Clearway Energy (CWEN.A) 10-K 1 Mar 21 2020 FY Annual report Financial data

Cover

Cover - USD ($)	12 Months Ended
	Dec. 31, 2020	Jan. 31, 2021	Jun. 30, 2020
Class of Stock [Line Items]
Document Type	10-K
Document Annual Report	true
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	333-203369
Entity Registrant Name	Clearway Energy LLC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	32-0407370
Entity Address, Address Line One	300 Carnegie Center, Suite 300
Entity Address, City or Town	Princeton
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	08540
City Area Code	609
Local Phone Number	608-1525
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
ICFR Auditor Attestation Flag	true
Entity Public Float			$ 0
Entity Central Index Key	0001637757
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Document Period End Date	Dec. 31, 2020
Common Class A
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		34,599,645
Common Class B
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		42,738,750
Common Class C
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		81,635,540
Common Class D
Class of Stock [Line Items]
Entity Common Stock, Shares Outstanding		42,738,750

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Revenues
Total operating revenues	$ 1,199	$ 1,032	$ 1,053
Operating Costs and Expenses
Cost of operations	366	337	327
Depreciation, amortization and accretion	428	401	336
Tangible Asset Impairment Charges	24	33	0
General and administrative	33	27	20
Transaction and integration costs	9	3	20
Development costs	5	5	3
Total operating costs and expenses	865	806	706
Operating Income	334	226	347
Other Income (Expense)
Equity in earnings of unconsolidated affiliates	7	83	74
Impairment loss on investment	(8)	0	0
Gain on sale of unconsolidated affiliate	49	0	0
Other income, net	4	9	8
Loss on debt extinguishment	(24)	(16)	0
Interest expense	(414)	(403)	(294)
Total other expense, net	(386)	(327)	(212)
Net (Loss) Income	(52)	(101)	135
Less: Net loss attributable to noncontrolling interests		(71)	(105)
Net Income (Loss) Attributable to Clearway Energy LLC	$ 61	$ (30)	$ 240

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (52)	$ (101)	$ 135
Other Comprehensive Income (Loss)
Unrealized gain on derivatives	2	8	24
Other comprehensive income	2	8	24
Comprehensive (Loss) Income	(50)	(93)	159
Less: Comprehensive loss attributable to noncontrolling interests	(115)	(70)	(105)
Comprehensive Income (Loss) Attributable to Clearway Energy LLC	$ 65	$ (23)	$ 264

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Current Assets
Cash and cash equivalents	$ 268	$ 152
Restricted cash	197	262
Accounts receivable — trade	143	116
Accounts receivable — affiliates	0	2
Inventory	42	40
Prepayments and other current assets	58	33
Total current assets	708	605
Property, plant and equipment, net	7,217	6,063
Other Assets
Equity investments in affiliates	741	1,183
Intangible assets, net	1,370	1,428
Derivative instruments	1	0
Right-of-use assets, net	337	223
Other non-current assets	114	103
Total other assets	2,563	2,937
Total Assets	10,488	9,605
Current Liabilities
Current portion of long-term debt — external	384	1,780
Current portion of long-term debt — affiliate	1	44
Accounts payable — trade	72	73
Accounts payable — affiliates	20	33
Derivative instruments	38	16
Accrued interest expense	44	41
Accrued expenses and other current liabilities	79	71
Total current liabilities	638	2,058
Other Liabilities
Long-term debt — external	6,585	4,956
Derivative instruments	135	76
Long-term lease liabilities	345	227
Other non-current liabilities	173	115
Total non-current liabilities	7,238	5,374
Total Liabilities	7,876	7,432
Commitments and Contingencies	0	0
Members' Equity
Contributed capital	1,723	1,882
(Accumulated deficit) retained earnings	(50)	5
Accumulated other comprehensive loss	(33)	(37)
Noncontrolling interest	972	323
Total Members' Equity	2,612	2,173
Total Liabilities and Members’ Equity	$ 10,488	$ 9,605

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash Flows from Operating Activities
Net (loss) income	$ (52)	$ (101)	$ 135
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Equity in earnings of unconsolidated affiliates	(7)	(83)	(74)
Distributions from unconsolidated affiliates	61	34	70
Depreciation, amortization and accretion	428	401	336
Amortization of financing costs	15	15	13
Amortization of intangibles and out-of-market contracts	90	71	70
Loss on debt extinguishment	24	16	0
Reduction in carrying amount of right-of-use assets	4	7	0
Gain on sale of unconsolidated affiliate	(49)	0	0
Impairment losses	32	33	0
Changes in derivative instruments	44	85	(16)
Loss on disposal of asset components	3	9	0
Changes in prepaid and accrued liabilities for tolling agreements	(1)	1	0
Changes in other working capital	(47)	(19)	(42)
Net Cash Provided by Operating Activities	545	469	492
Cash Flows from Investing Activities
Acquisitions	0	(100)	(11)
Partnership interest acquisition	0	(29)	0
Acquisition of Drop Down Assets, net of cash acquired	(122)	(161)	(126)
Capital expenditures	(124)	(228)	(83)
Buyout of Wind TE Holdco non-controlling interest	0	(19)	0
Cash receipts from notes receivable	0	0	13
Return of investment from unconsolidated affiliates	79	56	45
Investments in unconsolidated affiliates	(11)	(13)	(34)
Proceeds from sale of assets	90	20	0
Consolidation of DGPV Holdco 3 LLC	17	0	0
Other	9	6	11
Net Cash Used in Investing Activities	(62)	(468)	(185)
Cash Flows from Financing Activities
Net contributions from noncontrolling interests	247	174	91
Buyout of Repowering Partnership II LLC noncontrolling interest	(70)	0	0
Proceeds from the issuance of class C units	62	100	153
Payments of distributions	(211)	(155)	(238)
Proceeds from the revolving credit facility	265	152	35
Payments for the revolving credit facility	(265)	(152)	(90)
Proceeds from issuance of long-term debt — external	1,084	1,215	827
Proceeds from issuance of long-term debt — affiliate	3	0	0
Payments of debt issuance costs	(20)	(25)	(14)
Payments for long-term debt — external	(1,482)	(1,264)	(443)
Payments for long-term debt — affiliate	(45)	(215)	(359)
Net Cash Used in Financing Activities	(432)	(170)	(38)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	51	(169)	269
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	414	583	314
Cash, Cash Equivalents and Restricted Cash at End of Period	465	414	583
Supplemental Disclosures
Interest paid, net of amount capitalized	(325)	(307)	(292)
Non-cash investing and financing activities:
Reductions to fixed assets for accrued capital expenditures	$ (18)	(2)	(15)
Non-cash contributions from CEG, NRG, net of distributions		$ 35	$ 36

Consolidated Statements of Memb

Consolidated Statements of Members' Equity - USD ($) $ in Millions	Total	Wind TE Holdco	Carlsbad	DGPV	Mesquite Star	Langford	Raymond Central	Repowering Partnership II LLC	Cumulative Effect, Period of Adoption, Adjustment	NRG	CEG	Clearway Energy, Inc.	Tax Equity Investors	Contributed Capital	Contributed CapitalWind TE Holdco	Contributed CapitalCarlsbad	Contributed CapitalDGPV	Contributed CapitalMesquite Star	Contributed CapitalLangford	Contributed CapitalRaymond Central	Contributed CapitalRepowering Partnership II LLC	Contributed CapitalNRG	Contributed CapitalCEG	Contributed CapitalClearway Energy, Inc.	(Accumulated Deficit) Retained Earnings	(Accumulated Deficit) Retained EarningsCumulative Effect, Period of Adoption, Adjustment	(Accumulated Deficit) Retained EarningsNRG	(Accumulated Deficit) Retained EarningsCEG	(Accumulated Deficit) Retained EarningsClearway Energy, Inc.	Accumulated Other Comprehensive Loss	Noncontrolling Interest	Noncontrolling InterestWind TE Holdco	Noncontrolling InterestDGPV	Noncontrolling InterestMesquite Star	Noncontrolling InterestRaymond Central	Noncontrolling InterestRepowering Partnership II LLC	Noncontrolling InterestNRG	Noncontrolling InterestCEG	Noncontrolling InterestTax Equity Investors
Balance, beginning of period at Dec. 31, 2017	$ 2,029													$ 1,919											$ 16					$ (68)	$ 162
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	135																								240						(105)
Unrealized gain on derivatives	24																													24
Payment for Drop Down Assets	(52)													(52)
Capital contributions from tax equity investors/Contributions from noncontrolling interests, net of distributions, cash	106																														106
Distributions paid to NRG, net of contributions										$ (11)												$ (11)
Proceeds from the issuance of Class C Common Stock/Net proceeds from the sales of units, Clearway Energy, Inc	153													153
Distributions paid										(108)		$ (130)												$ (68)			$ (108)		$ (62)
Contributions net of distributions, non-cash										$ 36												$ (1)															$ 37
Balance, end of period at Dec. 31, 2018	2,182								$ (3)					1,940											86	$ (3)				(44)	200
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(101)																								(30)						(71)
Unrealized gain on derivatives	7																													7
Payment for Drop Down Assets		$ (19)	$ (35)												$ (9)	$ (35)																$ (10)
Proceeds from the issuance of Class C Common Stock/Net proceeds from the sales of units, Clearway Energy, Inc	100													100
Distributions paid											$ (68)												$ (38)					$ (30)
Contributions net of distributions, non-cash	35													7											4						24
Distributions paid to Clearway Energy, Inc., cash	(87)													(65)											(22)
Distributions paid to Clearway Energy, Inc., non-cash	(13)													(13)
Contributions to tax equity non-controlling interests, net of distributions, cash	243													(5)																	248
Distributions to CEG, net of contributions, cash											(68)																											$ (68)
Balance, end of period at Dec. 31, 2019	2,173													1,882											5					(37)	323
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(52)																								61						(113)
Unrealized gain on derivatives	2																													4	(2)
Payment for Drop Down Assets				$ (20)	$ 361	$ (44)	$ 55	$ (70)									$ (33)	$ 15	$ (44)	$ 3	$ (60)												$ 13	$ 346	$ 52	$ (10)
Capital contributions from tax equity investors/Contributions from noncontrolling interests, net of distributions, cash											6		$ 361																									6	$ 361
Proceeds from the issuance of Class C Common Stock/Net proceeds from the sales of units, Clearway Energy, Inc	62													62
Distributions paid											(121)	$ (90)											(59)	$ (36)				$ (62)	$ (54)									0
Contributions net of distributions, non-cash											$ 7												$ 8															$ (1)
Lighthouse Partnership Yield Protection Agreement	(15)													(15)
Balance, end of period at Dec. 31, 2020	$ 2,612													$ 1,723											$ (50)					$ (33)	$ 972

Segment Reporting

Segment Reporting	12 Months Ended
	Dec. 31, 2020
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, 2020, 2019 and 2018: 2020 2019 2018 Customer Conventional Renewables Conventional Renewables Conventional Renewables SCE 18% 16% 21% 19% 20% 20% PG&E 10% 8% 12% 10% 12% 11% Year ended December 31, 2020 (In millions) Conventional Generation Renewables Thermal Corporate (a) Total Operating revenues $ 437 $ 569 $ 193 $ — $ 1,199 Cost of operations 90 147 131 (2) 366 Depreciation, amortization and accretion 132 264 32 — 428 Impairment losses — 24 — — 24 General and administrative — — 3 30 33 Transaction and integration costs — — — 9 9 Development costs — — 5 — 5 Operating income (loss) 215 134 22 (37) 334 Equity in earnings (losses) of unconsolidated affiliates 8 (1) — — 7 Impairment loss on investment — (8) — — (8) Gain on sale of unconsolidated affiliates — — — 49 49 Other income, net 1 4 — (1) 4 Loss on debt extinguishment — (21) — (3) (24) Interest expense, net (84) (216) (19) (95) (414) Net Income (Loss) 140 (108) 3 (87) (52) Net Income (Loss) Attributable to Clearway Energy LLC $ 140 $ 4 $ 3 $ (86) $ 61 Balance Sheet Equity investment in affiliates $ 90 $ 651 $ — $ — $ 741 Capital expenditures (b) 12 44 50 — 106 Total Assets $ 2,575 $ 7,157 $ 627 $ 129 $ 10,488 (a) Includes eliminations (b) Includes accruals Year ended December 31, 2019 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues $ 346 $ 485 $ 201 $ — $ 1,032 Cost of operations 60 143 134 — 337 Depreciation amortization and accretion 103 271 27 — 401 Impairment losses — 14 19 — 33 General and administrative — 1 3 23 27 Transaction and integration costs — — — 3 3 Development costs — — 5 — 5 Operating income (loss) 183 56 13 (26) 226 Equity in earnings of unconsolidated affiliates 9 74 — — 83 Other income, net 2 6 — 1 9 Loss on debt extinguishment — (1) — (15) (16) Interest expense, net (59) (239) (18) (87) (403) Net Income (Loss) 135 (104) (5) (127) (101) Net Income (Loss) Attributable to Clearway Energy LLC $ 135 $ (33) $ (5) $ (127) $ (30) Balance Sheet Equity investments in affiliates $ 94 $ 1,089 $ — $ — $ 1,183 Capital expenditures (a) 4 185 34 — 223 Total Assets $ 2,753 $ 6,186 $ 633 $ 33 $ 9,605 (a) Includes accruals. Year ended December 31, 2018 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues $ 337 $ 523 $ 193 $ — $ 1,053 Cost of operations 61 139 127 — 327 Depreciation amortization and accretion 102 211 23 — 336 General and administrative — — 1 19 20 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, net (51) (154) (12) (77) (294) Net Income (Loss) 135 86 29 (115) 135 Net Income (Loss) Attributable to Clearway Energy LLC $ 135 $ 190 $ 29 $ (114) $ 240

Nature of Business

Nature of Business	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business	Nature of Business Clearway Energy LLC, together with its consolidated subsidiaries, or the Company, is an investor in and owner of modern, sustainable and long-term contracted assets across North America. On August 31, 2018, NRG Energy, Inc., or NRG, transferred its full ownership interest in the Company 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 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 Clearway, Inc. GIP is an independent fund manager that invests in infrastructure assets in energy and transport sectors. The Company is sponsored by GIP through its portfolio company, CEG. The Company is one of the largest renewable energy owners in the U.S. with over 4,200 net MW of installed wind and solar generation projects. The Company also owns approximately 2,500 net MW of environmentally-sound, highly efficient generation facilities as well as a portfolio of district energy systems. Through this environmentally-sound, diversified and primarily contracted portfolio, the Company endeavors to provide its investors with stable and growing dividend income. Substantially all of the Company's generation assets are under long-term contractual arrangements for the output or capacity from these assets. Clearway Energy, Inc. consolidates the results of the Company through its controlling interest, with CEG's interest shown as non-controlling interest in the financial statements. The holders of Clearway, Inc.'s outstanding shares of Class A and Class C common stock are entitled to dividends as declared. CEG receives its distributions from the Company through its ownership of the Company's Class B and Class D units. As a result of the Clearway, Inc. Class C common stock issuances during the year ended December 31, 2020, Clearway, Inc. currently owns 57.61% of the economic interests of the Company, with CEG retaining 42.39% of the economic interests of the Company. For further discussion, see Item 15 — Note 11, Members' Equity. The following table represents the structure of the Company as of December 31, 2020:

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
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 $149 million and $125 million as of December 31, 2020 and 2019, 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, 2020 2019 (In millions) Cash and cash equivalents $ 268 $ 152 Restricted cash 197 262 Cash, cash equivalents and restricted cash shown in the statements of cash flows $ 465 $ 414 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, 2020, these restricted funds comprised of $73 million designated to fund operating expenses, approximately $24 million designated for current debt service payments, and $45 million restricted for reserves including debt service, performance obligations and other reserves, as well as capital expenditures. The remaining $55 million is held in distributions reserve accounts. Accounts Receivable — Trade and Allowance for Doubtful Accounts Accounts receivable — trade 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, 2020 and 2019. 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. Construction in-progress represents cumulative construction costs, including the costs incurred for the purchase of major equipment and engineering costs and capitalized interest. Once the project achieves commercial operation, the Company reclassifies the amounts recorded in construction in progress to facilities and equipment. 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 their carrying values may not be recoverable. Such reviews are performed in accordance with ASC 360. An impairment loss is indicated if the total future estimated undiscounted cash flows expected from an asset are less than its carrying value. An impairment charge is measured by the difference between an asset's carrying amount and fair value with the difference recorded in operating costs and expenses in the statements of operations. Fair values are determined by a variety of valuation methods, including appraisals, sales prices of similar assets and present value techniques. For further discussion of the Company's long-lived asset impairments, refer to Note 9, Asset Impairments, to the Consolidated Financial Statements. Investments accounted for by the equity method are reviewed for impairment in accordance with ASC 323, Investments-Equity Method and Joint Ventures , which requires that a loss in value of an investment that is an other-than-temporary decline should be recognized. The Company identifies and measures losses in the value of equity method investments based upon a comparison of fair value to carrying value. Debt Issuance Costs Debt issuance costs are capitalized and amortized as interest expense on a basis which approximates the effective interest method over the term of the related debt. Debt issuance costs related to the long term debt are presented as a direct deduction from the carrying amount of the related debt in both the current and prior periods. Debt issuance costs related to the senior secured revolving credit facility line of credit are recorded as a non-current asset on the balance sheet and are amortized over the term of the credit facility. Intangible Assets Intangible assets represent contractual rights held by the Company. The Company recognizes specifically identifiable intangible assets including power purchase agreements, leasehold rights, 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. Previously ASC 840, and currently, ASC 842, 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, 2020, 2019 and 2018 was $589 million, $537 million and $583 million, respectively. See Note 15, Leases for additional information related to the Company's PPAs accounted for as leases. 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. Disaggregated Revenues The following tables represent the Company’s disaggregation of revenue from contracts with customers for the year ended December 31, 2020, along with the reportable segment for each category: Year ended December 31, 2020 (In millions) Conventional Generation Renewables Thermal Total Energy revenue (a) $ 10 $ 609 $ 101 $ 720 Capacity revenue (a) 451 — 63 514 Other revenues — 21 32 53 Contract amortization (24) (61) (3) (88) Total operating revenue 437 569 193 1,199 Less: Lease revenue (461) (554) (2) (1,017) Less: Contract amortization 24 61 3 88 Total revenue from contracts with customers $ — $ 76 $ 194 $ 270 (a) See Note 17, Leases for the amounts of energy and capacity revenue that relate to leases and are accounted for under ASC 842. The following tables represent the Company’s disaggregation of revenue from contracts with customers for the year ended December 31, 2019, along with the reportable segment for each category: Year ended December 31, 2019 (In millions) Conventional Generation Renewables Thermal Total Energy revenue (a) $ 5 $ 545 $ 120 $ 670 Capacity revenue (a) 348 — 54 402 Other revenues — 10 30 40 Contract amortization (7) (61) (3) (71) Mark-to-market for economic hedges — (9) — (9) Total operating revenue 346 485 201 1,032 Less: Lease revenue (353) (509) (2) (864) Less: Contract amortization 7 61 3 71 Total revenue from contracts with customers $ — $ 37 $ 202 $ 239 (a) See Note 17, Leases for the amounts of energy and capacity revenue that relate to leases and are accounted for under ASC 840 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 Total Energy revenue (a) $ 5 $ 572 $ 120 $ 697 Capacity revenue (a) 337 — 50 387 Other revenues — 13 26 39 Contract amortization (5) (62) (3) (70) Total operating revenue 337 523 193 1,053 Less: Lease revenue (342) (534) (2) (878) Less: Contract amortization 5 62 3 70 Total revenue from contracts with customers $ — $ 51 $ 194 $ 245 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 net amount of contract assets and liabilities included on the Company’s balance sheet as of December 31, 2020: (In millions) December 31, 2020 December 31, 2019 Accounts receivable, net - Contracts with customers $ 57 $ 34 Accounts receivable, net - Leases 86 82 Total accounts receivable, net $ 143 $ 116 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 analysis to measure the statistical correlation between the derivative and the associated hedged item to 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 industries. 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 Company's Business, 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, 2020 and 2019, along with the additions and accretion related to the Company's ARO obligations for the year ended December 31, 2020: (In millions) Balance as of December 31, 2019 $ 75 Revisions in estimates for current obligations 9 Additions 26 Accretion — expense 7 Balance as of December 31, 2020 $ 117 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 business acquisitions that relate to entities under common control, ASC 805 requires retrospective combination of the entities for all annual periods presented as if the combination has been in effect from the beginning of the earliest financial statement period presented or from the date the entities were under common control (if later than the beginning of the earliest financial statement period). The difference between the cash paid and historical value of the entities' equity is recorded as a distribution/contribution from/to CEG with the offset to noncontrolling interest. 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, AROs, 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 solar energy systems, under operating leases or PPAs, that are eligible for certain tax credits. The Company has determined that the provisions in the contractual agreements of these structures represent substantive profit sharing arrangements. Further, the Company has determined that the appropriate methodology for calculating the noncontrolling interest and investment in unconsolidated affiliates that reflects the substantive profit sharing arrangements is a balance sheet approach utilizing the hypothetical liquidation at book value, or HLBV, method. Under the HLBV method, the amounts reported as noncontrolling interests and investment in unconsolidated affiliates represent the amounts the investors to the tax equity arrangements would hypothetically receive at each balance sheet date under the liquidation provisions of the contractual agreements, assuming the net assets of the funding structures were liquidated at their recorded amounts determined in accordance with GAAP. The investors’ interests in the results of operations of the funding structures are determined as the difference in noncontrolling interests and investment in unconsolidated affiliates at the start and end of each reporting period, after taking into account any capital transactions between the structures and the funds’ investors. The calculations utilized to apply the HLBV method include estimated calculations of taxable income or losses for each reporting period. Reclassification Certain prior year amounts have been reclassified for comparative purposes. Recently Adopted Accounting Standards In March 2020, the FASB issued ASU No. 2020-4, Facilitation of the Effects of Reference Rate Reform on Financial Reporting. The amendments provide for optional expedients and exceptions for applying GAAP to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria is met. These amendments apply only to contracts that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. The guidance is effective for all entities as of March 12, 2020 through December 31, 2022. The Company intends to apply the amendments to all its eligible contract modifications where applicable during the reference rate reform period. As of December 31, 2020, the Company has not elected any optional expedients provided in the standard. Effective January 1, 2019, the Company adopted ASU No. 2016-02, Leases (Topic 842), or Topic 842 using the modified retrospective transition method. The Company elected available practical expedients permitted under the transition guidance within the new standard, which among other items, allowed the Company to carry forward its historical lease classification and not reassess existing leases under the new definition of a lease in ASC 842. In addition, the Company also elected to account for lease and non-lease components as a single lease component. The adoption of the standard resulted in the recording of operating lease liabilities of $165 million and related ROU assets of $159 million. There was no impact to the Company’s consolidated statement of operations or cash flows. Recently Issued Accounting Standards Not Yet Adopted In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. The amendments in this ASU simplify the accounting for income taxes by removing certain exceptions to the general principles in Topic 740, Income Taxes. The amendments also improve consistent application of and simplify GAAP for other areas of Topic 740 by clarifying and amending existing guidance. The guidance is effective January 1, 2021, with early adoption permitted. The Company does not expect the effect of the new guidance to be material on its consolidated financial statements.

