Sunnova Energy International (NOVA) 10-K 25 Feb 21 2020 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Feb. 22, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-38995
Entity Registrant Name	Sunnova Energy International Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	30-1192746
Entity Address, Address Line One	20 East Greenway Plaza, Suite 540
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77046
City Area Code	281
Local Phone Number	892-1588
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	NOVA
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 571.6
Entity Common Stock, Shares Outstanding		108,065,275
Documents Incorporated by Reference	Portions of the information called for by Part III of this Form 10-K are hereby incorporated by reference from either the definitive Proxy Statement for our annual meeting of stockholders or an amendment to this Form 10-K, either of which will be filed with the Securities and Exchange Commission not later than 120 days after December 31, 2020.
Entity Central Index Key	0001772695
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands		Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash		$ 209,859	$ 83,485
Accounts receivable—trade, net		10,243	10,672
Accounts receivable—other		21,378	6,147
Other current assets, net of allowance of $707 and $112 as of December 31, 2020 and 2019, respectively		215,175	174,016
Total current assets		456,655	274,320
Property and equipment, net		2,323,169	1,745,060
Customer notes receivable, net of allowance of $16,961 and $979 as of December 31, 2020 and 2019, respectively		513,386	297,975
Other assets		294,372	169,712
Total assets	[1]	3,587,582	2,487,067
Current liabilities:
Accounts payable		39,908	36,190
Accrued expenses		34,049	39,544
Current portion of long-term debt		110,883	97,464
Other current liabilities		26,013	21,804
Total current liabilities		210,853	195,002
Long-term debt, net		1,924,653	1,346,419
Other long-term liabilities		171,395	127,406
Total liabilities	[1]	2,306,901	1,668,827
Commitments and contingencies (Note 16)
Redeemable noncontrolling interests		136,124	127,129
Stockholders' equity:
Common stock, 100,412,036 and 83,980,885 shares issued as of December 31, 2020 and 2019, respectively, at $0.0001 par value		10	8
Additional paid-in capital—common stock		1,482,716	1,007,751
Accumulated deficit		(530,995)	(361,824)
Total stockholders' equity		951,731	645,935
Noncontrolling interests		192,826	45,176
Total equity		1,144,557	691,111
Total liabilities, redeemable noncontrolling interests and equity		$ 3,587,582	$ 2,487,067
[1]	The consolidated assets as of December 31, 2020 and 2019 include $1,471,796 and $790,211, respectively, of assets of variable interest entities ("VIEs") that can only be used to settle obligations of the VIEs. These assets include cash of $13,407 and $7,347 as of December 31, 2020 and 2019, respectively; accounts receivable—trade, net of $2,953 and $1,460 as of December 31, 2020 and 2019, respectively; accounts receivable—other of $583 and $4 as of December 31, 2020 and 2019, respectively; other current assets of $182,646 and $47,606 as of December 31, 2020 and 2019, respectively; property and equipment, net of $1,257,953 and $726,415 as of December 31, 2020 and 2019, respectively; and other assets of $14,254 and $7,379 as of December 31, 2020 and 2019, respectively. The consolidated liabilities as of December 31, 2020 and 2019 include $32,345 and $13,440, respectively, of liabilities of VIEs whose creditors have no recourse to Sunnova Energy International Inc. These liabilities include accounts payable of $2,744 and $1,926 as of December 31, 2020 and 2019, respectively; accrued expenses of $827 and $35 as of December 31, 2020 and 2019, respectively; other current liabilities of $3,284 and $612 as of December 31, 2020 and 2019, respectively; and other long-term liabilities of $25,490 and $10,867 as of December 31, 2020 and 2019, respectively.

