View Filing Data

Depreciation and amortization

$ 225

$ 221

^[1]

Operating Costs and Expenses

Cost of operations

^[1]

^[1]

General and administrative

^[1]

Total operating costs and expenses

176

167

^[1]

Operating Income

^[1]

Other Income (Expense)

Equity in earnings of unconsolidated affiliates

^[1]

Other income, net

^[1]

Loss on debt extinguishment

(2)

^[1]

Interest expense

(55)

(75)

^[1]

Total other expense, net

(50)

(57)

^[1]

Loss Before Income Taxes

(1)

(3)

^[1]

Income tax benefit

(1)

^[1]

Net Loss

(2)

^[1]

Less: Pre-acquisition net income of Drop Down Assets

^[1]

Net Loss Excluding Pre-acquisition Net Income of Drop Down Assets

(4)

(15)

^[1]

Less: Loss attributable to noncontrolling interests

(20)

(12)

^[1]

Net Income (Loss) Attributable to NRG Yield, Inc.

$ 16

$ (3)

^[1]

Earnings (Loss) Per Share Attributable to NRG Yield, Inc. Class A and Class C Common Stockholders

Dividends Per Common Share, Cash Paid

$ 0.298

Common Class C [Member]

Earnings Per Share, Basic

^[2]

$ 0.16

$ (0.03)

Other Income (Expense)

Net Income (Loss) Attributable to NRG Yield, Inc.

^[2]

$ 10

$ (2)

Earnings (Loss) Per Share Attributable to NRG Yield, Inc. Class A and Class C Common Stockholders

Weighted Average Number of Shares Outstanding, Basic and Diluted

^[2]

Earnings (Loss) per Weighted Average Class A and Class C Common Share - Basic and Diluted

^[2]

$ 0.16

$ (0.03)

Dividends Per Common Share, Cash Paid

$ 0.298

$ 0.260

Common Class A [Member]

Other Income (Expense)

Net Income (Loss) Attributable to NRG Yield, Inc.

^[2]

$ 6

$ (1)

Earnings (Loss) Per Share Attributable to NRG Yield, Inc. Class A and Class C Common Stockholders

Weighted Average Number of Shares Outstanding, Basic and Diluted

^[2]

Earnings (Loss) per Weighted Average Class A and Class C Common Share - Basic and Diluted

^[2]

$ 0.16

$ (0.03)

Dividends Per Common Share, Cash Paid

$ 0.298

$ 0.260

[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	(a) Basic and diluted earnings (loss) per share might not recalculate due to presenting values in millions rather than whole dollars.

Consolidated Statements of Comprehensive Loss - USD ($)
$ in Millions

3 Months Ended

Mar. 31, 2018

Mar. 31, 2017

^[1]

Net loss

$ 0

$ (2)

Other Comprehensive Gain, net of tax

Unrealized gain on derivatives, net of income tax expense of $3 and $1

Other comprehensive gain

Comprehensive Income

Less: Pre-acquisition net income of Drop Down Assets

Less: Comprehensive loss attributable to noncontrolling interests

(11)

(9)

Comprehensive Income Attributable to NRG Yield, Inc.

$ 24

$ 0

[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Consolidated Statements of Comprehensive Loss (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Unrealized gain/loss on derivatives, income tax expense /(benefit)	$ 3	$ 1

Consolidated Balance Sheets - USD ($)

Mar. 31, 2018

Dec. 31, 2017

Current Assets

Cash and cash equivalents

$ 173,000,000

$ 148,000,000

^[1]

Restricted cash

104,000,000

168,000,000

^[1]

Accounts receivable — trade

82,000,000

95,000,000

^[1]

Inventory

39,000,000

^[1]

Notes receivable

9,000,000

13,000,000

^[1]

Prepayments and other current assets

18,000,000

19,000,000

^[1]

Total current assets

425,000,000

482,000,000

^[1]

Property, plant and equipment, net

5,340,000,000

5,410,000,000

^[1]

Other Assets

1,169,000,000

1,178,000,000

^[1]

Intangible assets, net

1,210,000,000

1,228,000,000

^[1]

Derivative instruments

16,000,000

1,000,000

^[1]

Deferred income taxes

129,000,000

128,000,000

^[1]

Other non-current assets

73,000,000

62,000,000

^[1]

Total other assets

2,597,000,000

^[1]

Current portion of long-term debt

8,362,000,000

8,489,000,000

^[1]

Current Liabilities

698,000,000

339,000,000

^[1]

Accounts payable — trade

40,000,000

46,000,000

^[1]

Accounts payable — affiliate

54,000,000

49,000,000

^[1]

Derivative instruments

9,000,000

18,000,000

^[1]

Accrued expenses and other current liabilities

58,000,000

88,000,000

^[1]

Total current liabilities

859,000,000

540,000,000

^[1]

Other Liabilities

Long-term debt

5,261,000,000

5,659,000,000

^[1]

Derivative instruments

17,000,000

31,000,000

^[1]

Other non-current liabilities

99,000,000

100,000,000

^[1]

Total non-current liabilities

5,377,000,000

5,790,000,000

^[1]

Total Liabilities

6,236,000,000

6,330,000,000

^[1]

Commitments and Contingencies

Stockholders' Equity

Preferred stock, $0.01 par value; 10,000,000 shares authorized; none issued

^[1]

Class A, Class B, Class C and Class D common stock, $0.01 par value; 3,000,000,000 shares authorized (Class A 500,000,000, Class B 500,000,000, Class C 1,000,000,000, Class D 1,000,000,000); 185,407,326 shares issued and outstanding (Class A 34,586,250, Class B 42,738,750, Class C 65,343,576, Class D 42,738,750) at March 31, 2018 and 184,780,837 shares issued and outstanding (Class A 34,586,250, Class B 42,738,750, Class C 64,717,087, Class D 42,738,750) at December 31, 2017

1,000,000

^[1]

Additional paid-in capital

1,827,000,000

1,843,000,000

^[1]

Accumulated deficit

(53,000,000)

(69,000,000)

^[1]

Accumulated other comprehensive loss

(20,000,000)

(28,000,000)

^[1]

Noncontrolling interest

371,000,000

412,000,000

^[1]

Total Stockholders' Equity

2,126,000,000

2,159,000,000

^[1]

Total Liabilities and Stockholders' Equity

$ 8,362,000,000

$ 8,489,000,000

^[1]

[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Consolidated Balance Sheets (Parenthetical) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Common Stock, Par or Stated Value Per Share	$ 0.01
Preferred Stock, Par or Stated Value Per Share	$ 0.01
Preferred Stock, Shares Authorized	10,000,000	10,000,000
Preferred Stock, Shares Issued	0	0
Commitments and Contingencies	$ 0	$ 0
Common Class A [Member]
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	500,000,000	500,000,000
Common Stock, Shares, Issued	34,586,250	34,586,250
Preferred Stock [Member]
Preferred Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Class B [Member]
Common Stock, Shares Authorized	500,000,000	500,000,000
Common Stock, Shares, Issued	42,738,750	42,738,750
Common Class C [Member]
Common Stock, Shares Authorized	1,000,000,000	1,000,000,000
Common Stock, Shares, Issued	65,343,576	64,717,087
Common Class D [Member]
Common Stock, Shares Authorized	1,000,000,000	1,000,000,000
Common Stock, Shares, Issued	42,738,750	42,738,750

Consolidated Statements Of Cash Flows - USD ($)
$ in Millions

3 Months Ended

Mar. 31, 2018

Mar. 31, 2017

^[1]

Cash Flows from Operating Activities

Net loss

$ 0

$ (2)

Adjustments to reconcile net income to net cash provided by operating activities:

Equity in earnings of unconsolidated affiliates

(4)

(19)

Distributions from unconsolidated affiliates

Depreciation and amortization

Amortization of financing costs and debt discounts

Amortization of intangibles and out-of-market contracts

Adjustment for debt extinguishment

(2)

Changes in deferred income taxes

(1)

Changes in derivative instruments

(23)

(8)

Loss on disposal of asset components

Changes in prepaid and accrued liabilities for tolling agreements

(36)

Changes in other working capital

Net Cash Provided by Operating Activities

Cash Flows from Investing Activities

Payments for the Drop Down Assets

131

Capital expenditures

(18)

(6)

Cash receipts from notes receivable

Return of investment from unconsolidated affiliates

Investments in unconsolidated affiliates

(6)

(7)

Payments for (Proceeds from) Other Investing Activities

(4)

Net Cash Used in Investing Activities

(44)

(124)

Cash Flows from Financing Activities

Net contributions from noncontrolling interests

Net distributions and return of capital to NRG prior to the acquisition of Drop Down Assets

(21)

Net proceeds from the issuance of common stock

Payments of dividends and distributions

(55)

(48)

Payments of debt issuance costs

Proceeds from the revolving credit facility

Proceeds from the issuance of long-term debt

Payments for long-term debt

(79)

(105)

Net Cash Used in Financing Activities

(60)

(115)

Net Decrease in Cash, Cash Equivalents and Restricted Cash

(39)

(175)

Cash, Cash Equivalents and Restricted Cash at Beginning of Period

316

498

Cash, Cash Equivalents and Restricted Cash at End of Period

$ 277

$ 323

[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Nature of Business

3 Months Ended

Mar. 31, 2018

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Nature of Business

NRG Yield, Inc., together with its consolidated subsidiaries, or the Company, is a dividend growth-oriented company that has historically served as the primary vehicle through which NRG owns, operates and acquires contracted renewable and conventional generation and thermal infrastructure assets.

The Company believes it is well positioned to be a premier company for investors seeking stable and growing dividend income from a diversified portfolio of lower-risk assets. The Company owns a diversified portfolio of contracted renewable and conventional generation and thermal infrastructure assets in the U.S. The Company’s contracted generation portfolio collectively represents 5,118 net MW as of March 31, 2018. Nearly all of these assets sell substantially all of their output pursuant to long-term offtake agreements with creditworthy counterparties. The weighted average remaining contract duration of these offtake agreements was approximately 15 years as of March 31, 2018 based on CAFD. The Company also owns thermal infrastructure assets with an aggregate steam and chilled water capacity of 1,319 net MWt and electric generation capacity of 123 net MW. These thermal infrastructure assets provide steam, hot and/or chilled water, and, in some instances, electricity to commercial businesses, universities, hospitals and governmental units in multiple locations, principally through long-term contracts or pursuant to rates regulated by state utility commissions.

NRG Yield, Inc. consolidates the results of NRG Yield LLC through its controlling interest, with NRG's interest shown as noncontrolling interest in the financial statements. The holders of NRG Yield, Inc.'s outstanding shares of Class A and Class C common stock are entitled to dividends as declared. NRG receives its distributions from NRG Yield LLC through its ownership of NRG Yield LLC Class B and Class D units.

The following table represents the structure of the Company as of March 31, 2018:

On February 6, 2018, Global Infrastructure Partners, or GIP, entered into a purchase and sale agreement with NRG, or the NRG Transaction, for the acquisition of NRG's full ownership interests in the Company and NRG's renewable development and operations platform. The NRG Transaction is subject to certain closing conditions, including customary legal and regulatory approvals. The Company expects the NRG Transaction to close in the second half of 2018. NRG is currently the Company's controlling stockholder and the Company has been highly dependent on NRG for, among other things, growth opportunities and management and administration services. In connection with the NRG Transaction, the Company entered into a Consent and Indemnity Agreement with NRG and GIP setting forth key terms and conditions of the Company's consent to the NRG Transaction.

For further discussion of the NRG Transaction, refer to Item 1 - Business in the Company's 2017 Form 10-K. For risks related to the NRG Transaction and the Company's relationship with NRG see Part I, Item 1A, Risk Factors in the Company's 2017 Form 10-K.

As of March 31, 2018, the Company's operating assets are comprised of the following projects:



Projects	Percentage Ownership		Net Capacity (MW)^(a)	Offtake Counterparty	Expiration
Conventional
El Segundo	100	%	550	Southern California Edison	2023
GenConn Devon	50	%	95	Connecticut Light & Power	2040
GenConn Middletown	50	%	95	Connecticut Light & Power	2041
Marsh Landing	100	%	720	Pacific Gas and Electric	2023
Walnut Creek	100	%	485	Southern California Edison	2023
			1,945
Utility Scale Solar
Agua Caliente	16	%	46	Pacific Gas and Electric	2039
Alpine	100	%	66	Pacific Gas and Electric	2033
Avenal	50	%	23	Pacific Gas and Electric	2031
Avra Valley	100	%	26	Tucson Electric Power	2032
Blythe	100	%	21	Southern California Edison	2029
Borrego	100	%	26	San Diego Gas and Electric	2038
CVSR	100	%	250	Pacific Gas and Electric	2038
Desert Sunlight 250	25	%	63	Southern California Edison	2035
Desert Sunlight 300	25	%	75	Pacific Gas and Electric	2040
Kansas South	100	%	20	Pacific Gas and Electric	2033
Roadrunner	100	%	20	El Paso Electric	2031
TA High Desert	100	%	20	Southern California Edison	2033
Utah Solar Portfolio^{(b) (e)}	50	%	265	PacifiCorp	2036
			921
Distributed Solar
Apple I LLC Projects	100	%	9	Various	2032
AZ DG Solar Projects	100	%	5	Various	2025 - 2033
SPP Projects	100	%	25	Various	2026 - 2037
Other DG Projects	100	%	13	Various	2023 - 2039
			52
Wind
Alta I	100	%	150	Southern California Edison	2035
Alta II	100	%	150	Southern California Edison	2035
Alta III	100	%	150	Southern California Edison	2035
Alta IV	100	%	102	Southern California Edison	2035
Alta V	100	%	168	Southern California Edison	2035
Alta X^(b)	100	%	137	Southern California Edison	2038
Alta XI ^(b)	100	%	90	Southern California Edison	2038
Buffalo Bear	100	%	19	Western Farmers Electric Co-operative	2033
Crosswinds ^{(b) (f)}	99	%	21	Corn Belt Power Cooperative	2027
Elbow Creek ^{(b) (f)}	100	%	122	NRG Power Marketing LLC	2022
Elkhorn Ridge ^{(b) (f)}	66.7	%	54	Nebraska Public Power District	2029
Forward ^{(b) (f)}	100	%	29	Constellation NewEnergy, Inc.	2017
Goat Wind ^{(b) (f)}	100	%	150	Dow Pipeline Company	2025



Projects	Percentage Ownership		Net Capacity (MW)^(a)	Offtake Counterparty	Expiration
Hardin ^{(b) (f)}	99	%	15	Interstate Power and Light Company	2027
Laredo Ridge	100	%	80	Nebraska Public Power District	2031
Lookout ^{(b) (f)}	100	%	38	Southern Maryland Electric Cooperative	2030
Odin ^{(b) (f)}	99.9	%	20	Missouri River Energy Services	2028
Pinnacle	100	%	55	Maryland Department of General Services and University System of Maryland	2031
San Juan Mesa ^{(b) (f)}	75	%	90	Southwestern Public Service Company	2025
Sleeping Bear ^{(b) (f)}	100	%	95	Public Service Company of Oklahoma	2032
South Trent	100	%	101	AEP Energy Partners	2029
Spanish Fork ^{(b) (f)}	100	%	19	PacifiCorp	2028
Spring Canyon II ^(b)	90.1	%	29	Platte River Power Authority	2039
Spring Canyon III ^(b)	90.1	%	25	Platte River Power Authority	2039
Taloga	100	%	130	Oklahoma Gas & Electric	2031
Wildorado ^{(b) (f)}	100	%	161	Southwestern Public Service Company	2027
			2,200
Thermal
NRG Energy Center Dover LLC	100	%	103	NRG Power Marketing LLC	2018
Thermal generation	100	%	20	Various	Various
			123
Total net generation capacity^(c)			5,241

Thermal equivalent MWt ^(d)	100	%	1,319	Various	Various

^(a)Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of March 31, 2018.

^(b) Projects are part of tax equity arrangements.

^(c) The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247 MWs.

^(d) For thermal energy, net capacity represents MWt for steam or chilled water and excludes 134 MWt available under the right-to-use provisions contained in agreements between two of the Company's thermal facilities and certain of its customers.

^(e) Represents interests in Four Brothers Solar, LLC, Granite Mountain Holdings, LLC, and Iron Springs Holdings, LLC, all acquired as part of the March 2017 Drop Down Assets (ownership percentage is based upon cash to be distributed).

^(f) Projects are part of NRG Wind TE Holdco portfolio.

In addition to the facilities owned or leased in the table above, the Company entered into partnerships to own or purchase solar power generation projects, as well as other ancillary related assets from a related party via intermediate funds. The Company does not consolidate these partnerships and accounts for them as equity method investments. The Company's net interest in these projects is 262 MW based on cash to be distributed as of March 31, 2018. For further discussions, refer to Note 4, Investments Accounted for by the Equity Method and Variable Interest Entities of this Form 10-Q and Note 5, Investments Accounted for by the Equity Method and Variable Interest Entities to the consolidated financial statements included in the Company's 2017 Form 10-K.