Acquisitions and Dispositions

Acquisitions and Dispositions	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Acquisitions and Dispositions	Acquisitions and Dispositions 2021 Acquisitions Rattlesnake Drop Down — On January 12, 2021, the Company acquired 100% of CEG's equity interest and a third party investor's minority interest in Rattlesnake Flat, LLC, which owns the Rattlesnake Wind Project, a 160 net MW wind facility located in Adams County, WA for $132 million in cash consideration. Agua Caliente Acquisition — On February 3, 2021, the Company acquired an additional 35% equity interest in the Agua Caliente solar project from NRG Energy, Inc. for $202 million. Agua Caliente is a 290 MW solar project located in Dateland, Arizona in which Clearway previously owned a 16% equity interest. The project has a 25-year PPA with PG&E, with approximately 19 years remaining under the agreement. Following the close of the transaction, the Company owns a 51% equity interest in Agua Caliente. The Company will remove its equity method investment and consolidate its interest in Agua Caliente from the date of the acquisition. 2020 Acquisitions Langford Drop Down — On November 20, 2020, the Company acquired 100% of the Class B membership interest in Langford Holding LLC from CEG for $55 million as well as a minority interest from a third party investor for $9 million. Langford Holding LLC indirectly consolidates its interest in the Langford wind project as further described in Note 5, Investments Accounted for by the Equity Method and Variable Interest Entities. The Langford project is a 160 MW wind project located in West Texas which achieved repowering commercial operations in November 2020. The Langford operations are included in the Company's Renewables segment and the acquisition was funded with cash on hand. The acquisition was determined to be an asset acquisition and not a business combination, therefore the Company consolidated the financial information for Langford on a prospective basis. The membership interests acquired by the Company relate to interests under common control by GIP and were recorded at historical cost, which reflects GIP's basis recorded at fair value. The difference between the cash paid of $64 million and the historical value of the Company's acquired interests of $21 million was recorded as an adjustment to contributed capital. The following is a summary of assets and liabilities transferred in connection with the acquisition as of November 20, 2020: (In millions) Langford Current Assets $ 4 Property, plant and equipment, net 138 Other non-current assets 15 Total assets 157 Other current and non-current liabilities 17 Total liabilities 17 Noncontrolling interests 119 Net assets less noncontrolling interests $ 21 Rosamond Central Drop Down — On December 21, 2020, Rosamond Solar Investment LLC, a subsidiary of the Company, acquired 100% of the Class A membership interests of Rosie TargetCo LLC from Renew Development HoldCo LLC, a subsidiary of CEG, for $23 million in cash consideration and an additional $1 million adjustment concurrent with the tax equity investor's final funding which was paid in January 2021. Rosie Target Co LLC is the primary beneficiary and consolidates its interest in a tax equity fund that owns the 192 MW Rosamond Central solar project, located in Kern County, California as further described in Note 5, Investments Accounted for by the Equity Method and Variable Interest Entities . The Rosamond Central operations are included in the Company's Renewables segment. The acquisition was determined to be an asset acquisition and not a business combination, and therefore, the Company consolidated the financial information for Rosamond Central on a prospective basis. The membership interests acquired by the Company relate to interests under common control by GIP and were recorded at historical cost. The difference between the cash paid of $24 million and the historical value of the Company's acquired interests of $28 million was recorded as an adjustment to contributed capital. The following is a summary of assets and liabilities transferred in connection with the acquisition as of December 21, 2020: (In millions) Rosamond Central Current Assets $ 49 Property, plant and equipment, net 246 Other non-current assets 1 Total assets 296 Long-term debt 205 Other current and non-current liabilities 11 Total liabilities 216 Noncontrolling interests 52 Net assets less noncontrolling interests $ 28 Mesquite Star Drop Down — On September 1, 2020, the Company, through its indirect subsidiary Lighthouse Renewable Class A LLC, acquired the Class A membership interests in Lighthouse Renewable Holdco LLC (formerly Mesquite Star Pledgor LLC) from Clearway Renew LLC, a subsidiary of CEG, for $74 million in cash consideration inclusive of a purchase price adjustment received in the fourth quarter of 2020 concurrent with the partnership amendment referenced below. Lighthouse Renewable Holdco LLC indirectly owns 100% of the Class B membership interests in Mesquite Star Tax Equity Holdco LLC, a tax equity partnership that it consolidates as the primary beneficiary, and owns the Mesquite Star wind project, a 419 MW utility scale wind project located in Fisher County, Texas. A majority of the project’s output is backed by contracts with investment grade counterparties with a 12 year weighted average contract life. The Mesquite Star operations are reflected in the Company's Renewables segment and the acquisition was funded with cash on hand. The Company initially recorded its interest in Lighthouse Renewable Class A LLC as an equity method investment. The membership interests acquired by the Company relate to interests under common control by GIP and were recorded at historical cost. The difference between the $74 million cash paid and the historical value of the Company's acquired interests of $83 million was recorded as an adjustment to contributed capital. On December 21, 2020, Clearway Renew LLC sold the Class B membership interest in Lighthouse Renewable Holdco LLC to a third party investor as further described in Note 5, Investments Accounted for by the Equity Method and Variable Interest Entities. The investor and the Company amended the terms of the related partnership and as a result, the Company now consolidates its interest in the Mesquite Star wind project, through its consolidation of Lighthouse Renewable Holdco LLC. The membership interests acquired by the Company relate to interests under common control by GIP and were recorded at historical cost. The difference between the carrying value of the Company's equity method investment of $58 million and the historical value of the net assets consolidated for Mesquite Star of $63 million was recorded as an adjustment to contributed capital. The following table shows the balances that were consolidated effective on December 21, 2020: (In millions) Mesquite Star Current assets $ 22 Property, plant and equipment, net 443 Other non-current assets 31 Total assets 496 Other current and non-current liabilities 87 Total liabilities 87 Noncontrolling interests and redeemable noncontrolling interests 346 Net assets less noncontrolling interests $ 63 DG Residual Interest and SREC Contract Drop Down — On November 2, 2020, the Company acquired the Class B membership interests in DGPV Holdco 1, DGPV Holdco 2 and DGPV Holdco 3, or DGPV Holdco Entities, from Renew DG Holdings LLC, a subsidiary of CEG, for approximately $20 million in cash consideration and an SREC contract for approximately $24 million in cash consideration. The Company previously held the Class A membership interests in the DGPV Holdco Entities and accounted for its interests in DGPV Holdco 1 and DGPV Holdco 2 as equity method investments, while DGPV Holdco 3 was consolidated by the Company effective May 29, 2020 as further described in Note 5, Investments Accounted for by the Equity Method and Variable Interest Entities . Subsequent to the acquisition of the remaining interests in the DGPV Holdco Entities, the Company transferred its interests to DG-CS Master Borrower LLC, and issued debt that was utilized to repay existing project-level debt outstanding and unwind interest rate swaps for certain of the tax equity arrangements related to the underlying project funds, as further described in Note 10, Long-term Debt . The acquired SREC contract is a contract to receive incremental cash flows related to renewable energy credits from certain underlying solar projects. The membership interests acquired by the Company relate to interests under common control by GIP and were recorded at historical cost, which reflects GIP's basis recorded at fair value. The difference between the cash paid for the residual interest of the DGPV Holdco Entities and the historical value of the net assets consolidated less the carrying value of the equity method investments was recorded as an adjustment to contributed capital. The following table shows the balances that were consolidated: November 2, 2020 May 29, 2020 (In millions) DGPV Holdco 1 and 2 (a) DGPV Holdco 3 (b) Current assets $ 29 $ 32 Property, plant and equipment, net 324 331 Intangible assets, net 19 1 Other non-current assets 52 37 Total assets 424 401 Long-term debt 160 206 Other current and non-current liabilities 54 84 Total liabilities 214 290 Noncontrolling interests and redeemable noncontrolling interests 5 6 Net assets less noncontrolling interests $ 205 $ 105 (a) Includes DGPV 1, LLC, DGPV 2, LLC, CA Fund, LLC, DGPV 4 Borrower LLC and Puma Class B LLC (b) Includes Renew Solar CS4 Fund LLC and Chestnut Fund LLC The fair value of property, plant and equipment determined at GIP's acquisition date was determined primarily based on an income method using discounted cash flows and validated using a cost approach based on the replacement cost of the assets less economic depreciation. This methodology was utilized as the forecasted cash flows incorporate specific attributes of each asset including age, useful life, equipment condition and technology. The fair value of intangible assets was determined utilizing a variation of the income approach determined by discounting incremental cash flows associated with the contracts to present value. Primary assumptions utilized included estimates of generation, contractual prices, operating expenses and the weighted average cost of capital reflective of a market participant. These assumptions are considered to be a Level 3 measurement as defined in ASC 820, as they utilize inputs that are not observable in the market. 2019 Acquisitions Duquesne University District Energy System Acquisition — On May 1, 2019, the Company, through its indirect subsidiary ECP Uptown Campus LLC, acquired the Duquesne University district energy system, totaling 87 combined MWt, located in Pittsburgh, PA. As part of the acquisition, Duquesne University entered into a 40-year Energy Services Agreement through which ECP Uptown Campus LLC will fulfill the university's electricity, chilled water and steam requirements in exchange for monthly capacity payments. The Duquesne University District Energy System operations are reflected in the Company's Thermal segment. The total investment for the project was approximately $107 million. Carlsbad Drop Down — On December 6, 2019, the Company acquired 100% of GIP's membership interests in CBAD Holdings, LLC, which indirectly owns Carlsbad Energy Center LLC, a 527 MW natural gas fired power project located in Carlsbad, California, or the Carlsbad Drop Down Asset. The project has a 20-year power purchase and tolling agreement with San Diego Gas and Electric Company, which expires in 2038. The purchase price for the Carlsbad Drop Down was $184 million in cash, plus assumption of $803 million in project level financing including non-recourse senior notes, as further described in Note 10, Long-term Debt . The acquisition was funded with proceeds from the Clearway Energy, Inc. equity issuance, as described in Note 11, Members' Equity , as well as borrowings from the Company's revolving credit facility. The Carlsbad acquisition is the result of the Company having elected its option to purchase Carlsbad pursuant to the ROFO agreement, as amended, by and among the Company, CEG and GIP. The Carlsbad operations are reflected in the Company's Conventional segment. The assets and liabilities transferred to the Company relate to interests under common control by GIP and were recorded at historical cost in accordance with ASC 805-50, Business Combinations - Related Issues . The difference between the cash paid and the historical value of the entities' equity was recorded as a distribution to GIP and decreased the balance of contributed capital. The acquisition was determined to be an asset acquisition and not a business combination, therefore the Company consolidated the financial information for Carlsbad on a prospective basis. The following is a summary of assets and liabilities transferred in connection with the acquisition as of December 6, 2019: (In millions) CBAD Holdings, LLC Current Assets $ 36 Property, plant and equipment, net 572 Intangible assets, net 337 Other non-current assets 51 Total assets 996 Debt (a) 791 Other current and non-current liabilities (b) 56 Total liabilities 847 Net assets acquired $ 149 (a) Excludes net debt issuance costs of $12 million. (b) Other current liabilities and non-current liabilities include a contingent liability of $5 million assumed by the Company during the acquisition. 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. In addition, 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, and $1 million was paid in January 2020. The project added 73 MWt of thermal equivalent capacity and 7.5 MW of emergency backup electrical capacity to the Company's portfolio. The UPMC Thermal project operations are reflected in the Company's Thermal segment. The acquisition was funded with the proceeds from the sale of the Series E and Series F Notes. 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 the Company consolidated the financial information for UPMC Thermal project on a prospective basis. 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. The project added 2.8 MW of thermal capacity to the Company's portfolio, with a 20-year PPA contract with the City of Tulare. The operations of Central CA Fuel Cell are 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 $42 million. The Company also assumed non-recourse debt of $183 million and non-controlling interest of $19 million attributable to the Class A member. 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 Issue s. 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 asset under common control, the guidance required retrospective combination of the entities for all periods presented as if the combination had been in effect since the inception of common control. The project sells power under a 25-year PPA to the City of Georgetown, Texas, which commenced in July 2018. The operations of the Buckthorn project are reflected in the Company's Renewables segment. 2020 Dispositions Sale of RPV Holdco 1 LLC — On May 14, 2020, the Company sold its interests in RPV Holdco 1 LLC to a third party for net proceeds of approximately $75 million. The Company previously accounted for its interest in RPV Holdco 1 LLC as an equity method investment. The sale of the investment resulted in a gain of approximately $49 million. Sale of Energy Center Dover LLC and Energy Center Smyrna LLC Assets — On March 3, 2020, the Company, through Clearway Thermal LLC, sold 100% of its interests in Energy Center Dover LLC and Energy Center Smyrna LLC to DB Energy Assets, LLC for cash proceeds of approximately $15 million. 2019 Dispositions Sale of HSD Solar Holdings, LLC Assets — On October 8, 2019, the Company, through HSD Solar Holdings, LLC, or HSD, sold 100% of its interests in certain distributed generation solar facilities totaling 6 MW to the offtaker under the PPA, for cash consideration of $20 million, as a result of the offtaker exercising its right to purchase the project pursuant to the PPA. In conjunction with the sale, the Company repaid in full the non-recourse lease financing associated with the HSD projects. The repaid amount was net of cash released at closing and totaled $23 million.

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2020
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, 2020 December 31, 2019 Depreciable Lives (In millions) Facilities and equipment $ 9,254 $ 7,676 2 - 45 Years Land and improvements 224 173 Construction in progress (a) 62 94 Total property, plant and equipment 9,540 7,943 Accumulated depreciation (2,323) (1,880) Net property, plant and equipment $ 7,217 $ 6,063 (a) As of December 31, 2020 and 2019, construction in progress includes $14 million and $10 million of capital expenditures that relate to prepaid long-term service agreements in the Conventional segment, respectively. Depreciation expense related to property, plant and equipment during the years ended December 31, 2020, 2019 and 2018 was $420 million, $395 million and $330 million, respectively. The Company accelerated depreciation of the Pinnacle wind project in connection with the repowering project in 2020 , which resulted in additional depreciation expense in the amount of $9 million. The Company accelerated depreciation of the Wildorado Wind and Elbow Creek projects in connection with the repowering project in 2019 , which resulted in additional depreciation expense in the amount of $54 million . The Company recorded long-lived asset impairments during the year ended December 31, 2020 and December 31, 2019, 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, 2020
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 Company's maximum exposure to loss as of December 31, 2020 is limited to its equity investment in the unconsolidated entities, as further summarized in the table below: Name Economic Interest Investment Balance (In millions) Utah Solar Portfolio (a) 50% $ 255 Desert Sunlight 25% 244 Agua Caliente Solar (b) 16% 83 GenConn (c) 50% 90 San Juan Mesa 75% 33 Elkhorn Ridge 66.7% 38 Avenal 50% (2) $ 741 (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) On February 3, 2021, the Company acquired an additional 35% equity interest in Agua Caliente Solar and following the close of the transaction owns 51% equity interests in Agua Caliente and will remove its equity method investment and consolidate its interest from the date of the acquisition. (c) GenConn is a variable interest entity. As of December 31, 2020 and 2019, the Company had $10 million and $138 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 over the related useful life of the underlying assets acquired. The Company's pro-rata share of non-recourse debt held by unconsolidated affiliates was $481 million as of December 31, 2020. The following tables present summarized financial information for the Company's equity method investments: Year Ended December 31, 2020 2019 2018 Income Statement Data: (In millions) GenConn Operating revenues $ 60 $ 60 $ 65 Operating income 26 27 32 Net income 17 17 22 Desert Sunlight Operating revenues 209 205 208 Operating income 142 123 129 Net income 88 58 84 Other (a) Operating revenues 299 318 332 Operating income 138 110 126 Net income $ 60 $ 50 $ 86 As of December 31, 2020 2019 Balance Sheet Data: (In millions) GenConn Current assets $ 40 $ 37 Non-current assets 344 342 Current liabilities 17 16 Non-current liabilities 185 176 Desert Sunlight Current assets 132 209 Non-current assets 1,244 1,296 Current liabilities 71 545 Non-current liabilities 921 484 Other (a) Current assets 177 279 Non-current assets 2,201 3,412 Current liabilities 114 809 Non-current liabilities 700 500 Redeemable noncontrolling interest $ — $ (1) (a) Includes Agua Caliente, Elkhorn Ridge, Utah Solar Portfolio, San Juan Mesa, DGPV Holdco 1, DGPV Holdco 2 and DGPV Holdco 3. DGPV Holdco 1, DGPV Holdco 2 and DGPV Holdco 3. were consolidated by the Company during 2020 and are therefore excluded from the summarized balance sheet data as of December 31, 2020. 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 and solar facilities and are further described below. DGPV Holdco 3 Consolidation — DGPV Holdco 3 LLC or DGPV Holdco 3 owned approximately 113 MW of Distributed Solar capacity, based on cash to be distributed, with a weighted average remaining contract life of approximately 21 years. On May 29, 2020, the final construction projects for DGPV Holdco 3 were placed in service which resulted in a reconsideration event for consolidation of the entity. Upon the reconsideration event, the Company determined that it was the primary beneficiary of DGPV Holdco 3, as it is entitled to 99% of allocations of income and cash distributions from the entity. As such, effective on May 29, 2020, the Company consolidates DGPV Holdco 3, and records the interest owned by CEG as noncontrolling interest. DGPV Holdco 3 owns an interest in two tax equity funds with tax equity investors, both of which are consolidated by DGPV Holdco 3, and the interests owned by the tax equity investors are shown as noncontrolling interests. The Company removed its equity method investment in DGPV Holdco 3 of $155 million as of May 29, 2020 and recorded the difference between the net assets consolidated and the investment balance as a reduction to noncontrolling interests. The Company acquired CEG's interest in DGPV Holdco 3 on November 2, 2020 as further described in Note 3, Acquisitions and Dispositions and below . Prior to the reconsideration event described above, the Company invested $10 million of cash in DGPV Holdco 3 during the first half of 2020. DGPV Tax Equity Funds — As described in Note 3, Acquisitions and Dispositions , on November 2, 2020, the Company acquired the Class B membership interests in DGPV Holdco 1, DGPV Holdco 2 and DGPV Holdco 3, or the DGPV Holdco Entities, from Renew DG Holdings LLC, a subsidiary of CEG. The Company previously held the Class A membership interests in the DGPV Holdco Entities and accounted for its interests in DGPV Holdco 1 and DGPV Holdco 2 as equity method investments, while DGPV Holdco 3 was consolidated by the Company effective May 29, 2020 as further described above. Concurrent with the acquisition, the Company transferred its interests to DG-CS Master Borrower LLC. Effective with the acquisition of the Class B membership interests of the DGPV Holdco Entities, the Company consolidates all of the DGPV Holdco Entities, including DG-CS Master Borrower LLC, and its subsidiaries, which consist of seven projects including six tax equity funds that collectively own approximately 172 distributed solar projects with a combined 286 MW of capacity. Each of the six tax equity funds is a VIE, where the Company is the primary beneficiary and consolidates the fund, with the tax equity investor's interest shown as noncontrolling interest or redeemable noncontrolling interest. The Company utilizes the HLBV method to determine its share of the income or losses in the investees. The Company removed its equity method investments in DGPV Holdco 1 and DGPV Holdco 2 of $144 million as of November 2, 2020 and recorded the difference between the net assets consolidated and the investment balance as a reduction to noncontrolling interests. Langford Tax Equity Partnership, LLC — As described in Note 3, Acquisitions and Dispositions , on November 20, 2020, the Company acquired 100% of the Class B membership interest in Langford Holding LLC from CEG for $55 million as well as 100% of the Class A membership interests in Langford Holding LLC from a third party investor for $9 million. Langford Holding LLC owns 100% of the membership interests in Langford Class B Holdco LLC, which owns 100% of the Class B interest in Langford Tax Equity Partnership LLC, which indirectly owns 100% of the interest in a 160 MW wind project. Langford Tax Equity Partnership LLC is a variable interest entity. The Company is the primary beneficiary, through its position as managing member, and indirectly consolidates Langford Tax Equity Partnership LLC, through Langford Class B Holdco LLC. The Class A member is a tax equity investor whose interest is reflected as noncontrolling interest on the Company's consolidated balance sheet. The project achieved repowering COD in November 2020. The Company utilizes the HLBV method for income or loss allocation to the tax equity investor's noncontrolling interest. Lighthouse Partnership Arrangements Lighthouse Renewable Holdco LLC — As described in Note 3, Acquisitions and Dispositions , on September 1, 2020, the Company, through its indirect subsidiary Lighthouse Renewable Class A LLC, acquired the Class A membership interests in Lighthouse Renewable Holdco LLC (formerly Mesquite Star Pledgor LLC) from Clearway Renew LLC, a subsidiary of CEG. Lighthouse Renewable Holdco LLC is a VIE and at the time of the acquisition the Company was not the primary beneficiary. Accordingly, the Company recorded the acquired interest as an equity method investment. On December 21, 2020, CEG sold its Class B membership interest in Lighthouse Renewable Holdco LLC to a third-party investor which resulted in a reconsideration event for consolidation of the entity. Upon the reconsideration event, the Company determined that it was the primary beneficiary of Lighthouse Renewable Holdco LLC. As such, effective on December 21, 2020, the Company consolidates Lighthouse Renewable Holdco LLC, and shows the Class B interests owned by the third party investor as noncontrolling interests on the Company’s consolidated balance sheet. Through its Class A membership interests, the Company receives 50.01% of income and distributable cash. In addition, Lighthouse Renewable Holdco LLC holds the Class B interests in a tax equity fund, Mesquite Star Tax Equity Holdco LLC, that holds the Mesquite Star project. The tax equity investor's interest is shown as noncontrolling interest. The HLBV method is utilized to allocate the income or losses of Mesquite Star Tax Equity Holdco LLC. Rosie TargetCo LLC — As described in Note 3, Acquisitions and Dispositions , on December 21, 2020, the Company acquired 100% of CEG's Class A membership interests of Rosie TargetCo LLC which owns 100% interest in Rosie Class B LLC, which in turn owns 100% of the Class B membership interest of Rosie TE Holdco LLC. The Company consolidates Rosie TargetCo LLC as a VIE as the Company is the primary beneficiary, through its role as managing member. The Class B membership interest of Rosie TargetCo LLC is owned by a third-party investor and is reflected as noncontrolling interest on the Company’s consolidated balance sheet. Through its Class A membership interests in Rosie TargetCo LLC, the Company receives 50% of income and distributable cash. Rosie TargetCo indirectly consolidates Rosie TE Holdco LLC, which is also a VIE. The tax equity investor's interest is shown as noncontrolling interest. The HLBV method is utilized to allocate the income or losses of Rosie TE Holdco LLC. Yield Protection Agreement — In connection with the Lighthouse Partnership Agreements, the Company entered into an agreement which provides for a reallocation of cash distributions to the third-party investor in order to ensure that the investor achieves a target return. The agreement provides for the reallocation of up to 80% of cash distributed to the Company's Class A members beginning after the 15th year of the arrangement. The Company is accounting for this agreement as a guarantee and has recorded the fair value of its estimated liability under the arrangement of $15 million as a non-current liability with a corresponding offset to additional paid-in capital. Kawailoa Partnership — On August 31, 2018, the Company entered into an agreement with Clearway Renew LLC, a subsidiary of CEG, to acquire the Class A membership interests in the Kawailoa Solar Partnership LLC, or Kawailoa Partnership, for $9 million in cash consideration. The purpose of the partnership is to own, finance, operate, and maintain the Kawailoa Solar project, a 49 MW utility-scale solar generation project, an indirect subsidiary of the Kawailoa Partnership, located in Oahu, Hawaii. The Kawailoa Solar project is contracted to sell power under a 22-year PPA with Hawaiian Electric Company, or HECO. The Kawailoa Solar project is 51% owned by the Kawailoa Partnership, with the remaining 49% owned by a third-party investor. The Kawailoa Partnership consolidates the Kawailoa Solar project through its controlling majority interest. On May 7, 2019, the Company made an initial capital contribution of $2 million, which represents 20% of its total anticipated capital contributions. The Company assumed non-recourse debt of $120 million, as further described in Note 10 , Long-term Debt, and non-controlling interests attributable to third parties in the amount of $21 million. Effective May 1, 2019, the Company, as a Class A member, is the primary beneficiary through its position as managing member and consolidates Kawailoa Partnership. Allocations of income and taxable items are equal to the distributions of available cash, which is currently 95% to the Company and 5% to Clearway Renew LLC. The Company's acquisition of the Class A membership interests in the Kawailoa Partnership was accounted for as a transfer of assets under common control and was recorded at historical cost in accordance with ASC 805-50, Business Combinations — Related Issues . The difference between the cash paid and payable recorded and the historical value of the assets was recorded as a distribution to CEG and decreased the balance of its noncontrolling interest. Upon reaching COD in November of 2019, the Kawailoa Solar project's fixed assets were placed in service and began to depreciate. On December 22, 2019, Kawailoa Solar Holdings LLC, a tax equity fund, received its final equity contribution of $61 million. The proceeds were utilized to repay the ITC bridge loan in the amount of $57 million, and the construction debt was converted to term debt (and upsized, with an additional $5 million drawn). Distributions were paid to the third-party investor and Clearway Renew LLC, funded by the excess of the tax equity investment and the term loan upsizing above the amount of the bridge loan repayment and related fees. On December 27, 2019, the Company made its substantial completion contribution of $7 million into the Kawailoa Partnership, which was also utilized to make a distribution to Clearway Renew LLC. In addition, the Company started applying HLBV to allocate income attributable to the tax equity investor during the fourth quarter of 2019. Oahu Partnership — On August 31, 2018, the Company entered into an agreement with Clearway Renew LLC, a subsidiary of CEG, to acquire the Class A membership interests in the Zephyr Oahu Partnership LLC, or Oahu Partnership, for $20 million in cash consideration. The purpose of the partnership is to own, finance, operate, and maintain the Oahu Solar projects, which consist of Lanikuhana and Waipio, utility-scale solar generation projects with rated capacity of 15 MW and 46 MW, respectively, the indirect subsidiaries of the Oahu Partnership, located in Oahu, Hawaii. The Oahu Solar projects are contracted to sell power under a 22-year PPA with HECO. The Oahu Partnership consolidates the Oahu Solar projects through its controlling majority interest. On March 8, 2019, the Company made an initial capital contribution of $4 million, which represents 20% of its total anticipated capital contributions. The Company also assumed non-recourse debt of $143 million, as further described in Note 10 , Long-term Debt , and $18 million of non-controlling interest attributable to a tax equity investor's initial contribution. Effective March 8, 2019, the Company, as a Class A member, is the primary beneficiary through its position as managing member and consolidates Oahu Partnership. Allocations of income and taxable items are equal to the distributions of available cash, which is currently 95% to the Company and 5% to Clearway Renew LLC. The Company's acquisition of the Class A membership interests in the Oahu Partnership was accounted for as a transfer of assets under common control and was recorded at historical cost in accordance with ASC 805-50, Business Combinations - Related Issues . The difference between the cash paid and payable recorded and the historical value of the assets was recorded as a contribution from CEG and increased the balance of its noncontrolling interest. Upon reaching COD in September 2019, the Oahu Solar projects' fixed assets were placed in service and began to depreciate. On November 12, 2019, the tax equity investor made its final tax-equity contribution of $71 million and the proceeds were utilized to repay the related ITC bridge loan in the amount of $67 million, and the construction loan was converted to term debt. The Company paid the remaining 80% of the equity commitment in the amount of $16 million to Clearway Renew LLC when the Oahu Solar projects reached certain milestones in December 2019. In addition, the Company started applying HLBV to allocate income attributable to the tax equity investor during the third quarter of 2019. 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, 2019, the Company bought out 100% of the Class A membership interests from the TE Investor, for cash consideration of $19 million. The Company recorded the difference between the value of the interest bought and the cash received to equity and allocated it between non-controlling interest and additional paid in capital based on the economic ownership interest between CEG and public interest as of January 2, 2019. Repowering Partnership II LLC — On August 30, 2018, Wind TE Holdco, an indirect subsidiary of the Company, formed Repowering Partnership LLC with Clearway Renew LLC, an indirect subsidiary of CEG, in order to facilitate the repowering of wind facilities of two of its indirect subsidiaries, Elbow Creek Wind Project LLC, or Elbow Creek, and Wildorado Wind LLC, or Wildorado Wind. 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. Wind TE Holdco is the managing member of the partnership and consolidates the entity, which is a VIE. Clearway Renew LLC is initially entitled to allocations of 21% of income, which is reflected in Wind TE Holdco’s noncontrolling interests. On June 14, 2019, Repowering Partnership LLC was replaced with Repowering Partnership II LLC as the owner of the Elbow Creek and Wildorado Wind projects, as well as Repowering Partnership Holdco LLC, which concurrently entered into a financing agreement for construction debt commitment totaling $352 million, as further described in Note 10, Long-term Debt. Repowering of the Elbow Creek project was completed and on November 26, 2019, a third party tax equity investor purchased 100% of the Class A membership interests in Elbow Creek Repowering Tax Equity Holdco LLC, or Elbow TE Holdco for $89 million pursuant to a membership interest purchase agreement dated June 14, 2019. The Company also contributed $4 million. In connection with the completion of the Elbow Creek repowering, the construction loan of $93 million was repaid with the proceeds from the combined proceeds from the tax equity investor and the Company. The Company began applying HLBV during the fourth quarter to allocate income between the partners of Elbow TE Holdco. In connection with the closing, the allocations of income at Repowering Partnership II LLC (which indirectly consolidates both projects) changed to 59.63% for Wind TE Holdco LLC (the Company member) and 40.37% for CWSP Wildorado Elbow Holding LLC (the CEG member). In addition, approximately half of the repowered Wildorado equipment was placed in service in December 2019, with the remaining equipment being placed in service in January of 2020. In connection with repowering of the projects, the Company revised the remaining useful life of the property, plant and equipment that was replaced, resulting in additional expense of $54 million during the year ended December 31, 2019 related to accelerated depreciation. On February 7, 2020, a third party tax equity investor purchased 100% of the Class A membership interests in Wildorado TE Holdco, for $148 million. In addition, the Company contributed $112 million to Wildorado TE Holdco. The combined proceeds were used to repay construction debt under the Repowering Partnership Holdco credit agreement, as described in Note 10, Long-term Debt . The third party tax equity investor, or Wildorado Investor, will receive 99% of allocations of taxable income and other items until the Wildorado Investor obtains a specified return on its initial investment, or the last day of the PTC period, whichever occurs sooner. At such time, the allocations to the Wildorado Investor will change to 5%. Until such time, the Wildorado Investor will receive a variable percentage of cash distributions. Wildorado TE Holdco is a VIE and the Repowering Partnership II LLC is the primary beneficiary through its position as managing member. As a result, the Company consolidates Wildorado TE Holdco, with the Wildorado Investor's interest shown as noncontrolling interest. In connection with the Wildorado TE Holdco closing, the allocations of income at Repowering Partnership II LLC changed to 60.14% for Wind TE Holdco LLC (the Company member) and 39.86% for CWSP Wildorado Elbow Holding LLC (the CEG member). On May 11, 2020, the Company acquired CEG's interest in Repowering Partnership II LLC, for cash consideration of $70 million. Repowering Partnership II LLC is no longer a VIE and subsequent to the acquisition, is a wholly-owned subsidiary of the Company. Repowering Partnership II LLC continues to own interests in two VIEs, Wildorado Repowering Tax Equity Holdco LLC, or Wildorado TE Holdco, and Elbow Creek Repowering Tax Equity Holdco LLC, or Elbow Creek TE Holdco. The Company removed the related noncontrolling interest balance of $8 million and recorded the difference between the cash paid and the noncontrolling interest balance removed as a reduction to noncontrolling interests. The Company utilizes the HLBV method to determine the net income or loss allocated to tax equity noncontrolling interest. Buckthorn Renewables, LLC — 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 for income or loss allocation to the tax equity investor's noncontrolling interest. Alta TE Holdco — On June 30, 2015, the Company sold an economic interest in Alta TE Holdco to a financial institution in order to monetize certain cash and tax attributes, primarily PTCs. The financial institution, or Alta Investor, receives 99% of allocations of taxable income and other items until the flip point, which occurs when the Alta Investor obtains a specified return on its initial investment, at which time the allocations to the Alta Investor change to 5%. The Company receives 94.34% until the flip point, at which time the allocations to the Company of CAFD will change to 97.12%, unless the flip point will not have occurred by a specified date, which would result in 100% of CAFD allocated to the Alta Investor until the flip point occurs. Alta TE Holdco is a VIE and the Company is the primary beneficiary through its position as managing member, and therefore consolidates Alta TE Holdco, with the Alta Investor's interest shown as noncontrolling interest. The Company utilizes the HLBV method to determine the net income or loss allocated to the noncontrolling interest. Spring Canyon — The Company holds 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, 2020: (In millions) Oahu Kawailoa Partnership Wildorado DGPV Funds (a) Lighthouse Renewable Holdco LLC Rosie TargetCo LLC Langford TE Partnership LLC Alta TE Holdco Buckthorn Renewables, LLC Other (b) Other current and non-current assets $ 23 $ 21 $ 14 $ 105 $ 48 $ 40 $ 15 $ 56 $ 2 $ 21 Property, plant and equipment 179 141 240 778 444 258 138 356 210 184 Intangible assets — — — 2 — — 2 225 — 1 Total assets 202 162 254 885 492 298 155 637 212 206 Current and non-current liabilities 122 111 11 77 82 118 18 44 9 33 Total liabilities 122 111 11 77 82 118 18 44 9 33 Noncontrolling interest 14 31 123 4 347 150 108 33 58 99 Net assets less noncontrolling interests $ 66 $ 20 $ 120 $ 804 $ 63 $ 30 $ 29 $ 560 $ 145 $ 74 (a) DGPV Funds is comprised of DGPV Fund 2 LLC, Clearway & EFS Distributed Solar LLC, DGPV Fund 4 LLC, Golden Puma Fund LLC, Renew Solar CS4 Fund LLC and Chestnut Fund LLC (b) Other is comprised of Crosswinds, Hardin, Elbow Creek Holdco and Spring Canyon projects 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 — The company acquired 100% of the Class A equity interests in the Utah Solar Portfolio from NRG. The 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.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments 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. 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, 2020 As of December 31, 2019 Carrying Amount Fair Value Carrying Amount Fair Value (In millions) Liabilities: Long-term debt, including current portion — affiliate $ 1 $ 1 $ 44 $ 43 Long-term debt, including current portion — external (a) $ 7,048 $ 7,020 $ 6,813 $ 6,913 (a) Excludes net debt issuance costs, which are recorded as a reduction to long-term debt on the Company's consolidated balance sheets. 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 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, 2020 and 2019: As of December 31, 2020 As of December 31, 2019 Level 2 Level 3 Level 2 Level 3 (In millions) Long-term debt, including current portion $ 1,906 $ 5,115 $ 1,735 $ 5,221 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, 2020 As of December 31, 2020 As of December 31, 2019 As of December 31, 2019 Fair Value Fair Value (a) Fair Value (a) Fair Value (a) (In millions) Level 2 Level 3 Level 2 Level 3 Derivative assets Interest rate contracts $ 1 $ — $ — $ — Other financial instruments (b) — 29 — — Total assets $ 1 $ 29 $ — $ — Derivative liabilities Commodity contracts $ — $ 44 $ — $ 9 Interest rate contracts 129 — 83 — Total liabilities $ 129 $ 44 $ 83 $ 9 (a) There were no derivative assets classified as Level 1, or Level 3 and no liabilities classified as Level 1 as of December 31, 2020 and no derivative assets classified as Level 1, Level 2 or Level 3 and no liabilities classified as Level 1 as of December 31, 2019. (b) SREC contract acquired on November 2, 2020. The following table reconciles the beginning and ending balances for instruments that are recognized at fair value in the condensed consolidated financial statements using significant unobservable inputs: Year ended December 31, 2020 2019 (In millions) Fair Value Measurement Using Significant Unobservable Inputs (Level 3) Beginning balance $ (9) $ — Total losses for the period included in earnings — (3) Purchases (6) (6) Ending balance $ (15) $ (9) Change in unrealized losses included in earnings for derivatives held as of December 31, $ 1 $ (3) Derivative and Financial Instruments Fair Value Measurements The Company's contracts are non-exchange-traded and valued using prices provided by external sources. For the Company’s energy contracts, management uses quoted observable forward prices. To the extent that observable forward prices are not available, the quoted prices reflect the average of the forward prices from the prior year, adjusted for inflation. As of December 31, 2020, contracts valued with prices provided by models and other valuation techniques make up 25% of derivative liabilities and 100% of other financial instruments. The Company’s significant positions classified as Level 3 include physical power executed in illiquid markets. The significant unobservable inputs used in developing fair value include illiquid power tenors and location pricing, which is derived by extrapolating pricing and as a basis to liquid locations. The tenor pricing and basis spread are based on observable market data when available or derived from historic prices and forward market prices from similar observable markets when not available. The following table quantifies the significant unobservable inputs used in developing the fair value of the Company's Level 3 positions as of December 31, 2020: December 31, 2020 Fair Value Input/Range Assets Liabilities Valuation Technique Significant Unobservable Input Low High Weighted Average (In millions) Power Contracts $ — $ (44) Discounted Cash Flow Forward Market Price (per MWh) $ 8.64 $ 42.37 $ 17.93 Other Financial Instruments $ 29 — Discounted Cash Flow Forecast annual generation levels of certain DG solar facilities 80,872 MWh 131,374 MWh 126,063 MWh The following table provides sensitivity of fair value measurements to increases/(decreases) in significant unobservable inputs as of December 31, 2020: Significant Observable Input Position Change In Input Impact on Fair Value Measurement Forward Market Price Power Buy Increase/(Decrease) Higher/(Lower) Forward Market Price Power Sell Increase/(Decrease) Lower/(Higher) Forecast Generation Level Sell Increase/(Decrease) Higher/(Lower) 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 is, for interest rate swaps, calculated based on credit default swaps using the bilateral method. For commodities, to the extent that the Net Exposure under a specific master agreement is an asset, the Company uses the counterparty’s default swap rate. If the Net Exposure under a specific master agreement is a liability, the Company uses a proxy of 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, 2020, the non-performance reserve was a $6 million gain recorded primarily to interest expense in the consolidated statement of operations. 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) monitoring of counterparties' credit limits on as needed basis; (iii) as applicable, 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. 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 or adverse financial conditions, which the Company is unable to predict.