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands		Dec. 31, 2020	Dec. 31, 2019
Other current asset, allowance		$ 707	$ 112
Customer notes receivable, allowance		$ 16,961	$ 979
Common stock, issued (in shares)		100,412,036	83,980,885
Common stock, par value (in USD per share)		$ 0.0001	$ 0.0001
Assets	[1]	$ 3,587,582	$ 2,487,067
Cash		209,859	83,485
Accounts receivable—trade, net		10,243	10,672
Accounts receivable—other		21,378	6,147
Other current assets		215,175	174,016
Property and equipment, net		2,323,169	1,745,060
Other assets		294,372	169,712
Liabilities	[1]	2,306,901	1,668,827
Accounts payable		39,908	36,190
Accrued expenses		34,049	39,544
Other current liabilities		26,013	21,804
Other long-term liabilities		171,395	127,406
Primary beneficiary
Assets		1,471,796	790,211
Cash		13,407	7,347
Accounts receivable—trade, net		2,953	1,460
Accounts receivable—other		583	4
Other current assets		182,646	47,606
Property and equipment, net		1,257,953	726,415
Other assets		14,254	7,379
Liabilities		32,345	13,440
Accounts payable		2,744	1,926
Accrued expenses		827	35
Other current liabilities		3,284	612
Other long-term liabilities		$ 25,490	$ 10,867
[1]	The consolidated assets as of December 31, 2020 and 2019 include $1,471,796 and $790,211, respectively, of assets of variable interest entities ("VIEs") that can only be used to settle obligations of the VIEs. These assets include cash of $13,407 and $7,347 as of December 31, 2020 and 2019, respectively; accounts receivable—trade, net of $2,953 and $1,460 as of December 31, 2020 and 2019, respectively; accounts receivable—other of $583 and $4 as of December 31, 2020 and 2019, respectively; other current assets of $182,646 and $47,606 as of December 31, 2020 and 2019, respectively; property and equipment, net of $1,257,953 and $726,415 as of December 31, 2020 and 2019, respectively; and other assets of $14,254 and $7,379 as of December 31, 2020 and 2019, respectively. The consolidated liabilities as of December 31, 2020 and 2019 include $32,345 and $13,440, respectively, of liabilities of VIEs whose creditors have no recourse to Sunnova Energy International Inc. These liabilities include accounts payable of $2,744 and $1,926 as of December 31, 2020 and 2019, respectively; accrued expenses of $827 and $35 as of December 31, 2020 and 2019, respectively; other current liabilities of $3,284 and $612 as of December 31, 2020 and 2019, respectively; and other long-term liabilities of $25,490 and $10,867 as of December 31, 2020 and 2019, respectively.

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue	$ 160,820	$ 131,556	$ 104,382
Operating expense:
Cost of revenue—depreciation	58,431	43,536	34,710
Cost of revenue—other	6,747	3,877	2,007
Operations and maintenance	16,313	8,588	14,035
General and administrative	115,148	97,986	67,430
Other operating income	(41)	(161)	(70)
Total operating expense, net	196,598	153,826	118,112
Operating loss	(35,778)	(22,270)	(13,730)
Interest expense, net	154,580	108,024	51,582
Interest expense, net—affiliates	0	4,098	9,548
Interest income	(23,741)	(12,483)	(6,450)
Loss on extinguishment of long-term debt, net	142,772	0	0
Loss on extinguishment of long-term debt, net—affiliates	0	10,645	0
Other (income) expense	(1,752)	880	(1)
Loss before income tax	(307,637)	(133,434)	(68,409)
Income tax expense	181	0	0
Net loss	(307,818)	(133,434)	(68,409)
Net income (loss) attributable to redeemable noncontrolling interests and noncontrolling interests	(55,534)	10,917	5,837
Net loss attributable to stockholders	(252,284)	(144,351)	(74,246)
Deemed dividends on convertible preferred stock exchange	0	0	(19,332)
Net loss attributable to common stockholders—basic	(252,284)	(169,076)	(135,872)
Net loss attributable to common stockholders—diluted	$ (252,284)	$ (169,076)	$ (135,872)
Net loss per share attributable to common stockholders—basic and diluted (in USD per share)	$ (2.87)	$ (4.14)	$ (15.74)
Weighted average common shares outstanding—basic and diluted (in shares)	87,871,457	40,797,976	8,634,477
Series A Convertible Preferred Stock
Operating expense:
Dividends earned on convertible preferred stock	$ 0	$ (19,271)	$ (36,346)
Series C Convertible Preferred Stock
Operating expense:
Dividends earned on convertible preferred stock	$ 0	$ (5,454)	$ (5,948)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (307,818)	$ (133,434)	$ (68,409)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	66,066	49,340	39,290
Impairment and loss on disposals, net	5,824	1,772	7,565
Amortization of deferred financing costs	9,031	9,822	9,074
Amortization of debt discount	15,685	3,018	1,083
Non-cash effect of equity-based compensation plans	10,873	9,235	2,984
Non-cash payment-in-kind interest on loan—affiliates	0	2,716	5,524