Substantially all of the Company's generation assets are under long-term contractual arrangements for the output or capacity from these assets. The thermal assets are comprised of district energy systems and combined heat and power plants that produce steam, hot water and/or chilled water and, in some instances, electricity at a central plant. Certain district energy systems are subject to rate regulation by state public utility commissions (although they may negotiate certain rates) while the other district energy systems have rates determined by negotiated bilateral contracts.

As described in Note 3, Business Acquisitions, 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, or the Buckthorn Solar Drop Down Asset, for cash consideration of approximately $42 million, subject to working capital adjustments, plus assumed non-recourse debt of approximately $183 million. The project will sell power under a 25-year PPA to the City of Georgetown, Texas starting in July 2018 when it is expected to achieve commercial operation. The purchase price was funded with cash on hand and borrowings from the revolving credit facility.

The acquisition of the Buckthorn Solar Drop Down Asset was accounted for as a transfer of entities under common control. The accounting guidance requires retrospective combination of the entities for all periods presented as if the combinations had been in effect from the beginning of the financial statement period or from the date the entities were under common control (if later than the beginning of the financial statement period). The recast of the Company's financial statements for the Buckthorn Solar Drop Down Asset did not affect the historical net income attributable to NRG Yield, Inc., weighted average number of shares outstanding, earnings per share or dividends.

Additionally, as described in Note 3, Business Acquisitions, during the year ended December 31, 2017, the Company acquired the November 2017 Drop Down Assets and August 2017 Drop Down Assets from NRG. Similarly to the Buckthorn Solar Drop Down Asset, the Company recast its historical financial statements to combine the entities for the periods presented as if the combinations had been in effect from the beginning of the financial statements period. The recast of the Company's financial statements for the November 2017 Drop Down Assets and August 2017 Drop Down Assets did not affect the historical net income attributable to NRG Yield, Inc., weighted average number of shares outstanding, earnings per share or dividends.

The accompanying unaudited interim consolidated financial statements have been prepared in accordance with the SEC’s regulations for interim financial information and with the instructions to Form 10-Q. Accordingly, they do not include all of the information and notes required by GAAP for complete financial statements. The following notes should be read in conjunction with the accounting policies and other disclosures as set forth in the notes to the consolidated financial statements included in the Company's 2017 Form 10-K. Interim results are not necessarily indicative of results for a full year.

In the opinion of management, the accompanying unaudited interim consolidated financial statements contain all material adjustments consisting of normal and recurring accruals necessary to present fairly the Company's consolidated financial position as of March 31, 2018, and the results of operations, comprehensive income (loss) and cash flows for the three months ended March 31, 2018 and 2017.

Summary of Significant Accounting Policies

3 Months Ended

Mar. 31, 2018

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

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, and the reported amounts of revenues and expenses during the reporting period. Actual results could be different from these estimates.

Accumulated Depreciation, Accumulated Amortization

The following table presents the accumulated depreciation included in the property, plant and equipment, net, and accumulated amortization included in intangible assets, net, respectively, as of March 31, 2018 and December 31, 2017:



	March 31, 2018		December 31, 2017
	(In millions)
Property, Plant and Equipment Accumulated Depreciation	$	1,358	$	1,285
Intangible Assets Accumulated Amortization	255		237

Noncontrolling Interests

Stockholders' equity represents the equity associated with the Class A and Class C common stockholders, the equity associated with the Class B and Class D common stockholder, NRG, and the third-party interests under certain tax equity arrangements are classified as noncontrolling interests. The following table reflects the changes in the Company's noncontrolling interest balance:



	(In millions)
Balance as of December 31, 2017 as previously reported	$	391
Net Assets of Buckthorn Solar Drop Down Asset as of December 31, 2017	21
Balance as of December 31, 2017 as recast	$	412
Capital contributions from tax equity investors, net of distributions	30
Payment for the Buckthorn Solar Drop Down Asset	(42		)
Pre-acquisition net income of the Buckthorn Solar Drop Down Asset	4
Comprehensive loss	(11		)
Distributions to NRG, net	(22		)
Balance as of March 31, 2018	$	371

NRG Yield LLC Distributions to NRG

The following table lists the distributions paid to NRG on NRG Yield LLC's Class B and D units during the three months ended March 31, 2018:



	First Quarter 2018
Distributions per Class B Unit	$	0.298
Distributions per Class D Unit	$	0.298

On April 24, 2018, NRG Yield LLC declared a distribution on its Class A, Class B, Class C and Class D units of $0.309 per unit payable on June 15, 2018 to unit holders of record as of June 1, 2018.

Revenue Recognition

Revenue from Contracts with Customers

On January 1, 2018, the Company adopted the guidance in ASC 606, Revenue from Contracts with Customers, or Topic 606, using the modified retrospective method applied to contracts which were not completed as of the adoption date, with no adjustment required to the financial statements upon adoption. Following the adoption of the new standard, the Company’s revenue recognition of its contracts with customers remains materially consistent with its historical practice. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. The Company's policies with respect to its various revenue streams are detailed below. In general, the Company applies the invoicing practical expedient to recognize revenue for the revenue streams detailed below, except in circumstances where the invoiced amount does not represent the value transferred to the customer.

Thermal Revenues

Steam and chilled water revenue is recognized as the Company transfers the product to the customer, based on customer usage as determined by meter readings taken at month-end. Some locations read customer meters throughout the month, and recognize estimated revenue for the period between meter read date and month-end. For thermal contracts, the Company’s performance obligation to deliver steam and chilled water is satisfied over time and revenue is recognized based on the invoiced amount. The Thermal Business subsidiaries collect and remit state and local taxes associated with sales to their customers, as required by governmental authorities. These taxes are presented on a net basis in the income statement.

As contracts for steam and chilled water are long-term contracts, the Company has performance obligations under these contracts that have not yet been satisfied. These performance obligations have transaction prices that are both fixed and variable, and that vary based on the contract duration, customer type, inception date and other contract-specific factors. For the fixed price contracts, the Company cannot accurately estimate the amount of its unsatisfied performance obligations as it will vary based on customer usage, which will depend on factors such as weather and customer activity.

Power Purchase Agreements, or PPAs

The majority of the Company’s revenues are obtained through PPAs or other contractual agreements. Energy, capacity and where applicable, renewable attributes, from the majority of the Company’s renewable energy assets and certain conventional energy plants is sold through long-term PPAs and tolling agreements to a single counterparty, which is often a utility or commercial customer. The majority of these PPAs are accounted for as leases. ASC 840 requires the minimum lease payments received to be amortized over the term of the lease and contingent rentals are recorded when the achievement of the contingency becomes probable. Judgment is required by management in determining the economic life of each generating facility, in evaluating whether certain lease provisions constitute minimum payments or represent contingent rent and other factors in determining whether a contract contains a lease and whether the lease is an operating lease or capital lease.

Renewable Energy Credits

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 related energy is generated and simultaneously delivered even in cases where there is a certification lag as it has been deemed to be perfunctory.

In a bundled contract to sell energy, capacity and/or self-generated RECs, all performance obligations are deemed to be delivered at the same time and hence, timing of recognition of revenue for all performance obligations is the same and occurs over time. In such cases, it is often unnecessary to allocate transaction price to multiple performance obligations.

Sale of Emission Allowances

The Company records its bank of emission allowances as part of intangible assets. From time to time, management may authorize the transfer of emission allowances in excess of usage from the Company's emission bank to intangible assets held-for-sale for trading purposes. The Company records the sale of emission allowances on a net basis within operating revenue in the Company's consolidated statements of operations.

Disaggregated Revenues

The following table represents the Company’s disaggregation of revenue from contracts with customers for the three months ended March 31, 2018 along with the reportable segment for each category:



(In millions)	Conventional Generation			Renewables			Thermal			Total
Energy revenue^(a)	$	1		$	112		$	1		$	114
Capacity revenue^(a)	79			—			3			82
Contract amortization	(1		)	(15		)	(1		)	(17		)
Other revenue	—			1			45			46
Total operating revenue	79			98			48			225
Less: Lease revenue	(80		)	(101		)	—			(181		)
Less: Contract amortization	1			15			1			17
Total revenue from contracts with customers	$	—		$	12		$	49		$	61

^(a)The following amounts of energy and capacity revenue relate to leases and are accounted for under ASC 840:



	Conventional Generation		Renewables		Thermal		Total
Energy Revenue	$	1	$	101	$	—	$	102
Capacity Revenue	79		—		—		79

Contract Amortization

Assets and liabilities recognized from power sales agreements assumed through acquisitions related to the sale of electric capacity and energy in future periods for which the fair value has been determined to be significantly less (more) than market are amortized to revenue over the term of each underlying contract based on actual generation and/or contracted volumes or on a straight-line basis, where applicable.

Contract Balances

The following table reflects the contract assets and liabilities included on the Company’s balance sheet as of March 31, 2018:



(In millions)	March 31, 2018

Accounts receivable, net - Contracts with customers	$	26
Accounts receivable, net - Leases	56
Total accounts receivable, net	$	82

Income Taxes

NRG Yield, Inc. is included in certain NRG consolidated unitary state tax return filings which is reflected in NRG Yield, Inc.'s state effective tax rate. If NRG Yield, Inc. filed under a separate standalone methodology, there would be no material change to the state tax benefit as of March 31, 2018.

Reclassifications

Certain prior-year amounts have been reclassified for comparative purposes.

Recent Accounting Developments - Not Yet Adopted

ASU 2016-02 — In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842), or Topic 842, with the objective to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and to improve financial reporting by expanding the related disclosures. The guidance in Topic 842 provides that a lessee that may have previously accounted for a lease as an operating lease under current GAAP should recognize the assets and liabilities that arise from a lease on the balance sheet. In addition, Topic 842 expands the required quantitative and qualitative disclosures with regards to lease arrangements. The Company will adopt the standard effective January 1, 2019 and expects to elect certain of the practical expedients permitted, including the expedient that permits the Company to retain its existing lease assessment and classification. The Company is currently working through an adoption plan and evaluating the anticipated impact on the Company's results of operations, cash flows and financial position. While the Company is currently evaluating the impact the new guidance will have on its financial position and results of operations, the Company expects to recognize lease liabilities and right of use assets. The extent of the increase to assets and liabilities associated with these amounts remains to be determined pending the Company’s review of its existing lease contracts and service contracts which may contain embedded leases. While this review is still in process, the Company believes the adoption of Topic 842 may be material to its financial statements. The Company is continuing to monitor potential changes to Topic 842 that have been proposed by the FASB and will assess any necessary changes to the implementation as the guidance is updated.

Business Acquisitions Business Acquisitions (Notes)

3 Months Ended

Mar. 31, 2018

Business Acquisitions [Abstract]

Mergers, Acquisitions and Dispositions Disclosures [Text Block]

Business Acquisitions

2018 Acquisitions

Central CA Fuel Cell 1, LLC — On April 18, 2018, the Company acquired the Central CA Fuel Cell 1, LLC project in Tulare, California from FuelCell Energy Finance, Inc., for cash consideration of $11 million, subject to working capital adjustments. The project will add an additional 2.8 MW of thermal capacity to the Company's portfolio, with a 20-year PPA contract with the City of Tulare. The transaction will be reflected in the Company's Thermal segment.

Buckthorn Solar Drop Down Asset — On March 30, 2018, the Company acquired 100% of NRG's interests in Buckthorn Renewables, LLC, which owns a 154 MW construction-stage utility-scale solar generation project, located in Texas, or the Buckthorn Solar Drop Down Asset, for cash consideration of approximately $42 million, subject to working capital adjustments. The Company also assumed non-recourse debt of $183 million and non-controlling interest of $19 million (as of acquisition date) attributable to the Class A member, as further described below. A portion of non-recourse debt is expected to convert to a term loan and the remainder of the outstanding debt will be paid down with the remaining contributions from the Class A member upon the project achieving 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 relate to interests under common control by NRG and were recorded at historical cost in accordance with ASC 805-50, Business Combinations - Related Issues. The difference between the cash paid and historical value of the entities' equity was recorded as a distribution to NRG and decreased the balance of its noncontrolling interest. Because the transaction constituted a transfer of net assets under common control, the guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control.

Buckthorn Solar Portfolio, LLC, a wholly owned subsidiary of Buckthorn Renewables, LLC, is the Class B member in a tax equity partnership, Buckthorn Holdings, LLC, the owner of the Buckthorn Solar Drop Down Asset. The Class A member is a tax equity investor, or TE investor, who receives 99% of allocations of taxable income and other items through the six month anniversary of the placed in service date, at which time the allocations change to 67% through the last calendar year before the flip point, and then back to 99% through the flip point (which occurs when the TE Investor obtains a specified return on its initial investment), at which time the allocations to the TE Investor change to 5% for all the periods thereafter. Before the flip point, the TE investor would receive a priority distribution of distributable cash, as defined, plus a percentage of remaining distributable cash after the priority distribution subject to a percentage cap. On March 30, 2018, the TE Investor made its initial capital contribution of $19 million with the remaining contributions from each partner targeted to be funded in the second quarter of 2018. The project will sell power under a 25-year PPA to the City of Georgetown, Texas starting in July 2018 when it is expected to achieve commercial operation.

The following is a summary of net assets transferred in connection with the acquisition of the Buckthorn Solar Drop Down Asset as of March 31, 2018:



	(In millions)
Assets:
Current assets	$	20
Property, plant and equipment	212
Non-current assets	3
Total assets	235
Liabilities:
Debt (Current and non-current) ^(a)	176
Other current and non-current liabilities	15
Total liabilities	191
Less: noncontrolling interest	19
Net assets acquired	$	25

^(a) Net of $7 million of net debt issuance costs.

The following table presents the historical information summary combining the financial information for the Buckthorn Drop Down Asset transferred in connection with the acquisition:



	As of December 31, 2017
(In millions)	As Previously Reported		Buckthorn Solar Drop Down Asset		As Currently Reported
Assets:
Current assets	$	482	$	—	$	482
Property, plant and equipment	5,204		206		5,410
Non-current assets	2,597		—		2,597
Total assets	8,283		206		8,489
Liabilities:
Debt	5,837		161		5,998
Other current and non-current liabilities	308		24		332
Total liabilities	6,145		185		6,330
Net assets	$	2,138	$	21	$	2,159

2017 Acquisitions

November 2017 Drop Down Assets — On November 1, 2017, the Company acquired a 38 MW solar portfolio primarily comprised of assets from NRG's Solar Power Partners (SPP) funds and other projects developed by NRG, for cash consideration of $74 million, including working capital adjustments, plus assumed non-recourse debt of $26 million.

The purchase price for the November 2017 Drop Down Assets was funded with cash on hand. The assets and liabilities transferred to the Company relate to interests under common control by NRG and were recorded at historical cost in accordance with ASC 805-50, Business Combinations - Related Issues. The difference between the cash paid and historical value of the entities' equity was recorded as a contribution from NRG and increased the balance of its noncontrolling interest. Because the transaction constituted a transfer of net assets under common control, the guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect since the inception of common control.

August 2017 Drop Down Assets — On August 1, 2017, the Company acquired the remaining 25% interest in NRG Wind TE Holdco, a portfolio of 12 wind projects, from NRG for total cash consideration of $44 million, including working capital adjustments. The purchase agreement also included potential additional payments to NRG dependent upon actual energy prices for merchant periods beginning in 2027, which were estimated and accrued as contingent consideration in the amount of $8 million.

The Company originally acquired 75% of NRG Wind TE Holdco on November 3, 2015, or November 2015 Drop Down Assets, which were consolidated with 25% of the net assets recorded as noncontrolling interest. The assets and liabilities transferred to the Company related to interests under common control by NRG and were recorded at historical cost in accordance with ASC 805-50, Business Combination - Related Issues. As the Company had reflected NRG's 25% ownership of NRG Wind TE Holdco in noncontrolling interest, the difference between the cash paid of $44 million, net of the contingent consideration of $8 million, and the historical value of the remaining 25% of $87 million as of July 31, 2017, was recorded as an adjustment to NRG's noncontrolling interest. Since the transaction constituted a transfer of entities under common control, the accounting guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect from the beginning of the financial statement period or from the date the entities were under common control (if later than the beginning of the financial statement period).