Accounting for Derivative Instr

Accounting for Derivative Instruments and Hedging Activities	12 Months Ended
	Dec. 31, 2020
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. Interest Rate Swaps The Company enters into interest rate swap agreements in order to hedge the variability of expected future cash interest payments. As of December 31, 2020, the Company had interest rate derivative instruments on non-recourse debt extending through 2044, a portion of which were designated as cash flow hedges. Under the interest rate swap agreements, the Company pays a fixed rate and the counterparties to the agreements pay a variable interest rate. Energy Related Commodities As of December 31, 2020, the Company had energy-related derivative instruments extending through 2032. At December 31, 2020, these contracts were not designated as cash flow or fair value 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, 2020 and 2019: Total Volume December 31, 2020 December 31, 2019 Commodity Units (In millions) Natural Gas MMBtu 1 2 Power MWh (8) (2) Interest Dollars $ 1,600 $ 1,788 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, 2020 December 31, 2020 December 31, 2019 (In millions) Derivatives Designated as Cash Flow Hedges: Interest rate contracts current $ — $ 8 $ 3 Interest rate contracts long-term — 15 11 Total Derivatives Designated as Cash Flow Hedges $ — $ 23 $ 14 Derivatives Not Designated as Cash Flow Hedges: Interest rate contracts current — 25 13 Interest rate contracts long-term 1 81 56 Commodity contracts current — 5 — Commodity contracts long-term — 39 9 Total Derivatives Not Designated as Cash Flow Hedges 1 150 78 Total Derivatives $ 1 $ 173 $ 92 (a) There were no derivative assets as of December 31, 2019. 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, 2020 and 2019, there was no outstanding collateral paid or received. The following tables summarize the offsetting of derivatives by counterparty master agreement level: Gross Amounts Not Offset in the Statement of Financial Position As of December 31, 2020 Gross Amounts of Recognized Assets/Liabilities Derivative Instruments Net Amount Commodity contracts (In millions) Derivative liabilities (44) — (44) Total commodity contracts (44) — (44) Interest rate contracts Derivative assets $ 1 $ — $ 1 Derivative liabilities (129) — (129) Total interest rate contracts (128) — (128) Total derivative instruments $ (172) $ — $ (172) Gross Amounts Not Offset in the Statement of Financial Position As of December 31, 2019 Gross Amounts of Recognized Assets/Liabilities Derivative Instruments Net Amount Commodity contracts (In millions) Derivative liabilities (9) (1) (10) Total commodity contracts (9) (1) (10) Interest rate contracts Derivative liabilities (83) 1 (82) Total interest rate contracts (83) 1 (82) Total derivative instruments $ (92) $ — $ (92) 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, 2020 2019 2018 (In millions) Accumulated OCL beginning balance $ (37) $ (45) $ (69) Reclassified from accumulated OCL to income due to realization of previously deferred amounts 11 22 15 Mark-to-market of cash flow hedge accounting contracts (9) (14) 9 Accumulated OCL ending balance $ (35) $ (37) $ (45) Accumulated OCL attributable to noncontrolling interests (2) — (1) Accumulated OCL attributable to Clearway Energy LLC $ (33) $ (37) $ (44) Losses expected to be realized from OCL during the next 12 months $ (13) Amounts reclassified from accumulated OCL into income are recorded to interest expense. 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, 2020, 2019 and 2018 the impact to the consolidated statements of income was a loss of $38 million, a loss of $65 million and a gain of $15 million, respectively. The Company has long-term power hedge derivatives, for which changes in fair value are recorded in operating income. For the years ended December 31, 2020 and 2019 the impact to the consolidated statements of income was a loss of $4 million and a loss of $9 million, respectively. There were no long-term power hedge derivatives outstanding during 2018. 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 operations for these contracts. See Note 6, Fair Value of Financial Instruments

Intangible Assets

Intangible Assets	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets	Intangible Assets Intangible Assets — The Company's intangible assets as of December 31, 2020 and 2019 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, Laredo Ridge and Carlsbad Energy Center. These represent the fair value of the PPAs acquired. These are amortized 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 as a reduction to operating revenue on a straight-line basis over the term of the PPAs. • Customer relationships — Established with the acquisition of Energy Center Omaha and Energy Center Phoenix, these intangibles represent the fair value at the acquisition date of the businesses' customer base. The customer relationships related to Energy Center Omaha are amortized as a reduction to operating revenue, which approximates 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, Walnut Creek and Carlsbad Energy Center 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 Langford Wind 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, 2020 PPAs Leasehold Rights Customer Customer Contracts Emission Allowances Other Total (In millions) January 1, 2020 $ 1,630 $ 86 $ 66 $ 15 $ 17 $ 8 $ 1,822 Consolidation of DGPV Holdco Entities 23 — — — — — 23 Other 8 — — — — 4 12 December 31, 2020 $ 1,661 $ 86 $ 66 $ 15 $ 17 $ 12 $ 1,857 Less accumulated amortization (431) (26) (11) (11) (3) (5) (487) Net carrying amount $ 1,230 $ 60 $ 55 $ 4 $ 14 $ 7 $ 1,370 Year ended December 31, 2019 PPAs Leasehold Rights Customer Relationships Customer Contracts Emission Other Total (In millions) January 1, 2019 $ 1,280 $ 86 $ 66 $ 15 $ 9 $ 8 $ 1,464 Acquisition of Carlsbad 350 — — — 8 — 358 December 31, 2019 $ 1,630 $ 86 $ 66 $ 15 $ 17 $ 8 $ 1,822 Less accumulated amortization (347) (22) (9) (10) (2) (4) (394) Net carrying amount $ 1,283 $ 64 $ 57 $ 5 $ 15 $ 4 $ 1,428 The Company recorded amortization expense of $91 million during the year ended December 31, 2020, $73 million for the year ended December 31, 2019 and $71 million for the year ended December 31, 2018. Of these amounts, $88 million for the year ended December 31, 2020 and $72 million for the year ended December 31, 2019 and $70 million for the year ended December 31, 2018, 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 for the next five years as follows: (In millions) 2021 $ 91 2022 91 2023 88 2024 85 2025 $ 84

Asset Impairments

Asset Impairments	12 Months Ended
	Dec. 31, 2020
Asset Impairments [Abstract]
Asset Impairments	Asset Impairments 2020 Impairment Losses During the fourth quarter of 2020 in the preparation and review of its annual budget, the Company updated its long-term estimates of operating and capital expenditures and revised its assessment of long-term merchant power prices which was primarily informed by present conditions and does not contemplate future policy changes, which could impact renewable energy power prices. As a result, the Company updated its estimated future cash flows and determined that the future cash flows for several wind projects within the Renewables segment no longer supported the recoverability of the related long-lived asset. As such, the Company recorded an impairment loss of $24 million, which primarily relates to property, plant, and equipment to reflect the assets at fair market value. The fair value of the facilities were determined using an income approach by applying a discounted cash flow methodology to the long-term budgets for each respective plant. The income approach included key inputs such as forecasted merchant power prices, operations and maintenance expense, and discount rates. The resulting fair value is a Level 3 fair value measurement. Additionally, during the fourth quarter of 2020, 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 there was a significant decrease in the estimated future cash flows for its equity method investment in San Juan Mesa, a facility in the Renewables segment located in Elida, New Mexico. The decrease in the forecasted cash flows which is primarily driven by a decline in forecasted revenue in future merchant periods, is significant enough to be considered an indication of a decline in value of the investment that is not temporary. The Company concluded there was an other-than-temporary impairment of its investment and recorded an impairment loss of $8 million to reflect the investment at fair market value. The resulting fair value is a Level 3 fair value measurement. 2019 Impairment Losses The Company recorded an impairment loss of $19 million related to a facility in the Thermal segment during the second quarter of 2019. The impairment was triggered by a potential sale negotiation with a third party which resulted in signing the purchase and sale agreement in September, as further described in Note 3, Acquisitions and Dispositions . The fair value of the facility 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.

Long-term Debt

Long-term Debt	12 Months Ended
	Dec. 31, 2020
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, 2020 December 31, 2019 Interest rate % (a) Letters of Credit Outstanding at December 31, 2020 (In millions, except rates) Long-term debt - affiliate, due 2020 — 44 3.325 Intercompany Note with Clearway Energy, Inc. 1 — 1.490 2024 Senior Notes — 88 5.375 2025 Senior Notes 600 600 5.750 2026 Senior Notes 350 350 5.000 2028 Senior Notes 850 600 4.750 Clearway Energy LLC and Clearway Energy Operating LLC Revolving Credit Facility, due 2023 (b) — — L+1.50 $ 66 Project-level debt: Alpine, due 2022 (e) — 119 L+2.00 — Alta Wind I-V lease financing arrangements, due 2034 and 2035 800 844 5.696 - 7.015 44 Alta Wind Asset Management LLC, due 2031 14 15 L+2.50 — Alta Wind Realty Investments LLC, due 2031 25 27 7.000 — Borrego, due 2024 and 2038 57 60 Various 4 Buckthorn Solar, due 2025 126 129 L+1.750 22 Carlsbad Holdco, due 2038 210 216 4.210 4 Carlsbad Energy Holdings LLC, due 2027 156 175 L+1.625 63 Carlsbad Energy Holdings LLC, due 2038 407 407 4.120 — CVSR, due 2037 675 696 2.339 - 3.775 — CVSR Holdco Notes, due 2037 176 182 4.680 13 DG-CS Master Borrower LLC, due 2040 467 — 3.510 30 Duquesne, due 2059 95 95 4.620 — El Segundo Energy Center, due 2023 250 303 L+1.875 - L+2.500 138 Energy Center Minneapolis Series D, E, F, G, H Notes, due 2025-2037 327 328 various — Laredo Ridge, due 2028 78 84 L+2.125 10 Kawailoa Solar Portfolio LLC, due 2026 81 82 L+1.375 14 Marsh Landing, due 2023 146 206 L+2.125 27 NIMH Solar, due 2024 191 — L+2.00 11 Oahu Solar Holdings LLC, due 2026 89 91 L+1.375 10 Repowering Partnership Holdco LLC, due 2020 — 228 L+0.85 — Rosie Class B LLC, due 2027 80 — L+1.75 19 Tapestry, due 2031 143 156 L+1.375 17 Utah Solar Holdings, due 2036 290 — 3.590 11 Utah Solar Portfolio, due 2022 — 254 L+1.625 — Walnut Creek, due 2023 126 175 L+1.75 73 WCEP Holdings, LLC, due 2023 35 39 L+3.00 — Other (c) 199 264 various 50 Subtotal project-level debt 5,243 5,175 Total debt 7,044 6,857 Less current maturities (385) (1,824) Less net debt issuance costs (79) (77) Add premiums (d) 5 — Total long-term debt $ 6,585 $ 4,956 (a) As of December 31, 2020, L+ equals 3 month LIBOR plus x%, except Rosie Class B, due 2027 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) December 31, 2019 includes Blythe and Roadrunner debt outstanding of $14 million and $28 million, respectively which were transferred to NIMH in the third quarter of 2020, as described below (d) Premiums relate to the 2028 Senior Notes 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, 2020, the Company was in compliance with all of the required principal, interest, sinking fund and redemption covenants. Clearway Energy LLC and Clearway Energy Operating LLC Revolving Credit Facility On December 20, 2019, the Company entered into the Fifth Amendment to Amended and Restated Credit Agreement to provide for an increase of 0.50x to the borrower leverage ratio, as defined in the Amended and Restated Credit Agreement, for the last two fiscal quarters of 2020 and to implement certain other technical modifications. As of December 31, 2020, the Company had no outstanding borrowings under the revolving credit facility and $66 million in letters of credit outstanding. During the year ended December 31, 2020, the Company borrowed $265 million under the revolving credit facility, and subsequently repaid $265 million utilizing the proceeds from the issuance of additional 2028 Senior Notes, as described below, and cash on hand. The Company had $195 million outstanding under the revolving credit facility and a total of $70 million in letters of credit outstanding as of February 26, 2021. 2028 Senior Notes On May 21, 2020, the Company completed the issuance of an additional $250 million in aggregate principal amount of its 4.750% Senior Notes due 2028. The 2028 Senior Notes bear interest at 4.75% and mature on March 15, 2028. Interest on the 2028 Senior Notes is payable semi-annually on March 15 and September 15 of each year, and interest payments will commence on September 15, 2020. The 2028 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 notes were issued at a price of 102% of par plus accrued interest from December 11, 2019. The net proceeds were utilized to repay the $45 million outstanding principal amount of the Company's 2020 Convertible Notes on June 1, 2020, as well as to repay amounts outstanding under the Company’s revolving credit facility and for general corporate purposes. On December 11, 2019, the Company completed the sale of $600 million aggregate principal amount of the Senior Notes due 2028. The proceeds from the 2028 Senior Notes were partially used to repay the 2024 Senior Notes, as further described below. 2024 Senior Notes Redemption On January 3, 2020, the Company redeemed the $88 million aggregate principal amount of the 2024 Senior Notes that remained outstanding following the Company's tender offer for the 2024 Senior Notes in December 2019. The redemption was effectuated at a premium of 102.7% for a total consideration of $90 million and as a result, the Company recorded a loss on debt extinguishment in the amount of $3 million, which also included the write off of previously deferred financing fees related to the 2024 Senior Notes. Intercompany Note with Clearway Energy, Inc . On February 18, 2020, the Company entered into an intercompany demand promissory note with Clearway Energy, Inc. in the principal amount of $3 million. The unpaid principal amount bears interest at a rate equal to the short-term applicable federal rate, which is payable on the last day of each quarter, or at other times as agreed upon by the Company and Clearway Energy, Inc Project level Debt PG&E Bankruptcy On July 1, 2020, PG&E emerged from bankruptcy and assumed the Company's contracts without modification. In addition, PG&E paid to the Company's applicable projects the portion of the invoices corresponding to the electricity delivered between January 1 and January 28, 2019. These invoices related to the pre-petition period services and any payment therefore required the approval of the Bankruptcy Court. Subsequent to PG&E's emergence from bankruptcy, the Company entered into waiver agreements with the lenders to the respective financing agreements related to the PG&E Bankruptcy. Rosamond Central (Rosie Class B LLC) On December 21, 2020 as part of the acquisition of Rosie TargetCo LLC, as further descried in Note 3, Acquisitions and Dispositions , the Company assumed the Amended and Restated Financing Agreement, which provided for a construction loan of up to $91 million, a cash equity bridge loan of up to $24 million and an investment tax credit loan of up to $132 million. On December 31, 2020, Rosie Class B, LLC converted the construction loan to a $80 million term loan and repaid the investment tax credit loan of $130 million, utilizing tax equity funding. The term loan bears annual interest at a rate of LIBOR plus an applicable margin, which is 1.75% per annum through the third anniversary of the term conversion, and 2.00% per annum thereafter through the maturity date of December 31, 2027. In addition, Rosie Class B LLC is party to several letter of credit facility agreements, not to exceed $23 million. As of December 31, 2020, a total of $19 million in letters of credit were outstanding. Repowering Partnership Holdco LLC, due 2020 On June 14, 2019, as part of the Repowering Partnership, the Company entered into a financing agreement for non-recourse debt for a total commitment amount of $352 million related to the construction for the repowering activities at Wildorado and Elbow Creek. The debt consisted of a construction loan at an interest rate of LIBOR plus 0.85%. The Company borrowings were utilized to repay $109 million of the outstanding balance, including accrued interest, under the Viento financing agreement, to reimburse Clearway Renew LLC for previous contributions into the Repowering Partnership and pay construction invoices. On November 26, 2019, the construction loan of $93 million related to the repowering activities at Elbow Creek was repaid with the proceeds from the tax equity investor. On February 7, 2020 the construction loan of $260 million related to the repowering activities at Wildorado was repaid with the proceeds from the tax equity investor. Consolidation of DGPV Holdco 3 Upon consolidation of DGPV Holdco 3, as described in Note 5, Investments Accounted for by the Equity Method and Variable Interest Entities, the Company consolidates additional non-recourse debt for certain subsidiaries as further described below. Renew CS4 Borrower LLC, or CS4 Borrower, a consolidated subsidiary of DGPV Holdco 3, is party to a credit agreement for construction loans up to $97 million, an investment tax credit bridge loan, or ITC bridge loan, for up to $90 million and letter of credit facilities up to $5 million. The construction loan and the ITC bridge loan both have an interest rate of LIBOR plus an applicable margin of 2.00% per annum. As of June 30, 2020, all construction loans were converted to term loans and the ITC bridge loans were repaid in connection with tax equity funding. The term loan was repaid on November 2, 2020 with the proceeds of the term loan issued by DG-CS Master Borrower LLC, as described below. Chestnut Borrower LLC, a consolidated subsidiary of DGPV Holdco 3, is party to a credit agreement for term loans of up to $120 million and letters of credit of up to $8 million. The loans were repaid on November 2, 2020 with the proceeds of the term loan issued by DG-CS Master Borrower LLC, as described below DG-CS Master Borrower LLC On November 2, 2020, DG-CS Master Borrower LLC, a wholly owned subsidiary of Clearway Energy Operating LLC, entered into a financing arrangement, which included the issuance of a $467 million term loan, as well as $30 million in letters of credit in support of debt service. The term loan bears interest at 3.51% and mature on September 30, 2040. The proceeds from the loan were utilized to repay existing project-level debt outstanding for Chestnut Borrower LLC, Renew Solar CS 4 Borrower LLC, DGPV 4 Borrower LLC and Puma Class B LLC of $107 million, $102 million, $92 million and $73 million, respectively and unwind related interest rate swaps in the amount of $42 million. The remaining proceeds were utilized to pay related fees and expenses and in part to acquire the Class B membership interests in the DGPV Holdco Entities and an SREC contract from CEG as further described in Note 5, Investments Accounted for by the Equity Method and Variable Interest Entities. Concurrent with the refinancing, the projects were transferred under DG-CS Master Borrower LLC and the obligations under the financing arrangement are supported by the Company's interest in the projects. Utah Solar Holdings, LLC On September 1, 2020, Utah Solar Holdings, LLC, or Utah Solar, entered into a financing arrangement, which included the issuance of approximately $296 million in senior secured notes supported by the Company’s interest in the Utah projects (Four Brothers, Granite Mountain and Iron Springs, previously defined as the Utah Solar Portfolio), as well as $16 million in letters of credit in support of debt service obligations. The notes bear interest at 3.59% per annum and mature on December 31, 2036. The proceeds from the issuance were utilized to repay existing debt outstanding of approximately $247 million for the Utah projects and to unwind the related interest rate swaps in the amount of $33 million. The remaining proceeds were utilized to pay related fees and expenses, with the remaining $9 million distributed to Clearway Energy Operating LLC. NIMH Solar LLC On September 30, 2020, the Alpine, Blythe and Roadrunner projects were transferred under NIMH Solar LLC, a wholly owned subsidiary of Clearway Energy Operating LLC. Concurrently, total project-level debt outstanding for Alpine, Blythe and Roadrunner of $158 million was assigned to NIMH Solar LLC. The consolidated facility was amended to a term loan for $193 million, as well as $16 million in letters of credit in support of debt service and project obligations. The term loan bears annual interest rate of LIBOR, plus an applicable margin, which is 2.00% per annum through the third anniversary of closing, and 2.125% per annum thereafter through the maturity date in September 2024. As a result of the amendment the Company received $35 million which was utilized to pay related fees and expenses and along with existing project level cash provided a distribution to Clearway Energy Operating LLC of $45 million. The obligations under the financing arrangement are supported by the Company’s interests in the projects. Carlsbad Drop Down Asset Debt On December 6, 2019, as part of the Carlsbad Drop Down acquisition, as further described in Note 3, Acquisitions and Dispositions , the Company assumed $803 million of senior secured, non-recourse notes related to Carlsbad Holdco LLC and Carlsbad Energy Holding LLC. The Carlsbad Holdco LLC notes bear an interest rate of 4.21%, and are fully amortizing over 19 years. In addition, Carlsbad Holdco LLC is party to a letter of credit facility agreement with the issuing banks for an aggregate principal amount not to exceed $10 million. Fees on the unused commitment are 0.65%. Carlsbad Energy Holdings LLC is party to a note payable agreement with financial institutions for the issuance of up to $407 million of senior secured notes that bear interest at a rate of 4.12%, and mature on October 31, 2038. Carlsbad Energy Holdings LLC is also party to a term loan agreement with issuing banks for an aggregate principal amount of $194 million at an issuance rate of LIBOR plus an applicable margin of 1.625% until February 25, 2022, 1.750% until February 25, 2025, and 1.875% until maturity. Fees on the unused commitment are 0.50%. upon completion of the project. The agreement also includes a letter of credit facility with an aggregate principal amount not to exceed $83 million, and a working capital loan facility with an aggregate principal amount not to exceed $4 million. Agua Caliente Borrower 2 Debt Repayment On October 21, 2019 , the Company, through Agua Caliente Borrower 2 LLC, repaid $40 million of the outstanding notes balance, including accrued interest and premiums, issued under the Agua Caliente Holdco Financing Agreement. The repayment was funded with Company's existing liquidity. Duquesne University On May 1, 2019 , as part of the Duquesne University district energy system acquisition, ECP Uptown Campus LLC issued non-recourse debt of $95 million, excluding financing fees. The debt consists of senior notes at an interest rate of 4.62% that mature on May 1, 2059 . Interest on the notes are payable semi-annually in arrears. The proceeds of the debt, along with cash on hand, were utilized to fund the purchase price of the acquisition. Oahu Solar Holdings LLC Due to the Company consolidating the Oahu Partnership, as further described in Note 5, Investments Accounted for by the Equity Method and Variable Interest Entities , the Company assumed non-recourse debt of $143 million related to Oahu Solar Holdings, LLC. The debt consists of a construction loan and an ITC bridge loan with a total commitment amount of $162 million, both at an interest rate of LIBOR plus 1.375%. On November 13, 2019, $90 million of non-recourse debt was converted to a term loan with an expected maturity of November 2026, and the remainder of the non-recourse debt was repaid with the final contribution from the tax equity investor of $67 million upon the project reaching substantial completion. Interest on the term loan is payable quarterly in arrears. Kawailoa Solar Portfolio LLC Due to the Company consolidating the Kawailoa Partnership, as further described in Note 5, Investments Accounted for by the Equity Method and Variable Interest Entities , the Company assumed non-recourse debt of $120 million related to Kawailoa Solar Portfolio, LLC. The debt consists of a construction loan and an ITC bridge loan, with a total commitment amount of $137 million both at an interest rate of LIBOR plus 1.375%. On December 23, 2019, $82 million of non-recourse debt was converted to a term loan with an expected maturity of December 2026, and the remainder of the non-recourse debt was repaid with the final contribution from the tax equity investor of $57 million upon the project reaching substantial completion. Interest on the term loan is payable quarterly in arrears. South Trent Refinancing On June 14, 2019, the Company, through South Trent Wind LLC, refinanced $49 million of non-recourse debt due 2020 at an interest rate of LIBOR plus 1.625% by issuing $46 million of new non-recourse financing due 2028 at an interest rate of LIBOR plus 1.350%. Tapestry Refinancing On April 29, 2019, the Company, through Tapestry Wind LLC, refinanced $147 million of non-recourse debt due 2021 at interest rate of LIBOR plus 1.75% by issuing $164 million of new non-recourse financing due 2031 at an interest rate of LIBOR plus 1.375%. 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 a fixed rate 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, 2020: % of Principal Fixed Interest Rate Floating Interest Rate Notional Amount at December 31, 2020 (In millions) Effective Date Maturity Date Avra Valley 87 % 2.33 % 3-Month LIBOR 38 November 30, 2012 November 30, 2030 Alta Wind Asset Management 100 % 2.47 % 3-Month LIBOR 14 May 22, 2013 May 15, 2031 Borrego 100 % 0.476 % 3-Month LIBOR 13 June 30, 2020 December 31, 2024 Buckthorn Solar 82 % Various 3-Month LIBOR 103 February 28, 2018 December 31, 2041 Carlsbad 100 % Various 3-Month LIBOR 156 Various September 30, 2027 El Segundo 100 % Various 3-Month LIBOR 250 Various Various Kansas South 75 % 2.368 % 6-Month LIBOR 17 June 28, 2013 December 31, 2030 Kawailoa Solar 94 % Various 3-Month LIBOR 76 November 30, 2019 October 31, 2040 Laredo Ridge 100 % Various 3-Month LIBOR 78 December 17, 2014 December 31, 2028 Marsh Landing 100 % Various 3-Month LIBOR 146 June 28, 2013 June 30, 2023 NIMH Solar LLC 100 % Various 3-Month LIBOR 191 September 30, 2020 Various Oahu Solar 96 % Various 3-Month LIBOR 86 November 30, 2019 October 31, 2040 Rosie Class B 95 % 1.446 % 3-Month LIBOR 76 December 31, 2020 July 29, 2044 South Trent 90 % 3.847 % 3-Month LIBOR 35 June 14, 2019 June 30, 2028 Tapestry 75 % Various 3-Month LIBOR 107 Various Various Tapestry 50 % 3.57 % 3-Month LIBOR 12 December 21, 2021 December 21, 2029 Viento Funding II 100 % 3.03 % 6-Month LIBOR 33 Various Various Viento Funding II 100 % 4.985 % 6-Month LIBOR 21 July 11, 2023 June 30, 2028 Walnut Creek Energy 90 % 3.543 % 3-Month LIBOR 114 June 28, 2013 May 31, 2023 WCEP Holdings 100 % 4.003 % 3-Month LIBOR 34 June 28, 2013 May 31, 2023 Total $ 1,600 Annual Maturities Annual payments based on the maturities of the Company's debt, for the years ending after December 31, 2020, are as follows: (In millions) 2021 $ 384 2022 407 2023 431 2024 359 2025 934 Thereafter 4,528 Total $ 7,043

