Property, plant and equipment, net	0	0
Other Assets
Investment in consolidated subsidiaries	3,250	3,198
Equity investments in affiliates	361	368
Intangible assets, net	0	0
Derivative instruments	0	0
Other non-current assets	3	0
Total other assets	3,614	3,566
Total Assets	3,627	3,568
Current portion of long-term debt — external	0	0
Accounts payable — trade	8	0
Accounts payable — affiliate	11	16
Derivative instruments	0	0
Accrued interest expense	27	22
Accrued expenses and other current liabilities	4	3
Total current liabilities	265	41
Other Liabilities
Long-term debt — external	1,434	896
Long-term debt — affiliate	44	618
Derivative instruments	0	0
Other non-current liabilities	8	7
Total non-current liabilities	1,486	1,521
Total Liabilities	1,751	1,562
Contributed capital	1,930	2,119
Retained earnings	(210)	(207)
Accumulated other comprehensive loss	(44)	(68)
Noncontrolling interest	200	162
Total Members' Equity	1,876	2,006
Total Liabilities and Members’ Equity	3,627	3,568
Eliminations
Current Assets
Cash and cash equivalents	0	0
Restricted cash	0	0
Accounts receivable — trade	0	0
Accounts receivable — affiliates	(14)	0
Inventory		0
Notes receivable — current		0
Prepayments and other current assets	0	0
Total current assets	(14)	0
Property, plant and equipment, net	0	0
Other Assets
Investment in consolidated subsidiaries	(5,343)	(5,502)
Equity investments in affiliates	0	0
Intangible assets, net	0	0
Derivative instruments	0	0
Other non-current assets	0	0
Total other assets	(5,343)	(5,502)
Total Assets	(5,357)	(5,502)
Current portion of long-term debt — external	0	0
Current portion of long-term debt — affiliate	0
Accounts payable — trade	0	0
Accounts payable — affiliate	(14)	0
Derivative instruments	0	0
Accrued interest expense	0	0
Accrued expenses and other current liabilities	0
Total current liabilities	(14)	0
Other Liabilities
Long-term debt — external	0	0
Long-term debt — affiliate	0	0
Derivative instruments	0	0
Other non-current liabilities	0	0
Total non-current liabilities	0	0
Total Liabilities	(14)	0
Contributed capital	(5,442)	(5,875)
Retained earnings	126	290
Accumulated other comprehensive loss	95	140
Noncontrolling interest	(122)	(57)
Total Members' Equity	(5,343)	(5,502)
Total Liabilities and Members’ Equity	(5,357)	$ (5,502)
Clearway Energy LLC
Other Assets
Current portion of long-term debt — affiliate	0
Clearway Energy Operating LLC
Other Assets
Current portion of long-term debt — affiliate	$ 215
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.

Condensed Consolidating Finan_7

Condensed Consolidating Financial Information Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017		Dec. 31, 2016
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	$ 492	$ 517		$ 577	[1]
Cash Flows from Investing Activities
Changes in investments in consolidated subsidiaries	0	0		0
Acquisition of business, net of cash acquired	(11)	0		0	[1]
Acquisition of Drop Down Assets, net of cash acquired	(126)	(250)		(77)	[1]
Capital expenditures	(83)	(190)		(20)	[1]
Cash receipts from notes receivable	13	17		17	[1]
Return of investment from unconsolidated affiliates	45	47		28	[1]
Investments in unconsolidated affiliates	(34)	(73)		(83)	[1]
Other	11	7		4	[1]
Net Cash Used in Investing Activities	(185)	(442)		(131)	[1]
Cash Flows from Financing Activities
Net contributions from noncontrolling interests	106	13		5	[1]
Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets	0	(23)		(184)	[1]
Transfer of funds under intercompany cash management arrangement	0	0		0
Proceeds from the issuance of Class C units	(153)	(33)		0	[1]
(Payments of) proceeds from distributions	(253)	(202)		(173)
Proceeds from the revolving credit facility	35	55		60	[1]
Payments for the revolving credit facility	(90)	0		(366)	[1]
Proceeds from issuance of long-term debt — external	827	210		740	[1]
Payments for long-term debt — external	(443)	(332)		(269)	[1]
Payments for long-term debt — affiliate	(359)	0		0	[1]
Payments of debt issuance costs	(14)	(12)		(15)	[1]
Net Cash Used in Financing Activities	(38)	(258)		(202)	[1]
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	269	(183)		244	[1]
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	314	497	[1]	253	[1]
Cash, Cash Equivalents and Restricted Cash at End of Period	583	314		497	[1]
Parent Company
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	0	0		0
Cash Flows from Investing Activities
Changes in investments in consolidated subsidiaries	361	(15)		325
Acquisition of Drop Down Assets, net of cash acquired	0	0		0
Capital expenditures	0	0		0
Cash receipts from notes receivable	0	0		0
Return of investment from unconsolidated affiliates	0	0		0
Investments in unconsolidated affiliates	0	0		0
Other	0	0		0
Net Cash Used in Investing Activities	361	(15)		325
Cash Flows from Financing Activities
Net contributions from noncontrolling interests	0	0		0
Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets		0		0
Transfer of funds under intercompany cash management arrangement	0	(5)		44
Proceeds from the issuance of Class C units	(153)	(33)
(Payments of) proceeds from distributions	(238)	(202)		(173)