The following tables present a summary of the Company's historical information combining the financial information for the November 2017 Drop Down Assets and August 2017 Drop Down Assets transferred in connection with the acquisition:



	Three months ended March 31, 2017
	As Previously Reported ^(a)			November 2017 Drop Down Assets			August 2017 Drop Down Assets			As Currently Reported
(In millions)
Total operating revenues	$	218		$	3		$	—		$	221
Operating income	54			—			—			54
Net loss	(1		)	(1		)	—			(2		)
Less: Pre-acquisition net income of Drop Down Assets	12			(1		)	2			13
Less: Loss attributable to noncontrolling interests	(10		)	—			(2		)	(12		)
Net loss attributable to NRG Yield, Inc.	(3		)	—			—			(3		)

^(a) As previously reported in the Company's Form 10-Q for the quarter ended March 31, 2017

March 2017 Drop Down Assets — On March 27, 2017, the Company acquired the following interests from NRG: (i) Agua Caliente Borrower 2 LLC, which owns a 16% interest (approximately 31% of NRG's 51% interest) in the Agua Caliente solar farm, one of the ROFO Assets, representing ownership of approximately 46 net MW of capacity and (ii) NRG's interests in the Utah Solar Portfolio. Agua Caliente is located in Yuma County, AZ and sells power subject to a 25-year PPA with Pacific Gas and Electric, with 22 years remaining on that contract. The seven utility-scale solar farms in the Utah Solar Portfolio are owned by the following entities: Four Brothers Capital, LLC, Iron Springs Capital, LLC, and Granite Mountain Capital, LLC. These utility-scale solar farms achieved commercial operations in 2016, sell power subject to 20-year PPAs with PacifiCorp, a subsidiary of Berkshire Hathaway and are part of a tax equity structure with Dominion Solar Projects III, Inc., or Dominion, through which the Company is entitled to receive 50% of cash to be distributed, as further described below. The Company paid cash consideration of $128 million, which includes $4 million of final working capital adjustment paid to the Company by NRG during the period ended March 31, 2018. The acquisition of the March 2017 Drop Down Assets was funded with cash on hand. The Company recorded the acquired interests as equity method investments. The Company also assumed non-recourse debt of $41 million and $287 million on Agua Caliente Borrower 2 LLC and the Utah Solar Portfolio, respectively, as well as its pro-rata share of non-recourse project-level debt of Agua Caliente Solar LLC, as further described in Note 4, Investments Accounted for by the Equity Method and Variable Interest Entities.

The assets and liabilities transferred to the Company relate to interests under common control by NRG and were recorded at historical cost in accordance with ASC 805-50, Business Combination - Related Issues. The difference between the cash paid and the historical value of the entities' equity of $8 million was recorded as an adjustment to NRG's noncontrolling interest. Since the transaction constituted a transfer of entities under common control, the accounting guidance requires retrospective combination of the entities for all periods presented as if the combination has been in effect from the beginning of the financial statement period or from the date the entities were under common control (if later than the beginning of the financial statement period).

Variable Interest Entities

3 Months Ended

Mar. 31, 2018

Equity Method Investments and Joint Ventures [Abstract]

Investments Accounted for by the Equity Method and Variable Interest Entities

Entities that are Consolidated

The Company has a controlling financial interest in certain entities which have been identified as VIEs under ASC 810, Consolidations, or ASC 810. These arrangements are primarily related to tax equity arrangements entered into with third parties in order to monetize certain tax credits associated with wind facilities, as further described in Note 5, Investments Accounted for by the Equity Method and Variable Interest Entities, to the consolidated financial statements included in the Company's 2017 Form 10-K.

Buckthorn Renewables, LLC - As described in Note 3, Business Acquisitions, on March 30, 2018, the Company acquired 100% of NRG’s interest in a 154 MW construction-stage utility-scale solar generation project, Buckthorn Renewables, LLC, which owns 100% interest in Buckthorn Solar Portfolio, LLC, which in turn owns 100% of the Class B membership interests in Buckthorn Holdings, LLC for total consideration of approximately $42 million, subject to working capital adjustments. 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 capital contribution of $19 million on March 30, 2018, which is reflected as noncontrolling interest on the Company’s consolidated balance sheet. The project is expected to begin commercial operations in July 2018, at which time the remaining contributions from each partner would be funded. The Company utilizes the HLBV method to determine the net income or loss allocated to the tax equity investor noncontrolling interest.

Summarized financial information for the Company's consolidated VIEs consisted of the following as of March 31, 2018:



(In millions)	NRG Wind TE Holdco		Alta Wind TE Holdco		Spring Canyon		Buckthorn Renewables, LLC
Other current and non-current assets	$	172	$	18	$	2	$	23
Property, plant and equipment	369		430		94		212
Intangible assets	2		259		—		—
Total assets	543		707		96		235
Current and non-current liabilities	195		8		5		191
Total liabilities	195		8		5		191
Noncontrolling interest	9		77		50		19
Net assets less noncontrolling interests	$	339	$	622	$	41	$	25

Entities that are not Consolidated

The Company has interests in entities that are considered VIEs under ASC 810, 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, as further described in Note 5, Investments Accounted for by the Equity Method and Variable Interest Entities, to the consolidated financial statements included in the Company's 2017 Form 10-K.

The Company's maximum exposure to loss as of March 31, 2018 is limited to its equity investment in the unconsolidated entities, as further summarized in the table below:



(In millions)	Maximum exposure to loss
Four Brothers Solar, LLC	$	209
GenConn Energy LLC	100
Granite Mountain Holdings, LLC	76
NRG DGPV Holdco 1 LLC	73
NRG DGPV Holdco 3 LLC	62
NRG DGPV Holdco 2 LLC	61
Iron Springs Holdings, LLC	53
NRG RPV Holdco 1 LLC	52

NRG DGPV Holdco 3 LLC — The Company invested $6 million of cash during the three months ended March 31, 2018 into DGPV Holdco 3 LLC and recorded $16 million due to NRG in accounts payable - affiliate as of March 31, 2018 to be funded in tranches as the project milestones are completed. The Company owns approximately 59 MW of distributed solar capacity, based on cash to be distributed, with a weighted average remaining contract life of approximately 22 years as of March 31, 2018.

Utah Solar Portfolio — As described in Note 3, Business Acquisitions, on March 27, 2017, as part of the March 2017 Drop Down Assets acquisition, the Company acquired from NRG 100% of the Class A equity interests in the Utah Solar Portfolio, comprised of Four Brothers Solar, LLC, Granite Mountain Holdings, LLC, and Iron Springs Holdings, LLC. The Class B interests of the Utah Solar Portfolio are owned by a tax equity investor, who receives 99% of allocations of taxable income and other items until the flip point, which occurs when the tax equity investor obtains a specified return on its initial investment, at which time the allocations to the tax equity 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.

The following tables present summarized financial information for the Company's significant equity method investments:



	Three months ended March 31,
(In millions)	2018		2017
Income Statement Data:
DGPV entities ^(a)
Operating revenues	$	11	$	5
Operating loss	—		(1		)
Net income (loss)	3		(2		)
	March 31, 2018		December 31, 2017
Balance Sheet Data:	(In millions)
DGPV entities ^(a)
Current assets	$	92	$	74
Non-current assets	718		671
Current liabilities	84		83
Non-current liabilities	236		216
Redeemable noncontrolling interest	42		44

^(a) Includes DGPV Holdco 1, DGPV Holdco 2, and DGPV Holdco 3

Non-recourse project-level debt of unconsolidated affiliates

Agua Caliente Financing — As described in Note 3, Business Acquisitions, on March 27, 2017, the Company acquired a 16% interest in the Agua Caliente solar facility through its acquisition of Agua Caliente Borrower 2 LLC. As of March 31, 2018, Agua Caliente Solar LLC, the direct owner of the Agua Caliente solar facility, had $815 million outstanding under the Agua Caliente financing agreement with the Federal Financing Bank, or FFB, borrowed to finance the costs of constructing the facility. The Company's pro-rata share of the Agua Caliente financing arrangement was $130 million as of March 31, 2018. Amounts borrowed under the Agua Caliente financing agreement accrue interest at a fixed rate based on U.S. Treasury rates plus a spread of 0.375%, mature in 2037 and are secured by the assets of Agua Caliente Solar LLC. The loans provided by the FFB are guaranteed by the U.S. DOE.

Fair Value of Financial Instruments

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

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, accounts receivable — affiliate, accounts payable, current portion of the accounts payable — affiliates, accrued expenses and other liabilities, the carrying amounts approximate 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 March 31, 2018				As of December 31, 2017
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
(In millions)
Assets:
Notes receivable^(a)	$	9	$	9	$	13	$	13
Liabilities:
Long-term debt, including current portion^(b)	$	6,023	$	6,020	$	6,066	$	6,099

^(a) Carrying amount as of December 31, 2017, includes the long-term portion of notes receivable, which is recorded in other noncurrent assets on the Company's consolidated balance sheets.

^(b) Excludes deferred financing 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 March 31, 2018, and December 31, 2017:



	As of March 31, 2018				As of December 31, 2017
	Level 2		Level 3		Level 2		Level 3
	(In millions)
Long-term debt, including current portion	$	1,472	$	4,548	$	1,502	$	4,597

Recurring Fair Value Measurements

The Company records its derivative assets and liabilities at fair 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 March 31, 2018		As of December 31, 2017
	Fair Value ^(a)		Fair Value ^(a)
(In millions)	Level 2		Level 2
Derivative assets:
Commodity contracts	$	—	$	1
Interest rate contracts	17		1
Total assets	17		2
Derivative liabilities:
Commodity contracts	2		1
Interest rate contracts	24		48
Total liabilities	$	26	$	49

^(a) There were no derivative assets or liabilities classified as Level 1 or Level 3 as of March 31, 2018 and December 31, 2017.

Derivative Fair Value Measurements

The Company's contracts are non-exchange-traded and valued using prices provided by external sources. For the Company’s energy markets, management receives quotes from multiple sources. To the extent that multiple quotes are received, the prices reflect the average of the bid-ask mid-point prices obtained from all sources believed to provide the most liquid market for the commodity.

The fair value of each contract is discounted using a risk free interest rate. In addition, a credit reserve is applied to reflect credit risk, which 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 NRG's default swap rate. For interest rate swaps and commodities, the credit reserve is added to the discounted fair value to reflect the exit price that a market participant would be willing to receive to assume the liabilities or that a market participant would be willing to pay for the assets. As of March 31, 2018, the credit reserve was less than $1 million. 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 in Note 2, Summary of Significant Accounting Policies, to the consolidated financial statements included in the Company's 2017 Form 10-K, the following is a discussion of the concentration of credit risk for the Company's financial instruments. Credit risk relates to the risk of loss resulting from non-performance or non-payment by counterparties pursuant to the terms of their contractual obligations. The Company monitors and manages credit risk through credit policies that include: (i) an established credit approval process; (ii) daily monitoring of counterparties' credit limits; (iii) the use of credit mitigation measures such as margin, collateral, prepayment arrangements, or volumetric limits; (iv) the use of payment netting agreements; and (v) the use of master netting agreements that allow for the netting of positive and negative exposures of various contracts associated with a single counterparty. Risks surrounding counterparty performance and credit could ultimately impact the amount and timing of expected cash flows. The Company seeks to mitigate counterparty risk by having a diversified portfolio of counterparties.

Counterparty credit exposure includes credit risk exposure under certain long-term agreements, including solar and other PPAs. As external sources or observable market quotes are not available to estimate such exposure, the Company estimates the exposure related to these contracts based on various techniques including, but not limited to, internal models based on a fundamental analysis of the market and extrapolation of observable market data with similar characteristics. Based on these valuation techniques, as of March 31, 2018, credit risk exposure to these counterparties attributable to the Company's ownership interests was approximately $2.6 billion for the next five years. The majority of these power contracts are with utilities with strong credit quality and public utility commission or other regulatory support. However, such regulated utility counterparties can be impacted by changes in government regulations, which the Company is unable to predict.

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Accounting for Derivative Instruments and Hedging Activities

3 Months Ended

Mar. 31, 2018

Accounting for Derivative Instruments and Hedging Activities

This footnote should be read in conjunction with the complete description under Note 7, Accounting for Derivative Instruments and Hedging Activities, to the consolidated financial statements included in the Company's 2017 Form 10-K.

Energy-Related Commodities

As of March 31, 2018, the Company had energy-related derivative instruments extending through 2020. At March 31, 2018, these contracts were not designated as cash flow or fair value hedges.

Interest Rate Swaps

As of March 31, 2018, the Company had interest rate derivative instruments on non-recourse debt extending through 2041, a portion of which are designated as cash flow hedges.

Volumetric Underlying Derivative Transactions

The following table summarizes the net notional volume buy of the Company's open derivative transactions broken out by commodity:



		Total Volume
		March 31, 2018		December 31, 2017
Commodity	Units	(In millions)
Natural Gas	MMBtu	1		2
Interest	Dollars	$	2,001	$	2,050

Fair Value of Derivative Instruments

The following table summarizes the fair value within the derivative instrument valuation on the balance sheet:



	Fair Value
	Derivative Assets ^(a)				Derivative Liabilities
	March 31, 2018		December 31, 2017		March 31, 2018		December 31, 2017
	(In millions)
Derivatives Designated as Cash Flow Hedges:
Interest rate contracts current	$	1	$	—	$	2	$	4
Interest rate contracts long-term	7		1		6		9
Total Derivatives Designated as Cash Flow Hedges	8		1		8		13
Derivatives Not Designated as Cash Flow Hedges:
Interest rate contracts current	—		—		6		13
Interest rate contracts long-term	9		—		10		22
Commodity contracts current	—		1		1		1
Commodity contracts long-term	—		—		1		—
Total Derivatives Not Designated as Cash Flow Hedges	9		1		18		36
Total Derivatives	$	17	$	2	$	26	$	49

^(a) Derivative Assets balances classified as current are included within the prepayments and other current assets line item of the consolidated balance sheets as of March 31, 2018 and December 31, 2017.

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 March 31, 2018, and December 31, 2017, there was no outstanding collateral paid or received. The following tables summarize the offsetting of derivatives by the counterparty master agreement level as of March 31, 2018, and December 31, 2017:



As of March 31, 2018	Gross Amounts of Recognized Assets/Liabilities			Derivative Instruments			Net Amount
Commodity contracts^(a):	(In millions)
Derivative assets	$	—		$	—		$	—
Derivative liabilities	(2		)	—			(2		)
Total commodity contracts	(2		)	—			(2		)
Interest rate contracts:
Derivative assets	17			(2		)	15
Derivative liabilities	(24		)	2			(22		)
Total interest rate contracts	(7		)	—			(7		)
Total derivative instruments	$	(9	)	$	—		$	(9	)

^(a) There were no commodity contracts classified as derivative assets as of March 31, 2018.



As of December 31, 2017	Gross Amounts of Recognized Assets/Liabilities			Derivative Instruments			Net Amount
Commodity contracts:	(In millions)
Derivative assets	$	1		$	—		$	1
Derivative liabilities	(1		)	—			(1		)
Total commodity contracts	—			—			—
Interest rate contracts:
Derivative assets	1			(1		)	—
Derivative liabilities	(48		)	1			(47		)
Total interest rate contracts	(47		)	—			(47		)
Total derivative instruments	$	(47	)	$	—		$	(47	)

Accumulated Other Comprehensive Loss

The following table summarizes the effects on the Company’s accumulated OCL balance attributable to interest rate swaps designated as cash flow hedge derivatives, net of tax:



	Three months ended March 31,
	2018			2017
	(In millions)
Accumulated OCL beginning balance	$	(60	)	$	(70	)
Reclassified from accumulated OCL to income due to realization of previously deferred amounts	4			4
Mark-to-market of cash flow hedge accounting contracts	13			2
Accumulated OCL ending balance, net of income tax benefit of $6 and $15, respectively	(43		)	(64		)
Accumulated OCL attributable to noncontrolling interests	(23		)	(39		)
Accumulated OCL attributable to NRG Yield, Inc.	$	(20	)	$	(25	)
Losses expected to be realized from OCL during the next 12 months, net of income tax benefit of $1	$	11

The Company's regression analysis for Marsh Landing, Walnut Creek and Avra Valley interest rate swaps, while positively correlated, no longer contain matching terms for cash flow hedge accounting. As a result, the Company voluntarily de-designated the Marsh Landing, Walnut Creek and Avra Valley cash flow hedges as of April 28, 2017, and will prospectively mark these derivatives to market through the income statement.

Impact of Derivative Instruments on the Statements of Operations

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 three months ended March 31, 2018 and 2017, the impact to the consolidated statements of operations was a gain of $24 million and $4 million, respectively.

A portion of the Company’s derivative commodity contracts relates to its Thermal Business for the purchase of fuel commodities based on the forecasted usage of the thermal district energy centers. Realized gains and losses on these contracts are reflected in the fuel costs that are permitted to be billed to customers through the related customer contracts or tariffs and, accordingly, no gains or losses are reflected in the consolidated statements of income for these contracts.

See Note 5, Fair Value of Financial Instruments, for a discussion regarding concentration of credit risk.