Members' Equity

Members' Equity	12 Months Ended
	Dec. 31, 2020
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, 2020: Fourth Quarter 2020 Third Quarter 2020 Second Quarter 2020 First Quarter 2020 Distributions per Class A and Class B units $ 0.3180 $ 0.3125 $ 0.2100 $ 0.2100 Distributions per Class C and Class D units $ 0.3180 $ 0.3125 $ 0.2100 $ 0.2100 On February 12, 2021, the Company declared a quarterly distribution on its Class A, Class B, Class C and Class D units of $0.324 per share payable on March 15, 2021.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions In addition to the transactions and relationships described elsewhere in the notes to the consolidated financial statements, certain subsidiaries of CEG provide services to the Company's project entities. Amounts due to CEG subsidiaries are recorded as accounts payable - affiliates and amounts due to the Company from CEG subsidiaries are recorded as accounts receivable - affiliates in the Company's balance sheet. The disclosures below summarize the Company's material related party transactions with CEG and its subsidiaries that are included in the Company's operating revenues and operating costs. As discussed in Note 1, Nature of Business , on August 31, 2018, NRG sold 100% of its interest in CEG to GIP, and as a result, CEG and its subsidiaries are considered related parties during the year ended December 31, 2020 and December 31, 2019, and NRG and its subsidiaries were considered related parties during the first eight months of the year ended December 31, 2018. Related Party Transactions with CEG entities O&M Services Agreements by and between the Company and Clearway Renewable 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, or RENOM, a wholly-owned subsidiary of CEG, which provides operation and maintenance, or O&M, services to these subsidiaries. The Company incurred total expenses for these services of $37 million and $31 million for the year ended December 31, 2020 and 2019, respectively. The Company incurred total expenses of $11 million for the period from September 1, 2018 to December 31, 2018. There was a balance of $10 million and $7 million due to RENOM as of December 31, 2020 and 2019, respectively. Administrative Services Agreements by and between the Company and CEG Various wholly-owned subsidiaries of the Company are parties to administrative services agreements with Clearway Asset Services and Clearway Solar Asset Management, two wholly-owned subsidiaries of CEG, which provide various administrative services to the Company's subsidiaries. The Company incurred expenses under these agreements of $10 million and $7 million for the year ended December 31, 2020 and 2019, respectively. The Company incurred expenses under these agreements of $3 million for the period from September 1, 2018 to December 31, 2018. There was a balance of $2 million and $1 million due to CEG as of December 31, 2020 and 2019, respectively. CEG Master Services Agreements The Company is a party to Master Services Agreements with CEG, or MSAs, pursuant to which CEG and certain of its affiliates or third party service providers provide 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 provides certain services to CEG, including accounting, internal audit, tax and treasury services, in exchange for the payment of fees in respect of such services. The Company incurred net expenses of $2 million and $1 million under these agreements for the year ended December 31, 2020 and 2019, respectively. 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: O&M Services Agreements by and between the Company and NRG Renew Operation & Maintenance LLC Various wholly-owned subsidiaries of the Company in the Renewables segment were party to administrative services agreements with NRG Renew Operation & Maintenance LLC, or RENOM, formerly wholly-owned subsidiary of NRG, which provided O&M, services to these subsidiaries. The Company incurred total expenses for these services of $29 million for the eight months ended August 31, 2018. Administrative Services Agreements by and between the Company and NRG Various wholly-owned subsidiaries of the Company were parties to administrative services agreements with Clearway Asset Services (formerly NRG Asset Services) and Clearway Solar Asset Management (formerly NRG Solar Asset Management), two wholly-owned subsidiaries of CEG, which provided various administrative asset services to the Company's subsidiaries prior to GIP Transaction. The Company reimbursed costs under this agreement of $6 million for the eight months ended August 31, 2018. Power Purchase Agreements (PPAs) between the Company and NRG Power Marketing Elbow Creek and Dover were parties to PPAs with NRG Power Marketing and generate revenue under the PPAs, which were 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. 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, were parties to Energy Marketing Services Agreements with NRG Power Marketing, a wholly-owned subsidiary of NRG. Under the agreements, NRG Power Marketing procured 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. Operation and Maintenance (O&M) Services Agreements by and between the 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 were $27 million for the eight months ended August 31, 2018. 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. 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. 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. 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. Costs incurred under this agreement were $7 million for the eight months ended August 31, 2018. On August 31, 2018, in connection with the consummation of the GIP Transaction, Clearway Energy, Inc. 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. Concurrently with entering into the Termination Agreement on August 31, 2018, the Company entered into a Transition Services Agreement with NRG, or the NRG TSA, as further described below. Subsequent to the GIP Transaction, the Company entered into 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 pph 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, Acquisitions and Dispositions , 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	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies 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, 2020, 2019 and 2018, the Company purchased $32 million, $38 million, and $39 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. As of December 31, 2020, the Company's commitments under such outstanding agreements are estimated as follows: Period (In millions) 2021 $ 9 2022 3 2023 2 2024 — 2025 — Thereafter — Total $ 14 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 PPAs between NPPD and the projects. NPPD alleges that the Company moved forward with certain transactions without obtaining the consent of NPPD. NPPD threatened to terminate the applicable PPAs 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 PPAs. 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. On April 13, 2020, the U.S. District Court granted the wind projects' motion for summary judgment and permanently enjoined NPPD from terminating the PPAs in reliance on the alleged events of default. The U.S. District Court decision was appealed by NPPD on May 11, 2020 and the case in the Knox County District Court remains pending, but has been stayed pending the outcome of the U.S. District Court case. Argument before the U.S. Court of Appeals for the Eight Circuit is scheduled for March 18, 2021. The Company believes the allegations of NPPD are meritless and the Company is vigorously defending its rights under the PPAs. Buckthorn Solar Litigation On October 8, 2019, the City of Georgetown, Texas, or Georgetown, filed a petition in the District Court of Williamson County, Texas naming Buckthorn Westex, LLC, the Company’s subsidiary that owns the Buckthorn Westex solar project, as the defendant, alleging fraud by nondisclosure and breach of contract in connection with the project and the PPA, and seeking (i) rescission and/or cancellation of the PPA, (ii) declaratory judgment that the alleged breaches constitute an event of default under the PPA entitling Georgetown to terminate, and (iii) recovery of all damages, costs of court, and attorneys’ fees. On November 15, 2019, Buckthorn Westex filed an original answer and counterclaims (i) denying Georgetown’s claims, (ii) alleging Georgetown has breached its contracts with Buckthorn Westex by failing to pay amounts due, and (iii) seeking relief in the form of (x) declaratory judgment that Georgetown’s alleged failure to pay amounts due constitute breaches of and an event of default under the PPA and that Buckthorn did not commit any events of default under the PPA, (y) recovery of costs, expenses, interest, and attorneys’ fees, and (z) such other relief to which it is entitled at law or in equity. Buckthorn Westex believes the allegations of Georgetown are meritless, and Buckthorn Westex is vigorously defending its rights under the PPA.

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	Leases Accounting for Leases The Company evaluates each arrangement at inception to determine if it contains a lease. Substantially all of the Company’s leases are operating leases. Lessee The Company records its operating lease liabilities at the present value of the lease payments over the lease term at lease commencement date. Lease payments include fixed payment amounts, as well as variable rate payments based on an index initially measured at lease commencement date. Variable payments, including payments based on future performance and based on index changes, are recorded as the expense is incurred. The Company determines the relevant lease term by evaluating whether renewal and termination options are reasonably certain to be exercised. The Company uses its incremental borrowing rate to calculate the present value of the lease payments, based on information available at the lease commencement date. The Company’s leases consist of land leases for numerous operating asset locations, real estate leases and equipment leases. The terms and conditions for these leases vary by the type of underlying asset. Lease expense for the year ended December 31, 2020 and December 31, 2019 was comprised of the following: (In millions) December 31, 2020 December 31, 2019 Operating lease cost - Fixed $ 19 $ 13 Operating lease cost - Variable 9 8 Total lease cost $ 28 $ 21 Operating lease information as of December 31, 2020 and 2019 was as follows: (In millions, except term and rate) December 31, 2020 December 31, 2019 ROU Assets - operating leases, net (a) $ 337 $ 223 Short-term lease liability - operating leases (b) $ 8 $ 7 Long-term lease liability - operating leases (a) 345 227 Total lease liability $ 353 $ 234 Weighted average remaining lease term (in years) 25 25 Weighted average discount rate 4.3 % 4.4 % Cash paid for operating leases $ 19 $ 15 (a) Increase in ROU Assets and lease liabilities is primarily due to the acquisition of Drop Down Assets, as further described in Note 3, Acquisitions and Dispositions (b) Short-term lease liability balances are included within the accrued expenses and other current liabilities line item of the consolidated balance sheets as of December 31, 2020 and December 31, 2019 Maturities of operating lease liabilities as of December 31, 2020 are as follows: (In millions) 2021 $ 23 2022 23 2023 23 2024 23 2025 23 Thereafter 476 Total lease payments 591 Less imputed interest (238) Total lease liability - operating leases $ 353 Oahu Solar Lease Agreements The Oahu Solar projects are party to various land lease agreements with a wholly owned subsidiary of CEG. The projects are leasing the land for a period of 35 years, with the ability to renew the lease for two additional five Rosamond Lease Agreement The Rosamond Central project is party to a land lease agreement with a wholly owned subsidiary of CEG. The project is leasing the land for a period of 35 years, with the ability to renew the lease for two additional five Lessor The majority of the Company’s revenue is obtained through PPAs or other contractual agreements that are accounted for as leases. These leases are comprised of both fixed payments and variable payments contingent upon volumes or performance metrics. The terms of the leases are further described in Item 2 — Properties of this Form 10-K. Many of the leases have renewal options at the end of the lease term. Termination may be allowed under specific circumstances in the lease arrangements, such as under an event of default. All but one of the Company’s leases are operating leases. The remaining lease met the criteria of a s ales-type lease and the impact of this sales-type lease to the consolidated financial statements was immaterial. Certain of these leases have both lease and non-lease components, and the Company allocates the transaction price to the components based on standalone selling prices. The following amounts of energy and capacity revenue are related to the Company’s operating leases. December 31, 2020 (In millions) Conventional Generation Renewables Thermal Total Energy revenue $ 10 $ 554 $ 2 $ 566 Capacity revenue 451 — — 451 Operating revenue $ 461 $ 554 $ 2 $ 1,017 December 31, 2019 (In millions) Conventional Generation Renewables Thermal Total Energy revenue $ 5 $ 509 $ 2 $ 516 Capacity revenue 348 — — 348 Operating revenue $ 353 $ 509 $ 2 $ 864 Minimum future rent payments for the remaining periods related to the Conventional segment operating leases were as follows as of December 31, 2020: (In millions) 2021 $ 444 2022 450 2023 259 2024 106 2025 107 Thereafter 1,498 Total lease payments $ 2,864 Property, plant and equipment, net related to the Company’s operating leases were as follows: (In millions) December 31, 2020 December 31, 2019 Property, plant and equipment $ 7,201 $ 6,942 Accumulated depreciation (1,964) (1,649) Net property, plant and equipment $ 5,237 $ 5,293 Energy Center Caguas Sales-Type Lease Agreement On November 1, 2018, the Company, through its indirect subsidiary Energy Center Caguas LLC, entered into an Energy Services Agreement (ESA) for its Viatris (formerly Mylan) facility in Puerto Rico. The ESA was determined to be a sales-type lease, as the present value of the lease payments is greater than substantially all of the fair value of the facility. As a result, upon the service commencement date of the contract, the Company recorded a lease receivable of approximately $12 million which represents the net present value of the lease investment. The Company is permitted to receive approximately $1 million per year in fixed payments under the ESA, which expires in September 2032 based upon a service commencement date in September 2020, with options to extend the term for two additional five Minimum future rent payments for the remaining periods related to the Thermal segment sales-type lease were as follows as of December 31, 2020: (In millions) 2021 $ 1 2022 1 2023 1 2024 1 2025 1 Thereafter 9 Total sales-type lease payments $ 14
Leases	Leases Accounting for Leases The Company evaluates each arrangement at inception to determine if it contains a lease. Substantially all of the Company’s leases are operating leases. Lessee The Company records its operating lease liabilities at the present value of the lease payments over the lease term at lease commencement date. Lease payments include fixed payment amounts, as well as variable rate payments based on an index initially measured at lease commencement date. Variable payments, including payments based on future performance and based on index changes, are recorded as the expense is incurred. The Company determines the relevant lease term by evaluating whether renewal and termination options are reasonably certain to be exercised. The Company uses its incremental borrowing rate to calculate the present value of the lease payments, based on information available at the lease commencement date. The Company’s leases consist of land leases for numerous operating asset locations, real estate leases and equipment leases. The terms and conditions for these leases vary by the type of underlying asset. Lease expense for the year ended December 31, 2020 and December 31, 2019 was comprised of the following: (In millions) December 31, 2020 December 31, 2019 Operating lease cost - Fixed $ 19 $ 13 Operating lease cost - Variable 9 8 Total lease cost $ 28 $ 21 Operating lease information as of December 31, 2020 and 2019 was as follows: (In millions, except term and rate) December 31, 2020 December 31, 2019 ROU Assets - operating leases, net (a) $ 337 $ 223 Short-term lease liability - operating leases (b) $ 8 $ 7 Long-term lease liability - operating leases (a) 345 227 Total lease liability $ 353 $ 234 Weighted average remaining lease term (in years) 25 25 Weighted average discount rate 4.3 % 4.4 % Cash paid for operating leases $ 19 $ 15 (a) Increase in ROU Assets and lease liabilities is primarily due to the acquisition of Drop Down Assets, as further described in Note 3, Acquisitions and Dispositions (b) Short-term lease liability balances are included within the accrued expenses and other current liabilities line item of the consolidated balance sheets as of December 31, 2020 and December 31, 2019 Maturities of operating lease liabilities as of December 31, 2020 are as follows: (In millions) 2021 $ 23 2022 23 2023 23 2024 23 2025 23 Thereafter 476 Total lease payments 591 Less imputed interest (238) Total lease liability - operating leases $ 353 Oahu Solar Lease Agreements The Oahu Solar projects are party to various land lease agreements with a wholly owned subsidiary of CEG. The projects are leasing the land for a period of 35 years, with the ability to renew the lease for two additional five Rosamond Lease Agreement The Rosamond Central project is party to a land lease agreement with a wholly owned subsidiary of CEG. The project is leasing the land for a period of 35 years, with the ability to renew the lease for two additional five Lessor The majority of the Company’s revenue is obtained through PPAs or other contractual agreements that are accounted for as leases. These leases are comprised of both fixed payments and variable payments contingent upon volumes or performance metrics. The terms of the leases are further described in Item 2 — Properties of this Form 10-K. Many of the leases have renewal options at the end of the lease term. Termination may be allowed under specific circumstances in the lease arrangements, such as under an event of default. All but one of the Company’s leases are operating leases. The remaining lease met the criteria of a s ales-type lease and the impact of this sales-type lease to the consolidated financial statements was immaterial. Certain of these leases have both lease and non-lease components, and the Company allocates the transaction price to the components based on standalone selling prices. The following amounts of energy and capacity revenue are related to the Company’s operating leases. December 31, 2020 (In millions) Conventional Generation Renewables Thermal Total Energy revenue $ 10 $ 554 $ 2 $ 566 Capacity revenue 451 — — 451 Operating revenue $ 461 $ 554 $ 2 $ 1,017 December 31, 2019 (In millions) Conventional Generation Renewables Thermal Total Energy revenue $ 5 $ 509 $ 2 $ 516 Capacity revenue 348 — — 348 Operating revenue $ 353 $ 509 $ 2 $ 864 Minimum future rent payments for the remaining periods related to the Conventional segment operating leases were as follows as of December 31, 2020: (In millions) 2021 $ 444 2022 450 2023 259 2024 106 2025 107 Thereafter 1,498 Total lease payments $ 2,864 Property, plant and equipment, net related to the Company’s operating leases were as follows: (In millions) December 31, 2020 December 31, 2019 Property, plant and equipment $ 7,201 $ 6,942 Accumulated depreciation (1,964) (1,649) Net property, plant and equipment $ 5,237 $ 5,293 Energy Center Caguas Sales-Type Lease Agreement On November 1, 2018, the Company, through its indirect subsidiary Energy Center Caguas LLC, entered into an Energy Services Agreement (ESA) for its Viatris (formerly Mylan) facility in Puerto Rico. The ESA was determined to be a sales-type lease, as the present value of the lease payments is greater than substantially all of the fair value of the facility. As a result, upon the service commencement date of the contract, the Company recorded a lease receivable of approximately $12 million which represents the net present value of the lease investment. The Company is permitted to receive approximately $1 million per year in fixed payments under the ESA, which expires in September 2032 based upon a service commencement date in September 2020, with options to extend the term for two additional five Minimum future rent payments for the remaining periods related to the Thermal segment sales-type lease were as follows as of December 31, 2020: (In millions) 2021 $ 1 2022 1 2023 1 2024 1 2025 1 Thereafter 9 Total sales-type lease payments $ 14

Unaudited Quarterly Financial D

Unaudited Quarterly Financial Data	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Unaudited Quarterly Data	Unaudited Quarterly Data Below is summarized unaudited quarterly financial data for the periods ending December 31, 2020 and 2019. Quarter Ended December 31, September 30, June 30, March 31, 2020 (In millions) Operating Revenues $ 280 $ 332 $ 329 $ 258 Operating Income 28 123 131 52 Net (Loss) Income $ (78) $ 51 $ 104 $ (129) Quarter Ended December 31, September 30, June 30, March 31, 2019 (In millions) Operating Revenues $ 235 $ 296 $ 284 $ 217 Operating Income 7 90 88 41 Net (Loss) Income $ (41) $ 25 $ (31) $ (54)

Schedule I - Condensed Financia

Schedule I - Condensed Financial Information of Registrant	12 Months Ended
	Dec. 31, 2020
Condensed Financial Information Disclosure [Abstract]
Condensed Financial Information of Registrant	Clearway Energy LLC (Parent) Condensed Financial Information of Registrant Condensed Statements of Operations Year ended December 31, (In millions) 2020 2019 2018 Equity in earnings (losses) of consolidated affiliates $ 61 $ (32) $ 237 Other income, net — 2 3 Loss on debt extinguishment — — — Interest expense — — — Total other income, net — 2 3 Net Income (Loss) Attributable to Clearway Energy LLC $ 61 $ (30) $ 240 Clearway Energy LLC (Parent) Condensed Balance Sheets December 31, December 31, 2020 2019 ASSETS (In millions) Current Assets Cash and cash equivalents $ 119 $ 27 Investment in consolidated subsidiaries 1,545 1,824 Total Assets $ 1,664 $ 1,851 LIABILITIES AND MEMBERS' EQUITY Current Liabilities Accounts payable — affiliates 24 1 Total Liabilities 24 1 Commitments and Contingencies Members' Equity Contributed capital 1,723 1,882 (Accumulated deficit) retained earnings (50) 5 Accumulated other comprehensive loss (33) (37) Total Members' Equity 1,640 1,850 Total Liabilities and Members’ Equity $ 1,664 $ 1,851 Clearway Energy LLC (Parent) Condensed Statements of Cash Flows Years ended December 31, 2020 2019 2018 (In millions) Cash Flows from Operating Activities Net Cash Provided by Operating Activities $ — $ — $ — Cash Flows from Investing Activities Investments in consolidated affiliates 306 (211) 361 Net Cash Provided by (Used in) Investing Activities 306 (211) 361 Cash Flows from Financing Activities Transfer of funds under intercompany cash management arrangement (65) (5) — Proceeds from issuance of Class C units 62 100 153 Payments of distributions (211) (155) (238) Net Cash Used in Financing Activities (214) (60) (85) Net Increase (Decrease) in Cash and Cash Equivalents 92 (271) 276 Cash and Cash Equivalents at Beginning of Period 27 298 22 Cash and Cash Equivalents at End of Period $ 119 $ 27 $ 298 Background Clearway Energy LLC, together with its consolidated subsidiaries, or the Company, is an investor in and owner of modern, sustainable and long-term contracted assets across North America. On August 31, 2018, NRG Energy, Inc., or NRG, transferred its full ownership interest in the Company 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 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 Clearway, Inc. GIP is an independent fund manager that invests in infrastructure assets in energy and transport sectors. The Company is sponsored by GIP through its portfolio company, CEG. The Company is one of the largest renewable energy owners in the U.S. with over 4,200 net MW of installed wind and solar generation projects. The Company also owns approximately 2,500 net MW of environmentally-sound, highly efficient generation facilities as well as a portfolio of district energy systems. Through this environmentally-sound, diversified and primarily contracted portfolio, the Company endeavors to provide its investors with stable and growing dividend income. Substantially all of the Company's generation assets are under long-term contractual arrangements for the output or capacity from these assets. Clearway Energy, Inc. 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, 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, Inc. Class C common stock issuances during the year ended December 31, 2020, Clearway, Inc. currently owns 57.61% of the economic interests of the Company, with CEG retaining 42.39% of the economic interests of the Company. For further discussion, see Item 15 — Note 11, Members' Equity. Basis of Presentation The condensed parent-only company financial statements have been prepared in accordance with Rule 12-04 of Regulation S-X, as the restricted net assets of Clearway Energy LLC's subsidiaries exceed 25% of the consolidated net assets of Clearway Energy LLC. The parent's 100% investment in its subsidiaries has been recorded using the equity basis of accounting in the accompanying condensed parent-only financial statements. These statements should be read in conjunction with the consolidated financial statements and notes thereto of Clearway Energy LLC. Note 2 — Long-Term Debt For a discussion of Clearway Energy LLC’s financing arrangements, see Note 10, Long-term Debt, to the Company's consolidated financial statements. Note 3 — Commitments, Contingencies and Guarantees See Note 14, Commitments and Contingencies, to the Company's consolidated financial statements for a detailed discussion of Clearway Energy LLC’s commitments and contingencies. Note 4 — Dividends

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
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.
Accounts Receivable - Trade and Allowance for Doubtful Accounts	Accounts receivable — trade 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, 2020 and 2019.
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. Construction in-progress represents cumulative construction costs, including the costs incurred for the purchase of major equipment and engineering costs and capitalized interest. Once the project achieves commercial operation, the Company reclassifies the amounts recorded in construction in progress to facilities and equipment. 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 their carrying values may not be recoverable. Such reviews are performed in accordance with ASC 360. An impairment loss is indicated if the total future estimated undiscounted cash flows expected from an asset are less than its carrying value. An impairment charge is measured by the difference between an asset's carrying amount and fair value with the difference recorded in operating costs and expenses in the statements of operations. Fair values are determined by a variety of valuation methods, including appraisals, sales prices of similar assets and present value techniques. For further discussion of the Company's long-lived asset impairments, refer to Note 9, Asset Impairments, to the Consolidated Financial Statements. Investments accounted for by the equity method are reviewed for impairment in accordance with ASC 323, Investments-Equity Method and Joint Ventures , which requires that a loss in value of an investment that is an other-than-temporary decline should be recognized. The Company identifies and measures losses in the value of equity method investments based upon a comparison of fair value to carrying value.
Debt Issuance Costs	Debt issuance costs are capitalized and amortized as interest expense on a basis which approximates the effective interest method over the term of the related debt. Debt issuance costs related to the long term debt are presented as a direct deduction from the carrying amount of the related debt in both the current and prior periods. Debt issuance costs related to the senior secured revolving credit facility line of credit are recorded as a non-current asset on the balance sheet and are amortized over the term of the credit facility.
Intangible Assets	Intangible assets represent contractual rights held by the Company. The Company recognizes specifically identifiable intangible assets including power purchase agreements, leasehold rights, 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	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. Previously ASC 840, and currently, ASC 842, 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, 2020, 2019 and 2018 was $589 million, $537 million and $583 million, respectively. See Note 15, Leases for additional information related to the Company's PPAs accounted for as leases. 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.
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 analysis to measure the statistical correlation between the derivative and the associated hedged item to 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 industries. 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 Company's Business, 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.
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.
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 business acquisitions that relate to entities under common control, ASC 805 requires retrospective combination of the entities for all annual periods presented as if the combination has been in effect from the beginning of the earliest financial statement period presented or from the date the entities were under common control (if later than the beginning of the earliest financial statement period). The difference between the cash paid and historical value of the entities' equity is recorded as a distribution/contribution from/to CEG with the offset to noncontrolling interest. 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, AROs, 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 solar energy systems, under operating leases or PPAs, that are eligible for certain tax credits. The Company has determined that the provisions in the contractual agreements of these structures represent substantive profit sharing arrangements. Further, the Company has determined that the appropriate methodology for calculating the noncontrolling interest and investment in unconsolidated affiliates that reflects the substantive profit sharing arrangements is a balance sheet approach utilizing the hypothetical liquidation at book value, or HLBV, method. Under the HLBV method, the amounts reported as noncontrolling interests and investment in unconsolidated affiliates represent the amounts the investors to the tax equity arrangements would hypothetically receive at each balance sheet date under the liquidation provisions of the contractual agreements, assuming the net assets of the funding structures were liquidated at their recorded amounts determined in accordance with GAAP. The investors’ interests in the results of operations of the funding structures are determined as the difference in noncontrolling interests and investment in unconsolidated affiliates at the start and end of each reporting period, after taking into account any capital transactions between the structures and the funds’ investors. The calculations utilized to apply the HLBV method include estimated calculations of taxable income or losses for each reporting period.
Reclassification	Certain prior year amounts have been reclassified for comparative purposes.
Recent Accounting Developments	In March 2020, the FASB issued ASU No. 2020-4, Facilitation of the Effects of Reference Rate Reform on Financial Reporting. The amendments provide for optional expedients and exceptions for applying GAAP to contracts, hedging relationships and other transactions affected by reference rate reform if certain criteria is met. These amendments apply only to contracts that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. The guidance is effective for all entities as of March 12, 2020 through December 31, 2022. The Company intends to apply the amendments to all its eligible contract modifications where applicable during the reference rate reform period. As of December 31, 2020, the Company has not elected any optional expedients provided in the standard. Effective January 1, 2019, the Company adopted ASU No. 2016-02, Leases (Topic 842), or Topic 842 using the modified retrospective transition method. The Company elected available practical expedients permitted under the transition guidance within the new standard, which among other items, allowed the Company to carry forward its historical lease classification and not reassess existing leases under the new definition of a lease in ASC 842. In addition, the Company also elected to account for lease and non-lease components as a single lease component. The adoption of the standard resulted in the recording of operating lease liabilities of $165 million and related ROU assets of $159 million. There was no impact to the Company’s consolidated statement of operations or cash flows. Recently Issued Accounting Standards Not Yet Adopted In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes. The amendments in this ASU simplify the accounting for income taxes by removing certain exceptions to the general principles in Topic 740, Income Taxes. The amendments also improve consistent application of and simplify GAAP for other areas of Topic 740 by clarifying and amending existing guidance. The guidance is effective January 1, 2021, with early adoption permitted. The Company does not expect the effect of the new guidance to be material on its consolidated financial statements.