Unrealized (gain) loss on derivatives	(13,768)	19,237	6,100
Unrealized (gain) loss on fair value option instruments	(907)	150	0
Loss on extinguishment of long-term debt, net	142,772	0	0
Loss on extinguishment of long-term debt, net—affiliates	0	10,645	0
Other non-cash items	14,962	8,442	4,818
Changes in components of operating assets and liabilities:
Accounts receivable	(4,297)	(9,349)	(4,983)
Other current assets	(24,256)	(131,741)	(11,568)
Other assets	(42,411)	(40,118)	(8,529)
Accounts payable	(1,141)	5,292	(996)
Accrued expenses	(4,504)	15,099	4,234
Other current liabilities	5,397	8,452	4,938
Long-term debt—paid-in-kind—affiliates	0	(719)	(3,184)
Other long-term liabilities	(2,974)	1,879	489
Net cash used in operating activities	(131,466)	(170,262)	(11,570)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of property and equipment	(578,369)	(430,822)	(252,618)
Payments for investments and customer notes receivable	(285,238)	(159,303)	(108,354)
Proceeds from customer notes receivable	35,479	21,604	7,715
State utility rebates and tax credits	641	668	853
Other, net	(2,032)	(463)	3,555
Net cash used in investing activities	(829,519)	(568,316)	(348,849)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from long-term debt	1,651,765	883,360	445,586
Payments of long-term debt	(963,872)	(342,540)	(292,091)
Proceeds of long-term debt from affiliates	0	15,000	15,000
Payments of long-term debt to affiliates	0	(56,236)	(40,000)
Payments on notes payable	(4,981)	(4,672)	0
Payments of deferred financing costs	(24,084)	(12,110)	(8,598)
Payments of debt discounts	(3,374)	(1,084)	(2,465)
Proceeds from issuance of common stock, net	152,277	164,452	0
Proceeds from equity component of debt instrument, net	73,657	13,984	0
Proceeds from issuance of convertible preferred stock, net	0	(2,510)	172,771
Contributions from redeemable noncontrolling interests and noncontrolling interests	320,245	157,149	79,017
Distributions to redeemable noncontrolling interests and noncontrolling interests	(6,527)	(7,559)	(2,017)
Payments of costs related to redeemable noncontrolling interests and noncontrolling interests	(6,517)	(5,395)	(1,510)
Other, net	(2)	(16)	(6)
Net cash provided by financing activities	1,188,587	801,823	365,687
Net increase in cash and restricted cash	227,602	63,245	5,268
Cash and restricted cash at beginning of period	150,291	87,046	81,778
Cash and restricted cash at end of period	377,893	150,291	87,046
Restricted cash included in other current assets	(73,020)	(10,474)	(5,190)
Restricted cash included in other assets	(95,014)	(56,332)	(29,150)
Cash at end of period	209,859	83,485	52,706
Non-cash investing and financing activities:
Change in receivables for dealers in a net receivable position, state utility rebates and state tax credits related to purchases of property and equipment	12,109	(975)	(1,219)
Change in accounts payable and accrued expenses related to purchases of property and equipment	21,041	26,952	3,191
Change in accounts payable and accrued expenses related to payments for investments and customer notes receivable	(18,383)	(10,557)	(10,461)
Non-cash conversion of convertible senior notes for common stock	149,352	0	0
Supplemental cash flow information:
Cash paid for interest	87,829	58,060	57,887
Cash paid for income taxes	$ 181	$ 0	$ 0

CONSOLIDATED STATEMENTS OF REDE

CONSOLIDATED STATEMENTS OF REDEEMABLE NONCONTROLLING INTERESTS AND EQUITY - USD ($) $ in Thousands	Total	Cumulative-effect adjustment	Series A, Series B and Series C Convertible Preferred Stock	Series A and Series B Common Stock	Total Stockholders' Equity	Total Stockholders' EquityCumulative-effect adjustment	Total Stockholders' EquitySeries A, Series B and Series C Convertible Preferred Stock	Total Stockholders' EquitySeries A and Series B Common Stock	Preferred StockSeries A, Series B and Series C Convertible Preferred Stock	Common Stock	Common StockSeries A and Series B Common Stock	Series A and Series B Treasury Stock	Additional Paid-in Capital - Convertible Preferred Stock	Additional Paid-in Capital - Convertible Preferred StockSeries A, Series B and Series C Convertible Preferred Stock	Additional Paid-in Capital - Common Stock	Additional Paid-in Capital - Common StockSeries A and Series B Common Stock	Accumulated Deficit	Accumulated DeficitCumulative-effect adjustment	Noncontrolling Interests
Redeemable noncontrolling interest, beginning balance at Dec. 31, 2017	$ 38,590
Increase (Decrease) in Redeemable Noncontrolling Interests [Roll Forward]
Net income (loss)	5,837
Contributions from redeemable noncontrolling interests and noncontrolling interests	79,017
Distributions to redeemable noncontrolling interests and noncontrolling interests	(2,017)
Costs related to redeemable noncontrolling interests and noncontrolling interests	(1,062)