Long-term Debt

3 Months Ended

Mar. 31, 2018

Debt Disclosure [Abstract]

Changes in Capital Structure [Abstract]

This footnote should be read in conjunction with the complete description under Note 10, Long-term Debt, to the consolidated financial statements included in the Company's 2017 Form 10-K. Long-term debt consisted of the following:



	March 31, 2018			December 31, 2017			March 31, 2018, interest rate % ^(a)	Letters of Credit Outstanding at March 31, 2018
	(In millions, except rates)
2019 Convertible Notes	$	345		$	345		3.500
2020 Convertible Notes	288			288			3.250
2024 Senior Notes	500			500			5.375
2026 Senior Notes	350			350			5.000
NRG Yield LLC and NRG Yield Operating LLC Revolving Credit Facility, due 2019 ^(b)	75			55			L+2.500	$	67
Project-level debt:
Agua Caliente Borrower 2, due 2038	40			41			5.430	17
Alpine, due 2022	135			135			L+1.750	16
Alta Wind I - V lease financing arrangements, due 2034 and 2035	926			926			5.696 - 7.015	118
Buckthorn Solar, due 2018 and 2025	183			169			L + 1.750	10
CVSR, due 2037	731			746			2.339 - 3.775	—
CVSR Holdco Notes, due 2037	188			194			4.680	13
El Segundo Energy Center, due 2023	369			400			L+1.75 - L+2.375	139
Energy Center Minneapolis, due 2025	83			83			5.950	—
Energy Center Minneapolis Series D Notes, due 2031	125			125			3.550	—
Laredo Ridge, due 2028	93			95			L+1.875	10
Marsh Landing, due 2023	309			318			L+2.125	38
Tapestry, due 2021	158			162			L+1.625	20
Utah Solar Portfolio, due 2022	278			278			various	13
Viento, due 2023	163			163			L+3.00	27
Walnut Creek, due 2023	259			267			L+1.625	65
Other	440			443			various	39
Subtotal project-level debt:	4,480			4,545
Total debt	6,038			6,083
Less current maturities ^(c)	(698		)	(339		)
Less net debt issuance costs	(64		)	(68		)
Less discounts ^(d)	(15		)	(17		)
Total long-term debt	$	5,261		$	5,659

^(a) As of March 31, 2018, L+ equals 3 month LIBOR plus x%, except for Viento, due 2023 where L+ equals 6 month LIBOR plus 3.00% and Buckthorn Solar and Utah Solar Portfolio, where L+ equals 1 month LIBOR plus x%.

^(b) Applicable rate is determined by the borrower leverage ratio, as defined in the credit agreement.

^(c)The 2019 Convertible Notes become due in February 2019 and are included in current portion of long-term debt on the Company's consolidated balance sheet as of March 31, 2018.

^(d)Discounts relate to the 2019 Convertible Notes and 2020 Convertible 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 March 31, 2018, the Company was in compliance with all of the required covenants.

The discussion below describes material changes to or additions of long-term debt for the three months ended March 31, 2018.

NRG Yield LLC and NRG Yield Operating LLC Revolving Credit Facility

As of March 31, 2018, the Company had outstanding borrowings of $75 million under the revolving credit facility, which included borrowings of $20 million made during the period ended March 31, 2018, to finance the acquisition of the Buckthorn Solar Drop Down Asset, as well as for general corporate purposes. The Company also had $67 million of letters of credit outstanding.

On February 6, 2018, NRG Yield Operating LLC and NRG Yield LLC amended the revolving credit facility to modify the "change of control" provisions to permit the consummation of the NRG Transaction, and also to permit NRG Yield Operating LLC, NRG Yield LLC and certain subsidiaries to incur up to $1.5 billion of unsecured indebtedness in order to repurchase or make other required cash payments, in each case if applicable, with respect to NRG Yield Operating LLC’s outstanding senior notes and NRG Yield's outstanding convertible notes in connection with the NRG Transaction.

On April 30, 2018, the Company closed on the refinancing of the revolving credit facility, which extended the maturity of the facility to April 28, 2023, and decreased the Company's overall cost of borrowing from L+ 2.50% to L+1.75%. The facility will continue to be used for general corporate purposes including financing of future acquisitions and posting letters of credit.

Project - level Debt

Buckthorn Solar Drop Down Asset Debt

As part of the Buckthorn Solar Drop Down Asset acquisition, the Company assumed non-recourse debt of $183 million relating to Buckthorn Portfolio Solar, LLC. The assumed debt consisted of a Construction Loan and an Investment Tax Credits, or ITC, Bridge Loan, both at an interest rate of LIBOR plus 1.75%. The Construction Loan will convert to a Term Loan with an expected maturity of May 2025, and the ITC Bridge Loan will be paid at substantial completion of the Buckthorn Solar project with the final proceeds from the TE Investor.

Buckthorn Solar entered into a series of fixed for floating interest rate swaps that would fix the interest rate for a minimum of 80% of the outstanding notional amount. All interest rate swap payments by Buckthorn Solar and its counterparties are made quarterly and LIBOR is determined in advance of each interest period.

Earnings Per Share

3 Months Ended

Mar. 31, 2018

Earnings Per Share [Abstract]

Earnings Per Share

Basic earnings per common share is computed by dividing net income by the weighted average number of common shares outstanding. Shares issued during the year are weighted for the portion of the year that they were outstanding. Diluted earnings per share is computed in a manner consistent with that of basic earnings per share while giving effect to all potentially dilutive common shares that were outstanding during the period.

The reconciliation of the Company's basic and diluted earnings per share is shown in the following tables:



	Three months ended March 31,
	2018				2017
(In millions, except per share data) ^(a)	Common Class A		Common Class C		Common Class A			Common Class C
Basic and diluted earnings (loss) per share attributable to NRG Yield, Inc. common stockholders
Net income (loss) attributable to NRG Yield, Inc.	$	6	$	10	$	(1	)	$	(2	)
Weighted average number of common shares outstanding — basic and diluted	35		65		35			63
Earnings (Loss) per weighted average common share — basic and diluted	$	0.16	$	0.16	$	(0.03	)	$	(0.03	)

^(a)Basic and diluted earnings (loss) per share might not recalculate due to presenting values in millions rather than whole dollars.

The following table summarizes the Company's outstanding equity instruments that are anti-dilutive and were not included in the computation of the Company's diluted earnings per share:



	Three months ended March 31,
	2018	2017
	(In millions of shares)
2019 Convertible Notes - Common Class A	15	15
2020 Convertible Notes - Common Class C	10	10

Changes in Capital Structure

3 Months Ended

Mar. 31, 2018

Partners' Capital Notes Disclosure [Text Block]

Changes in Capital Structure

At-the-Market Equity Offering Program, or the ATM Program

NRG Yield, Inc. is party to an equity distribution agreement with Barclays Capital Inc., Credit Suisse Securities (USA) LLC, J.P. Morgan Securities LLC and RBC Capital Markets, LLC, as sales agents. Pursuant to the terms of the equity distribution agreement, NRG Yield, Inc. may offer and sell shares of its Class C common stock par value $0.01 per share, from time to time through the sales agents up to an aggregate sales price of $150 million through an at-the-market equity offering program, or the ATM Program. NRG Yield, Inc. may also sell shares of its Class C common stock to any of the sales agents, as principals for its own account, at a price agreed upon at the time of sale.

The Company sold a total of 936,662 of Class C common stock for net proceeds of $16 million during the period ended March 31, 2018, $6 million of which were received in the second quarter of 2018. The Company incurred commission fees of $105 thousand during the period ended March 31, 2018.

As of April 3, 2018, approximately $99 million of Class C common stock remains available for issuance under the ATM Program.

As a result of the Company's sale of shares of Class C common stock under the ATM Program, the public shareholders of Class A and Class C common stock increased their economic and voting interests in NRG Yield, Inc. to 53.9%, and 44.9%, respectively, as of March 31, 2018.

Dividends to Class A and Class C common stockholders

The following table lists the dividends paid on the Company's Class A common stock and Class C common stock during the three months ended March 31, 2018:



	First Quarter 2018
Dividends per Class A share	$	0.298
Dividends per Class C share	$	0.298

Dividends on the Class A common stock and Class C common stock are subject to available capital, market conditions, and compliance with associated laws, regulations and other contractual obligations. The Company expects that, based on current circumstances, comparable cash dividends will continue to be paid in the foreseeable future.

On April 24, 2018, the Company declared quarterly dividends on its Class A common stock and Class C common stock of $0.309 per share payable on June 15, 2018, to stockholders of record as of June 1, 2018.

The Company also has authorized 10 million shares of preferred stock, par value $0.01 per share. None of the shares of preferred stock have been issued.

Segment Reporting

3 Months Ended

Mar. 31, 2018

Segment Reporting [Abstract]

Segment Reporting

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



	Three months ended March 31, 2018
(In millions)	Conventional Generation			Renewables			Thermal			Corporate			Total
Operating revenues	$	79		$	98		$	48		$	—		$	225
Cost of operations	22			34			33			—			89
Depreciation and amortization	26			50			5			—			81
General and administrative	—			—			—			5			5
Acquisition-related transaction and integration costs	—			—			—			1			1
Operating income (loss)	31			14			10			(6		)	49
Equity in earnings of unconsolidated affiliates	3			1			—			—			4
Other income, net	—			1			—			—			1
Interest expense	(7		)	(24		)	(2		)	(22		)	(55		)
Income (loss) before income taxes	27			(8		)	8			(28		)	(1		)
Income tax benefit	—			—			—			(1		)	(1		)
Net Income (Loss)	$	27		$	(8	)	$	8		$	(27	)	$	—
Total Assets	$	1,815		$	5,953		$	424		$	170		$	8,362



	Three months ended March 31, 2017
(In millions)	Conventional Generation			Renewables			Thermal			Corporate			Total
Operating revenues	$	75		$	102		$	44		$	—		$	221
Cost of operations	22			33			30			—			85
Depreciation and amortization	24			48			5			—			77
General and administrative	—			—			—			4			4
Acquisition-related transaction and integration costs	—			—			—			1			1
Operating income (loss)	29			21			9			(5		)	54
Equity in earnings of unconsolidated affiliates	3			16			—			—			19
Other income, net	—			1			—			—			1
Loss on debt extinguishment	—			(2		)	—			—			(2		)
Interest expense	(12		)	(39		)	(3		)	(21		)	(75		)
Income (loss) before income taxes	20			(3		)	6			(26		)	(3		)
Income tax benefit	—			—			—			(1		)	(1		)
Net Income (Loss)	$	20		$	(3	)	$	6		$	(25	)	$	(2	)

Income Taxes

3 Months Ended

Mar. 31, 2018

Income Tax Disclosure [Abstract]

Income Taxes

Effective Tax Rate

The income tax provision consisted of the following:



	Three months ended March 31,
	2018			2017
	(In millions, except percentages)
Loss before income taxes	$	(1	)	$	(3	)
Income tax benefit	(1		)	(1		)
Effective income tax rate	100.0		%	33.3		%

For the three months ended March 31, 2018 and 2017, the overall effective tax rate was different than the statutory rate of 21% and 35%, respectively, primarily due to production and investment tax credits generated from certain wind and solar assets, respectively, and earnings allocated to NRG resulting from its interest in NRG Yield LLC.

For tax purposes, NRG Yield LLC is treated as a partnership; therefore, the Company and NRG each record their respective share of taxable income or loss.

Related Party Transactions

3 Months Ended

Mar. 31, 2018

Related Party Transactions Disclosure

Related Party Transactions

In addition to the transactions and relationships described elsewhere in the notes to the consolidated financial statements, NRG or certain subsidiaries of NRG provide services to the Company's project entities. Amounts due to NRG or its subsidiaries are recorded as accounts payable - affiliate and amounts due to the Company from NRG subsidiaries are recorded as accounts receivable - affiliate on the Company's consolidated balance sheet. The disclosures below summarize the Company's material related party transactions with NRG and its subsidiaries that are included in the Company's operating revenues and operating costs.

Power Purchase Agreements (PPAs) between the Company and NRG Power Marketing

Elbow Creek and Dover are parties to PPAs with NRG Power Marketing and generate revenue under the PPAs, which are recorded to operating revenues in the Company's consolidated statements of operations. For the three months ended March 31, 2018 and 2017, Elbow Creek and Dover, collectively, generated revenues of $3 million and $4 million, respectively.

Energy Marketing Services Agreement by and between Thermal entities and NRG Power Marketing

NRG Energy Center Dover LLC, NRG Energy Center Minneapolis, NRG Energy Center Phoenix LLC, and NRG Energy Center Paxton LLC, or Thermal entities, which are subsidiaries of the Company, are parties to Energy Marketing Services Agreements with NRG Power Marketing, a wholly-owned subsidiary of NRG. Under the agreements, NRG Power Marketing procures fuel and fuel transportation for the operation of the Thermal entities. For each of the three months ended March 31, 2018 and 2017, the Thermal entities purchased $4 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 $10 million for each of the three months ended March 31, 2018 and 2017. The Company had $9 million and $13 million due to NRG for the services performed under the O&M Agreements in accounts payable — affiliate as of March 31, 2018 and December 31, 2017, respectively.

O&M Services Agreements by and between GenConn and NRG

GenConn incurs fees under two O&M agreements with wholly-owned subsidiaries of NRG. For the three months ended March 31, 2018 and 2017, the aggregate fees incurred under the agreements were $1 million for each period.

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 $3 million for each of the three months ended March 31, 2018 and 2017. There was a balance of $3 million and $1 million due to NRG West Coast LLC in accounts payable—affiliate as of March 31, 2018 and December 31, 2017, respectively.

Administrative Services Agreements by and between the Company and NRG Renew Operation & Maintenance LLC

Various wholly-owned subsidiaries of the Company in the Renewables segment are party to administrative services agreements with NRG Renew Operation & Maintenance LLC, or RENOM, a wholly-owned subsidiary of NRG, which provides O&M services to these subsidiaries. The Company incurred total expenses for these services of $7 million and $6 million for the three months ended March 31, 2018 and 2017, respectively. There was a balance of $4 million and $5 million due to RENOM as of March 31, 2018 and December 31, 2017, respectively.

Management Services Agreement by and between the Company and NRG

NRG provides the Company with various operational, management, and administrative services, which include human resources, accounting, tax, legal, information systems, treasury, and risk management, as set forth in the Management Services Agreement. As of March 31, 2018, the base management fee was approximately $9 million per year, subject to an inflation-based adjustment annually at an inflation factor based on the year-over-year U.S. consumer price index. The fee is also subject to adjustments following the consummation of future acquisitions and as a result of a change in the scope of services provided under the Management Services Agreement. Costs incurred under this agreement for each of the three months ended March 31, 2018 and 2017 were $2 million. The costs incurred under the Management Service Agreement included certain direct expenses incurred by NRG on behalf of the Company in addition to the base management fee.

EPC Agreement by and between NECP and NRG

On October 31, 2016, NRG Business Services LLC, a subsidiary of NRG, and NECP, a wholly owned subsidiary of the Company, entered into an EPC agreement for the construction of a 73 MWt district energy system for NECP to provide 150 kpph of steam, 6,750 tons of chilled water and 7.5 MW of emergency backup power service to UPMC Mercy. The initial term of the energy services agreement with UPMC Mercy will be for a period of twenty years from the service commencement date. Pursuant to the terms of the EPC agreement and amendments made through the end of 2017, NECP agreed to pay NRG Business Services LLC $88 million, subject to adjustment based upon certain conditions in the EPC agreement, upon substantial completion of the project. In addition, the capacity of the district energy system increased from 73 MWt to 80 MWt. The project is expected to reach commercial operations in the second quarter of 2018.

Contingencies (Notes)	3 Months Ended
Contingencies (Notes)	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Contingencies Disclosure [Text Block]	Contingencies This note should be read in conjunction with the complete description under Note 16, Commitments and Contingencies, to the Company's 2017 Form 10-K. The Company's material legal proceedings are described below. The Company believes that it has valid defenses to these legal proceedings and intends to defend them vigorously. The Company records reserves for estimated losses from contingencies when information available indicates that a loss is probable and the amount of the loss, or range of loss, can be reasonably estimated. As applicable, the Company has established an adequate reserve for the matters discussed below. In addition, legal costs are expensed as incurred. Management assesses such matters based on current information and makes a judgment concerning its potential outcome, considering the nature of the claim, the amount and nature of damages sought, and the probability of success. The Company is unable to predict the outcome of the legal proceedings below or reasonably estimate the scope or amount of any associated costs and potential liabilities. As additional information becomes available, management adjusts its assessment and estimates of such contingencies accordingly. Because litigation is subject to inherent uncertainties and unfavorable rulings or developments, it is possible that the ultimate resolution of the Company's liabilities and contingencies could be at amounts that are different from its currently recorded reserves and that such difference could be material. In addition to the legal proceedings noted below, the Company and its subsidiaries are party to other litigation or legal proceedings arising in the ordinary course of business. In management's opinion, the disposition of these ordinary course matters will not materially adversely affect the Company's consolidated financial position, results of operations, or cash flows. Braun v. NRG Yield, Inc. — On April 19, 2016, plaintiffs filed a putative class action lawsuit against NRG Yield, Inc., the current and former members of its board of directors individually, and other parties in California Superior Court in Kern County, CA. Plaintiffs allege various violations of the Securities Act due to the defendants’ alleged failure to disclose material facts related to low wind production prior to the NRG Yield, Inc.'s June 22, 2015 Class C common stock offering. Plaintiffs seek compensatory damages, rescission, attorney’s fees and costs. The Defendants filed demurrers and a motion challenging jurisdiction on October 18, 2016. The case is currently stayed by agreement of the parties. On May 2, 2018, the court approved a joint stipulation which provides: (i) plaintiffs' opposition brief is due on or before July 30, 2018; (ii) defendants' reply brief is due on or before October 5, 2018; and (iii) a hearing on the motions is scheduled on October 30, 2018. GenOn Noteholders' Lawsuit — On December 13, 2016, certain indenture trustees for an ad hoc group of holders, or the Noteholders, of the GenOn Energy, Inc., or GenOn, 7.875% Senior Notes due 2017, 9.500% Notes due 2018, and 9.875% Notes due 2020, and the GenOn Americas Generation, LLC 8.50% Senior Notes due 2021 and 9.125% Senior Notes due 2031, along with certain of the Noteholders, filed a complaint in the Superior Court of the State of Delaware against NRG and GenOn alleging certain claims related to the Services Agreement between NRG and GenOn. On April 30, 2017, the Noteholders filed an amended complaint that asserts additional claims of fraudulent transfer, insider preference and breach of fiduciary duties. In addition to NRG and GenOn, the amended complaint names NRG Yield LLC and certain current and former officers and directors of GenOn as defendants. The plaintiffs, among other things, generally seek return of all monies paid under the Services Agreement and any other damages that the court deems appropriate. On April 28, 2017, the bondholders filed an amended complaint adding the GenOn directors and officers as defendants and asserting claims that they breached certain fiduciary duties. Plaintiffs specifically allege that the transfer of Marsh Landing to NRG Yield LLC constituted a fraudulent transfer. On June 12, 2017, certain GenOn entities, NRG and certain holders of the GenOn and GenOn Americas Generation, LLC senior notes entered into a restructuring support and lock-up agreement. On December 14, 2017, a settlement agreement was entered into between GenOn and NRG which should ultimately resolve this lawsuit.