Nature of Business (Tables)

Nature of Business (Tables)	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Company Organization Chart	The following table represents the structure of the Company as of December 31, 2020:

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
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, 2020 2019 (In millions) Cash and cash equivalents $ 268 $ 152 Restricted cash 197 262 Cash, cash equivalents and restricted cash shown in the statements of cash flows $ 465 $ 414
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, 2020 2019 (In millions) Cash and cash equivalents $ 268 $ 152 Restricted cash 197 262 Cash, cash equivalents and restricted cash shown in the statements of cash flows $ 465 $ 414
Disaggregation of Revenue	The following tables represent the Company’s disaggregation of revenue from contracts with customers for the year ended December 31, 2020, along with the reportable segment for each category: Year ended December 31, 2020 (In millions) Conventional Generation Renewables Thermal Total Energy revenue (a) $ 10 $ 609 $ 101 $ 720 Capacity revenue (a) 451 — 63 514 Other revenues — 21 32 53 Contract amortization (24) (61) (3) (88) Total operating revenue 437 569 193 1,199 Less: Lease revenue (461) (554) (2) (1,017) Less: Contract amortization 24 61 3 88 Total revenue from contracts with customers $ — $ 76 $ 194 $ 270 (a) See Note 17, Leases for the amounts of energy and capacity revenue that relate to leases and are accounted for under ASC 842. The following tables represent the Company’s disaggregation of revenue from contracts with customers for the year ended December 31, 2019, along with the reportable segment for each category: Year ended December 31, 2019 (In millions) Conventional Generation Renewables Thermal Total Energy revenue (a) $ 5 $ 545 $ 120 $ 670 Capacity revenue (a) 348 — 54 402 Other revenues — 10 30 40 Contract amortization (7) (61) (3) (71) Mark-to-market for economic hedges — (9) — (9) Total operating revenue 346 485 201 1,032 Less: Lease revenue (353) (509) (2) (864) Less: Contract amortization 7 61 3 71 Total revenue from contracts with customers $ — $ 37 $ 202 $ 239 (a) See Note 17, Leases for the amounts of energy and capacity revenue that relate to leases and are accounted for under ASC 840 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 Total Energy revenue (a) $ 5 $ 572 $ 120 $ 697 Capacity revenue (a) 337 — 50 387 Other revenues — 13 26 39 Contract amortization (5) (62) (3) (70) Total operating revenue 337 523 193 1,053 Less: Lease revenue (342) (534) (2) (878) Less: Contract amortization 5 62 3 70 Total revenue from contracts with customers $ — $ 51 $ 194 $ 245
Schedule of Contract Balances	(In millions) December 31, 2020 December 31, 2019 Accounts receivable, net - Contracts with customers $ 57 $ 34 Accounts receivable, net - Leases 86 82 Total accounts receivable, net $ 143 $ 116
Schedule of Change in Asset Retirement Obligation	The following table represents the balance of ARO obligations as of December 31, 2020 and 2019, along with the additions and accretion related to the Company's ARO obligations for the year ended December 31, 2020: (In millions) Balance as of December 31, 2019 $ 75 Revisions in estimates for current obligations 9 Additions 26 Accretion — expense 7 Balance as of December 31, 2020 $ 117

Acquisitions and Dispositions (

Acquisitions and Dispositions (Tables)	12 Months Ended
	Dec. 31, 2020
Business Combinations [Abstract]
Schedule of Recognized Identified Assets Acquired and Liabilities Assumed	The following is a summary of assets and liabilities transferred in connection with the acquisition as of November 20, 2020: (In millions) Langford Current Assets $ 4 Property, plant and equipment, net 138 Other non-current assets 15 Total assets 157 Other current and non-current liabilities 17 Total liabilities 17 Noncontrolling interests 119 Net assets less noncontrolling interests $ 21 The following is a summary of assets and liabilities transferred in connection with the acquisition as of December 21, 2020: (In millions) Rosamond Central Current Assets $ 49 Property, plant and equipment, net 246 Other non-current assets 1 Total assets 296 Long-term debt 205 Other current and non-current liabilities 11 Total liabilities 216 Noncontrolling interests 52 Net assets less noncontrolling interests $ 28 The following table shows the balances that were consolidated effective on December 21, 2020: (In millions) Mesquite Star Current assets $ 22 Property, plant and equipment, net 443 Other non-current assets 31 Total assets 496 Other current and non-current liabilities 87 Total liabilities 87 Noncontrolling interests and redeemable noncontrolling interests 346 Net assets less noncontrolling interests $ 63 The following table shows the balances that were consolidated: November 2, 2020 May 29, 2020 (In millions) DGPV Holdco 1 and 2 (a) DGPV Holdco 3 (b) Current assets $ 29 $ 32 Property, plant and equipment, net 324 331 Intangible assets, net 19 1 Other non-current assets 52 37 Total assets 424 401 Long-term debt 160 206 Other current and non-current liabilities 54 84 Total liabilities 214 290 Noncontrolling interests and redeemable noncontrolling interests 5 6 Net assets less noncontrolling interests $ 205 $ 105 (a) Includes DGPV 1, LLC, DGPV 2, LLC, CA Fund, LLC, DGPV 4 Borrower LLC and Puma Class B LLC (b) Includes Renew Solar CS4 Fund LLC and Chestnut Fund LLC (In millions) CBAD Holdings, LLC Current Assets $ 36 Property, plant and equipment, net 572 Intangible assets, net 337 Other non-current assets 51 Total assets 996 Debt (a) 791 Other current and non-current liabilities (b) 56 Total liabilities 847 Net assets acquired $ 149 (a) Excludes net debt issuance costs of $12 million. (b) Other current liabilities and non-current liabilities include a contingent liability of $5 million assumed by the Company during the acquisition.

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
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, 2020 December 31, 2019 Depreciable Lives (In millions) Facilities and equipment $ 9,254 $ 7,676 2 - 45 Years Land and improvements 224 173 Construction in progress (a) 62 94 Total property, plant and equipment 9,540 7,943 Accumulated depreciation (2,323) (1,880) Net property, plant and equipment $ 7,217 $ 6,063 (a) As of December 31, 2020 and 2019, construction in progress includes $14 million and $10 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, 2020
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	Name Economic Interest Investment Balance (In millions) Utah Solar Portfolio (a) 50% $ 255 Desert Sunlight 25% 244 Agua Caliente Solar (b) 16% 83 GenConn (c) 50% 90 San Juan Mesa 75% 33 Elkhorn Ridge 66.7% 38 Avenal 50% (2) $ 741 (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) On February 3, 2021, the Company acquired an additional 35% equity interest in Agua Caliente Solar and following the close of the transaction owns 51% equity interests in Agua Caliente and will remove its equity method investment and consolidate its interest from the date of the acquisition. (c) GenConn is a variable interest entity. The following tables present summarized financial information for the Company's equity method investments: Year Ended December 31, 2020 2019 2018 Income Statement Data: (In millions) GenConn Operating revenues $ 60 $ 60 $ 65 Operating income 26 27 32 Net income 17 17 22 Desert Sunlight Operating revenues 209 205 208 Operating income 142 123 129 Net income 88 58 84 Other (a) Operating revenues 299 318 332 Operating income 138 110 126 Net income $ 60 $ 50 $ 86 As of December 31, 2020 2019 Balance Sheet Data: (In millions) GenConn Current assets $ 40 $ 37 Non-current assets 344 342 Current liabilities 17 16 Non-current liabilities 185 176 Desert Sunlight Current assets 132 209 Non-current assets 1,244 1,296 Current liabilities 71 545 Non-current liabilities 921 484 Other (a) Current assets 177 279 Non-current assets 2,201 3,412 Current liabilities 114 809 Non-current liabilities 700 500 Redeemable noncontrolling interest $ — $ (1) (a) Includes Agua Caliente, Elkhorn Ridge, Utah Solar Portfolio, San Juan Mesa, DGPV Holdco 1, DGPV Holdco 2 and DGPV Holdco 3. DGPV Holdco 1, DGPV Holdco 2 and DGPV Holdco 3. were consolidated by the Company during 2020 and are therefore excluded from the summarized balance sheet data as of December 31, 2020.
Schedule of Variable Interest Entities	Summarized financial information for the Company's consolidated VIEs consisted of the following as of December 31, 2020: (In millions) Oahu Kawailoa Partnership Wildorado DGPV Funds (a) Lighthouse Renewable Holdco LLC Rosie TargetCo LLC Langford TE Partnership LLC Alta TE Holdco Buckthorn Renewables, LLC Other (b) Other current and non-current assets $ 23 $ 21 $ 14 $ 105 $ 48 $ 40 $ 15 $ 56 $ 2 $ 21 Property, plant and equipment 179 141 240 778 444 258 138 356 210 184 Intangible assets — — — 2 — — 2 225 — 1 Total assets 202 162 254 885 492 298 155 637 212 206 Current and non-current liabilities 122 111 11 77 82 118 18 44 9 33 Total liabilities 122 111 11 77 82 118 18 44 9 33 Noncontrolling interest 14 31 123 4 347 150 108 33 58 99 Net assets less noncontrolling interests $ 66 $ 20 $ 120 $ 804 $ 63 $ 30 $ 29 $ 560 $ 145 $ 74 (a) DGPV Funds is comprised of DGPV Fund 2 LLC, Clearway & EFS Distributed Solar LLC, DGPV Fund 4 LLC, Golden Puma Fund LLC, Renew Solar CS4 Fund LLC and Chestnut Fund LLC (b) Other is comprised of Crosswinds, Hardin, Elbow Creek Holdco and Spring Canyon projects

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2020
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, 2020 As of December 31, 2019 Carrying Amount Fair Value Carrying Amount Fair Value (In millions) Liabilities: Long-term debt, including current portion — affiliate $ 1 $ 1 $ 44 $ 43 Long-term debt, including current portion — external (a) $ 7,048 $ 7,020 $ 6,813 $ 6,913 (a) Excludes net debt issuance costs, which are recorded as a reduction to long-term debt on the Company's consolidated balance sheets.
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, 2020 and 2019: As of December 31, 2020 As of December 31, 2019 Level 2 Level 3 Level 2 Level 3 (In millions) Long-term debt, including current portion $ 1,906 $ 5,115 $ 1,735 $ 5,221
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, 2020 As of December 31, 2020 As of December 31, 2019 As of December 31, 2019 Fair Value Fair Value (a) Fair Value (a) Fair Value (a) (In millions) Level 2 Level 3 Level 2 Level 3 Derivative assets Interest rate contracts $ 1 $ — $ — $ — Other financial instruments (b) — 29 — — Total assets $ 1 $ 29 $ — $ — Derivative liabilities Commodity contracts $ — $ 44 $ — $ 9 Interest rate contracts 129 — 83 — Total liabilities $ 129 $ 44 $ 83 $ 9 (a) There were no derivative assets classified as Level 1, or Level 3 and no liabilities classified as Level 1 as of December 31, 2020 and no derivative assets classified as Level 1, Level 2 or Level 3 and no liabilities classified as Level 1 as of December 31, 2019. (b) SREC contract acquired on November 2, 2020. The following table reconciles the beginning and ending balances for instruments that are recognized at fair value in the condensed consolidated financial statements using significant unobservable inputs: Year ended December 31, 2020 2019 (In millions) Fair Value Measurement Using Significant Unobservable Inputs (Level 3) Beginning balance $ (9) $ — Total losses for the period included in earnings — (3) Purchases (6) (6) Ending balance $ (15) $ (9) Change in unrealized losses included in earnings for derivatives held as of December 31, $ 1 $ (3)
Fair Value Measurement Inputs and Valuation Techniques	The following table quantifies the significant unobservable inputs used in developing the fair value of the Company's Level 3 positions as of December 31, 2020: December 31, 2020 Fair Value Input/Range Assets Liabilities Valuation Technique Significant Unobservable Input Low High Weighted Average (In millions) Power Contracts $ — $ (44) Discounted Cash Flow Forward Market Price (per MWh) $ 8.64 $ 42.37 $ 17.93 Other Financial Instruments $ 29 — Discounted Cash Flow Forecast annual generation levels of certain DG solar facilities 80,872 MWh 131,374 MWh 126,063 MWh The following table provides sensitivity of fair value measurements to increases/(decreases) in significant unobservable inputs as of December 31, 2020: Significant Observable Input Position Change In Input Impact on Fair Value Measurement Forward Market Price Power Buy Increase/(Decrease) Higher/(Lower) Forward Market Price Power Sell Increase/(Decrease) Lower/(Higher) Forecast Generation Level Sell Increase/(Decrease) Higher/(Lower)

Accounting for Derivative Ins_2

Accounting for Derivative Instruments and Hedging Activities (Tables)	12 Months Ended
	Dec. 31, 2020
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, 2020 and 2019: Total Volume December 31, 2020 December 31, 2019 Commodity Units (In millions) Natural Gas MMBtu 1 2 Power MWh (8) (2) Interest Dollars $ 1,600 $ 1,788
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, 2020 December 31, 2020 December 31, 2019 (In millions) Derivatives Designated as Cash Flow Hedges: Interest rate contracts current $ — $ 8 $ 3 Interest rate contracts long-term — 15 11 Total Derivatives Designated as Cash Flow Hedges $ — $ 23 $ 14 Derivatives Not Designated as Cash Flow Hedges: Interest rate contracts current — 25 13 Interest rate contracts long-term 1 81 56 Commodity contracts current — 5 — Commodity contracts long-term — 39 9 Total Derivatives Not Designated as Cash Flow Hedges 1 150 78 Total Derivatives $ 1 $ 173 $ 92
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, 2020 Gross Amounts of Recognized Assets/Liabilities Derivative Instruments Net Amount Commodity contracts (In millions) Derivative liabilities (44) — (44) Total commodity contracts (44) — (44) Interest rate contracts Derivative assets $ 1 $ — $ 1 Derivative liabilities (129) — (129) Total interest rate contracts (128) — (128) Total derivative instruments $ (172) $ — $ (172) Gross Amounts Not Offset in the Statement of Financial Position As of December 31, 2019 Gross Amounts of Recognized Assets/Liabilities Derivative Instruments Net Amount Commodity contracts (In millions) Derivative liabilities (9) (1) (10) Total commodity contracts (9) (1) (10) Interest rate contracts Derivative liabilities (83) 1 (82) Total interest rate contracts (83) 1 (82) Total derivative instruments $ (92) $ — $ (92)
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, 2020 2019 2018 (In millions) Accumulated OCL beginning balance $ (37) $ (45) $ (69) Reclassified from accumulated OCL to income due to realization of previously deferred amounts 11 22 15 Mark-to-market of cash flow hedge accounting contracts (9) (14) 9 Accumulated OCL ending balance $ (35) $ (37) $ (45) Accumulated OCL attributable to noncontrolling interests (2) — (1) Accumulated OCL attributable to Clearway Energy LLC $ (33) $ (37) $ (44) Losses expected to be realized from OCL during the next 12 months $ (13)

Intangible Assets (Tables)

Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2020
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, 2020 PPAs Leasehold Rights Customer Customer Contracts Emission Allowances Other Total (In millions) January 1, 2020 $ 1,630 $ 86 $ 66 $ 15 $ 17 $ 8 $ 1,822 Consolidation of DGPV Holdco Entities 23 — — — — — 23 Other 8 — — — — 4 12 December 31, 2020 $ 1,661 $ 86 $ 66 $ 15 $ 17 $ 12 $ 1,857 Less accumulated amortization (431) (26) (11) (11) (3) (5) (487) Net carrying amount $ 1,230 $ 60 $ 55 $ 4 $ 14 $ 7 $ 1,370 Year ended December 31, 2019 PPAs Leasehold Rights Customer Relationships Customer Contracts Emission Other Total (In millions) January 1, 2019 $ 1,280 $ 86 $ 66 $ 15 $ 9 $ 8 $ 1,464 Acquisition of Carlsbad 350 — — — 8 — 358 December 31, 2019 $ 1,630 $ 86 $ 66 $ 15 $ 17 $ 8 $ 1,822 Less accumulated amortization (347) (22) (9) (10) (2) (4) (394) Net carrying amount $ 1,283 $ 64 $ 57 $ 5 $ 15 $ 4 $ 1,428
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The Company estimates the future amortization expense for its intangibles for the next five years as follows: (In millions) 2021 $ 91 2022 91 2023 88 2024 85 2025 $ 84

Long-term Debt (Tables)

Long-term Debt (Tables)	12 Months Ended
	Dec. 31, 2020
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, 2020 December 31, 2019 Interest rate % (a) Letters of Credit Outstanding at December 31, 2020 (In millions, except rates) Long-term debt - affiliate, due 2020 — 44 3.325 Intercompany Note with Clearway Energy, Inc. 1 — 1.490 2024 Senior Notes — 88 5.375 2025 Senior Notes 600 600 5.750 2026 Senior Notes 350 350 5.000 2028 Senior Notes 850 600 4.750 Clearway Energy LLC and Clearway Energy Operating LLC Revolving Credit Facility, due 2023 (b) — — L+1.50 $ 66 Project-level debt: Alpine, due 2022 (e) — 119 L+2.00 — Alta Wind I-V lease financing arrangements, due 2034 and 2035 800 844 5.696 - 7.015 44 Alta Wind Asset Management LLC, due 2031 14 15 L+2.50 — Alta Wind Realty Investments LLC, due 2031 25 27 7.000 — Borrego, due 2024 and 2038 57 60 Various 4 Buckthorn Solar, due 2025 126 129 L+1.750 22 Carlsbad Holdco, due 2038 210 216 4.210 4 Carlsbad Energy Holdings LLC, due 2027 156 175 L+1.625 63 Carlsbad Energy Holdings LLC, due 2038 407 407 4.120 — CVSR, due 2037 675 696 2.339 - 3.775 — CVSR Holdco Notes, due 2037 176 182 4.680 13 DG-CS Master Borrower LLC, due 2040 467 — 3.510 30 Duquesne, due 2059 95 95 4.620 — El Segundo Energy Center, due 2023 250 303 L+1.875 - L+2.500 138 Energy Center Minneapolis Series D, E, F, G, H Notes, due 2025-2037 327 328 various — Laredo Ridge, due 2028 78 84 L+2.125 10 Kawailoa Solar Portfolio LLC, due 2026 81 82 L+1.375 14 Marsh Landing, due 2023 146 206 L+2.125 27 NIMH Solar, due 2024 191 — L+2.00 11 Oahu Solar Holdings LLC, due 2026 89 91 L+1.375 10 Repowering Partnership Holdco LLC, due 2020 — 228 L+0.85 — Rosie Class B LLC, due 2027 80 — L+1.75 19 Tapestry, due 2031 143 156 L+1.375 17 Utah Solar Holdings, due 2036 290 — 3.590 11 Utah Solar Portfolio, due 2022 — 254 L+1.625 — Walnut Creek, due 2023 126 175 L+1.75 73 WCEP Holdings, LLC, due 2023 35 39 L+3.00 — Other (c) 199 264 various 50 Subtotal project-level debt 5,243 5,175 Total debt 7,044 6,857 Less current maturities (385) (1,824) Less net debt issuance costs (79) (77) Add premiums (d) 5 — Total long-term debt $ 6,585 $ 4,956 (a) As of December 31, 2020, L+ equals 3 month LIBOR plus x%, except Rosie Class B, due 2027 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) December 31, 2019 includes Blythe and Roadrunner debt outstanding of $14 million and $28 million, respectively which were transferred to NIMH in the third quarter of 2020, as described below (d) Premiums relate to the 2028 Senior Notes
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, 2020: % of Principal Fixed Interest Rate Floating Interest Rate Notional Amount at December 31, 2020 (In millions) Effective Date Maturity Date Avra Valley 87 % 2.33 % 3-Month LIBOR 38 November 30, 2012 November 30, 2030 Alta Wind Asset Management 100 % 2.47 % 3-Month LIBOR 14 May 22, 2013 May 15, 2031 Borrego 100 % 0.476 % 3-Month LIBOR 13 June 30, 2020 December 31, 2024 Buckthorn Solar 82 % Various 3-Month LIBOR 103 February 28, 2018 December 31, 2041 Carlsbad 100 % Various 3-Month LIBOR 156 Various September 30, 2027 El Segundo 100 % Various 3-Month LIBOR 250 Various Various Kansas South 75 % 2.368 % 6-Month LIBOR 17 June 28, 2013 December 31, 2030 Kawailoa Solar 94 % Various 3-Month LIBOR 76 November 30, 2019 October 31, 2040 Laredo Ridge 100 % Various 3-Month LIBOR 78 December 17, 2014 December 31, 2028 Marsh Landing 100 % Various 3-Month LIBOR 146 June 28, 2013 June 30, 2023 NIMH Solar LLC 100 % Various 3-Month LIBOR 191 September 30, 2020 Various Oahu Solar 96 % Various 3-Month LIBOR 86 November 30, 2019 October 31, 2040 Rosie Class B 95 % 1.446 % 3-Month LIBOR 76 December 31, 2020 July 29, 2044 South Trent 90 % 3.847 % 3-Month LIBOR 35 June 14, 2019 June 30, 2028 Tapestry 75 % Various 3-Month LIBOR 107 Various Various Tapestry 50 % 3.57 % 3-Month LIBOR 12 December 21, 2021 December 21, 2029 Viento Funding II 100 % 3.03 % 6-Month LIBOR 33 Various Various Viento Funding II 100 % 4.985 % 6-Month LIBOR 21 July 11, 2023 June 30, 2028 Walnut Creek Energy 90 % 3.543 % 3-Month LIBOR 114 June 28, 2013 May 31, 2023 WCEP Holdings 100 % 4.003 % 3-Month LIBOR 34 June 28, 2013 May 31, 2023 Total $ 1,600
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, 2020, are as follows: (In millions) 2021 $ 384 2022 407 2023 431 2024 359 2025 934 Thereafter 4,528 Total $ 7,043

Members' Equity (Tables)

Members' Equity (Tables)	12 Months Ended
	Dec. 31, 2020
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, 2020: Fourth Quarter 2020 Third Quarter 2020 Second Quarter 2020 First Quarter 2020 Distributions per Class A and Class B units $ 0.3180 $ 0.3125 $ 0.2100 $ 0.2100 Distributions per Class C and Class D units $ 0.3180 $ 0.3125 $ 0.2100 $ 0.2100

Segment Reporting (Tables)

Segment Reporting (Tables)	12 Months Ended
	Dec. 31, 2020
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, 2020, 2019 and 2018: 2020 2019 2018 Customer Conventional Renewables Conventional Renewables Conventional Renewables SCE 18% 16% 21% 19% 20% 20% PG&E 10% 8% 12% 10% 12% 11%
Schedule of Segment Reporting Information, by Segment	Year ended December 31, 2020 (In millions) Conventional Generation Renewables Thermal Corporate (a) Total Operating revenues $ 437 $ 569 $ 193 $ — $ 1,199 Cost of operations 90 147 131 (2) 366 Depreciation, amortization and accretion 132 264 32 — 428 Impairment losses — 24 — — 24 General and administrative — — 3 30 33 Transaction and integration costs — — — 9 9 Development costs — — 5 — 5 Operating income (loss) 215 134 22 (37) 334 Equity in earnings (losses) of unconsolidated affiliates 8 (1) — — 7 Impairment loss on investment — (8) — — (8) Gain on sale of unconsolidated affiliates — — — 49 49 Other income, net 1 4 — (1) 4 Loss on debt extinguishment — (21) — (3) (24) Interest expense, net (84) (216) (19) (95) (414) Net Income (Loss) 140 (108) 3 (87) (52) Net Income (Loss) Attributable to Clearway Energy LLC $ 140 $ 4 $ 3 $ (86) $ 61 Balance Sheet Equity investment in affiliates $ 90 $ 651 $ — $ — $ 741 Capital expenditures (b) 12 44 50 — 106 Total Assets $ 2,575 $ 7,157 $ 627 $ 129 $ 10,488 (a) Includes eliminations (b) Includes accruals Year ended December 31, 2019 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues $ 346 $ 485 $ 201 $ — $ 1,032 Cost of operations 60 143 134 — 337 Depreciation amortization and accretion 103 271 27 — 401 Impairment losses — 14 19 — 33 General and administrative — 1 3 23 27 Transaction and integration costs — — — 3 3 Development costs — — 5 — 5 Operating income (loss) 183 56 13 (26) 226 Equity in earnings of unconsolidated affiliates 9 74 — — 83 Other income, net 2 6 — 1 9 Loss on debt extinguishment — (1) — (15) (16) Interest expense, net (59) (239) (18) (87) (403) Net Income (Loss) 135 (104) (5) (127) (101) Net Income (Loss) Attributable to Clearway Energy LLC $ 135 $ (33) $ (5) $ (127) $ (30) Balance Sheet Equity investments in affiliates $ 94 $ 1,089 $ — $ — $ 1,183 Capital expenditures (a) 4 185 34 — 223 Total Assets $ 2,753 $ 6,186 $ 633 $ 33 $ 9,605 (a) Includes accruals. Year ended December 31, 2018 (In millions) Conventional Generation Renewables Thermal Corporate Total Operating revenues $ 337 $ 523 $ 193 $ — $ 1,053 Cost of operations 61 139 127 — 327 Depreciation amortization and accretion 102 211 23 — 336 General and administrative — — 1 19 20 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, net (51) (154) (12) (77) (294) Net Income (Loss) 135 86 29 (115) 135 Net Income (Loss) Attributable to Clearway Energy LLC $ 135 $ 190 $ 29 $ (114) $ 240

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Long-term Purchase Commitment	As of December 31, 2020, the Company's commitments under such outstanding agreements are estimated as follows: Period (In millions) 2021 $ 9 2022 3 2023 2 2024 — 2025 — Thereafter — Total $ 14

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Lease, Cost	Lease expense for the year ended December 31, 2020 and December 31, 2019 was comprised of the following: (In millions) December 31, 2020 December 31, 2019 Operating lease cost - Fixed $ 19 $ 13 Operating lease cost - Variable 9 8 Total lease cost $ 28 $ 21 Operating lease information as of December 31, 2020 and 2019 was as follows: (In millions, except term and rate) December 31, 2020 December 31, 2019 ROU Assets - operating leases, net (a) $ 337 $ 223 Short-term lease liability - operating leases (b) $ 8 $ 7 Long-term lease liability - operating leases (a) 345 227 Total lease liability $ 353 $ 234 Weighted average remaining lease term (in years) 25 25 Weighted average discount rate 4.3 % 4.4 % Cash paid for operating leases $ 19 $ 15 (a) Increase in ROU Assets and lease liabilities is primarily due to the acquisition of Drop Down Assets, as further described in Note 3, Acquisitions and Dispositions (b) Short-term lease liability balances are included within the accrued expenses and other current liabilities line item of the consolidated balance sheets as of December 31, 2020 and December 31, 2019
Maturities of Operating Lease Liabilities	Maturities of operating lease liabilities as of December 31, 2020 are as follows: (In millions) 2021 $ 23 2022 23 2023 23 2024 23 2025 23 Thereafter 476 Total lease payments 591 Less imputed interest (238) Total lease liability - operating leases $ 353
Energy and Capacity Revenue	The following amounts of energy and capacity revenue are related to the Company’s operating leases. December 31, 2020 (In millions) Conventional Generation Renewables Thermal Total Energy revenue $ 10 $ 554 $ 2 $ 566 Capacity revenue 451 — — 451 Operating revenue $ 461 $ 554 $ 2 $ 1,017 December 31, 2019 (In millions) Conventional Generation Renewables Thermal Total Energy revenue $ 5 $ 509 $ 2 $ 516 Capacity revenue 348 — — 348 Operating revenue $ 353 $ 509 $ 2 $ 864
Minimum Future Rent Payments Under the Operating Leases	Minimum future rent payments for the remaining periods related to the Conventional segment operating leases were as follows as of December 31, 2020: (In millions) 2021 $ 444 2022 450 2023 259 2024 106 2025 107 Thereafter 1,498 Total lease payments $ 2,864
Property, Plant, and Equipment Net	Property, plant and equipment, net related to the Company’s operating leases were as follows: (In millions) December 31, 2020 December 31, 2019 Property, plant and equipment $ 7,201 $ 6,942 Accumulated depreciation (1,964) (1,649) Net property, plant and equipment $ 5,237 $ 5,293
Sales-type and Direct Financing Leases, Lease Receivable, Maturity	Minimum future rent payments for the remaining periods related to the Thermal segment sales-type lease were as follows as of December 31, 2020: (In millions) 2021 $ 1 2022 1 2023 1 2024 1 2025 1 Thereafter 9 Total sales-type lease payments $ 14

Unaudited Quarterly Financial_2

Unaudited Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Schedule of Unaudited Quarterly Data	Below is summarized unaudited quarterly financial data for the periods ending December 31, 2020 and 2019. Quarter Ended December 31, September 30, June 30, March 31, 2020 (In millions) Operating Revenues $ 280 $ 332 $ 329 $ 258 Operating Income 28 123 131 52 Net (Loss) Income $ (78) $ 51 $ 104 $ (129) Quarter Ended December 31, September 30, June 30, March 31, 2019 (In millions) Operating Revenues $ 235 $ 296 $ 284 $ 217 Operating Income 7 90 88 41 Net (Loss) Income $ (41) $ 25 $ (31) $ (54)

Nature of Business - Narrative

Nature of Business - Narrative (Details) - MW	12 Months Ended
	Dec. 31, 2020	Aug. 31, 2018	Mar. 30, 2018
Nature of Business
Economic ownership interest			100.00%
Conventional Generation, Utility-Scale Solar, Distributed Solar, and Wind
Nature of Business
Power generation capacity, megawatts	4,200
Generational Facilities and District Energy Systems
Nature of Business
Power generation capacity, megawatts	2,500
Clearway Energy LLC
Nature of Business
Ownership percentage	57.61%
Clearway Energy LLC | GIP
Nature of Business
Voting interest	54.95%
Ownership percentage	42.99%
Clearway Energy LLC | Shareholders
Nature of Business
Voting interest	45.05%
Ownership percentage	57.01%
NRG
Nature of Business
Economic ownership interest			100.00%
CEG | Clearway Energy LLC
Nature of Business
Ownership percentage	42.39%
Clearway Energy, Inc. | GIP
Nature of Business
Economic ownership interest		55.00%
Clearway Energy, Inc. | NRG
Nature of Business
Ownership percentage sold		100.00%
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, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 268	$ 152
Restricted cash	197	262
Cash, cash equivalents and restricted cash shown in the statements of cash flows	465	414	$ 583	$ 314
Project Level Subsidiaries
Cash and Cash Equivalents [Line Items]
Other cash and cash equivalents	149	$ 125
Operating Funds
Cash and Cash Equivalents [Line Items]
Restricted cash	73
Long-Term Debt, Current
Cash and Cash Equivalents [Line Items]
Restricted cash	24
Debt Service Obligations
Cash and Cash Equivalents [Line Items]
Restricted cash	45
Cash Distribution
Cash and Cash Equivalents [Line Items]
Restricted cash	$ 55

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Revenue Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Contingent rental income	$ 589	$ 537	$ 583