Equity in subsidiaries attributable to parent	(30,697)
Other, net	(3,988)
Redeemable noncontrolling interest, ending balance at Dec. 31, 2018	85,680
Stockholders' equity, beginning balance (in shares) at Dec. 31, 2017									44,763,084	0	8,634,455
Stockholders' equity, beginning balance at Dec. 31, 2017	371,183				$ 371,183				$ 448	$ 0	$ 86	$ 0	$ 530,951		$ 82,455		$ (242,757)		$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(74,246)				(74,246)												(74,246)
Issuance of stock, net (in shares)									13,019,793		644
Issuance of stock, net			$ 170,506	$ (2)			$ 170,506	$ (2)	$ 130					$ 170,376		$ (2)
Non-cash exchange of convertible preferred stock (in shares)									166,497
Non-cash exchange of convertible preferred stock	0								$ 2				(2)
Contributions from redeemable noncontrolling interests and noncontrolling interests	0
Distributions to redeemable noncontrolling interests and noncontrolling interests	0
Costs related to redeemable noncontrolling interests and noncontrolling interests	0
Equity in subsidiaries attributable to parent	30,697				30,697												30,697
Equity-based compensation expense	2,984				2,984										2,984
Acquisition of treasury stock	(4)				(4)							(4)
Retirement of treasury stock (in shares)											(644)
Retirement of treasury stock	0											4			2		(6)
Other, net	0								$ (1)				1
Stockholders' equity, ending balance (in shares) at Dec. 31, 2018									57,949,374	0	8,634,455
Stockholders' equity, ending balance at Dec. 31, 2018	501,118				501,118				$ 579	$ 0	$ 86	0	701,326		85,439		(286,312)		0
Increase (Decrease) in Redeemable Noncontrolling Interests [Roll Forward]
Net income (loss)	8,521
Contributions from redeemable noncontrolling interests and noncontrolling interests	77,579
Distributions to redeemable noncontrolling interests and noncontrolling interests	(7,559)
Costs related to redeemable noncontrolling interests and noncontrolling interests	(2,338)
Equity in subsidiaries attributable to parent	(37,112)
Other, net	2,358
Redeemable noncontrolling interest, ending balance at Dec. 31, 2019	127,129
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(141,955)				(144,351)												(144,351)		2,396
Issuance of stock, net (in shares)										14,865,267	2,143
Issuance of stock, net	163,966				163,966					$ 1					163,965
Repurchase of convertible preferred stock (in shares)									(13,484)
Repurchase of convertible preferred stock	(191)				(191)								(183)				(8)
Non-cash exchange of convertible preferred stock (in shares)									2,543,127
Non-cash exchange of convertible preferred stock	32,834				32,834				$ 25				32,809
Non-cash exchange of Series A and Series C convertible preferred stock and Series A and Series B common stock for common stock (in shares)									(60,479,017)	69,115,618	(8,636,601)
Non-cash exchange of Series A and Series C convertible preferred stock and Series A and Series B common stock for common stock	0								$ (605)	$ 7	$ (86)		(734,444)		735,128
Equity component of debt instrument, net	13,984				13,984										13,984
Contributions from redeemable noncontrolling interests and noncontrolling interests	79,570																		79,570
Distributions to redeemable noncontrolling interests and noncontrolling interests	0																		0
Costs related to redeemable noncontrolling interests and noncontrolling interests	(5,054)																		(5,054)
Equity in subsidiaries attributable to parent	37,112				68,848												68,848		(31,736)
Equity-based compensation expense	9,235				9,235										9,235
Other, net	492				492				$ 1				492				(1)		0
Other, net (in shares)											3
Stockholders' equity, ending balance (in shares) at Dec. 31, 2019									0	83,980,885	0
Stockholders' equity, ending balance at Dec. 31, 2019	691,111	$ (9,908)			645,935	$ (9,908)			$ 0	$ 8	$ 0	0	0		1,007,751		(361,824)	$ (9,908)	45,176
Increase (Decrease) in Redeemable Noncontrolling Interests [Roll Forward]
Net income (loss)	10,164
Contributions from redeemable noncontrolling interests and noncontrolling interests	3,449
Distributions to redeemable noncontrolling interests and noncontrolling interests	(4,802)
Costs related to redeemable noncontrolling interests and noncontrolling interests	187
Equity in subsidiaries attributable to parent	(883)
Other, net	880
Redeemable noncontrolling interest, ending balance at Dec. 31, 2020	136,124
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(317,982)				(252,284)												(252,284)		(65,698)
Issuance of stock, net (in shares)										16,431,151
Issuance of stock, net	469,271				469,271					$ 2					469,269
Equity component of debt instrument, net	(5,177)				(5,177)										(5,177)