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2018

Accounting Policies [Abstract]

Revenue Recognition, Policy [Policy Text Block]

Revenue Recognition

Revenue from Contracts with Customers

Thermal Revenues

Power Purchase Agreements, or PPAs

Renewable Energy Credits

Sale of Emission Allowances

Disaggregated Revenues

The following table represents the Company’s disaggregation of revenue from contracts with customers for the three months ended March 31, 2018 along with the reportable segment for each category:



(In millions)	Conventional Generation			Renewables			Thermal			Total
Energy revenue^(a)	$	1		$	112		$	1		$	114
Capacity revenue^(a)	79			—			3			82
Contract amortization	(1		)	(15		)	(1		)	(17		)
Other revenue	—			1			45			46
Total operating revenue	79			98			48			225
Less: Lease revenue	(80		)	(101		)	—			(181		)
Less: Contract amortization	1			15			1			17
Total revenue from contracts with customers	$	—		$	12		$	49		$	61

^(a)The following amounts of energy and capacity revenue relate to leases and are accounted for under ASC 840:



	Conventional Generation		Renewables		Thermal		Total
Energy Revenue	$	1	$	101	$	—	$	102
Capacity Revenue	79		—		—		79

Contract Amortization

Contract Balances

The following table reflects the contract assets and liabilities included on the Company’s balance sheet as of March 31, 2018:



(In millions)	March 31, 2018

Accounts receivable, net - Contracts with customers	$	26
Accounts receivable, net - Leases	56
Total accounts receivable, net	$	82

Income Tax, Policy [Policy Text Block]

Income Taxes

Use of Estimates

Noncontrolling Interest Disclosure [Text Block]

Noncontrolling Interests



	(In millions)
Balance as of December 31, 2017 as previously reported	$	391
Net Assets of Buckthorn Solar Drop Down Asset as of December 31, 2017	21
Balance as of December 31, 2017 as recast	$	412
Capital contributions from tax equity investors, net of distributions	30
Payment for the Buckthorn Solar Drop Down Asset	(42		)
Pre-acquisition net income of the Buckthorn Solar Drop Down Asset	4
Comprehensive loss	(11		)
Distributions to NRG, net	(22		)
Balance as of March 31, 2018	$	371

NRG Yield LLC Distributions to NRG

The following table lists the distributions paid to NRG on NRG Yield LLC's Class B and D units during the three months ended March 31, 2018:



	First Quarter 2018
Distributions per Class B Unit	$	0.298
Distributions per Class D Unit	$	0.298

On April 24, 2018, NRG Yield LLC declared a distribution on its Class A, Class B, Class C and Class D units of $0.309 per unit payable on June 15, 2018 to unit holders of record as of June 1, 2018.

Distributions [Policy Text Block]

NRG Yield LLC Distributions to NRG

The following table lists the distributions paid to NRG on NRG Yield LLC's Class B and D units during the three months ended March 31, 2018:



	First Quarter 2018
Distributions per Class B Unit	$	0.298
Distributions per Class D Unit	$	0.298

On April 24, 2018, NRG Yield LLC declared a distribution on its Class A, Class B, Class C and Class D units of $0.309 per unit payable on June 15, 2018 to unit holders of record as of June 1, 2018

Recent Accounting Developments

Recent Accounting Developments - Not Yet Adopted

Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements.

Nature of Business Disclosure [Abstract]

Segment Reporting Segment Reporting (Policies)	3 Months Ended
Segment Reporting Segment Reporting (Policies)	Mar. 31, 2018
Segment Reporting [Abstract]
Segment Reporting, Policy [Policy Text Block]	The Company’s segment structure reflects how management currently operates and allocates resources. The Company's businesses are segregated based on conventional power generation, renewable businesses which consist of solar and wind, and the thermal and chilled water business. The Corporate segment reflects the Company's corporate costs. The Company's chief operating decision maker, its Chief Executive Officer, evaluates the performance of its segments based on operational measures including adjusted earnings before interest, taxes, depreciation and amortization, or Adjusted EBITDA, and CAFD, as well as economic gross margin and net income (loss).

Nature of Business Nature of Business (Tables)

3 Months Ended

Mar. 31, 2018

IPO of NRG Yield

The following table represents the structure of the Company as of March 31, 2018:

Schedule of Ownership

As of March 31, 2018, the Company's operating assets are comprised of the following projects:



Projects	Percentage Ownership		Net Capacity (MW)^(a)	Offtake Counterparty	Expiration
Conventional
El Segundo	100	%	550	Southern California Edison	2023
GenConn Devon	50	%	95	Connecticut Light & Power	2040
GenConn Middletown	50	%	95	Connecticut Light & Power	2041
Marsh Landing	100	%	720	Pacific Gas and Electric	2023
Walnut Creek	100	%	485	Southern California Edison	2023
			1,945
Utility Scale Solar
Agua Caliente	16	%	46	Pacific Gas and Electric	2039
Alpine	100	%	66	Pacific Gas and Electric	2033
Avenal	50	%	23	Pacific Gas and Electric	2031
Avra Valley	100	%	26	Tucson Electric Power	2032
Blythe	100	%	21	Southern California Edison	2029
Borrego	100	%	26	San Diego Gas and Electric	2038
CVSR	100	%	250	Pacific Gas and Electric	2038
Desert Sunlight 250	25	%	63	Southern California Edison	2035
Desert Sunlight 300	25	%	75	Pacific Gas and Electric	2040
Kansas South	100	%	20	Pacific Gas and Electric	2033
Roadrunner	100	%	20	El Paso Electric	2031
TA High Desert	100	%	20	Southern California Edison	2033
Utah Solar Portfolio^{(b) (e)}	50	%	265	PacifiCorp	2036
			921
Distributed Solar
Apple I LLC Projects	100	%	9	Various	2032
AZ DG Solar Projects	100	%	5	Various	2025 - 2033
SPP Projects	100	%	25	Various	2026 - 2037
Other DG Projects	100	%	13	Various	2023 - 2039
			52
Wind
Alta I	100	%	150	Southern California Edison	2035
Alta II	100	%	150	Southern California Edison	2035
Alta III	100	%	150	Southern California Edison	2035
Alta IV	100	%	102	Southern California Edison	2035
Alta V	100	%	168	Southern California Edison	2035
Alta X^(b)	100	%	137	Southern California Edison	2038
Alta XI ^(b)	100	%	90	Southern California Edison	2038
Buffalo Bear	100	%	19	Western Farmers Electric Co-operative	2033
Crosswinds ^{(b) (f)}	99	%	21	Corn Belt Power Cooperative	2027
Elbow Creek ^{(b) (f)}	100	%	122	NRG Power Marketing LLC	2022
Elkhorn Ridge ^{(b) (f)}	66.7	%	54	Nebraska Public Power District	2029
Forward ^{(b) (f)}	100	%	29	Constellation NewEnergy, Inc.	2017
Goat Wind ^{(b) (f)}	100	%	150	Dow Pipeline Company	2025



Projects	Percentage Ownership		Net Capacity (MW)^(a)	Offtake Counterparty	Expiration
Hardin ^{(b) (f)}	99	%	15	Interstate Power and Light Company	2027
Laredo Ridge	100	%	80	Nebraska Public Power District	2031
Lookout ^{(b) (f)}	100	%	38	Southern Maryland Electric Cooperative	2030
Odin ^{(b) (f)}	99.9	%	20	Missouri River Energy Services	2028
Pinnacle	100	%	55	Maryland Department of General Services and University System of Maryland	2031
San Juan Mesa ^{(b) (f)}	75	%	90	Southwestern Public Service Company	2025
Sleeping Bear ^{(b) (f)}	100	%	95	Public Service Company of Oklahoma	2032
South Trent	100	%	101	AEP Energy Partners	2029
Spanish Fork ^{(b) (f)}	100	%	19	PacifiCorp	2028
Spring Canyon II ^(b)	90.1	%	29	Platte River Power Authority	2039
Spring Canyon III ^(b)	90.1	%	25	Platte River Power Authority	2039
Taloga	100	%	130	Oklahoma Gas & Electric	2031
Wildorado ^{(b) (f)}	100	%	161	Southwestern Public Service Company	2027
			2,200
Thermal
NRG Energy Center Dover LLC	100	%	103	NRG Power Marketing LLC	2018
Thermal generation	100	%	20	Various	Various
			123
Total net generation capacity^(c)			5,241

Thermal equivalent MWt ^(d)	100	%	1,319	Various	Various

^(a)Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of March 31, 2018.

^(b) Projects are part of tax equity arrangements.

^(f) Projects are part of NRG Wind TE Holdco portfolio.

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2018

Accounting Policies [Abstract]

Schedule of Accumulated Depreciation and Amortization [Table Text Block]



	March 31, 2018		December 31, 2017
	(In millions)
Property, Plant and Equipment Accumulated Depreciation	$	1,358	$	1,285
Intangible Assets Accumulated Amortization	255		237

Schedule of Change in Noncontrolling Interest [Table Text Block]

The following table reflects the changes in the Company's noncontrolling interest balance:



	(In millions)
Balance as of December 31, 2017 as previously reported	$	391
Net Assets of Buckthorn Solar Drop Down Asset as of December 31, 2017	21
Balance as of December 31, 2017 as recast	$	412
Capital contributions from tax equity investors, net of distributions	30
Payment for the Buckthorn Solar Drop Down Asset	(42		)
Pre-acquisition net income of the Buckthorn Solar Drop Down Asset	4
Comprehensive loss	(11		)
Distributions to NRG, net	(22		)
Balance as of March 31, 2018	$	371

Distributions Made to Limited Liability Company (LLC) Member, by Distribution [Table Text Block]

The following table lists the distributions paid to NRG on NRG Yield LLC's Class B and D units during the three months ended March 31, 2018:



	First Quarter 2018
Distributions per Class B Unit	$	0.298
Distributions per Class D Unit	$	0.298

Disaggregation of Revenue [Table Text Block]

The following table represents the Company’s disaggregation of revenue from contracts with customers for the three months ended March 31, 2018 along with the reportable segment for each category:



(In millions)	Conventional Generation			Renewables			Thermal			Total
Energy revenue^(a)	$	1		$	112		$	1		$	114
Capacity revenue^(a)	79			—			3			82
Contract amortization	(1		)	(15		)	(1		)	(17		)
Other revenue	—			1			45			46
Total operating revenue	79			98			48			225
Less: Lease revenue	(80		)	(101		)	—			(181		)
Less: Contract amortization	1			15			1			17
Total revenue from contracts with customers	$	—		$	12		$	49		$	61

^(a)The following amounts of energy and capacity revenue relate to leases and are accounted for under ASC 840:



	Conventional Generation		Renewables		Thermal		Total
Energy Revenue	$	1	$	101	$	—	$	102
Capacity Revenue	79		—		—		79

Contract with Customer, Asset and Liability [Table Text Block]

The following table reflects the contract assets and liabilities included on the Company’s balance sheet as of March 31, 2018:



(In millions)	March 31, 2018

Accounts receivable, net - Contracts with customers	$	26
Accounts receivable, net - Leases	56
Total accounts receivable, net	$	82

Business Acquisitions Business Acquisitions (Tables)

3 Months Ended

Mar. 31, 2018

November 2017 Drop Down Assets and August 2017 Drop Down Assets [Member]

Business Acquisition, Pro Forma Information [Table Text Block]



	Three months ended March 31, 2017
	As Previously Reported ^(a)			November 2017 Drop Down Assets			August 2017 Drop Down Assets			As Currently Reported
(In millions)
Total operating revenues	$	218		$	3		$	—		$	221
Operating income	54			—			—			54
Net loss	(1		)	(1		)	—			(2		)
Less: Pre-acquisition net income of Drop Down Assets	12			(1		)	2			13
Less: Loss attributable to noncontrolling interests	(10		)	—			(2		)	(12		)
Net loss attributable to NRG Yield, Inc.	(3		)	—			—			(3		)

^(a) As previously reported in the Company's Form 10-Q for the quarter ended March 31, 2017

Schedule of Recognized Identified Assets Acquired and Liabilities Assumed [Table Text Block]

The following is a summary of net assets transferred in connection with the acquisition of the Buckthorn Solar Drop Down Asset as of March 31, 2018:



	(In millions)
Assets:
Current assets	$	20
Property, plant and equipment	212
Non-current assets	3
Total assets	235
Liabilities:
Debt (Current and non-current) ^(a)	176
Other current and non-current liabilities	15
Total liabilities	191
Less: noncontrolling interest	19
Net assets acquired	$	25

^(a) Net of $7 million of net debt issuance costs.

Business Acquisition, Pro Forma Information [Table Text Block]

The following table presents the historical information summary combining the financial information for the Buckthorn Drop Down Asset transferred in connection with the acquisition:



	As of December 31, 2017
(In millions)	As Previously Reported		Buckthorn Solar Drop Down Asset		As Currently Reported
Assets:
Current assets	$	482	$	—	$	482
Property, plant and equipment	5,204		206		5,410
Non-current assets	2,597		—		2,597
Total assets	8,283		206		8,489
Liabilities:
Debt	5,837		161		5,998
Other current and non-current liabilities	308		24		332
Total liabilities	6,145		185		6,330
Net assets	$	2,138	$	21	$	2,159

Variable Interest Entities (Tables)

3 Months Ended

Mar. 31, 2018

Schedule of Equity Method Investments [Line Items]

Equity Method Investments [Table Text Block]

The following tables present summarized financial information for the Company's significant equity method investments:



	Three months ended March 31,
(In millions)	2018		2017
Income Statement Data:
DGPV entities ^(a)
Operating revenues	$	11	$	5
Operating loss	—		(1		)
Net income (loss)	3		(2		)
	March 31, 2018		December 31, 2017
Balance Sheet Data:	(In millions)
DGPV entities ^(a)
Current assets	$	92	$	74
Non-current assets	718		671
Current liabilities	84		83
Non-current liabilities	236		216
Redeemable noncontrolling interest	42		44

Entities that are not consolidated [Member]

Schedule of Equity Method Investments [Line Items]

Schedule of Variable Interest Entities [Table Text Block]

The Company's maximum exposure to loss as of March 31, 2018 is limited to its equity investment in the unconsolidated entities, as further summarized in the table below:



(In millions)	Maximum exposure to loss
Four Brothers Solar, LLC	$	209
GenConn Energy LLC	100
Granite Mountain Holdings, LLC	76
NRG DGPV Holdco 1 LLC	73
NRG DGPV Holdco 3 LLC	62
NRG DGPV Holdco 2 LLC	61
Iron Springs Holdings, LLC	53
NRG RPV Holdco 1 LLC	52

Consolidated Entities [Member]

Schedule of Equity Method Investments [Line Items]

Schedule of Variable Interest Entities [Table Text Block]

Summarized financial information for the Company's consolidated VIEs consisted of the following as of March 31, 2018:



(In millions)	NRG Wind TE Holdco		Alta Wind TE Holdco		Spring Canyon		Buckthorn Renewables, LLC
Other current and non-current assets	$	172	$	18	$	2	$	23
Property, plant and equipment	369		430		94		212
Intangible assets	2		259		—		—
Total assets	543		707		96		235
Current and non-current liabilities	195		8		5		191
Total liabilities	195		8		5		191
Noncontrolling interest	9		77		50		19
Net assets less noncontrolling interests	$	339	$	622	$	41	$	25

Tabular disclosure of the significant judgments and assumptions made in determining whether a variable interest (as defined) held by the entity requires the variable interest entity (VIE) (as defined) to be consolidated and (or) disclose information about its involvement with the VIE, individually or in aggregate (as applicable); the nature of restrictions, if any, on the consolidated VIE's assets and on the settlement of its liabilities reported by an entity in its statement of financial position, including the carrying amounts of such assets and liabilities; the nature of, and changes in, the risks associated with involvement in the VIE; how involvement with the VIE affects the entity's financial position, financial performance, and cash flows; the lack of recourse if creditors (or beneficial interest holders) of the consolidated VIE have no recourse to the general credit of the primary beneficiary (if applicable); the terms of arrangements, giving consideration to both explicit arrangements and implicit variable interests, if any, that could require the entity to provide financial support to the VIE, including events or circumstances that could expose the entity to a loss; the methodology used by the entity for determining whether or not it is the primary beneficiary of the variable interest entity; the significant factors considered and judgments made in determining that the power to direct the activities of a VIE that most significantly impact the VIE's economic performance are shared (as defined); the carrying amounts and classification of assets and liabilities of the VIE included in the statement of financial position; the entity's maximum exposure to loss, if any, as a result of its involvement with the VIE, including how the maximum exposure is determined and significant sources of the entity's exposure to the VIE; a comparison of the carrying amounts of the assets and liabilities and the entity's maximum exposure to loss; information about any liquidity arrangements, guarantees, and (or) other commitments by third parties that may affect the fair value or risk of the entity's variable interest in the VIE; whether or not the entity has provided financial support or other support (explicitly or implicitly) to the VIE that it was not previously contractually required to provide or whether the entity intends to provide that support, including the type and amount of the support and the primary reasons for providing the support; and supplemental information the entity determines necessary to provide.