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Disaggregated Revenues (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 280	$ 332	$ 329	$ 258	$ 235	$ 296	$ 284	$ 217	$ 1,199	$ 1,032	$ 1,053
Energy Revenue
Disaggregation of Revenue [Line Items]
Less: Lease revenue									(566)	(516)
Capacity Revenue
Disaggregation of Revenue [Line Items]
Less: Lease revenue									(451)	(348)
Conventional | Energy Revenue
Disaggregation of Revenue [Line Items]
Less: Lease revenue									(10)	(5)
Conventional | Capacity Revenue
Disaggregation of Revenue [Line Items]
Less: Lease revenue									(451)	(348)
Renewables | Energy Revenue
Disaggregation of Revenue [Line Items]
Less: Lease revenue									(554)	(509)
Renewables | Capacity Revenue
Disaggregation of Revenue [Line Items]
Less: Lease revenue									0	0
Thermal | Energy Revenue
Disaggregation of Revenue [Line Items]
Less: Lease revenue									(2)	(2)
Thermal | Capacity Revenue
Disaggregation of Revenue [Line Items]
Less: Lease revenue									0	0
Operating Segments
Disaggregation of Revenue [Line Items]
Revenues									1,199	1,032	1,053
Less: Lease revenue									(1,017)	(864)	(878)
Less: Contract amortization									(88)	(71)	(70)
Mark-to-market for economic hedges										(9)
Total revenue from contracts with customers									270	239	245
Operating Segments | Energy Revenue
Disaggregation of Revenue [Line Items]
Revenues									720	670	697
Operating Segments | Capacity Revenue
Disaggregation of Revenue [Line Items]
Revenues									514	402	387
Operating Segments | Other Revenues
Disaggregation of Revenue [Line Items]
Revenues									53	40	39
Operating Segments | Conventional
Disaggregation of Revenue [Line Items]
Revenues									437	346	337
Less: Lease revenue									(461)	(353)	(342)
Less: Contract amortization									(24)	(7)	(5)
Mark-to-market for economic hedges										0
Total revenue from contracts with customers									0	0	0
Operating Segments | Conventional | Energy Revenue
Disaggregation of Revenue [Line Items]
Revenues									10	5	5
Operating Segments | Conventional | Capacity Revenue
Disaggregation of Revenue [Line Items]
Revenues									451	348	337
Operating Segments | Conventional | Other Revenues
Disaggregation of Revenue [Line Items]
Revenues									0	0	0
Operating Segments | Renewables
Disaggregation of Revenue [Line Items]
Revenues									569	485	523
Less: Lease revenue									(554)	(509)	(534)
Less: Contract amortization									(61)	(61)	(62)
Mark-to-market for economic hedges										(9)
Total revenue from contracts with customers									76	37	51
Operating Segments | Renewables | Energy Revenue
Disaggregation of Revenue [Line Items]
Revenues									609	545	572
Operating Segments | Renewables | Capacity Revenue
Disaggregation of Revenue [Line Items]
Revenues									0	0	0
Operating Segments | Renewables | Other Revenues
Disaggregation of Revenue [Line Items]
Revenues									21	10	13
Operating Segments | Thermal
Disaggregation of Revenue [Line Items]
Revenues									193	201	193
Less: Lease revenue									(2)	(2)	(2)
Less: Contract amortization									(3)	(3)	(3)
Mark-to-market for economic hedges										0
Total revenue from contracts with customers									194	202	194
Operating Segments | Thermal | Energy Revenue
Disaggregation of Revenue [Line Items]
Revenues									101	120	120
Operating Segments | Thermal | Capacity Revenue
Disaggregation of Revenue [Line Items]
Revenues									63	54	50
Operating Segments | Thermal | Other Revenues
Disaggregation of Revenue [Line Items]
Revenues									$ 32	$ 30	$ 26

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Contract Balances (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Accounts receivable, net	$ 143	$ 116
Customer Contracts
Disaggregation of Revenue [Line Items]
Accounts receivable, net	57	34
Lease Agreements
Disaggregation of Revenue [Line Items]
Accounts receivable, net	$ 86	$ 82

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Asset Retirement Obligation (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance as of December 31, 2019	$ 75
Revisions in estimates for current obligations	9
Additions	26
Accretion — expense	7
Balance as of December 31, 2020	$ 117

Acquisitions and Dispositions A

Acquisitions and Dispositions Acquisitions and Dispositions (Details) $ in Millions

Feb. 03, 2021USD ($)MW

Jan. 12, 2021USD ($)MW

Dec. 21, 2020USD ($)MW

Nov. 20, 2020USD ($)MW

Nov. 02, 2020USD ($)

Sep. 01, 2020USD ($)MW

May 14, 2020USD ($)

Mar. 03, 2020USD ($)

Dec. 06, 2019USD ($)MW

Oct. 08, 2019USD ($)MW

May 01, 2019USD ($)MW

Jun. 19, 2018USD ($)

Apr. 18, 2018USD ($)MW

Mar. 30, 2018USD ($)MW

Jan. 31, 2021USD ($)

Jan. 31, 2021USD ($)

Jan. 31, 2020USD ($)

Jan. 31, 2019USD ($)

May 31, 2018USD ($)

Feb. 02, 2021

Dec. 31, 2020USD ($)MW

Dec. 31, 2019USD ($)

Dec. 31, 2018USD ($)MW

Business Acquisition [Line Items]

Voting interest acquired

100.00%

Equity investments in affiliates

$ 741

$ 1,183

Long-term debt

$ 7,043

Mesquite Star

Business Acquisition [Line Items]

Historical value of acquired interests, adjustment to noncontrolling interest

$ 63

Equity investments in affiliates

$ 58

RPV Holdco 1 LLC

Business Acquisition [Line Items]

Net proceeds

$ 75

Gain on sale of investment

$ 49

Energy Center Dover LLC

Business Acquisition [Line Items]

Net proceeds

$ 15

Sale of assets percentage ownership interest sold

100.00%

NRG

Business Acquisition [Line Items]

Voting interest acquired

100.00%

Accounts payable, related parties

$ 4

UPMC Thermal | Thermal

Business Acquisition [Line Items]

Power generation capacity, megawatts | MW

7.5

Steam and chilled water capacity, megawatts | MW

73

Buckthorn Solar Drop Down Asset

Business Acquisition [Line Items]

Proceeds from noncontrolling interests

$ 80

Buckthorn Solar, due 2025

Business Acquisition [Line Items]

Long-term debt

$ 132

Mesquite Star Tax Equity Holdco LLC | Lighthouse Renewable Holdco LLC

Business Acquisition [Line Items]

Ownership interest

100.00%

Langford Holding LLC

Business Acquisition [Line Items]

Voting interest acquired

100.00%

Power generation capacity, megawatts | MW

160

Payments to acquire business

$ 64

Historical value of acquired interests, adjustment to noncontrolling interest

21

Noncontrolling interest

$ 119

Langford Holding LLC | CEG

Business Acquisition [Line Items]

Voting interest acquired

100.00%

Business combination consideration transferred

$ 55

Langford Holding LLC | Third Party Investor

Business Acquisition [Line Items]

Voting interest acquired

100.00%

Business combination consideration transferred

$ 9

Rosie TargetCo LLC

Business Acquisition [Line Items]

Voting interest acquired

100.00%

Power generation capacity, megawatts | MW

192

Payments to acquire business

$ 23

Historical value of acquired interests, adjustment to noncontrolling interest

28

Noncontrolling interest

$ 52

Rosie TargetCo LLC | CEG

Business Acquisition [Line Items]

Voting interest acquired

100.00%

Mesquite Star

Business Acquisition [Line Items]

Power generation capacity, megawatts | MW

419

Payments to acquire business

$ 74

Historical value of acquired interests, adjustment to noncontrolling interest

$ 83

Contracts with investment grade counterparties, weighted average contract life

12 years

DGPV Funds | Renew DG Holdings LLC | Affiliated Entity

Business Acquisition [Line Items]

Payments to acquire business

$ 20

DGPV Funds | SREC

Business Acquisition [Line Items]

Payments to acquire business

$ 24

Duquesne University District Energy System

Business Acquisition [Line Items]

Power generation capacity, megawatts | MW

87

Business combination consideration transferred

$ 107

Power purchase agreement period

40 years

Carlsbad Drop Down

Business Acquisition [Line Items]

Voting interest acquired

100.00%

Business combination consideration transferred

$ 184

Power purchase agreement period

20 years

Long-term debt

$ 803

Carlsbad Drop Down | Natural Gas

Business Acquisition [Line Items]

Power generation capacity, megawatts | MW

527

UPMC Thermal

Business Acquisition [Line Items]

Business combination consideration transferred

$ 84

$ 1

$ 3

UPMC Thermal | UPMC Thermal

Business Acquisition [Line Items]

Power generation capacity, megawatts | MW

7.5

Steam and chilled water capacity, megawatts | MW

73

Central CA Fuel Cell 1

Business Acquisition [Line Items]

Business combination consideration transferred

$ 11

Power purchase agreement period

20 years

Central CA Fuel Cell 1 | Thermal

Business Acquisition [Line Items]

Power generation capacity, megawatts | MW

2.8

Buckthorn Solar Drop Down Asset

Business Acquisition [Line Items]

Power generation capacity, megawatts | MW

154

Business combination consideration transferred

$ 42

Noncontrolling interest

19

Buckthorn Solar Drop Down Asset | Buckthorn Solar, due 2025

Business Acquisition [Line Items]

Long-term debt

$ 183

HSD Solar Holdings, LLC

Business Acquisition [Line Items]

Power generation capacity, megawatts | MW

6

Business combination consideration transferred

$ 20

Sale of assets percentage ownership interest sold

100.00%

November 2017 Drop Down Assets

Business Acquisition [Line Items]

Long-term debt

$ 23

Subsequent Event | Clearway Energy, Inc.

Business Acquisition [Line Items]

Percent equity interest previously owned

16.00%

Subsequent Event | Agua Caliente

Business Acquisition [Line Items]

Ownership interest

51.00%

Subsequent Event | Rattlesnake Flat, LLC

Business Acquisition [Line Items]

Voting interest acquired

100.00%

Power generation capacity, megawatts | MW

160

Business combination consideration transferred

$ 132

Subsequent Event | Agua Caliente

Business Acquisition [Line Items]

Voting interest acquired

35.00%

Power generation capacity, megawatts | MW

290

Business combination consideration transferred

$ 202

Power purchase agreement period

25 years

Power purchase agreement period

19 years

Subsequent Event | Rosie TargetCo LLC

Business Acquisition [Line Items]

Payments to acquire business

$ 1

$ 24

Acquisitions and Dispositions -

Acquisitions and Dispositions - Summary of Assets and Liabilities Transferred (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 21, 2020	Nov. 20, 2020	Dec. 31, 2019	Dec. 06, 2019
Business Acquisition [Line Items]
Net debt issuance costs	$ 79			$ 77
Langford Holding LLC
Business Acquisition [Line Items]
Current Assets			$ 4
Property, plant and equipment, net			138
Other non-current assets			15
Total assets			157
Other current and non-current liabilities			17
Total liabilities			17
Noncontrolling interest			119
Net assets less noncontrolling interests			$ 21
Rosie TargetCo LLC
Business Acquisition [Line Items]
Current Assets		$ 49
Property, plant and equipment, net		246
Other non-current assets		1
Total assets		296
Long-term debt		205
Other current and non-current liabilities		11
Total liabilities		216
Noncontrolling interest		52
Net assets less noncontrolling interests		$ 28
CBAD Holdings, LLC
Business Acquisition [Line Items]
Current Assets					$ 36
Property, plant and equipment, net					572
Intangible assets, net					337
Other non-current assets					51
Total assets					996
Debt					791
Other current and non-current liabilities					56
Total liabilities					847
Net assets acquired					149
Net debt issuance costs					12
Contingent liability					$ 5

Acquisitions and Dispositions_2

Acquisitions and Dispositions - Summary Consolidated Balances (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 21, 2020	Nov. 02, 2020	May 29, 2020	Dec. 31, 2019
Assets:
Current assets	$ 708				$ 605
Property, plant and equipment, net	7,217				6,063
Other non-current assets	114				103
Total Assets	10,488				9,605
Liabilities:
Long-term debt	7,043
Total Liabilities	$ 7,876				$ 7,432
Mesquite Star
Assets:
Current assets		$ 22
Property, plant and equipment, net		443
Other non-current assets		31
Total Assets		496
Liabilities:
Other current and non-current liabilities		87
Total Liabilities		87
Noncontrolling interest		346
Historical value of acquired interests, adjustment to noncontrolling interest		$ 63
DGPV Holdco 1 and 2
Assets:
Current assets			$ 29
Property, plant and equipment, net			324
Intangible assets, net			19
Other non-current assets			52
Total Assets			424
Liabilities:
Long-term debt			160
Other current and non-current liabilities			54
Total Liabilities			214
Noncontrolling interest			5
Historical value of acquired interests, adjustment to noncontrolling interest			$ 205
DGPV Holdco 3
Assets:
Current assets				$ 32
Property, plant and equipment, net				331
Intangible assets, net				1
Other non-current assets				37
Total Assets				401
Liabilities:
Long-term debt				206
Other current and non-current liabilities				84
Total Liabilities				290
Noncontrolling interest				6
Historical value of acquired interests, adjustment to noncontrolling interest				$ 105

Property, Plant and Equipment_2

Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 9,540	$ 7,943
Accumulated depreciation	(2,323)	(1,880)
Net property, plant and equipment	7,217	6,063
Prepaid long-term service agreement	14	10
Depreciation expense	420	395	$ 330
Facilities and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 9,254	7,676
Facilities and equipment | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	2 years
Facilities and equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	45 years
Land and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 224	173
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment	62	94
Pinnacle
Property, Plant and Equipment [Line Items]
Depreciation expense	$ 9
Wildorado Wind and Elbow Creek
Property, Plant and Equipment [Line Items]
Depreciation expense		$ 54

Investments Accounted for by _3

Investments Accounted for by the Equity Method and Variable Interest Entities - Equity method investments (Details) - USD ($) $ in Millions	Feb. 03, 2021	Jun. 30, 2015	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Equity investments in affiliates			$ 741	$ 1,183
Undistributed earnings from equity method investees			10	138
Payments to acquire equity method investments			11	$ 13	$ 34
Non-resource debt			$ 481
Agua Caliente Solar | Subsequent Event
Schedule of Equity Method Investments [Line Items]
VIE ownership percentage	51.00%
Utah Solar Portfolio
Schedule of Equity Method Investments [Line Items]
Equity method, ownership percentage			50.00%
Equity investments in affiliates			$ 255
Working capital			$ 106
Desert Sunlight
Schedule of Equity Method Investments [Line Items]
Equity method, ownership percentage			25.00%
Equity investments in affiliates			$ 244
Payments to acquire equity method investments		$ 285
Working capital		$ 171
Agua Caliente Solar
Schedule of Equity Method Investments [Line Items]
Equity method, ownership percentage			16.00%
Equity investments in affiliates			$ 83
Agua Caliente Solar | Subsequent Event
Schedule of Equity Method Investments [Line Items]
Additional equity method investment interests acquired	35.00%
GenConn
Schedule of Equity Method Investments [Line Items]
Equity method, ownership percentage			50.00%
Equity investments in affiliates			$ 90
San Juan Mesa
Schedule of Equity Method Investments [Line Items]
Equity method, ownership percentage			75.00%
Equity investments in affiliates			$ 33
Elkhorn Ridge
Schedule of Equity Method Investments [Line Items]
Equity method, ownership percentage			66.70%
Equity investments in affiliates			$ 38
Avenal
Schedule of Equity Method Investments [Line Items]
Equity method, ownership percentage			50.00%
Equity investments in affiliates			$ (2)

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, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Revenues	$ 280	$ 332	$ 329	$ 258	$ 235	$ 296	$ 284	$ 217	$ 1,199	$ 1,032	$ 1,053
Operating Income	28	123	131	52	7	90	88	41	334	226	347
Net (loss) income	(78)	$ 51	$ 104	$ (129)	(41)	$ 25	$ (31)	$ (54)	(52)	(101)	135
Current assets	708				605				708	605
Current liabilities	638				2,058				638	2,058
Non-current liabilities	7,238				5,374				7,238	5,374
GenConn
Schedule of Equity Method Investments [Line Items]
Revenues									60	60	65
Operating Income									26	27	32
Net (loss) income									17	17	22
Current assets	40				37				40	37
Non-current assets	344				342				344	342
Current liabilities	17				16				17	16
Non-current liabilities	185				176				185	176
Desert Sunlight
Schedule of Equity Method Investments [Line Items]
Revenues									209	205	208
Operating Income									142	123	129
Net (loss) income									88	58	84
Current assets	132				209				132	209
Non-current assets	1,244				1,296				1,244	1,296
Current liabilities	71				545				71	545
Non-current liabilities	921				484				921	484
Other
Schedule of Equity Method Investments [Line Items]
Revenues									299	318	332
Operating Income									138	110	126
Net (loss) income									60	50	$ 86
Current assets	177				279				177	279
Non-current assets	2,201				3,412				2,201	3,412
Current liabilities	114				809				114	809
Non-current liabilities	700				500				700	500
Redeemable Noncontrolling Interest	$ 0				$ (1)				$ 0	$ (1)

Investments Accounted for by _5

Investments Accounted for by the Equity Method and Variable Interest Entities - Entities that are consolidated (Details) $ in Millions

Dec. 21, 2020USD ($)MW

Nov. 20, 2020USD ($)MW

May 11, 2020USD ($)

Feb. 07, 2020USD ($)

Dec. 22, 2019USD ($)

Nov. 26, 2019USD ($)

Nov. 12, 2019USD ($)

Jan. 02, 2019USD ($)

Aug. 31, 2018USD ($)MW

Mar. 30, 2018USD ($)MW

May 31, 2018USD ($)

Mar. 31, 2020USD ($)

Jun. 30, 2020USD ($)

Dec. 31, 2020USD ($)MW

Dec. 31, 2019USD ($)

Dec. 31, 2018USD ($)

Nov. 02, 2020USD ($)projectfundMW

May 29, 2020USD ($)

May 28, 2020USD ($)

Dec. 27, 2019USD ($)

Jun. 14, 2019USD ($)

May 07, 2019USD ($)

Mar. 08, 2019USD ($)

Aug. 30, 2018

Dec. 31, 2017

Jun. 30, 2015USD ($)

Variable Interest Entity [Line Items]

Equity investments in affiliates

$ 741

$ 1,183

Payments to acquire equity method investments

$ 11

13

$ 34

Economic ownership interest

100.00%

Percentage of cash available for distributions

95.00%

Taxable income allocation pre-flip

99.00%

Long-term debt

$ 7,043

Depreciation expense

$ 420

395

330

Decrease from redemptions or purchase of interests in noncontrolling interests

$ 8

$ 52

Repowering Partnership Holdco LLC, due 2020

Variable Interest Entity [Line Items]

Long-term debt

$ 352

Repayments of debt

$ 260

$ 93

Construction Loan

Variable Interest Entity [Line Items]

Long-term debt

$ 93

Affiliated Entity

Variable Interest Entity [Line Items]

Percentage of cash available for distributions

5.00%

Yield Protection Agreement

Variable Interest Entity [Line Items]

Cash distribution reallocation percentage

80.00%

Number of years after date of arrangement that reallocation of cash contributions begins

15 years

Estimated liability under arrangement

$ 15

Wind | Wind Global LLC

Variable Interest Entity [Line Items]

Ownership percentage by noncontrolling owners

9.90%

Buckthorn Solar Drop Down Asset

Variable Interest Entity [Line Items]

Power generation capacity, megawatts | MW

154

Business combination consideration transferred

$ 42

Noncontrolling interest

$ 19

Spring Canyon II | Wind

Variable Interest Entity [Line Items]

Power generation capacity, megawatts | MW

32

Economic ownership interest

90.10%

Spring Canyon III | Wind

Variable Interest Entity [Line Items]

Power generation capacity, megawatts | MW

28

Langford Holding LLC

Variable Interest Entity [Line Items]

Power generation capacity, megawatts | MW

160

Economic ownership interest

100.00%

Payments to acquire business

$ 64

Noncontrolling interest

$ 119

Langford Holding LLC | CEG

Variable Interest Entity [Line Items]

Economic ownership interest

100.00%

Business combination consideration transferred

$ 55

Langford Holding LLC | Third Party Investor

Variable Interest Entity [Line Items]

Economic ownership interest

100.00%

Business combination consideration transferred

$ 9

Kawailoa Partnership

Variable Interest Entity [Line Items]

Power generation capacity, megawatts | MW

49

Payments to acquire business

$ 9

Power purchase agreement period

22 years

Noncontrolling interest

$ 2

Capital contribution, percent

20.00%

Long-term debt

$ 120

Stockholders' equity attributable to noncontrolling interest

$ 21

November 2015 Drop Down Assets | Financial Institutions

Variable Interest Entity [Line Items]

Economic ownership interest

100.00%

Business combination consideration transferred

$ 19

Taxable income allocation pre-flip

99.00%

Rosie TargetCo LLC

Variable Interest Entity [Line Items]

Power generation capacity, megawatts | MW

192

Economic ownership interest

100.00%

Payments to acquire business

$ 23

Noncontrolling interest

52

Long-term debt

$ 205

Rosie TargetCo LLC | CEG

Variable Interest Entity [Line Items]

Economic ownership interest

100.00%

Zephyr Oahu Partnership LLC

Variable Interest Entity [Line Items]

Noncontrolling interest

$ 4

Capital contribution, percent

20.00%

Long-term debt

$ 143

Zephyr Oahu Partnership LLC | Tax Equity Investors

Variable Interest Entity [Line Items]

Stockholders' equity attributable to noncontrolling interest

$ 18

NRG

Variable Interest Entity [Line Items]

Economic ownership interest

100.00%

Buckthorn Solar Drop Down Asset

Variable Interest Entity [Line Items]

Proceeds from noncontrolling interests

$ 80

Alta X and XI TE Holdco | Second Year through Flip Point

Variable Interest Entity [Line Items]

Percentage of cash available for distributions

94.34%

Alta X and XI TE Holdco | Post-Flip Point

Variable Interest Entity [Line Items]

Percentage of cash available for distributions

97.12%

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%

Alta X and XI TE Holdco | Financial Institutions | Pre-determined Date Through Flip Point if Flip Has Not Occured

Variable Interest Entity [Line Items]

Percentage of cash available for distributions

100.00%

Spring Canyon | Post-Flip Point

Variable Interest Entity [Line Items]

Percentage of cash available for distributions

95.00%

Spring Canyon | Pre-Flip Point

Variable Interest Entity [Line Items]

Percentage of cash available for distributions

65.19%

Spring Canyon | Financial Institutions | Post-Flip Point

Variable Interest Entity [Line Items]

Percentage of cash available for distributions

5.00%

Spring Canyon | Financial Institutions | Pre-Flip Point

Variable Interest Entity [Line Items]

Percentage of cash available for distributions

34.81%

Langford Holding LLC | Langford Tax Equity Partnership LLC

Variable Interest Entity [Line Items]

Percentage ownership

100.00%

Langford Holding LLC | Langford Class B Holdco LLC

Variable Interest Entity [Line Items]

Ownership interest

100.00%

Kawailoa Solar Project | Kawailoa Solar Partnership LLC

Variable Interest Entity [Line Items]

Ownership interest

51.00%

Kawailoa Solar Project | Third Party Investor

Variable Interest Entity [Line Items]

Ownership interest

49.00%

Rosie TargetCo LLC | Rosie Class B LLC

Variable Interest Entity [Line Items]

Percentage ownership

100.00%

Rosie Class B LLC | Rosie TE Holdco LLC

Variable Interest Entity [Line Items]

Percentage ownership

100.00%

Langford Wind Project

Variable Interest Entity [Line Items]

Power generation capacity, megawatts | MW

160

Langford Tax Equity Partnership LLC | Langford Wind Project

Variable Interest Entity [Line Items]

Ownership interest

100.00%

Repowering Partnership II LLC

Variable Interest Entity [Line Items]

Depreciation expense

$ 54

Payments to acquire interest in joint venture

$ 70

Repowering Partnership II LLC | Wind TE Holdco

Variable Interest Entity [Line Items]

Income allocation percentage

59.63%

Repowering Partnership II LLC | CWSP Wildorado Elbow Holding LLC

Variable Interest Entity [Line Items]

Income allocation percentage

40.37%

Buckthorn Solar Portfolio, LLC | Buckthorn Renewables, LLC

Variable Interest Entity [Line Items]

Percentage ownership

100.00%

Buckthorn Holdings, LLC | Buckthorn Solar Portfolio, LLC | Capital Unit, Class B

Variable Interest Entity [Line Items]

Percentage ownership

100.00%

Kawailoa Solar Holdings LLC

Variable Interest Entity [Line Items]

Noncontrolling interest

$ 61

$ 7

Kawailoa Solar Holdings LLC | ITC Bridge Loan

Variable Interest Entity [Line Items]

Repayments of debt

57

Kawailoa Solar Holdings LLC | Term Debt

Variable Interest Entity [Line Items]

Proceeds from debt, net of issuance costs

$ 5

Repowering Partnership LLC

Variable Interest Entity [Line Items]

Equity method, ownership percentage

21.00%

Elbow TE Holdco

Variable Interest Entity [Line Items]

Business combination consideration transferred

$ 4

Elbow TE Holdco | Capital Unit, Class A | Third Party Investor

Variable Interest Entity [Line Items]

Economic ownership interest

100.00%

Equity attributable to parent

$ 89

Oahu Solar Partnership | ITC Bridge Loan

Variable Interest Entity [Line Items]

Repayments of debt

$ 67

Oahu Solar Partnership | Tax Equity Investors

Variable Interest Entity [Line Items]

Proceeds from noncontrolling interests

$ 71

Oahu Solar Partnership | Clearway Renew LLC | Affiliated Entity

Variable Interest Entity [Line Items]

Percentage ownership

80.00%

Stockholders' equity attributable to noncontrolling interest

$ 16

Oahu Solar Partnership | Zephyr Oahu Partnership LLC

Variable Interest Entity [Line Items]

Payments to acquire business

$ 20

Oahu Solar, Lanikuhana

Variable Interest Entity [Line Items]

Power generation capacity, megawatts | MW

15

Power purchase agreement period

22 years

Oahu Solar, Waipio

Variable Interest Entity [Line Items]

Power generation capacity, megawatts | MW

46

Wildorado TE Holdco

Variable Interest Entity [Line Items]

Income allocation percentage

5.00%

Business combination consideration transferred

$ 112

Wildorado TE Holdco | Capital Unit, Class A | Third Party Investor

Variable Interest Entity [Line Items]

Economic ownership interest

100.00%

Equity attributable to parent

$ 148

Wind TE Holdco LLC | Repowering Partnership II LLC

Variable Interest Entity [Line Items]

Income allocation percentage

60.14%

CWSP Wildorado Elbow Holding LLC | Repowering Partnership II LLC

Variable Interest Entity [Line Items]

Income allocation percentage

39.86%

DGPV Holdco 3

Variable Interest Entity [Line Items]

Power generation capacity, megawatts | MW

113

286

Remaining lease term

21 years

Income allocation percentage

99.00%

Equity investments in affiliates

$ (155)

Payments to acquire equity method investments

$ 10

Number of projects | fund

7

Number of tax equity funds | fund

6

Number of solar projects | project

172

Long-term debt

$ 206

DGPV Holdco 1 and 2

Variable Interest Entity [Line Items]

Equity investments in affiliates

$ 144

Long-term debt

$ 160

Variable Interest Entity, Primary Beneficiary | Repowering Partnership Holdco LLC, due 2020

Variable Interest Entity [Line Items]

Debt instrument, face amount

$ 352

Lighthouse Renewable Holdco LLC

Variable Interest Entity [Line Items]

Income allocation percentage

50.01%

Rosie TargetCo LLC

Variable Interest Entity [Line Items]

Income allocation percentage

50.00%

Investments Accounted for by _6

Investments Accounted for by the Equity Method and Variable Interest Entities - Schedule of summarized financial information of consolidated entities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Other current and non-current assets	$ 2,563	$ 2,937
Property, plant and equipment, net	7,217	6,063
Intangible assets, net	1,370	1,428
Total Assets	10,488	9,605
Liabilities	7,876	$ 7,432
Oahu Solar Partnership
Variable Interest Entity [Line Items]
Other current and non-current assets	23
Property, plant and equipment, net	179
Intangible assets, net	0
Total Assets	202
Liabilities	122
Noncontrolling interest	14
Net assets less noncontrolling interests	66
Kawailoa Solar Partnership LLC
Variable Interest Entity [Line Items]
Other current and non-current assets	21
Property, plant and equipment, net	141
Intangible assets, net	0
Total Assets	162
Liabilities	111
Noncontrolling interest	31
Net assets less noncontrolling interests	20
Wildorado TE Holdco
Variable Interest Entity [Line Items]
Other current and non-current assets	14
Property, plant and equipment, net	240
Intangible assets, net	0
Total Assets	254
Liabilities	11
Noncontrolling interest	123
Net assets less noncontrolling interests	120
DGPV Funds
Variable Interest Entity [Line Items]
Other current and non-current assets	105
Property, plant and equipment, net	778
Intangible assets, net	2
Total Assets	885
Liabilities	77
Noncontrolling interest	4
Net assets less noncontrolling interests	804
Lighthouse Renewable Holdco LLC
Variable Interest Entity [Line Items]
Other current and non-current assets	48
Property, plant and equipment, net	444
Intangible assets, net	0
Total Assets	492
Liabilities	82
Noncontrolling interest	347
Net assets less noncontrolling interests	63
Rosie TargetCo LLC
Variable Interest Entity [Line Items]
Other current and non-current assets	40
Property, plant and equipment, net	258
Intangible assets, net	0
Total Assets	298
Liabilities	118
Noncontrolling interest	150
Net assets less noncontrolling interests	30
Langford TE Partnership LLC
Variable Interest Entity [Line Items]
Other current and non-current assets	15
Property, plant and equipment, net	138
Intangible assets, net	2
Total Assets	155
Liabilities	18
Noncontrolling interest	108
Net assets less noncontrolling interests	29
Alta TE Holdco
Variable Interest Entity [Line Items]
Other current and non-current assets	56
Property, plant and equipment, net	356
Intangible assets, net	225
Total Assets	637
Liabilities	44
Noncontrolling interest	33
Net assets less noncontrolling interests	560
Buckthorn Renewables, LLC
Variable Interest Entity [Line Items]
Other current and non-current assets	2
Property, plant and equipment, net	210
Intangible assets, net	0
Total Assets	212
Liabilities	9
Noncontrolling interest	58
Net assets less noncontrolling interests	145
Other Consolidated Variable Interest Entities
Variable Interest Entity [Line Items]
Other current and non-current assets	21
Property, plant and equipment, net	184
Intangible assets, net	1
Total Assets	206
Liabilities	33
Noncontrolling interest	99
Net assets less noncontrolling interests	$ 74