Proceeds from the revolving credit facility	0	0		0
Payments for the revolving credit facility	0			0
Proceeds from issuance of long-term debt — external	0	0		0
Payments for long-term debt — external	0	0		0
Payments for long-term debt — affiliate	0
Payments of debt issuance costs	0	0		0
Net Cash Used in Financing Activities	(85)	(174)		(129)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	276	(189)		196
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	22	211		15
Cash, Cash Equivalents and Restricted Cash at End of Period	298	22		211
Guarantor Subsidiaries
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	23	51		67
Cash Flows from Investing Activities
Changes in investments in consolidated subsidiaries	0	0		0
Acquisition of business, net of cash acquired	0
Acquisition of Drop Down Assets, net of cash acquired	0	0		0
Capital expenditures	0	0		0
Cash receipts from notes receivable	0	0		0
Return of investment from unconsolidated affiliates	11	10		16
Investments in unconsolidated affiliates	(34)	(64)		(80)
Other	0	0		0
Net Cash Used in Investing Activities	(23)	(54)		(64)
Cash Flows from Financing Activities
Net contributions from noncontrolling interests	0	0		0
Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets		30		(3)
Transfer of funds under intercompany cash management arrangement	0	0		2
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		0
Payments for the revolving credit facility	0			0
Proceeds from issuance of long-term debt — external	0	0		0
Payments for long-term debt — external	0	(36)		(3)
Payments for long-term debt — affiliate	0
Payments of debt issuance costs	0	0		0
Net Cash Used in Financing Activities	0	(6)		(4)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	0	(9)		(1)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	0	9		10
Cash, Cash Equivalents and Restricted Cash at End of Period	0	0		9
Non-Guarantor Subsidiaries
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	550	537		549
Cash Flows from Investing Activities
Changes in investments in consolidated subsidiaries	0	0		(21)
Acquisition of business, net of cash acquired	0
Acquisition of Drop Down Assets, net of cash acquired	0	0		0
Capital expenditures	(83)	(190)		(20)
Cash receipts from notes receivable	13	17		17
Return of investment from unconsolidated affiliates	20	14		0
Investments in unconsolidated affiliates	0	(7)		(3)
Other	11	7		4
Net Cash Used in Investing Activities	(39)	(159)		(23)
Cash Flows from Financing Activities
Net contributions from noncontrolling interests	97	2		0
Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets		(46)		(171)
Transfer of funds under intercompany cash management arrangement	4	(1)		0
Proceeds from the issuance of Class C units	0	0
(Payments of) proceeds from distributions	(400)	(220)		(420)
Proceeds from the revolving credit facility	0	0		0
Payments for the revolving credit facility	0			0
Proceeds from issuance of long-term debt — external	227	210		390
Payments for long-term debt — external	(443)	(296)		(266)
Payments for long-term debt — affiliate	0
Payments of debt issuance costs	(3)	(12)		(10)
Net Cash Used in Financing Activities	(518)	(363)		(477)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	(7)	15		49
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	292	277		228
Cash, Cash Equivalents and Restricted Cash at End of Period	285	292		277
Subsidiary Issuer
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by Operating Activities	(81)	(71)		(39)
Cash Flows from Investing Activities
Changes in investments in consolidated subsidiaries	(361)	15		(304)
Acquisition of Drop Down Assets, net of cash acquired	(126)	(250)		(77)
Capital expenditures	0	0		0
Cash receipts from notes receivable	0	0		0
Return of investment from unconsolidated affiliates	14	23		12
Investments in unconsolidated affiliates	0	(2)		0
Other	0	0		0
Net Cash Used in Investing Activities	(484)	(214)		(369)
Cash Flows from Financing Activities
Net contributions from noncontrolling interests	9	11		5
Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets		(7)		(10)
Transfer of funds under intercompany cash management arrangement	(4)	6		(46)
Proceeds from the issuance of Class C units	0	0
(Payments of) proceeds from distributions	385	220		420
Proceeds from the revolving credit facility	35	55		60
Payments for the revolving credit facility	(90)			(366)
Proceeds from issuance of long-term debt — external	600	0		350
Payments for long-term debt — external	0	0		0
Payments for long-term debt — affiliate	(359)
Payments of debt issuance costs	(11)	0		(5)
Net Cash Used in Financing Activities	565	285		408
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	0	0		0
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	0	0		0
Cash, Cash Equivalents and Restricted Cash at End of Period	0	$ 0		$ 0
Clearway Energy LLC
Cash Flows from Investing Activities
Acquisition of business, net of cash acquired	0
Clearway Energy Operating LLC
Cash Flows from Investing Activities
Acquisition of business, net of cash acquired	$ (11)
[1]	Retrospectively adjusted as discussed in Note 1, Nature of Business.