Estimated carrying values and fair values

Fair Value of Financial Instruments (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

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 March 31, 2018				As of December 31, 2017
	Carrying Amount		Fair Value		Carrying Amount		Fair Value
(In millions)
Assets:
Notes receivable^(a)	$	9	$	9	$	13	$	13
Liabilities:
Long-term debt, including current portion^(b)	$	6,023	$	6,020	$	6,066	$	6,099

Fair Value, Option, Quantitative Disclosures [Table Text Block]



	As of March 31, 2018				As of December 31, 2017
	Level 2		Level 3		Level 2		Level 3
	(In millions)
Long-term debt, including current portion	$	1,472	$	4,548	$	1,502	$	4,597

Schedule of Fair Value, Assets and Liabilities [Table Text Block]



	As of March 31, 2018		As of December 31, 2017
	Fair Value ^(a)		Fair Value ^(a)
(In millions)	Level 2		Level 2
Derivative assets:
Commodity contracts	$	—	$	1
Interest rate contracts	17		1
Total assets	17		2
Derivative liabilities:
Commodity contracts	2		1
Interest rate contracts	24		48
Total liabilities	$	26	$	49

^(a) There were no derivative assets or liabilities classified as Level 1 or Level 3 as of March 31, 2018 and December 31, 2017.

Tabular disclosure of the application of the fair value option for measurement and reporting of eligible financial assets and liabilities (as defined), as well as certain other eligible items (as defined) included in the statement of financial position, whether such option is elected for a single eligible item or a group of similar eligible items and is in addition to other disclosures concerning fair value which the company may be required to provide. Such disclosure might be expected to include: (1) for items included in the statement of financial position: (a) for each line item in the statement of financial position that includes an item or items for which the fair value option has been elected, provide the aggregate carrying amount of ineligible items included in each line item in the balance sheet, if any; (b) the difference between the aggregate fair value and the aggregate unpaid principal balance (assuming contractual principal amounts and fair value option elected) of: (i) loans and long-term receivables (other than securities otherwise reported at fair value) and (ii) long-term debt instruments; (c) for loans held as assets for which the fair value option has been elected: (i) the aggregate fair value of loans that are 90 days or more past due, (ii) if the policy is to recognize interest income separately from other changes in fair value, the aggregate fair value of loans in nonaccrual status, and (iii) the difference between the aggregate fair value and the aggregate unpaid principal balance for loans that are 90 days or more past due, in nonaccrual status, or both; (2) for items included in the income statement: (a) the amounts of gains and losses from fair value changes included in earnings and in which line in the income statement those gains and losses are reported whether or not combined with gains and losses from items required to be accounted for at fair value; (b) for loans and other receivables held as assets, the estimated amount of gains or losses included in earnings attributable to changes in instrument-specific credit risk; (c) for liabilities with fair values that have been significantly affected during the reporting period by changes in the instrument-specific credit risk, the estimated amount of gains and losses from fair value changes included in earnings that are attributable to changes in the instrument-specific credit risk; and (3) certain other disclosures as required or determined to be provided.

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Accounting for Derivative Instruments and Hedging Activities (Tables)

3 Months Ended

Mar. 31, 2018

Net notional volume buy/(sell) of NRG Yield's open derivative transactions broken out by commodity

The following table summarizes the net notional volume buy of the Company's open derivative transactions broken out by commodity:



		Total Volume
		March 31, 2018		December 31, 2017
Commodity	Units	(In millions)
Natural Gas	MMBtu	1		2
Interest	Dollars	$	2,001	$	2,050

Fair value within the derivative instrument valuation on the balance sheets

he following table summarizes the fair value within the derivative instrument valuation on the balance sheet:



	Fair Value
	Derivative Assets ^(a)				Derivative Liabilities
	March 31, 2018		December 31, 2017		March 31, 2018		December 31, 2017
	(In millions)
Derivatives Designated as Cash Flow Hedges:
Interest rate contracts current	$	1	$	—	$	2	$	4
Interest rate contracts long-term	7		1		6		9
Total Derivatives Designated as Cash Flow Hedges	8		1		8		13
Derivatives Not Designated as Cash Flow Hedges:
Interest rate contracts current	—		—		6		13
Interest rate contracts long-term	9		—		10		22
Commodity contracts current	—		1		1		1
Commodity contracts long-term	—		—		1		—
Total Derivatives Not Designated as Cash Flow Hedges	9		1		18		36
Total Derivatives	$	17	$	2	$	26	$	49

Offsetting of derivatives by counterparty master agreement level and collateral received or paid

The following tables summarize the offsetting of derivatives by the counterparty master agreement level as of March 31, 2018, and December 31, 2017:



As of March 31, 2018	Gross Amounts of Recognized Assets/Liabilities			Derivative Instruments			Net Amount
Commodity contracts^(a):	(In millions)
Derivative assets	$	—		$	—		$	—
Derivative liabilities	(2		)	—			(2		)
Total commodity contracts	(2		)	—			(2		)
Interest rate contracts:
Derivative assets	17			(2		)	15
Derivative liabilities	(24		)	2			(22		)
Total interest rate contracts	(7		)	—			(7		)
Total derivative instruments	$	(9	)	$	—		$	(9	)

^(a) There were no commodity contracts classified as derivative assets as of March 31, 2018.



As of December 31, 2017	Gross Amounts of Recognized Assets/Liabilities			Derivative Instruments			Net Amount
Commodity contracts:	(In millions)
Derivative assets	$	1		$	—		$	1
Derivative liabilities	(1		)	—			(1		)
Total commodity contracts	—			—			—
Interest rate contracts:
Derivative assets	1			(1		)	—
Derivative liabilities	(48		)	1			(47		)
Total interest rate contracts	(47		)	—			(47		)
Total derivative instruments	$	(47	)	$	—		$	(47	)

Effects of NRG Yield's accumulated OCI balance attributable to interest rate swaps designated as cash flow hedge derivatives, net of tax

The following table summarizes the effects on the Company’s accumulated OCL balance attributable to interest rate swaps designated as cash flow hedge derivatives, net of tax:



	Three months ended March 31,
	2018			2017
	(In millions)
Accumulated OCL beginning balance	$	(60	)	$	(70	)
Reclassified from accumulated OCL to income due to realization of previously deferred amounts	4			4
Mark-to-market of cash flow hedge accounting contracts	13			2
Accumulated OCL ending balance, net of income tax benefit of $6 and $15, respectively	(43		)	(64		)
Accumulated OCL attributable to noncontrolling interests	(23		)	(39		)
Accumulated OCL attributable to NRG Yield, Inc.	$	(20	)	$	(25	)
Losses expected to be realized from OCL during the next 12 months, net of income tax benefit of $1	$	11

Long-term Debt (Tables)

3 Months Ended

Mar. 31, 2018

Debt Disclosure [Abstract]

Schedule of long-term debt

Long-term debt consisted of the following:



	March 31, 2018			December 31, 2017			March 31, 2018, interest rate % ^(a)	Letters of Credit Outstanding at March 31, 2018
	(In millions, except rates)
2019 Convertible Notes	$	345		$	345		3.500
2020 Convertible Notes	288			288			3.250
2024 Senior Notes	500			500			5.375
2026 Senior Notes	350			350			5.000
NRG Yield LLC and NRG Yield Operating LLC Revolving Credit Facility, due 2019 ^(b)	75			55			L+2.500	$	67
Project-level debt:
Agua Caliente Borrower 2, due 2038	40			41			5.430	17
Alpine, due 2022	135			135			L+1.750	16
Alta Wind I - V lease financing arrangements, due 2034 and 2035	926			926			5.696 - 7.015	118
Buckthorn Solar, due 2018 and 2025	183			169			L + 1.750	10
CVSR, due 2037	731			746			2.339 - 3.775	—
CVSR Holdco Notes, due 2037	188			194			4.680	13
El Segundo Energy Center, due 2023	369			400			L+1.75 - L+2.375	139
Energy Center Minneapolis, due 2025	83			83			5.950	—
Energy Center Minneapolis Series D Notes, due 2031	125			125			3.550	—
Laredo Ridge, due 2028	93			95			L+1.875	10
Marsh Landing, due 2023	309			318			L+2.125	38
Tapestry, due 2021	158			162			L+1.625	20
Utah Solar Portfolio, due 2022	278			278			various	13
Viento, due 2023	163			163			L+3.00	27
Walnut Creek, due 2023	259			267			L+1.625	65
Other	440			443			various	39
Subtotal project-level debt:	4,480			4,545
Total debt	6,038			6,083
Less current maturities ^(c)	(698		)	(339		)
Less net debt issuance costs	(64		)	(68		)
Less discounts ^(d)	(15		)	(17		)
Total long-term debt	$	5,261		$	5,659

^(b) Applicable rate is determined by the borrower leverage ratio, as defined in the credit agreement.

^(c)The 2019 Convertible Notes become due in February 2019 and are included in current portion of long-term debt on the Company's consolidated balance sheet as of March 31, 2018.

^(d)Discounts relate to the 2019 Convertible Notes and 2020 Convertible Notes.

Earnings Per Share (Tables)

3 Months Ended

Mar. 31, 2018

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

The reconciliation of the Company's basic and diluted earnings per share is shown in the following tables:



	Three months ended March 31,
	2018				2017
(In millions, except per share data) ^(a)	Common Class A		Common Class C		Common Class A			Common Class C
Basic and diluted earnings (loss) per share attributable to NRG Yield, Inc. common stockholders
Net income (loss) attributable to NRG Yield, Inc.	$	6	$	10	$	(1	)	$	(2	)
Weighted average number of common shares outstanding — basic and diluted	35		65		35			63
Earnings (Loss) per weighted average common share — basic and diluted	$	0.16	$	0.16	$	(0.03	)	$	(0.03	)

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

The following table summarizes the Company's outstanding equity instruments that are anti-dilutive and were not included in the computation of the Company's diluted earnings per share:



	Three months ended March 31,
	2018	2017
	(In millions of shares)
2019 Convertible Notes - Common Class A	15	15
2020 Convertible Notes - Common Class C	10	10

Changes in Capital Structure Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 2018

Changes in Capital Structure [Abstract]

Schedule of Stock by Class [Table Text Block]

Dividends Declared [Table Text Block]

The following table lists the dividends paid on the Company's Class A common stock and Class C common stock during the three months ended March 31, 2018:



	First Quarter 2018
Dividends per Class A share	$	0.298
Dividends per Class C share	$	0.298

Schedule of Segment Reporting Information, by Segment

Tabular disclosure of an entity's stock, including par or stated value per share, number and dollar amount of share subscriptions, shares authorized, shares issued, shares outstanding, number and dollar amount of shares held in an employee trust, dividend per share, total dividends, share conversion features, par value plus additional paid in capital, the value of treasury stock and other information necessary to a fair presentation, and EPS information. Stock by class includes common, convertible, and preferred stocks which are not redeemable or redeemable solely at the option of the issuer. Includes preferred stock with redemption features that are solely within the control of the issuer and mandatorily redeemable stock if redemption is required to occur only upon liquidation or termination of the reporting entity. If more than one issue is outstanding, state the title of each issue and the corresponding dollar amount; dollar amount of any shares subscribed but unissued and the deduction of subscriptions receivable there from; number of shares authorized, issued, and outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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Reference 4: http://www.xbrl.org/2003/role/presentationRef
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Reference 6: http://www.xbrl.org/2003/role/presentationRef
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Reference 7: http://www.xbrl.org/2003/role/presentationRef
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Reference 10: http://www.xbrl.org/2003/role/presentationRef
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-Subparagraph (SX 210.5-02(27))
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+ Details

Segment Reporting (Tables)

3 Months Ended

Mar. 31, 2018

Segment Reporting [Abstract]



	Three months ended March 31, 2018
(In millions)	Conventional Generation			Renewables			Thermal			Corporate			Total
Operating revenues	$	79		$	98		$	48		$	—		$	225
Cost of operations	22			34			33			—			89
Depreciation and amortization	26			50			5			—			81
General and administrative	—			—			—			5			5
Acquisition-related transaction and integration costs	—			—			—			1			1
Operating income (loss)	31			14			10			(6		)	49
Equity in earnings of unconsolidated affiliates	3			1			—			—			4
Other income, net	—			1			—			—			1
Interest expense	(7		)	(24		)	(2		)	(22		)	(55		)
Income (loss) before income taxes	27			(8		)	8			(28		)	(1		)
Income tax benefit	—			—			—			(1		)	(1		)
Net Income (Loss)	$	27		$	(8	)	$	8		$	(27	)	$	—
Total Assets	$	1,815		$	5,953		$	424		$	170		$	8,362



	Three months ended March 31, 2017
(In millions)	Conventional Generation			Renewables			Thermal			Corporate			Total
Operating revenues	$	75		$	102		$	44		$	—		$	221
Cost of operations	22			33			30			—			85
Depreciation and amortization	24			48			5			—			77
General and administrative	—			—			—			4			4
Acquisition-related transaction and integration costs	—			—			—			1			1
Operating income (loss)	29			21			9			(5		)	54
Equity in earnings of unconsolidated affiliates	3			16			—			—			19
Other income, net	—			1			—			—			1
Loss on debt extinguishment	—			(2		)	—			—			(2		)
Interest expense	(12		)	(39		)	(3		)	(21		)	(75		)
Income (loss) before income taxes	20			(3		)	6			(26		)	(3		)
Income tax benefit	—			—			—			(1		)	(1		)
Net Income (Loss)	$	20		$	(3	)	$	6		$	(25	)	$	(2	)

Income Taxes (Tables)

3 Months Ended

Mar. 31, 2018

Income Tax Disclosure [Abstract]

Reconciliation of the U.S. federal statutory rate to the Company's effective rate

The income tax provision consisted of the following:



	Three months ended March 31,
	2018			2017
	(In millions, except percentages)
Loss before income taxes	$	(1	)	$	(3	)
Income tax benefit	(1		)	(1		)
Effective income tax rate	100.0		%	33.3		%

Nature of Business (Details)
$ in Millions

3 Months Ended

Mar. 31, 2018

USD ($)

Aug. 02, 2017

USD ($)

Mar. 27, 2017

USD ($)

Mar. 31, 2018

USD ($)

Dec. 31, 2017

USD ($)

Weighted Average Remaining PPA Term

15 years

Power Generation Capacity, Megawatts, including portion attributable to noncontrolling interest

^[1],[2]

5,241

^[1]

5,247

Megawatts Thermal Equivalent, Available Under right-to-use Provisions

134

Conventional Generation, Utility-Scale Solar, Distributed Solar, and Wind [Member]

$ 6,038

$ 6,083

Conventional Generation [Member]

^[1]

5,118

^[1]

1,945

Utility-Scale Solar

Distributed Solar [Member]

^[1]

921

^[1]

Wind Farms [Member]

^[1]

2,200

Thermal [Member]

^[2]

100.00%

Steam and Chilled Water Capacity, Megawatts Thermal Equivalent

^[1]

123

^[1],[2],[3]

1,319

NRG Energy Center Dover [Member]

100.00%

NRG Yield, Inc. [Member]

Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Voting Interest

44.90%

Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest

53.90%

NRG Yield LLC | NRG [Member]

Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Voting Interest

55.10%

Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest

46.10%

GenConn Middletown | Conventional Generation [Member]

50.00%

GenConn Devon [Member] | Conventional Generation [Member]

^[1]

50.00%

Marsh Landing | Conventional Generation [Member]

^[1]

100.00%

El Segundo [Member] | Conventional Generation [Member]

^[1]

720

100.00%

Walnut Creek [Member] | Conventional Generation [Member]

^[1]

550

100.00%

Agua Caliente [Member] | Utility-Scale Solar

^[1]

485

16.00%

Alpine [Member] | Utility-Scale Solar

^[1]

100.00%

Avenal [Member] | Utility-Scale Solar

^[1]

50.00%

Avra Valley | Utility-Scale Solar

^[1]

100.00%

NRG Solar Blythe LLC [Member] | Utility-Scale Solar

^[1]

100.00%

Borrego [Member] | Utility-Scale Solar

^[1]

100.00%

CVSR [Member] | Utility-Scale Solar

^[1]