Investments Accounted for by _7

Investments Accounted for by the Equity Method and Variable Interest Entities - Entities that are not consolidated (Details)	Dec. 31, 2020	Feb. 07, 2020
Variable Interest Entity [Line Items]
Taxable income allocation pre-flip		99.00%
Percentage of cash available for distributions	95.00%
Utah Solar Portfolio
Variable Interest Entity [Line Items]
Percentage of cash available for distributions	50.00%
Utah Solar Portfolio | Capital Unit, Class A
Variable Interest Entity [Line Items]
Percentage ownership	100.00%
Utah Solar Portfolio | Capital Unit, Class B | Financial Institutions
Variable Interest Entity [Line Items]
Taxable income allocation pre-flip	99.00%
Taxable income allocation, post flip	50.00%

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Balance Sheet Grouping and Debt (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt — affiliate	$ 1	$ 44
Long-term debt, including current portion — external	7,048	6,813
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt — affiliate	1	43
Long-term debt, including current portion — external	7,020	6,913
Level 2 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion — external	1,906	1,735
Level 3 | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, including current portion — external	$ 5,115	$ 5,221

Fair Value of Financial Instr_4

Fair Value of Financial Instruments - Recurring Fair Value (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	$ 1
Derivative liabilities	173	$ 92
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Change in unrealized losses included in earnings for derivatives held as of December 31,	2	7	$ 24
Commodity contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	44	9
Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	1
Derivative liabilities	129	83
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other financial instruments	0	0
Assets, Fair Value Disclosure	1	0
Derivative liabilities	129	83
Recurring | Level 2 | Commodity contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	0	0
Recurring | Level 2 | Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	1	0
Derivative liabilities	129	83
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other financial instruments	29	0
Assets, Fair Value Disclosure	29	0
Derivative liabilities	44	9
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance	(9)	0
Total losses for the period included in earnings	0	(3)
Purchases	(6)	(6)
Ending balance	(15)	(9)	$ 0
Change in unrealized losses included in earnings for derivatives held as of December 31,	1	(3)
Recurring | Level 3 | Commodity contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative liabilities	44	9
Recurring | Level 3 | Interest rate contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	0	0
Derivative liabilities	$ 0	$ 0

Fair Value of Financial Instr_5

Fair Value of Financial Instruments - Narrative (Details) $ in Millions	Dec. 31, 2020USD ($)
Nature of Business [Line Items]
Percent of derivative liabilities using level 3 fair value inputs	25.00%
Impact of credit reserve to fair value	$ 6
Other Financial Instrument
Nature of Business [Line Items]
Percent of financial instrument liabilities using Level 3 fair value inputs	100.00%

Fair Value of Financial Instr_6

Fair Value of Financial Instruments - Significant Unobservable Inputs (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)$ / MWhMWh	Dec. 31, 2019USD ($)
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other financial instruments | $	$ 29	$ 0
Energy Related Derivative | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative Liability | $	$ (44)
Minimum | Forecast Annual Generation Levels Of Certain DG Solar Facilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other financial assets, measurement input | MWh	80,872
Minimum | Energy Related Derivative | Measurement Input, Commodity Forward Price
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, measurement input | $ / MWh	8.64
Maximum | Forecast Annual Generation Levels Of Certain DG Solar Facilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other financial assets, measurement input | MWh	131,374
Maximum | Energy Related Derivative | Measurement Input, Commodity Forward Price
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, measurement input | $ / MWh	42.37
Weighted Average | Forecast Annual Generation Levels Of Certain DG Solar Facilities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other financial assets, measurement input | MWh	126,063
Weighted Average | Energy Related Derivative | Measurement Input, Commodity Forward Price
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative asset, measurement input | $ / MWh	17.93

Accounting for Derivative Ins_3

Accounting for Derivative Instruments and Hedging Activities - Notional Amount and FV of Derivatives (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)MMBTUMWh	Dec. 31, 2019USD ($)MMBTUMWh
Derivatives, Fair Value [Line Items]
Derivative notional amount	$ 1,600
Derivative assets	1
Derivative liabilities	$ 173	$ 92
Commodity | Natural Gas
Derivatives, Fair Value [Line Items]
Derivative nonmonetary volume | MMBTU	1	2
Commodity | Power
Derivatives, Fair Value [Line Items]
Derivative nonmonetary volume | MWh	(8)	(2)
Interest Rate Swap | Interest
Derivatives, Fair Value [Line Items]
Derivative notional amount	$ 1,600	$ 1,788
Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative assets	0
Derivative liabilities	23	14
Designated as Hedging Instrument | Interest Rate Contract Current
Derivatives, Fair Value [Line Items]
Derivative assets	0
Derivative liabilities	8	3
Designated as Hedging Instrument | Interest Rate Contract Non Current
Derivatives, Fair Value [Line Items]
Derivative assets	0
Derivative liabilities	15	11
Not Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative assets	1
Derivative liabilities	150	78
Not Designated as Hedging Instrument | Interest Rate Contract Current
Derivatives, Fair Value [Line Items]
Derivative assets	0
Derivative liabilities	25	13
Not Designated as Hedging Instrument | Interest Rate Contract Non Current
Derivatives, Fair Value [Line Items]
Derivative assets	1
Derivative liabilities	81	56
Not Designated as Hedging Instrument | Commodity Contract Current
Derivatives, Fair Value [Line Items]
Derivative assets	0
Derivative liabilities	5	0
Not Designated as Hedging Instrument | Commodity Contract Long-Term
Derivatives, Fair Value [Line Items]
Derivative assets	0
Derivative liabilities	$ 39	$ 9

Accounting for Derivative Ins_4

Accounting for Derivative Instruments and Hedging Activities - Offsetting (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Offsetting Derivative Assets [Abstract]
Gross Amounts of Recognized Assets	$ 1
Offsetting Derivative Liabilities [Abstract]
Gross Amounts of Recognized Liabilities	(173)	$ (92)
Gross Amounts of Recognized Assets/Liabilities	(172)	(92)
Derivative Instruments	0	0
Net Amount	(172)	(92)
Commodity contracts
Offsetting Derivative Liabilities [Abstract]
Gross Amounts of Recognized Liabilities	(44)	(9)
Derivative Instruments	0	(1)
Net Amount	(44)	(10)
Gross Amounts of Recognized Assets/Liabilities	(44)	(9)
Derivative Instruments	0	(1)
Net Amount	(44)	(10)
Interest rate contracts
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	(129)	(83)
Derivative Instruments	0	1
Net Amount	(129)	(82)
Gross Amounts of Recognized Assets/Liabilities	(128)	(83)
Derivative Instruments	0	1
Net Amount	$ (128)	$ (82)

Accounting for Derivative Ins_5

Accounting for Derivative Instruments and Hedging Activities - AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Mark-to-market of cash flow hedge accounting contracts	$ 2	$ 8	$ 24
Losses expected to be realized from OCL during the next 12 months	(13)
Accumulated Net Gain (Loss) from Cash Flow Hedges Including Portion Attributable to Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated OCL beginning balance	(37)	(45)	(69)
Reclassified from accumulated OCL to income due to realization of previously deferred amounts	11	22	15
Mark-to-market of cash flow hedge accounting contracts	(9)	(14)	9
Accumulated OCL ending balance	(35)	(37)	(45)
Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated OCL beginning balance	0	(1)
Accumulated OCL ending balance	(2)	0	(1)
Accumulated Other Comprehensive Loss
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Accumulated OCL beginning balance	(37)	(44)
Accumulated OCL ending balance	$ (33)	$ (37)	$ (44)

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, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized losses included in earnings for derivatives held as of December 31,	$ (2)	$ (7)	$ (24)
Interest rate contracts | Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Change in unrealized losses included in earnings for derivatives held as of December 31,	38	65	$ (15)
Energy Related Derivative
Derivative Instruments, Gain (Loss) [Line Items]
Derivative, loss on derivative	$ 4	$ 9

Intangible Assets (Details)

Intangible Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Finite-lived Intangible Assets [Roll Forward]
Intangible assets, beginning balance	$ 1,822	$ 1,464
Acquisition		358
Intangible assets ending balance	1,857	1,822	$ 1,464
Less accumulated amortization	(487)	(394)
Net carrying amount	1,370	1,428
Amortization of intangible assets	91	73	71
Contra revenue intangibles amortization	88	72	70
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2021	91
2022	91
2023	88
2024	85
2025	84
DGPV Holdco Entities
Finite-lived Intangible Assets [Roll Forward]
Acquisition	23
Other Acquisitions
Finite-lived Intangible Assets [Roll Forward]
Acquisition	12
PPAs
Finite-lived Intangible Assets [Roll Forward]
Intangible assets, beginning balance	1,630	1,280
Acquisition		350
Intangible assets ending balance	1,661	1,630	1,280
Less accumulated amortization	(431)	(347)
Net carrying amount	1,230	1,283
PPAs | DGPV Holdco Entities
Finite-lived Intangible Assets [Roll Forward]
Acquisition	23
PPAs | Other Acquisitions
Finite-lived Intangible Assets [Roll Forward]
Acquisition	8
Leasehold Rights
Finite-lived Intangible Assets [Roll Forward]
Intangible assets, beginning balance	86	86
Acquisition		0
Intangible assets ending balance	86	86	86
Less accumulated amortization	(26)	(22)
Net carrying amount	60	64
Leasehold Rights | DGPV Holdco Entities
Finite-lived Intangible Assets [Roll Forward]
Acquisition	0
Leasehold Rights | Other Acquisitions
Finite-lived Intangible Assets [Roll Forward]
Acquisition	0
Customer Relationships
Finite-lived Intangible Assets [Roll Forward]
Intangible assets, beginning balance	66	66
Acquisition		0
Intangible assets ending balance	66	66	66
Less accumulated amortization	(11)	(9)
Net carrying amount	55	57
Customer Relationships | DGPV Holdco Entities
Finite-lived Intangible Assets [Roll Forward]
Acquisition	0
Customer Relationships | Other Acquisitions
Finite-lived Intangible Assets [Roll Forward]
Acquisition	0
Customer Contracts
Finite-lived Intangible Assets [Roll Forward]
Intangible assets, beginning balance	15	15
Acquisition		0
Intangible assets ending balance	15	15	15
Less accumulated amortization	(11)	(10)
Net carrying amount	4	5
Customer Contracts | DGPV Holdco Entities
Finite-lived Intangible Assets [Roll Forward]
Acquisition	0
Customer Contracts | Other Acquisitions
Finite-lived Intangible Assets [Roll Forward]
Acquisition	0
Emission Allowances
Finite-lived Intangible Assets [Roll Forward]
Intangible assets, beginning balance	17	9
Acquisition		8
Intangible assets ending balance	17	17	9
Less accumulated amortization	(3)	(2)
Net carrying amount	14	15
Emission Allowances | DGPV Holdco Entities
Finite-lived Intangible Assets [Roll Forward]
Acquisition	0
Emission Allowances | Other Acquisitions
Finite-lived Intangible Assets [Roll Forward]
Acquisition	0
Other
Finite-lived Intangible Assets [Roll Forward]
Intangible assets, beginning balance	8	8
Acquisition		0
Intangible assets ending balance	12	8	$ 8
Less accumulated amortization	(5)	(4)
Net carrying amount	7	$ 4
Other | DGPV Holdco Entities
Finite-lived Intangible Assets [Roll Forward]
Acquisition	0
Other | Other Acquisitions
Finite-lived Intangible Assets [Roll Forward]
Acquisition	$ 4

Asset Impairments Asset Impairm

Asset Impairments Asset Impairments (Details) - USD ($) $ in Millions	3 Months Ended			12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Impaired Long-Lived Assets Held and Used [Line Items]
Tangible Asset Impairment Charges				$ 24	$ 33	$ 0
Other-than-temporary impairment loss on investment				$ 8	$ 0	$ 0
Property, Plant and Equipment
Impaired Long-Lived Assets Held and Used [Line Items]
Tangible Asset Impairment Charges	$ 24
Renewables
Impaired Long-Lived Assets Held and Used [Line Items]
Tangible Asset Impairment Charges		$ 14
Other-than-temporary impairment loss on investment	$ 8
Thermal
Impaired Long-Lived Assets Held and Used [Line Items]
Tangible Asset Impairment Charges			$ 19

Long-term Debt - Schedule of Bo

Long-term Debt - Schedule of Borrowings (Details) - USD ($)	Dec. 23, 2019	Apr. 29, 2019	Dec. 31, 2020	Dec. 31, 2019	May 01, 2019
Debt Instrument [Line Items]
Long-term debt			$ 7,044,000,000	$ 6,857,000,000
Less current maturities			(385,000,000)	(1,824,000,000)
Less net debt issuance costs			(79,000,000)	(77,000,000)
Add premiums			5,000,000	0
Total long-term debt			6,585,000,000	4,956,000,000
Basis spread on variable rate	1.375%
Long-term debt - affiliate, due 2020
Debt Instrument [Line Items]
Long-term debt			$ 0	44,000,000
Interest rate stated rate			3.325%
Intercompany Note with Clearway Energy, Inc.
Debt Instrument [Line Items]
Long-term debt			$ 1,000,000	0
Interest rate stated rate			1.49%
2024 Senior Notes
Debt Instrument [Line Items]
Long-term debt			$ 0	88,000,000
Interest rate stated rate			5.375%
2025 Senior Notes
Debt Instrument [Line Items]
Long-term debt			$ 600,000,000	600,000,000
Interest rate stated rate			5.75%
2026 Senior Notes
Debt Instrument [Line Items]
Long-term debt			$ 350,000,000	350,000,000
Interest rate stated rate			5.00%
2028 Senior Notes
Debt Instrument [Line Items]
Long-term debt			$ 850,000,000	600,000,000
Interest rate stated rate			4.75%
Alpine, due 2022
Debt Instrument [Line Items]
Long-term debt			$ 0	119,000,000
Alpine, due 2022 | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			2.00%
Alta Wind I-V lease financing arrangements, due 2034 and 2035
Debt Instrument [Line Items]
Long-term debt			$ 800,000,000	844,000,000
Alta Wind Asset Management LLC, due 2031
Debt Instrument [Line Items]
Long-term debt			$ 14,000,000	15,000,000
Alta Wind Asset Management LLC, due 2031 | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			2.50%
Alta Wind Realty Investments LLC, due 2031
Debt Instrument [Line Items]
Long-term debt			$ 25,000,000	27,000,000
Interest rate stated rate			700.00%
Borrego, due 2024 and 2038
Debt Instrument [Line Items]
Long-term debt			$ 57,000,000	60,000,000
Buckthorn Solar, due 2025
Debt Instrument [Line Items]
Long-term debt			$ 126,000,000	129,000,000
Buckthorn Solar, due 2025 | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			1.75%
Carlsbad Holdco, due 2038
Debt Instrument [Line Items]
Long-term debt			$ 210,000,000	216,000,000
Interest rate stated rate			4.21%
Carlsbad Energy Holdings LLC, due 2027
Debt Instrument [Line Items]
Long-term debt			$ 156,000,000	175,000,000
Carlsbad Energy Holdings LLC, due 2027 | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			1.625%
Carlsbad Energy Holdings LLC, due 2038
Debt Instrument [Line Items]
Long-term debt			$ 407,000,000	407,000,000
Interest rate stated rate			412.00%
CVSR, due 2037
Debt Instrument [Line Items]
Long-term debt			$ 675,000,000	696,000,000
CVSR Holdco Notes, due 2037
Debt Instrument [Line Items]
Long-term debt			$ 176,000,000	182,000,000
Interest rate stated rate			4.68%
DG-CS Master Borrower LLC, due 2040
Debt Instrument [Line Items]
Long-term debt			$ 467,000,000	0
Interest rate stated rate			3.51%
Duquesne, due 2059
Debt Instrument [Line Items]
Long-term debt			$ 95,000,000	95,000,000
Interest rate stated rate			4.62%		4.62%
El Segundo Energy Center, due 2023
Debt Instrument [Line Items]
Long-term debt			$ 250,000,000	303,000,000
Energy Center Minneapolis Series D, E, F, G, H Notes, due 2025-2037
Debt Instrument [Line Items]
Long-term debt			327,000,000	328,000,000
Laredo Ridge, due 2028
Debt Instrument [Line Items]
Long-term debt			$ 78,000,000	84,000,000
Laredo Ridge, due 2028 | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			2.125%
Kawailoa Solar Portfolio LLC, due 2026
Debt Instrument [Line Items]
Long-term debt			$ 81,000,000	82,000,000
Kawailoa Solar Portfolio LLC, due 2026 | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			1.375%
Marsh Landing, due 2023
Debt Instrument [Line Items]
Long-term debt			$ 146,000,000	206,000,000
Marsh Landing, due 2023 | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			2.125%
NIMH Solar, due 2024
Debt Instrument [Line Items]
Long-term debt			$ 191,000,000	0
NIMH Solar, due 2024 | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			2.00%
Oahu Solar Holdings LLC, due 2026
Debt Instrument [Line Items]
Long-term debt			$ 89,000,000	91,000,000
Oahu Solar Holdings LLC, due 2026 | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			1.375%
Repowering Partnership Holdco LLC, due 2020
Debt Instrument [Line Items]
Long-term debt			$ 0	228,000,000
Repowering Partnership Holdco LLC, due 2020 | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			0.0085%
Rosie Class B LLC, due 2027
Debt Instrument [Line Items]
Long-term debt			$ 80,000,000	0
Rosie Class B LLC, due 2027 | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			1.75%
Tapestry, due 2031
Debt Instrument [Line Items]
Long-term debt			$ 143,000,000	156,000,000
Basis spread on variable rate		1.375%
Tapestry, due 2031 | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			1.375%
Utah Solar Holdings, due 2036
Debt Instrument [Line Items]
Long-term debt			$ 290,000,000	0
Interest rate stated rate			3.59%
Utah Solar Holdings, due 2036 | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			1.625%
Utah Solar Portfolio, due 2022
Debt Instrument [Line Items]
Long-term debt			$ 0	254,000,000
Walnut Creek, due 2023
Debt Instrument [Line Items]
Long-term debt			$ 126,000,000	175,000,000
Walnut Creek, due 2023 | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			1.75%
WCEP Holdings, LLC, due 2023
Debt Instrument [Line Items]
Long-term debt			$ 35,000,000	39,000,000
WCEP Holdings, LLC, due 2023 | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			3.00%
Other
Debt Instrument [Line Items]
Long-term debt			$ 199,000,000	264,000,000
Subtotal project-level debt
Debt Instrument [Line Items]
Long-term debt			5,243,000,000	5,175,000,000
Blythe
Debt Instrument [Line Items]
Long-term debt				14,000,000
Roadrunner
Debt Instrument [Line Items]
Long-term debt				28,000,000
Letter of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt			0	$ 0
Letters of credit outstanding			$ 66,000,000
Letter of Credit | Revolving Credit Facility | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			1.50%
Letter of Credit | Alpine, due 2022
Debt Instrument [Line Items]
Letters of credit outstanding			$ 0
Letter of Credit | Alta Wind I-V lease financing arrangements, due 2034 and 2035
Debt Instrument [Line Items]
Letters of credit outstanding			44,000,000
Letter of Credit | Alta Wind Realty Investments LLC, due 2031
Debt Instrument [Line Items]
Letters of credit outstanding			0
Letter of Credit | Borrego, due 2024 and 2038
Debt Instrument [Line Items]
Letters of credit outstanding			4,000,000
Letter of Credit | Buckthorn Solar, due 2025
Debt Instrument [Line Items]
Letters of credit outstanding			22,000,000
Letter of Credit | Carlsbad Holdco, due 2038
Debt Instrument [Line Items]
Letters of credit outstanding			4,000,000
Letter of Credit | Carlsbad Energy Holdings LLC, due 2027
Debt Instrument [Line Items]
Letters of credit outstanding			63,000,000
Letter of Credit | Carlsbad Energy Holdings LLC, due 2038
Debt Instrument [Line Items]
Letters of credit outstanding			0
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			13,000,000
Letter of Credit | DG-CS Master Borrower LLC, due 2040
Debt Instrument [Line Items]
Letters of credit outstanding			30,000,000
Letter of Credit | Duquesne, due 2059
Debt Instrument [Line Items]
Letters of credit outstanding			0
Letter of Credit | El Segundo Energy Center, due 2023
Debt Instrument [Line Items]
Letters of credit outstanding			138,000,000
Letter of Credit | Energy Center Minneapolis Series 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			10,000,000
Letter of Credit | Kawailoa Solar Portfolio LLC, due 2026
Debt Instrument [Line Items]
Letters of credit outstanding			14,000,000
Letter of Credit | Marsh Landing, due 2023
Debt Instrument [Line Items]
Letters of credit outstanding			27,000,000
Letter of Credit | NIMH Solar, due 2024
Debt Instrument [Line Items]
Letters of credit outstanding			11,000,000
Letter of Credit | Oahu Solar Holdings LLC, due 2026
Debt Instrument [Line Items]
Letters of credit outstanding			10,000,000
Letter of Credit | Repowering Partnership Holdco LLC, due 2020
Debt Instrument [Line Items]
Letters of credit outstanding			0
Letter of Credit | Rosie Class B LLC, due 2027
Debt Instrument [Line Items]
Letters of credit outstanding			19,000,000
Letter of Credit | Tapestry, due 2031
Debt Instrument [Line Items]
Letters of credit outstanding			17,000,000
Letter of Credit | Utah Solar Holdings, due 2036
Debt Instrument [Line Items]
Letters of credit outstanding			11,000,000
Letter of Credit | Utah Solar Portfolio, due 2022
Debt Instrument [Line Items]
Letters of credit outstanding			0
Letter of Credit | Walnut Creek, due 2023
Debt Instrument [Line Items]
Letters of credit outstanding			73,000,000
Letter of Credit | WCEP Holdings, LLC, due 2023
Debt Instrument [Line Items]
Letters of credit outstanding			0
Letter of Credit | Other
Debt Instrument [Line Items]
Letters of credit outstanding			$ 50,000,000
Minimum | Alta Wind I-V lease financing arrangements, due 2034 and 2035
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 | El Segundo Energy Center, due 2023 | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			1.875%
Maximum | Alta Wind I-V lease financing arrangements, due 2034 and 2035
Debt Instrument [Line Items]
Interest rate stated rate			7.015%
Maximum | CVSR, due 2037
Debt Instrument [Line Items]
Interest rate stated rate			3.775%
Maximum | El Segundo Energy Center, due 2023 | London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate			2.50%

Long-term Debt - Revolving Cred

Long-term Debt - Revolving Credit Facility (Details)	Dec. 20, 2019	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Feb. 26, 2021USD ($)
Debt Instrument [Line Items]
Proceeds from the revolving credit facility		$ 265,000,000	$ 152,000,000	$ 35,000,000
Repayments of lines of credit		265,000,000	$ 152,000,000	$ 90,000,000
Revolving Credit Facility
Debt Instrument [Line Items]
Increase in leverage ratio	0.50
Line of credit fair value amount outstanding		0
Clearway Energy LLC and Clearway Energy Operating LLC Revolving Credit Facility
Debt Instrument [Line Items]
Proceeds from the revolving credit facility		265,000,000
Repayments of lines of credit		265,000,000
Letter of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Letters of credit outstanding		$ 66,000,000
Subsequent Event | Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit fair value amount outstanding					$ 195,000,000
Subsequent Event | Letter of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Letters of credit outstanding					$ 70,000,000

Long-term Debt - Senior Notes a

Long-term Debt - Senior Notes and Convertible Notes (Details) - USD ($)

Nov. 02, 2020

Sep. 30, 2020

Sep. 01, 2020

Jun. 01, 2020

May 21, 2020

Feb. 07, 2020

Jan. 03, 2020

Dec. 23, 2019

Dec. 20, 2019

Dec. 06, 2019

Nov. 26, 2019

Oct. 21, 2019

Jun. 14, 2019

Dec. 31, 2023

Dec. 31, 2020

Dec. 31, 2019

Dec. 31, 2018

Dec. 21, 2020

Feb. 18, 2020

Dec. 11, 2019

May 01, 2019

Debt Instrument [Line Items]

Gain (loss) on extinguishment of debt

$ (24,000,000)

$ (16,000,000)

$ 0

Basis spread on variable rate

1.375%

Repayments of related party debt

45,000,000

215,000,000

359,000,000

Proceeds from the revolving credit facility

$ 265,000,000

$ 152,000,000

$ 35,000,000

DG-CS Master Borrower LLC

Debt Instrument [Line Items]

Derivative liability

$ 42,000,000

4.75% Senior Notes due in 2028

Debt Instrument [Line Items]

Long-term debt — affiliate

$ 600,000,000

4.75% Senior Notes due in 2028 | Notes Payable, Other Payables

Debt Instrument [Line Items]

Debt instrument, repurchased face amount

$ 250,000,000

Interest rate stated rate

4.75%

Debt instrument, redemption price, percentage

102.00%

4.75% Senior Notes due in 2028 | Notes Payable, Other Payables | Clearway Energy, Inc.

Debt Instrument [Line Items]

Repayments of senior debt

$ 45,000,000

2024 Senior Notes

Debt Instrument [Line Items]

Debt instrument, repurchased face amount

$ 88,000,000

Interest rate stated rate

5.375%

Debt instrument, redemption price, percentage

102.70%

Debt instrument, repurchase amount

$ 90,000,000

Gain (loss) on extinguishment of debt

$ (3,000,000)

Intercompany Note with Clearway Energy, Inc.