100.00%

Desert Sunlight [Member] | Utility-Scale Solar

^[1]

250

Kansas South [Member] | Utility-Scale Solar

25.00%

100.00%

Roadrunner | Utility-Scale Solar

^[1]

100.00%

TA - High Desert LLC [Member] | Utility-Scale Solar

^[1]

100.00%

Utah Portfolio [Member] | Utility-Scale Solar

^[1]

^[4]

50.00%

AZ DG Solar Projects [Member] | Distributed Solar [Member]

^[1],[4]

265

100.00%

PFMG DG Solar Projects [Member] | Distributed Solar [Member]

^[1]

100.00%

Alta I [Member] | Wind Farms [Member]

^[1]

100.00%

Alta II [Member] | Wind Farms [Member]

^[1]

150

100.00%

Alta III [Member] | Wind Farms [Member]

^[1]

150

100.00%

Alta IV [Member] | Wind Farms [Member]

^[1]

150

100.00%

Alta V [Member] | Wind Farms [Member]

^[1]

102

100.00%

Alta X [Member] | Wind Farms [Member]

^[1]

168

^[5]

100.00%

Alta XI [Member] | Wind Farms [Member]

^[1],[5]

137

^[5]

100.00%

South Trent | Wind Farms [Member]

^[1],[5]

100.00%

Spanish Fork [Member] | Wind Farms [Member]

^[1]

101

^[5],[6]

100.00%

Spring Canyon II [Member] | Wind Farms [Member]

^[1],[5],[6]

^[5]

90.10%

Laredo Ridge [Member] | Wind Farms [Member]

^[1],[5]

100.00%

Lookout [Member] | Wind Farms [Member]

^[1]

^[5],[6]

100.00%

Odin Wind Farm [Member] | Wind Farms [Member]

^[1],[5],[6]

^[5],[6]

99.90%

Taloga [Member] | Wind Farms [Member]

^[1],[5],[6]

100.00%

Wildorado [Member] | Wind Farms [Member]

^[1]

130

^[5],[6]

100.00%

Pinnacle [Member] | Wind Farms [Member]

^[1],[5],[6]

161

100.00%

San Juan Mesa Wind Project, LLC [Member] | Wind Farms [Member]

^[1]

^[5],[6]

75.00%

Sleeping Bear [Member] | Wind Farms [Member]

^[1],[5],[6]

^[5],[6]

100.00%

Buffalo Bear [Member] | Wind Farms [Member]

^[1],[5],[6]

100.00%

Crosswinds [Member] | Wind Farms [Member]

^[1]

^[5],[6]

99.00%

Elbow Creek [Member] | Wind Farms [Member]

^[1],[5],[6]

^[5],[6]

100.00%

Elkhorn Ridge Wind, LLC [Member] | Wind Farms [Member]

^[1],[5],[6]

122

^[5],[6]

66.70%

Forward [Member] | Wind Farms [Member]

^[1],[5],[6]

^[5],[6]

100.00%

Goat Wind [Member] | Wind Farms [Member]

^[1],[5],[6]

^[5],[6]

100.00%

Hardin [Member] | Wind Farms [Member]

^[1],[5],[6]

150

^[5],[6]

99.00%

Spring Canyon [Member] | Wind Farms [Member]

^[1],[5],[6]

Power Generation Capacity, Megawatts attributed to noncontrolling interest

^[1],[5]

Spring Canyon III [Member] | Wind Farms [Member]

^[5]

90.10%

Thermal [Member] | Thermal [Member]

^[1],[5]

NRG Energy Center Dover [Member] | Thermal [Member]

^[1]

SPP Projects [Member] | Distributed Solar [Member]

^[1]

103

100.00%

Other DG Assets [Member] | Distributed Solar [Member]

100.00%

Business Acquisitions, Purchase Price | $

154

$ 42

August 2017 Drop Down Assets [Member]

Business Acquisitions, Purchase Price | $

$ 44

Southern California Edison [Member] | Desert Sunlight [Member] | Utility-Scale Solar

Pacific Gas and Electric [Member] | Desert Sunlight [Member] | Utility-Scale Solar

^[1]

Common Class D [Member] | NRG Yield LLC

^[1]

Sale of Stock, Percentage of Ownership after Transaction

100.00%

Unconsolidated Solar Partnerships [Member]

262

Agua Caliente [Member]

March 2017 Drop Down Assets [Member]

$ 815

Business Acquisitions, Purchase Price | $

$ 128

Agua Caliente Borrower 2 [Member]

16.00%

Agua Caliente Borrower 2 [Member] | NRG [Member]

51.00%

Buckthorn Solar Drop Down Asset [Member] | Buckthorn Solar Drop Down Asset [Member]

$ 183

$ 169

Summary of Significant Accounting Policies [Line Items]

$ 183

[1]	Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of March 31, 2018.
[2]	The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247 MWs.
[3]	For thermal energy, net capacity represents MWt for steam or chilled water and excludes 134 MWt available under the right-to-use provisions contained in agreements between two of the Company's thermal facilities and certain of its customers.
[4]	Represents interests in Four Brothers Solar, LLC, Granite Mountain Holdings, LLC, and Iron Springs Holdings, LLC, all acquired as part of the March 2017 Drop Down Assets (ownership percentage is based upon cash to be distributed).
[5]	Projects are part of tax equity arrangements
[6]	Projects are part of NRG Wind TE Holdco portfolio.

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

3 Months Ended

Mar. 31, 2018

Mar. 31, 2017

Dec. 31, 2017

Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment

$ 1,358,000,000

$ 1,285,000,000

Finite-Lived Intangible Assets, Accumulated Amortization

255,000,000

237,000,000

Stockholders' Equity Attributable to Noncontrolling Interest

(371,000,000)

(412,000,000)

^[1]

Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest

2,126,000,000

2,159,000,000

^[1]

Pre-acquisition net income of the Buckthorn Solar Drop Down Asset

4,000,000

$ 13,000,000

^[1]

Comprehensive loss

(11,000,000)

(9,000,000)

^[1]

Distributions to NRG, net

$ (22,000,000)

Dividends Payable, Date Declared

Apr. 24, 2018

Common Stock, Dividends, Per Share, Declared

$ 0.309

Dividends Payable, Date to be Paid

Jun. 15, 2018

Dividends Payable, Date of Record

Jun. 01, 2018

Revenue from Contract with Customer, Excluding Assessed Tax

$ 61,000,000

(17,000,000)

Operating Leases, Income Statement, Contingent Revenue

225,000,000

221,000,000

^[1]

181,000,000

Accounts Receivable, Net

82,000,000

Summary of Significant Accounting Policies [Line Items]

Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest

21,000,000

Payment for the Buckthorn Solar Drop Down Asset

(42,000,000)

Financial Institutions [Member]

Summary of Significant Accounting Policies [Line Items]

Capital contributions from tax equity investors, net of distributions

$ 30,000,000

Common Class B [Member]

Summary of Significant Accounting Policies [Line Items]

Distribution Made to Limited Liability Company (LLC) Member, Distributions Paid, Per Unit

$ 0.298

Common Class D [Member]

Summary of Significant Accounting Policies [Line Items]

Distribution Made to Limited Liability Company (LLC) Member, Distributions Paid, Per Unit

$ 0.298

Scenario, Previously Reported [Member]

Summary of Significant Accounting Policies [Line Items]

Stockholders' Equity Attributable to Noncontrolling Interest

(391,000,000)

Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest

$ 2,138,000,000

Pre-acquisition net income of the Buckthorn Solar Drop Down Asset

^[2]

12,000,000

Customer Contracts [Member]

^[2]

218,000,000

Summary of Significant Accounting Policies [Line Items]

Accounts Receivable, Net

$ 26,000,000

Lease Agreements [Member]

Summary of Significant Accounting Policies [Line Items]

Accounts Receivable, Net

56,000,000

Conventional Generation [Member]

Summary of Significant Accounting Policies [Line Items]

Revenue from Contract with Customer, Excluding Assessed Tax

(1,000,000)

Operating Leases, Income Statement, Contingent Revenue

79,000,000

75,000,000

(80,000,000)

Renewables [Member]

Summary of Significant Accounting Policies [Line Items]

Revenue from Contract with Customer, Excluding Assessed Tax

12,000,000

(15,000,000)

Operating Leases, Income Statement, Contingent Revenue

98,000,000

102,000,000

(101,000,000)

Thermal [Member]

Summary of Significant Accounting Policies [Line Items]

Revenue from Contract with Customer, Excluding Assessed Tax

49,000,000

(1,000,000)

Operating Leases, Income Statement, Contingent Revenue

48,000,000

$ 44,000,000

Energy Revenue [Member]

Summary of Significant Accounting Policies [Line Items]

Revenue from Contract with Customer, Excluding Assessed Tax

^[3]

114,000,000

Operating Leases, Income Statement, Contingent Revenue

102,000,000

Energy Revenue [Member] | Conventional Generation [Member]

Summary of Significant Accounting Policies [Line Items]

Revenue from Contract with Customer, Excluding Assessed Tax

^[3]

1,000,000

Operating Leases, Income Statement, Contingent Revenue

1,000,000

Energy Revenue [Member] | Renewables [Member]

Summary of Significant Accounting Policies [Line Items]

Revenue from Contract with Customer, Excluding Assessed Tax

^[3]

112,000,000

Operating Leases, Income Statement, Contingent Revenue

101,000,000

Energy Revenue [Member] | Thermal [Member]

Summary of Significant Accounting Policies [Line Items]

Revenue from Contract with Customer, Excluding Assessed Tax

^[3]

1,000,000

Operating Leases, Income Statement, Contingent Revenue

Capacity Revenue [Member]

Summary of Significant Accounting Policies [Line Items]

Revenue from Contract with Customer, Excluding Assessed Tax

^[3]

82,000,000

Operating Leases, Income Statement, Contingent Revenue

79,000,000

Capacity Revenue [Member] | Conventional Generation [Member]

Summary of Significant Accounting Policies [Line Items]

Revenue from Contract with Customer, Excluding Assessed Tax

^[3]

79,000,000

Operating Leases, Income Statement, Contingent Revenue

79,000,000

Capacity Revenue [Member] | Renewables [Member]

Summary of Significant Accounting Policies [Line Items]

Revenue from Contract with Customer, Excluding Assessed Tax

^[3]

Operating Leases, Income Statement, Contingent Revenue

Capacity Revenue [Member] | Thermal [Member]

Summary of Significant Accounting Policies [Line Items]

Revenue from Contract with Customer, Excluding Assessed Tax

^[3]

3,000,000

Operating Leases, Income Statement, Contingent Revenue

Products And Services, Other [Member]

Summary of Significant Accounting Policies [Line Items]

Revenue from Contract with Customer, Excluding Assessed Tax

46,000,000

Products And Services, Other [Member] | Conventional Generation [Member]

Summary of Significant Accounting Policies [Line Items]

Revenue from Contract with Customer, Excluding Assessed Tax

Products And Services, Other [Member] | Renewables [Member]

Summary of Significant Accounting Policies [Line Items]

Revenue from Contract with Customer, Excluding Assessed Tax

1,000,000

Products And Services, Other [Member] | Thermal [Member]

Summary of Significant Accounting Policies [Line Items]

Revenue from Contract with Customer, Excluding Assessed Tax

$ 45,000,000

[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	As previously reported in the Company's Form 10-Q for the quarter ended March 31, 2017
[3]	The following amounts of energy and capacity revenue relate to leases and are accounted for under ASC 840:

Business Acquisitions Business Acquisitions - Central CA Fuel Cell (Details)
$ in Millions

Apr. 18, 2018

USD ($)

Mar. 31, 2018

Subsequent Event [Member] | Central CA Fuel Cell 1 [Member]

^[1],[2]

5,241

Business Combination, Consideration Transferred | $

$ 11

Power Purchase Agreement Period

2.8

20 years

[1]	Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of March 31, 2018.
[2]	The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247 MWs.

Business Acquisitions Business Acquisitions - Buckthorn Solar Drop Down Asset (Details)
$ in Millions

Mar. 31, 2018

USD ($)

Dec. 31, 2017

USD ($)

$ 425

$ 482

^[1]

^[2],[3]

5,241

$ 6,038

6,083

5,340

5,410

^[1]

2,597

^[1]

Debt, Long-term and Short-term, Combined Amount

8,362

8,489

^[1]

5,998

Other Liabilities

332

Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest

6,236

6,330

^[1]

$ 2,126

2,159

^[1]

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets

154

$ 20

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment

212

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets

235

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financial Liabilities

^[4]

176

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities

191

Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net

206

Debt, Long-term and Short-term, Combined Amount

206

161

Other Liabilities

Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest

185

Buckthorn Solar Drop Down Asset [Member] | Buckthorn Solar Drop Down Asset [Member]

183

169

Scenario, Previously Reported [Member]

$ 183

482

5,204

2,597

Debt, Long-term and Short-term, Combined Amount

8,283

5,837

Other Liabilities

308

Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest

6,145

$ 2,138

[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of March 31, 2018.
[3]	The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247 MWs.
[4]	Net of $7 million of net debt issuance costs.

Business Acquisitions Business Acquisitions - November 2017 Drop Down (Details)
$ in Millions

Nov. 02, 2017

USD ($)

Mar. 31, 2018

USD ($)

Dec. 31, 2017

USD ($)

Nov. 01, 2017

USD ($)

^[1],[2]

5,241

November 2017 Drop Down Assets [Member]

$ 6,038

$ 6,083

November 2017 Drop Down Assets [Member]

$ 74

$ 26

[1]	Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of March 31, 2018.
[2]	The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247 MWs.

Business Acquisitions Business Acquisitions - August 2017 Drop Down (Details) - USD ($)
$ in Millions

3 Months Ended

Nov. 02, 2017

Aug. 02, 2017

Mar. 27, 2017

Mar. 31, 2018

Mar. 31, 2017

Aug. 01, 2017

$ 225

$ 221

^[1]

^[1]

Less: Pre-acquisition net income of Drop Down Assets

(2)

^[1]

^[1]

Less: Loss attributable to noncontrolling interests

(20)

(12)

^[1]

Net Income (Loss) Available to Common Stockholders, Basic

(3)

^[1]

August 2017 Drop Down Assets [Member]

Business Combination, Contingent Consideration, Liability

$ 44

$ 8

Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net

$ 87

Less: Pre-acquisition net income of Drop Down Assets

Less: Loss attributable to noncontrolling interests

(2)

Net Income (Loss) Available to Common Stockholders, Basic

November 2017 Drop Down Assets [Member]

$ 74

Less: Pre-acquisition net income of Drop Down Assets

(1)

(1)

Less: Loss attributable to noncontrolling interests

Net Income (Loss) Available to Common Stockholders, Basic

August 2017 Drop Down Assets [Member]

Business Acquisition, Percentage of Voting Interests Acquired

25.00%

March 2017 Drop Down Assets [Member]

Scenario, Previously Reported [Member]

$ 128

^[2]

218

^[2]

Less: Pre-acquisition net income of Drop Down Assets

^[2]

(1)

^[2]

Less: Loss attributable to noncontrolling interests

^[2]

(10)

Net Income (Loss) Available to Common Stockholders, Basic

^[2]

$ (3)

[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	As previously reported in the Company's Form 10-Q for the quarter ended March 31, 2017

Business Acquisitions Business Acquisitions - March 2017 Drop Down (Details)
$ in Millions

Mar. 27, 2017

USD ($)

Mar. 31, 2018

USD ($)

Agua Caliente Borrower 2 [Member]

^[1],[2]

5,241

Percentage of NRG's Ownership

16.00%

31.00%

Power Purchase Agreement Period

25 years

Remaining Power Purchase Agreement term

22 years

Non-Recourse Debt

$ 41

Utah Portfolio [Member]

Remaining Power Purchase Agreement term

20 years

Percentage of Cash Available for Distributions

50.00%

Non-Recourse Debt

$ 287

March 2017 Drop Down Assets [Member]

Business Acquisition, Consideration Transferred, Working Capital

128

$ 4

Business Combination, Separately Recognized Transactions, Net Gains and Losses

$ 8

NRG [Member] | Agua Caliente Borrower 2 [Member]

NRG [Member] | Utah Portfolio [Member]

51.00%

Percentage of Cash Available for Distributions

50.00%

[1]	Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of March 31, 2018.
[2]	The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247 MWs.

Variable Interest Entities Variable Interest Entities - Consolidated Entities (Details)
$ in Millions

Mar. 31, 2018

USD ($)

Dec. 31, 2017

USD ($)

Schedule of Equity Method Investments [Line Items]

^[1],[2]

5,241

$ 2,597

^[3]

5,340

5,410

^[3]

8,362

8,489

^[3]

November 2015 Drop Down Assets [Member]

6,236

6,330

^[3]

Schedule of Equity Method Investments [Line Items]

172

369

543

Noncontrolling Interest in Variable Interest Entity

195

Alta X and XI TE Holdco [Member]

339

Schedule of Equity Method Investments [Line Items]

430

259

707

Noncontrolling Interest in Variable Interest Entity

Schedule of Equity Method Investments [Line Items]

622

Spring Canyon [Member]

Noncontrolling Interest in Variable Interest Entity

Schedule of Equity Method Investments [Line Items]

212

235

Noncontrolling Interest in Variable Interest Entity

191

$ 25

Schedule of Equity Method Investments [Line Items]

154

Business Combination, Acquisition of Less than 100 Percent, Noncontrolling Interest, Fair Value

$ 42

$ 19

206

206

Schedule of Equity Method Investments [Line Items]

$ 185

[1]	Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of March 31, 2018.
[2]	The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247 MWs.
[3]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Variable Interest Entities Variable Interest Entities - Unconsolidated Entities (Details)
$ in Millions

3 Months Ended

Mar. 31, 2018

USD ($)

Mar. 31, 2017

USD ($)

Dec. 31, 2017

USD ($)

$ 1,169

$ 1,178

^[1]

^[2],[3]

5,241

Operating revenues

$ 225

$ 221

^[1]

^[1]

(2)

^[1]

Four Brothers Solar [Member]

425

482

^[1]

Liabilities, Current

859

540

^[1]

Liabilities, Noncurrent

5,377

5,790

^[1]

Schedule of Equity Method Investments [Line Items]

Granite Mountain Holdings [Member]

209

Schedule of Equity Method Investments [Line Items]

Iron Springs Holdings [Member]

Schedule of Equity Method Investments [Line Items]

Gen Conn Energy LLC [Member]

Schedule of Equity Method Investments [Line Items]

NRG DGPV Holdco 1 [Member]

100

Schedule of Equity Method Investments [Line Items]

Schedule of Equity Method Investments [Line Items]

NRG RPV Holdco [Member]

NRG DGPV Holdco 2 [Member]

Schedule of Equity Method Investments [Line Items]

NRG DGPV Holdco 3 [Member]

Schedule of Equity Method Investments [Line Items]

Payments to Acquire Interest in Subsidiaries and Affiliates

Due to Affiliate

$ 16

Schedule of Equity Method Investments [Line Items]

Remaining Lease Term

22 years

Utah Portfolio [Member]

Operating revenues

$ 11

(1)

$ (2)

Schedule of Equity Method Investments [Line Items]

Assets, Noncurrent

718

671

Liabilities, Current

Liabilities, Noncurrent

236

216

NRG DGPV Holdco [Member]

Redeemable Noncontrolling Interest, Equity, Carrying Amount

$ 42

$ 44

[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	Net capacity represents the maximum, or rated, generating capacity of the facility multiplied by the Company's percentage ownership in the facility as of March 31, 2018.
[3]	The Company's total generation capacity is net of 6 MWs for noncontrolling interest for Spring Canyon II and III. The Company's generation capacity including this noncontrolling interest was 5,247 MWs.

Variable Interest Entities Variable Interest Entities - Utah Solar Portfolio (Details) - Utah Portfolio [Member]	Mar. 31, 2018
Variable Interest Entity [Line Items]
Percentage of Cash Available for Distributions	50.00%
Capital Unit, Class A [Member]
Variable Interest Entity [Line Items]
Percentage of Ownership	100.00%
Financial Institutions [Member] \| Capital Unit, Class B [Member]
Variable Interest Entity [Line Items]
Taxable Income Allocation, Pre-Flip	99.00%
Taxable Income Allocation, Post-Flip	50.00%

Variable Interest Entities Variable Interest Entities - Debt Held by Unconsolidated Affiliates (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Long-term Debt	$ 6,038	$ 6,083
Agua Caliente [Member]
Schedule of Equity Method Investments [Line Items]
Long-term Debt	$ 815
Debt Instrument, Basis Spread on Libor Rate	0.375%
Agua Caliente Borrower 2 [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	16.00%
Pro-Rate Share of Debt Held by Unconsolidated Affiliates	$ 130

Fair Value of Financial Instruments Fair Value of Financial Instruments - Balance Sheet Grouping (Details) - USD ($)
$ in Millions

Mar. 31, 2018

Dec. 31, 2017

Estimate of Fair Value Measurement [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Financing Receivable, Net

^[1]

$ 9

$ 13

Long-term Debt and Capital Lease Obligations, Including Current Maturities

^[2]

6,020

6,099

Reported Value Measurement [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Financing Receivable, Net

^[1]

Long-term Debt and Capital Lease Obligations, Including Current Maturities

^[2]

6,023

6,066

Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Long-term Debt and Capital Lease Obligations, Including Current Maturities

1,472

1,502

Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member]

Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]

Long-term Debt and Capital Lease Obligations, Including Current Maturities

$ 4,548

$ 4,597

[1]	(a) Carrying amount as of December 31, 2017, includes the long-term portion of notes receivable, which is recorded in other noncurrent assets on the Company's consolidated balance sheets.
[2]	(b) Excludes deferred financing costs, which are recorded as a reduction to long-term debt on the Company's consolidated balance sheets.

Fair Value of Financial Instruments Fair Value of Financial Instruments - Recurring Fair Value (Details) - USD ($)

Mar. 31, 2018

Dec. 31, 2017

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

^[1]

$ 17,000,000

$ 2,000,000

Fair Value, Inputs, Level 2 [Member]

26,000,000

49,000,000

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]

^[2]

17,000,000

2,000,000

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Derivative Assets (Liabilities), at Fair Value, Net

Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]

^[2]

26,000,000

49,000,000

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Derivative Assets (Liabilities), at Fair Value, Net

Commodity Contract [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

^[3]

1,000,000

Commodity Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]

2,000,000

^[3]

1,000,000

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

^[2]

1,000,000

Interest Rate Contract [Member]

^[2]

2,000,000

1,000,000

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

17,000,000

1,000,000

Interest Rate Contract [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]

24,000,000

48,000,000

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

^[2]

17,000,000

1,000,000

^[2]

$ 24,000,000

$ 48,000,000

[1]	Derivative Assets balances classified as current are included within the prepayments and other current assets line item of the consolidated balance sheets as of March 31, 2018 and December 31, 2017.
[2]	(a) There were no derivative assets or liabilities classified as Level 1 or Level 3 as of March 31, 2018 and December 31, 2017.
[3]	There were no commodity contracts classified as derivative assets as of March 31, 2018.

Fair Value of Financial Instruments Fair Value of Financial Instruments - Credit Risk and Derivative FV Measurements (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($)
Fair Value, Concentration of Risk, Financial Statement Captions [Line Items]
Fair Value Assets, Valuation Techniques, Impact of Credit Reserve to Fair Value	$ 0
Concentration Risk, Credit Risk, Financial Instrument, Maximum Exposure	$ 2,600
Estimated Counterparty Credit Risk Exposure to Certain Counterparties, Period	5 years

Accounting for Derivative Instruments and Hedging Activities Accounting for Derivative Instruments and Hedging Activities - FV of Derivatives (Details) - USD ($)
$ in Millions

Mar. 31, 2018

Dec. 31, 2017

^[1]

$ 17

$ 2

Fair Value of Gross Derivative Assets/(Liabilities), Net

(9)

(47)

Derivative Asset Fair Value Gross Liability Net Of Derivative Liability Fair Value Gross Asset

Derivative Asset, Fair Value, Amount Offset Against Collateral Net Of Derivative Liability, Fair Value, Amount Offset Against Collateral

(9)

(47)

Derivative, Collateral, Right to Reclaim Cash

Derivative, Collateral, Obligation to Return Cash

Designated as Hedging Instrument [Member]

^[1]

Not Designated as Hedging Instrument [Member]

^[1]

Interest Rate Contract Current [Member] | Designated as Hedging Instrument [Member]

^[1]

Interest Rate Contract Current [Member] | Not Designated as Hedging Instrument [Member]

^[1]

Interest Rate Contract Non Current [Member] | Designated as Hedging Instrument [Member]

^[1]

Interest Rate Contract Non Current [Member] | Not Designated as Hedging Instrument [Member]

^[1]

Commodity Contract Current [Member] | Not Designated as Hedging Instrument [Member]

^[1]

Commodity Contract Non Current [Member] | Not Designated as Hedging Instrument [Member]

^[1]

Commodity Contract [Member]

^[2]

Derivative Asset, Fair Value, Gross Liability

^[2]

^[2]

Derivative Liability, Fair Value, Gross Asset

^[2]

Derivative Asset

^[2]

Derivative Liability

^[2]

Fair Value of Gross Derivative Assets/(Liabilities), Net

(2)

^[2]

Derivative Asset Fair Value Gross Liability Net Of Derivative Liability Fair Value Gross Asset

^[2]

Derivative Asset, Fair Value, Amount Offset Against Collateral Net Of Derivative Liability, Fair Value, Amount Offset Against Collateral

(2)

^[2]

Interest Rate Contract [Member]

Derivative Asset, Fair Value, Gross Liability

Derivative Liability, Fair Value, Gross Asset

Derivative Asset

Derivative Liability

Fair Value of Gross Derivative Assets/(Liabilities), Net

(7)

(47)

Derivative Asset Fair Value Gross Liability Net Of Derivative Liability Fair Value Gross Asset

Derivative Asset, Fair Value, Amount Offset Against Collateral Net Of Derivative Liability, Fair Value, Amount Offset Against Collateral

(7)

(47)

Interest [Member] | United States of America, Dollars

Derivative, Notional Amount

2,001

2,050

Natural Gas [Member] | MMbtu [Member]

Derivative, Notional Amount

$ 1

$ 2

[1]	Derivative Assets balances classified as current are included within the prepayments and other current assets line item of the consolidated balance sheets as of March 31, 2018 and December 31, 2017.
[2]	There were no commodity contracts classified as derivative assets as of March 31, 2018.

Accounting for Derivative Instruments and Hedging Activities Accounting for Derivative Instruments and Hedging Activities - AOCI (Details) - USD ($)
$ in Millions

3 Months Ended

Mar. 31, 2018

Mar. 31, 2017

Dec. 31, 2017

Dec. 31, 2016

Sep. 30, 2016

Jun. 30, 2016

Derivative [Line Items]

Accumulated Other Comprehensive Loss, Net of Tax

$ (43)

$ (60)

$ (70)

$ (64)

Accumulated Other Comprehensive Loss, Cumulative Change in Loss from Cash Flow Hedges, Tax Amount

(6)

(15)

Reclassified from accumulated OCL to income due to realization of previously deferred amounts

$ 4

Mark-to-market of cash flow hedge accounting contracts

Accumulated other comprehensive loss

(20)

$ (28)

^[1]

$ (25)

Losses expected to be realized from OCL during the next 12 months, net of income tax benefit of $1

Losses expected to be realized from OCL during the next 12 months, Tax Amount

(1)

Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net

$ 0

Noncontrolling Interest [Member]

Derivative [Line Items]

Accumulated other comprehensive loss

$ (23)

$ (39)

[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.

Accounting for Derivative Instruments and Hedging Activities Accounting for Derivative Instruments and Hedging Activities - Impact to Statement of Operations (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Interest Rate Contract [Member] \| Interest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized Gain (Loss) on Derivatives	$ (24)	$ (4)

Long-term Debt Long-term Debt - Debt Table (Details) - USD ($)
$ in Millions

3 Months Ended

Mar. 31, 2018

Dec. 31, 2017

Current portion of long-term debt

$ 6,038

$ 6,083

(698)

(339)

^[1]

Debt Issuance Costs, Net

(64)

(68)

Long-term Debt, Excluding Current Maturities

5,261

5,659

Debt Instrument, Unamortized Discount

^[2]

(15)

(17)

3.5% Convertible Notes due 2019 [Member]

$ 345

345

3.25% Convertible Notes due 2020 [Member]

^[3]

3.50%

$ 288

288

5.375% Senior Notes due in 2024 [Member]

^[3]

3.25%

Senior Notes

$ 500

500

5.00% Senior Notes due in 2026 [Member]

^[3]

5.375%

Senior Notes

$ 350

350

NRG Yield Revolving Credit Facility [Member]

^[3]

5.00%

Debt Instrument, Description of Variable Rate Basis

$ 75

^[3]

3 month LIBOR

Alta Wind Asset Management, due 2031 [Member]

^[2]

2.50%

Debt Instrument, Description of Variable Rate Basis

^[3]

3 month LIBOR

Agua Caliente Borrower 2 [Member]

2.375%

$ 40

Alpine Financing Agreement, due 2022 [Member]

^[3]

5.43%

Debt Instrument, Description of Variable Rate Basis

$ 135

135

^[3]

3-Month LIBOR

Alta Wind I-V, lease financing arrangement, due 2034 and 2035 [Member]

1.75%

$ 926

926

Debt Instrument, Description of Variable Rate Basis

$ 183

169

1-Month LIBOR

1.75%

CVSR, due 2037

CVSR Holdco due 2037 [Member]

$ 731

746

$ 188

194

El Segundo Energy Center, due 2023

^[3]

4.68%

Debt Instrument, Description of Variable Rate Basis

$ 369

400

^[3]

3-Month LIBOR

El Segundo Energy Center due 2023 Tranche B [Member]

El Segundo Energy Center due 2023 Tranche A [Member]

2.375%

Energy Center Minneapolis, due 2025

1.75%

$ 83

Energy Center Minneapolis Series D Notes, due 2031

5.95%

$ 125

125

Laredo Ridge Wind, LLC, due in 2026 [Member]

^[3]

3.55%

Debt Instrument, Description of Variable Rate Basis

$ 93

^[3]

3-Month LIBOR

Marsh Landing Term Loan Facility [Member]

1.875%

Marsh Landing Tranche B due 2023 [Member]

$ 309

318

Debt Instrument, Description of Variable Rate Basis

^[3]

3-Month LIBOR

Tapestry Wind LLC due in 2021 [Member]

2.125%

Debt Instrument, Description of Variable Rate Basis

$ 158

162

^[3]

3-Month LIBOR

Utah Solar Portfolio, due 2022 [Member]

1.625%

Viento Funding II, Inc., due in 2023 [Member]

$ 278

278

Debt Instrument, Description of Variable Rate Basis

$ 163

163

^[3]

3-Month LIBOR

Walnut Creek Energy, LLC, due in 2023 [Member]

3.00%

Debt Instrument, Description of Variable Rate Basis

$ 259

267

^[3]

3-Month LIBOR

1.625%

Other Debt [Member]

$ 440

443

Project [Domain]

Minimum [Member] | Alta Wind I-V, lease financing arrangement, due 2034 and 2035 [Member]

$ 4,480

$ 4,545

Minimum [Member] | CVSR, due 2037

5.696%

Maximum [Member] | Alta Wind I-V, lease financing arrangement, due 2034 and 2035 [Member]

2.339%

Maximum [Member] | CVSR, due 2037

7.015%

Letter of Credit [Member] | NRG Yield Revolving Credit Facility [Member]

3.775%

Letter of Credit [Member] | Agua Caliente Borrower 2 [Member]

$ 67

Letter of Credit [Member] | Alpine Financing Agreement, due 2022 [Member]

Letter of Credit [Member] | Alta Wind I-V, lease financing arrangement, due 2034 and 2035 [Member]

Letter of Credit [Member] | Buckthorn Solar Drop Down Asset [Member]

118

Letter of Credit [Member] | CVSR, due 2037

Letter of Credit [Member] | CVSR Holdco due 2037 [Member]

Letter of Credit [Member] | El Segundo Energy Center, due 2023

Letter of Credit [Member] | Energy Center Minneapolis, due 2025

139

Letter of Credit [Member] | Energy Center Minneapolis Series D Notes, due 2031

Letter of Credit [Member] | Laredo Ridge Wind, LLC, due in 2026 [Member]

Letter of Credit [Member] | Marsh Landing Term Loan Facility [Member]

Letter of Credit [Member] | Tapestry Wind LLC due in 2021 [Member]

Letter of Credit [Member] | Utah Solar Portfolio, due 2022 [Member]

Letter of Credit [Member] | Viento Funding II, Inc., due in 2023 [Member]

Letter of Credit [Member] | Walnut Creek Energy, LLC, due in 2023 [Member]

$ 65

[1]	(a) Retrospectively adjusted as discussed in Note 1, Nature of Business.
[2]	Discounts relate to the 2019 Convertible Notes and 2020 Convertible Notes.
[3]	As of March 31, 2018, L+ equals 3 month LIBOR plus x%, except for Viento, due 2023 where L+ equals 6 month LIBOR plus 3.00%

Long-term Debt Long-term Debt - Debt Disclosures (Details) - USD ($)
$ in Millions

3 Months Ended

Apr. 30, 2018

Mar. 31, 2018

Dec. 31, 2017

Line of Credit Facility, Maximum Borrowing Capacity

$ 1,500

NRG Yield Revolving Credit Facility [Member]

6,038

$ 6,083

Line of Credit Facility, Fair Value of Amount Outstanding

Proceeds from Issuance of Debt

$ 75

^[1]

2.50%

$ 183

$ 169

Letter of Credit [Member] | NRG Yield Revolving Credit Facility [Member]

1.75%

Letter of Credit [Member] | Buckthorn Solar Drop Down Asset [Member]

$ 67

Buckthorn Solar Drop Down Asset [Member] | Buckthorn Solar Drop Down Asset [Member]

Derivative, Nonmonetary Notional Amount, Percent of Required Need, Coverage

$ 183

80.00%

Subsequent Event [Member] | NRG Yield Revolving Credit Facility [Member]