Debt Instrument [Line Items]

Interest rate stated rate

1.49%

Debt instrument, face amount

$ 3,000,000

Rosie TargetCo LLC Construction Loan | Construction Loans

Debt Instrument [Line Items]

Maximum borrowing capacity

$ 91,000,000

Rosie TargetCo LLC Construction Loan | Bridge Loan

Debt Instrument [Line Items]

Maximum borrowing capacity

24,000,000

Rosie TargetCo LLC Construction Loan | Investment Tax Credit Loan

Debt Instrument [Line Items]

Maximum borrowing capacity

$ 132,000,000

Repayments of Long-term Debt

$ 130,000,000

Rosie Class B LLC, due 2027

Debt Instrument [Line Items]

Debt instrument, face amount

$ 80,000,000

Rosie Class B LLC, due 2027 | London Interbank Offered Rate (LIBOR)

Debt Instrument [Line Items]

Basis spread on variable rate

1.75%

Rosie Class B LLC, due 2027 | London Interbank Offered Rate (LIBOR) | Scenario, Forecast

Debt Instrument [Line Items]

Basis spread on variable rate

2.00%

Rosie Class B LLC, due 2027 | Letter of Credit

Debt Instrument [Line Items]

Maximum borrowing capacity

$ 23,000,000

Letters of credit outstanding

$ 19,000,000

Repowering Partnership Holdco LLC, due 2020

Debt Instrument [Line Items]

Long-term debt

$ 352,000,000

Repayments of debt

$ 260,000,000

$ 93,000,000

Repowering Partnership Holdco LLC, due 2020 | Loans Payable

Debt Instrument [Line Items]

Repayments of related party debt

$ 109,000,000

Repowering Partnership Holdco LLC, due 2020 | London Interbank Offered Rate (LIBOR)

Debt Instrument [Line Items]

Basis spread on variable rate

0.0085%

Repowering Partnership Holdco LLC, due 2020 | London Interbank Offered Rate (LIBOR) | Loans Payable

Debt Instrument [Line Items]

Basis spread on variable rate

0.85%

Repowering Partnership Holdco LLC, due 2020 | Letter of Credit

Debt Instrument [Line Items]

Letters of credit outstanding

$ 0

CS4 Borrower | Renew CS4 Borrower LLC | London Interbank Offered Rate (LIBOR)

Debt Instrument [Line Items]

Basis spread on variable rate

2.00%

CS4 Borrower | Construction Loans | Renew CS4 Borrower LLC

Debt Instrument [Line Items]

Debt instrument, face amount

$ 97,000,000

CS4 Borrower | Bridge Loan | Renew CS4 Borrower LLC

Debt Instrument [Line Items]

Debt instrument, face amount

90,000,000

CS4 Borrower | Letter of Credit | Renew CS4 Borrower LLC

Debt Instrument [Line Items]

Debt instrument, face amount

5,000,000

Chestnut Borrower Credit Agreement | Letter of Credit | Chestnut Borrower, LLC

Debt Instrument [Line Items]

Debt instrument, face amount

8,000,000

Chestnut Borrower Credit Agreement | Loans Payable | Chestnut Borrower, LLC

Debt Instrument [Line Items]

Debt instrument, face amount

$ 120,000,000

DG-CS Master Borrower LLC Financing Arrangement | DG-CS Master Borrower LLC

Debt Instrument [Line Items]

Interest rate stated rate

3.51%

DG-CS Master Borrower LLC Financing Arrangement | Letter of Credit | DG-CS Master Borrower LLC

Debt Instrument [Line Items]

Proceeds from the revolving credit facility

$ 30,000,000

DG-CS Master Borrower LLC Financing Arrangement | Loans Payable | DG-CS Master Borrower LLC

Debt Instrument [Line Items]

Proceeds from the revolving credit facility

467,000,000

Chestnut Borrower, LLC

Debt Instrument [Line Items]

Repayments of debt

107,000,000

Renew Solar CS 4 Borrower LLC

Debt Instrument [Line Items]

Repayments of debt

102,000,000

DGPV 4 Borrower LLC

Debt Instrument [Line Items]

Repayments of debt

92,000,000

Puma Class B LLC

Debt Instrument [Line Items]

Repayments of debt

$ 73,000,000

Utah Solar Holdings, due 2036

Debt Instrument [Line Items]

Interest rate stated rate

3.59%

Utah Solar Holdings, due 2036 | London Interbank Offered Rate (LIBOR)

Debt Instrument [Line Items]

Basis spread on variable rate

1.625%

Utah Solar Holdings, due 2036 | Notes Payable, Other Payables | Utah Solar Holdings, LLC

Debt Instrument [Line Items]

Interest rate stated rate

3.59%

Repayments of debt

$ 247,000,000

Proceeds from the revolving credit facility

296,000,000

Derivative liability

(33,000,000)

Utah Solar Holdings, due 2036 | Notes Payable, Other Payables | Utah Solar Holdings, LLC | Clearway Energy Operating LLC | Affiliated Entity

Debt Instrument [Line Items]

Decrease from distributions to noncontrolling interest holders

9,000,000

Utah Solar Holdings, due 2036 | Letter of Credit

Debt Instrument [Line Items]

Letters of credit outstanding

$ 11,000,000

Utah Solar Holdings, due 2036 | Letter of Credit | Utah Solar Holdings, LLC

Debt Instrument [Line Items]

Debt instrument, face amount

$ 16,000,000

Subtotal project-level debt | Loans Payable | Blythe

Debt Instrument [Line Items]

Repayments of debt

$ 158,000,000

Subtotal project-level debt | Loans Payable | Alpine

Debt Instrument [Line Items]

Repayments of debt

158,000,000

Subtotal project-level debt | Loans Payable | Roadrunner

Debt Instrument [Line Items]

Repayments of debt

158,000,000

NIMH Solar LLC Financing Arrangement | Letter of Credit | NIMH Solar LLC

Debt Instrument [Line Items]

Proceeds from the revolving credit facility

16,000,000

NIMH Solar LLC Financing Arrangement | Loans Payable | Clearway Energy Operating LLC | Affiliated Entity

Debt Instrument [Line Items]

Decrease from distributions to noncontrolling interest holders

45,000,000

NIMH Solar LLC Financing Arrangement | Loans Payable | London Interbank Offered Rate (LIBOR) | Through Third Party Anniversary of Closing

Debt Instrument [Line Items]

Interest rate stated rate

2.00%

NIMH Solar LLC Financing Arrangement | Loans Payable | London Interbank Offered Rate (LIBOR) | After Third Party Anniversary of Closing

Debt Instrument [Line Items]

Interest rate stated rate

2.125%

NIMH Solar LLC Financing Arrangement | Loans Payable | NIMH Solar LLC

Debt Instrument [Line Items]

Proceeds from the revolving credit facility

193,000,000

Proceeds from issuance of long-term debt — external

$ 35,000,000

Carlsbad Energy Holdings LLC, due 2038

Debt Instrument [Line Items]

Interest rate stated rate

412.00%

Maximum borrowing capacity

$ 803,000,000

Carlsbad Energy Holdings LLC, due 2038 | Letter of Credit

Debt Instrument [Line Items]

Letters of credit outstanding

$ 0

CVSR, due 2037

Debt Instrument [Line Items]

Maximum borrowing capacity

$ 4,000,000

$ 83,000,000

Basis spread on variable rate

1.75%

4.12% Senior Notes due 2038

Debt Instrument [Line Items]

Interest rate stated rate

4.12%

Agua Caliente Solar

Debt Instrument [Line Items]

Repayments of debt

$ 40,000,000

Duquesne, due 2059

Debt Instrument [Line Items]

Interest rate stated rate

4.62%

4.62%

Debt instrument, face amount

$ 95,000,000

Duquesne, due 2059 | Letter of Credit

Debt Instrument [Line Items]

Letters of credit outstanding

$ 0

Long-term Debt - Drop Down Asse

Long-term Debt - Drop Down Assets and Other (Details) - USD ($) $ in Millions	Dec. 23, 2019	Dec. 06, 2019	Nov. 13, 2019	Oct. 21, 2019	Jun. 14, 2019	Apr. 29, 2019	Dec. 31, 2020	May 01, 2019
Debt Instrument [Line Items]
Long-term debt							$ 7,043
Basis spread on variable rate	1.375%
Non-resource debt							$ 481
Carlsbad Drop Down
Debt Instrument [Line Items]
Long-term debt		$ 803
Carlsbad Energy Holdings LLC, due 2038
Debt Instrument [Line Items]
Maximum borrowing capacity		803
Interest rate stated rate							412.00%
Carlsbad Energy Holdings LLC, due 2038 | Carlsbad Drop Down
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 10
Interest rate stated rate		4.21%
Debt instrument, convertible, remaining discount amortization period		19 years
Fees on the unused commitment (percent)		0.65%
CVSR, due 2037
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 4					$ 83
Fees on the unused commitment (percent)		0.50%
Long-term debt		$ 194
Basis spread on variable rate		1.75%
CVSR, due 2037 | Maturity - February 25, 2025
Debt Instrument [Line Items]
Basis spread on variable rate		1.625%
CVSR, due 2037 | Maturity - October 31, 2038
Debt Instrument [Line Items]
Basis spread on variable rate		1.875%
CVSR, due 2037 | Carlsbad Drop Down
Debt Instrument [Line Items]
Long-term debt		$ 407
4.12% Senior Notes due 2038
Debt Instrument [Line Items]
Interest rate stated rate		4.12%
Agua Caliente Solar
Debt Instrument [Line Items]
Repayments of debt				$ 40
Duquesne, due 2059
Debt Instrument [Line Items]
Interest rate stated rate							4.62%	4.62%
Oahu Solar Holdings LLC Debt
Debt Instrument [Line Items]
Long-term debt			$ 143
Basis spread on variable rate			1.375%
Long-term debt			$ 162
Oahu Solar Holdings LLC, due 2026
Debt Instrument [Line Items]
Long-term debt			90
Repayments of debt			$ 67
Kawailoa Solar Holdings LLC Debt
Debt Instrument [Line Items]
Long-term debt	$ 137
Non-resource debt	120
Kawailoa Solar Holdings LLC Debt | Kawailoa Solar Portfolio LLC, due 2026
Debt Instrument [Line Items]
Long-term debt	82
Kawailoa Solar Portfolio LLC, due 2026
Debt Instrument [Line Items]
Repayments of debt	$ 57
South Trent
Debt Instrument [Line Items]
Long-term debt					$ 49
Basis spread on variable rate					1.625%
South Trent Wind Due 2028
Debt Instrument [Line Items]
Long-term debt					$ 46
Basis spread on variable rate					1.35%
Tapestry, due 2021
Debt Instrument [Line Items]
Long-term debt						$ 147
Basis spread on variable rate						1.75%
Tapestry, due 2031
Debt Instrument [Line Items]
Long-term debt						$ 164
Basis spread on variable rate						1.375%

Long-term Debt - Interest Rate

Long-term Debt - Interest Rate Swaps (Details) $ in Millions	Dec. 31, 2020USD ($)
Debt Instrument [Line Items]
Derivative notional amount	$ 1,600
El Segundo
Debt Instrument [Line Items]
% of Principal	100.00%
Derivative notional amount	$ 250
NIMH Solar LLC
Debt Instrument [Line Items]
% of Principal	100.00%
Derivative notional amount	$ 191
Tapestry Wind
Debt Instrument [Line Items]
% of Principal	75.00%
Derivative notional amount	$ 107
Viento Funding II
Debt Instrument [Line Items]
% of Principal	100.00%
Fixed Interest Rate	3.03%
Derivative notional amount	$ 33
Maturity - November 30, 2030 | Avra Valley
Debt Instrument [Line Items]
% of Principal	87.00%
Fixed Interest Rate	2.33%
Derivative notional amount	$ 38
Maturity - May 15, 2031 | AWAM
Debt Instrument [Line Items]
% of Principal	100.00%
Fixed Interest Rate	2.47%
Derivative notional amount	$ 14
Maturity - December 31, 2024 | Borrego
Debt Instrument [Line Items]
% of Principal	100.00%
Fixed Interest Rate	0.476%
Derivative notional amount	$ 13
Maturity - December 31, 2041 | Buckthorn Solar
Debt Instrument [Line Items]
% of Principal	82.00%
Derivative notional amount	$ 103
Maturity - September 30, 2027 | Carlsbad
Debt Instrument [Line Items]
% of Principal	100.00%
Derivative notional amount	$ 156
Maturity - December 31, 2030 | Kansas South
Debt Instrument [Line Items]
% of Principal	75.00%
Fixed Interest Rate	2.368%
Derivative notional amount	$ 17
Maturity - October 31, 2040 | Kawailoa Solar Holdings LLC Debt
Debt Instrument [Line Items]
% of Principal	94.00%
Derivative notional amount	$ 76
Maturity - October 31, 2040 | Oahu Solar Holdings LLC Debt
Debt Instrument [Line Items]
% of Principal	96.00%
Derivative notional amount	$ 86
Maturity - December 21, 2028 | Laredo Ridge
Debt Instrument [Line Items]
% of Principal	100.00%
Derivative notional amount	$ 78
Maturity - June 30, 2023 | Marsh Landing
Debt Instrument [Line Items]
% of Principal	100.00%
Derivative notional amount	$ 146
Maturity - July 29, 2044 | Rosie Class B LLC, due 2027
Debt Instrument [Line Items]
% of Principal	95.00%
Fixed Interest Rate	1.446%
Derivative notional amount	$ 76
Maturity - June 30, 2028 | South Trent
Debt Instrument [Line Items]
% of Principal	90.00%
Fixed Interest Rate	3.847%
Derivative notional amount	$ 35
Maturity - June 30, 2028 | Viento Funding II
Debt Instrument [Line Items]
% of Principal	100.00%
Fixed Interest Rate	4.985%
Derivative notional amount	$ 21
Maturity - December 21, 2029 | Tapestry Wind
Debt Instrument [Line Items]
% of Principal	50.00%
Fixed Interest Rate	3.57%
Derivative notional amount	$ 12
Maturity - May 31, 2023 | Walnut Creek
Debt Instrument [Line Items]
% of Principal	90.00%
Fixed Interest Rate	3.543%
Derivative notional amount	$ 114
Maturity - May 31, 2023 | WCEP Holdings
Debt Instrument [Line Items]
% of Principal	100.00%
Fixed Interest Rate	4.003%
Derivative notional amount	$ 34

Long-term Debt - Maturities (De

Long-term Debt - Maturities (Details) $ in Millions	Dec. 31, 2020USD ($)
Maturities of Long-term Debt [Abstract]
2021	$ 384
2022	407
2023	431
2024	359
2025	934
Thereafter	4,528
Long-term debt	$ 7,043

Members' Equity (Details)

Members' Equity (Details) - $ / shares	Mar. 15, 2021	Feb. 12, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020
Class of Stock [Line Items]
Distributions paid (in dollars per share)			$ 0.3180	$ 0.3125	$ 0.2100	$ 0.2100
Subsequent Event
Class of Stock [Line Items]
Dividends payable, date declared		Feb. 12, 2021
Common stock dividends declared (in dollars per share)		$ 0.324
Dividends date paid	Mar. 15, 2021

Segment Reporting (Details)

Segment Reporting (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting
Total operating revenues	$ 280	$ 332	$ 329	$ 258	$ 235	$ 296	$ 284	$ 217	$ 1,199	$ 1,032	$ 1,053
Cost of operations									366	337	327
Depreciation, amortization and accretion									428	401	336
Tangible Asset Impairment Charges									24	33	0
General and administrative									33	27	20
Transaction and integration costs									9	3	20
Development costs									5	5	3
Operating Income	28	123	131	52	7	90	88	41	334	226	347
Equity in earnings of unconsolidated affiliates									7	83	74
Impairment loss on investment									(8)	0	0
Gain on sale of unconsolidated affiliate									49	0	0
Other income, net									4	9	8
Loss on debt extinguishment									(24)	(16)	0
Interest expense									(414)	(403)	(294)
Net (Loss) Income	(78)	$ 51	$ 104	$ (129)	(41)	$ 25	(31)	$ (54)	(52)	(101)	135
Net Income Attributable to Clearway Energy LLC									61	(30)	$ 240
Equity investment in affiliates	741				1,183				741	1,183
Capital expenditures	106				223				106	223
Total assets	10,488				9,605				$ 10,488	$ 9,605
Renewables
Segment Reporting
Tangible Asset Impairment Charges					14
Impairment loss on investment	(8)
Thermal
Segment Reporting
Tangible Asset Impairment Charges							$ 19
SCE | Conventional
Segment Reporting
Customer's percentage of total revenue									18.00%	21.00%	20.00%
SCE | Renewables
Segment Reporting
Customer's percentage of total revenue									16.00%	19.00%	20.00%
PG&E | Conventional
Segment Reporting
Customer's percentage of total revenue									10.00%	12.00%	12.00%
PG&E | Renewables
Segment Reporting
Customer's percentage of total revenue									8.00%	10.00%	11.00%
Operating Segments
Segment Reporting
Total operating revenues									$ 1,199	$ 1,032	$ 1,053
Operating Segments | Conventional
Segment Reporting
Total operating revenues									437	346	337
Cost of operations									90	60	61
Depreciation, amortization and accretion									132	103	102
Tangible Asset Impairment Charges									0	0
General and administrative									0	0	0
Transaction and integration costs									0	0	0
Development costs									0	0	0
Operating Income									215	183	174
Equity in earnings of unconsolidated affiliates									8	9	11
Impairment loss on investment									0
Gain on sale of unconsolidated affiliate									0
Other income, net									1	2	1
Loss on debt extinguishment									0	0
Interest expense									(84)	(59)	(51)
Net (Loss) Income									140	135	135
Net Income Attributable to Clearway Energy LLC									140	135	135
Equity investment in affiliates	90				94				90	94
Capital expenditures	12				4				12	4
Total assets	2,575				2,753				2,575	2,753
Operating Segments | Renewables
Segment Reporting
Total operating revenues									569	485	523
Cost of operations									147	143	139
Depreciation, amortization and accretion									264	271	211
Tangible Asset Impairment Charges									24	14
General and administrative									0	1	0
Transaction and integration costs									0	0	0
Development costs									0	0	0
Operating Income									134	56	173
Equity in earnings of unconsolidated affiliates									(1)	74	63
Impairment loss on investment									(8)
Gain on sale of unconsolidated affiliate									0
Other income, net									4	6	4
Loss on debt extinguishment									(21)	(1)
Interest expense									(216)	(239)	(154)
Net (Loss) Income									(108)	(104)	86
Net Income Attributable to Clearway Energy LLC									4	(33)	190
Equity investment in affiliates	651				1,089				651	1,089
Capital expenditures	44				185				44	185
Total assets	7,157				6,186				7,157	6,186
Operating Segments | Thermal
Segment Reporting
Total operating revenues									193	201	193
Cost of operations									131	134	127
Depreciation, amortization and accretion									32	27	23
Tangible Asset Impairment Charges									0	19
General and administrative									3	3	1
Transaction and integration costs									0	0	0
Development costs									5	5	2
Operating Income									22	13	40
Equity in earnings of unconsolidated affiliates									0	0	0
Impairment loss on investment									0
Gain on sale of unconsolidated affiliate									0
Other income, net									0	0	1
Loss on debt extinguishment									0	0
Interest expense									(19)	(18)	(12)
Net (Loss) Income									3	(5)	29
Net Income Attributable to Clearway Energy LLC									3	(5)	29
Equity investment in affiliates	0				0				0	0
Capital expenditures	50				34				50	34
Total assets	627				633				627	633
Corporate
Segment Reporting
Total operating revenues									0	0	0
Cost of operations									(2)	0	0
Depreciation, amortization and accretion									0	0	0
Tangible Asset Impairment Charges									0	0
General and administrative									30	23	19
Transaction and integration costs									9	3	20
Development costs									0	0	1
Operating Income									(37)	(26)	(40)
Equity in earnings of unconsolidated affiliates									0	0	0
Impairment loss on investment									0
Gain on sale of unconsolidated affiliate									49
Other income, net									(1)	1	2
Loss on debt extinguishment									(3)	(15)
Interest expense									(95)	(87)	(77)
Net (Loss) Income									(87)	(127)	(115)
Net Income Attributable to Clearway Energy LLC									(86)	(127)	$ (114)
Equity investment in affiliates	0				0				0	0
Capital expenditures	0				0				0	0
Total assets	$ 129				$ 33				$ 129	$ 33

Related Party Transactions (Det

Related Party Transactions (Details) $ in Millions	Jun. 19, 2018USD ($)	Jan. 31, 2020USD ($)	Jan. 31, 2019USD ($)	Dec. 31, 2018USD ($)MW	Aug. 31, 2018USD ($)	Dec. 31, 2020USD ($)kpphMWton	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)MW
Related Party Transaction [Line Items]
General and administrative						$ 33	$ 27	$ 20
RENOM
Related Party Transaction [Line Items]
Expenses from transactions with related party				$ 11	$ 29	37	31
Due to related party						10	7
Affiliated Entity | Administrative Services Agreements
Related Party Transaction [Line Items]
Expenses from transactions with related party					6	10	7
CEG
Related Party Transaction [Line Items]
Expenses from transactions with related party				$ 3
Due to related party						2	1
General and administrative						$ 2	$ 1
NRG
Related Party Transaction [Line Items]
Revenue from related parties					8
NRG | Operations and Maintenance services
Related Party Transaction [Line Items]
Expenses from transactions with related party					27
Thermal | NRG
Related Party Transaction [Line Items]
Expenses from transactions with related party					7
GenConn | NRG | Operations and Maintenance services
Related Party Transaction [Line Items]
Expenses from transactions with related party					4
Marsh Landing | NRG
Related Party Transaction [Line Items]
Expenses from transactions with related party					11
Thermal | UPMC Thermal
Related Party Transaction [Line Items]
Steam and chilled water capacity, megawatts | MW						73
Steam energy, pph | kpph						150
Chilled water capacity, tons | ton						6,750
Power generation capacity, megawatts | MW						7.5
Thermal | NRG
Related Party Transaction [Line Items]
Expenses from transactions with related party					$ 7
UPMC Thermal
Related Party Transaction [Line Items]
Related party transaction term	20 years
Business combination consideration transferred	$ 84	$ 1	$ 3
UPMC Thermal | UPMC Thermal
Related Party Transaction [Line Items]
Steam and chilled water capacity, megawatts | MW				73				73
Power generation capacity, megawatts | MW				7.5				7.5
Clearway Energy, Inc. | NRG
Related Party Transaction [Line Items]
Ownership percentage sold					100.00%
Management Service, Base | PML | NRG
Related Party Transaction [Line Items]
Reimbursed costs					$ 11

Commitments and Contingencies_2

Commitments and Contingencies (Details) - USD ($) $ in Millions	8 Months Ended	12 Months Ended
	Aug. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Long-term Purchase Commitment [Line Items]
Power procurement arrangements		$ 32	$ 38	$ 39
2021		9
2022		3
2023		2
2024		0
2025		0
Purchase obligation, thereafter		0
Total		$ 14
Thermal | NRG
Long-term Purchase Commitment [Line Items]
Expenses from transactions with related party	$ 7

Leases - Lease Cost (Details)

Leases - Lease Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease cost - Fixed	$ 19	$ 13
Operating lease cost - Variable	9	8
Total lease cost	28	21
ASSETS
ROU Assets - operating leases, net (a)	337	223
Liabilities [Abstract]
Short-term lease liability - operating leases	8	7
Long-term lease liabilities	345	227
Total lease liability	$ 353	$ 234
Weighted average remaining lease term (in years)	25 years	25 years
Weighted average discount rate (as a percent)	4.30%	4.40%
Cash paid for operating leases	$ 19	$ 15
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherAccruedLiabilitiesCurrent	us-gaap:OtherAccruedLiabilitiesCurrent

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Millions	Dec. 31, 2020USD ($)renewalOption	Dec. 31, 2019USD ($)
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease liability	$ 353	$ 234
Right-of-use assets, net	$ 337	223
Oahu Solar Partnership
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease period	35 years
Number of renewal options | renewalOption	2
Renewal period	5 years
Lease liability	$ 20	21
Right-of-use assets, net	$ 18	$ 19
Rosamond Central
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease period	35 years
Number of renewal options | renewalOption	2
Renewal period	5 years
Lease liability	$ 12
Right-of-use assets, net	$ 11

Leases - Maturities of Operatin

Leases - Maturities of Operating Lease Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
2021	$ 23
2022	23
2023	23
2024	23
2025	23
Thereafter	476
Total lease payments	591
Less imputed interest	238
Lease liability	$ 353	$ 234

Leases - Revenue Related to Lea

Leases - Revenue Related to Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Energy Revenue
Disaggregation of Revenue [Line Items]
Lease revenue	$ 566	$ 516
Energy Revenue | Conventional
Disaggregation of Revenue [Line Items]
Lease revenue	10	5
Energy Revenue | Renewables
Disaggregation of Revenue [Line Items]
Lease revenue	554	509
Energy Revenue | Thermal
Disaggregation of Revenue [Line Items]
Lease revenue	2	2
Capacity Revenue
Disaggregation of Revenue [Line Items]
Lease revenue	451	348
Capacity Revenue | Conventional
Disaggregation of Revenue [Line Items]
Lease revenue	451	348
Capacity Revenue | Renewables
Disaggregation of Revenue [Line Items]
Lease revenue	0	0
Capacity Revenue | Thermal
Disaggregation of Revenue [Line Items]
Lease revenue	0	0
Operating Revenues
Disaggregation of Revenue [Line Items]
Lease revenue	1,017	864
Operating Revenues | Conventional
Disaggregation of Revenue [Line Items]
Lease revenue	461	353
Operating Revenues | Renewables
Disaggregation of Revenue [Line Items]
Lease revenue	554	509
Operating Revenues | Thermal
Disaggregation of Revenue [Line Items]
Lease revenue	$ 2	$ 2

Leases - Minimum Future Rent Pa

Leases - Minimum Future Rent Payments Under Operating Leases (Details) $ in Millions	Dec. 31, 2020USD ($)
Leases [Abstract]
2021	$ 444
2022	450
2023	259
2024	106
2025	107
Thereafter	1,498
Total lease payments	$ 2,864

Leases - Property, Plant and Eq

Leases - Property, Plant and Equipment Related to Operating Leases (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 9,540	$ 7,943
Accumulated depreciation	(2,323)	(1,880)
Property, plant and equipment, net	7,217	6,063
Assets Leased to Others
Property, Plant and Equipment [Line Items]
Property, plant and equipment	7,201	6,942
Accumulated depreciation	(1,964)	(1,649)
Property, plant and equipment, net	$ 5,237	$ 5,293

Leases - Sales-Type Lease Agree

Leases - Sales-Type Lease Agreement (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)renewalOption
Leases [Abstract]
Lease receivable	$ 12
Maximum annual fixed payments allowed under agreement	$ 1
Number of renewal options | renewalOption	2
Sale-type lease, renewal term	5 years

Leases - Future Minimum Lease R

Leases - Future Minimum Lease Receivables Schedule (Details) $ in Millions	Dec. 31, 2020USD ($)
Leases [Abstract]
2021	$ 1
2022	1
2023	1
2024	1
2025	1
Thereafter	9
Total sales-type lease payments	$ 14

Unaudited Quarterly Financial_3

Unaudited Quarterly Financial Data (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Total operating revenues	$ 280	$ 332	$ 329	$ 258	$ 235	$ 296	$ 284	$ 217	$ 1,199	$ 1,032	$ 1,053
Operating Income	28	123	131	52	7	90	88	41	334	226	347
Net (loss) income	$ (78)	$ 51	$ 104	$ (129)	$ (41)	$ 25	$ (31)	$ (54)	$ (52)	$ (101)	$ 135

Schedule I - Condensed Financ_2

Schedule I - Condensed Financial Information of Registrant - P/L (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Income Statements, Captions [Line Items]
Other income, net									$ 4	$ 9	$ 8
Loss on debt extinguishment									(24)	(16)	0
Interest expense									(414)	(403)	(294)
Total other expense, net									(386)	(327)	(212)
Net (Loss) Income	$ (78)	$ 51	$ 104	$ (129)	$ (41)	$ 25	$ (31)	$ (54)	(52)	(101)	135
Net Income (Loss) Attributable to Clearway Energy LLC									61	(30)	240
Clearway Energy LLC
Condensed Income Statements, Captions [Line Items]
Equity in earnings (losses) of consolidated affiliates									61	(32)	237
Other income, net									0	2	3
Loss on debt extinguishment									0	0	0
Interest expense									0	0	0
Total other expense, net									0	2	3
Net Income (Loss) Attributable to Clearway Energy LLC									$ 61	$ (30)	$ 240

Schedule I - Condensed Financ_3

Schedule I - Condensed Financial Information of Registrant - B/S (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	$ 268	$ 152
Total Assets	10,488	9,605
Accounts payable — affiliates	20	33
Total Liabilities	7,876	7,432
Contributed capital	1,723	1,882
(Accumulated deficit) retained earnings	(50)	5
Accumulated other comprehensive loss	(33)	(37)
Total Members' Equity	2,612	2,173	$ 2,182	$ 2,029
Total Liabilities and Members’ Equity	10,488	9,605
Clearway Energy LLC
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	119	27
Investment in consolidated subsidiaries	1,545	1,824
Total Assets	1,664	1,851
Accounts payable — affiliates	24	1
Total Liabilities	24	1
Contributed capital	1,723	1,882
(Accumulated deficit) retained earnings	(50)	5
Accumulated other comprehensive loss	(33)	(37)
Total Members' Equity	1,640	1,850
Total Liabilities and Members’ Equity	$ 1,664	$ 1,851

Schedule I - Condensed Financ_4

Schedule I - Condensed Financial Information of Registrant - CF (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by (Used in) Operating Activities	$ 545	$ 469	$ 492
Net Cash Used in Investing Activities	(62)	(468)	(185)
Proceeds from the issuance of class C units	62	100	153
Net Cash Used in Financing Activities	(432)	(170)	(38)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	51	(169)	269
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	414	583	314
Cash, Cash Equivalents and Restricted Cash at End of Period	465	414	583
Clearway Energy LLC
Condensed Cash Flow Statements, Captions [Line Items]
Net Cash Provided by (Used in) Operating Activities	0	0	0
Investments in consolidated affiliates	306	(211)	361
Net Cash Used in Investing Activities	306	(211)	361
Transfer of funds under intercompany cash management arrangement	(65)	(5)	0
Payments of distributions	(211)	(155)	(238)
Net Cash Used in Financing Activities	(214)	(60)	(85)
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	92	(271)	276
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	27	298	22
Cash, Cash Equivalents and Restricted Cash at End of Period	119	27	298
Clearway Energy LLC | Common Class C
Condensed Cash Flow Statements, Captions [Line Items]
Proceeds from the issuance of class C units	$ 62	$ 100	$ 153

Schedule I - Condensed Financ_5

Schedule I - Condensed Financial Information of Registrant - Footnotes (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)MW	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 06, 2019MW	Aug. 31, 2018	Mar. 30, 2018
Condensed Cash Flow Statements, Captions [Line Items]
Economic ownership interest						100.00%
Clearway Energy LLC
Condensed Cash Flow Statements, Captions [Line Items]
Cash distributions | $	$ 211	$ 155	$ 238
Clearway Energy LLC
Condensed Cash Flow Statements, Captions [Line Items]
Ownership percentage	57.61%
Clearway Energy, Inc. | GIP
Condensed Cash Flow Statements, Captions [Line Items]
Economic ownership interest					55.00%
Clearway Energy LLC | GIP
Condensed Cash Flow Statements, Captions [Line Items]
Economic ownership interest					45.20%
Carlsbad Drop Down
Condensed Cash Flow Statements, Captions [Line Items]
Economic ownership interest				100.00%
Conventional Generation, Utility-Scale Solar, Distributed Solar, and Wind
Condensed Cash Flow Statements, Captions [Line Items]
Power generation capacity, megawatts	4,200
Natural Gas | Carlsbad Drop Down
Condensed Cash Flow Statements, Captions [Line Items]
Power generation capacity, megawatts				527

Uncategorized Items - cwen-2020

Label	Element	Value
Tax Equity Investors [Member]
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	$ 3,000,000
Tax Equity Investors [Member] | Noncontrolling Interest [Member]
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders	us-gaap_MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	$ 3,000,000