Contributions from redeemable noncontrolling interests and noncontrolling interests	316,796																		316,796
Distributions to redeemable noncontrolling interests and noncontrolling interests	(1,725)																		(1,725)
Costs related to redeemable noncontrolling interests and noncontrolling interests	(7,895)																		(7,895)
Equity in subsidiaries attributable to parent	883				93,021												93,021		(92,138)
Equity-based compensation expense	10,873				10,873										10,873
Other, net	(1,690)																		(1,690)
Stockholders' equity, ending balance (in shares) at Dec. 31, 2020									0	100,412,036	0
Stockholders' equity, ending balance at Dec. 31, 2020	$ 1,144,557				$ 951,731				$ 0	$ 10	$ 0	$ 0	$ 0		$ 1,482,716		$ (530,995)		$ 192,826

Description of Business and Bas

Description of Business and Basis of Presentation	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Basis of Presentation	Description of Business and Basis of Presentation We are a leading residential solar and energy storage service provider, serving over 107,000 customers in more than 20 United States ("U.S.") states and territories. Sunnova Energy Corporation was incorporated in Delaware on October 22, 2012 and formed Sunnova Energy International Inc. ("SEI") as a Delaware corporation on April 1, 2019. We completed our initial public offering on July 29, 2019 (our "IPO"); and in connection with our IPO, all of Sunnova Energy Corporation's ownership interests were contributed to SEI. Unless the context otherwise requires, references in this report to "Sunnova," the "Company," "we," "our," "us," or like terms, refer to SEI and its consolidated subsidiaries. We have a differentiated residential solar dealer model in which we partner with local dealers who originate, design and install our customers' solar energy systems and energy storage systems on our behalf. Our focus on our dealer model enables us to leverage our dealers' specialized knowledge, connections and experience in local markets to drive customer origination while providing our dealers with access to high quality products at competitive prices, as well as technical oversight and expertise. We believe this structure provides operational flexibility , reduces exposure to labor shortages and lowers fixed costs relative to our peers, furthering our competitive advantage. We provide our services through long-term residential solar service agreements with a diversified pool of high credit quality customers. Our solar service agreements typically are structured as either a legal-form lease (a "lease") of a solar energy system or energy storage system to the customer, the sale of the solar energy system's output to the customer under a power purchase agreement ("PPA") or the purchase of a solar energy system or energy storage system with financing provided by us (a "loan"). The initial term of our solar service agreements is typically 10, 15 or 25 years, during which time we provide or arrange for ongoing services to customers, including monitoring, maintenance and warranty services. Our lease and PPA agreements typically include an opportunity for customers to renew for up to an additional 10 years, via two five-year renewal options. Customer payments and rates can be fixed for the duration of the solar service agreement or escalated at a pre-determined percentage annually. We also receive tax benefits and other incentives from leases and PPAs, a portion of which we finance through tax equity, non-recourse debt structures and hedging arrangements in order to fund our upfront costs, overhead and growth investments. Our future success depends in part on our ability to raise capital from third-party investors and commercial sources. We have an established track record of attracting capital from diverse sources. From our inception through December 31, 2020, we have raised more than $6.7 billion in total capital commitments from equity, debt and tax equity investors. Basis of Presentation The accompanying annual audited consolidated financial statements ("consolidated financial statements") include our consolidated balance sheets, statements of operations, statements of redeemable noncontrolling interests and equity and statements of cash flows and have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") from records maintained by us. Our consolidated financial statements include our accounts and those of our subsidiaries in which we have a controlling financial interest. In accordance with the provisions of the Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") 810, Consolidation , we consolidate any VIE of which we are the primary beneficiary. We form VIEs with our investors in the ordinary course of business to facilitate the funding and monetization of certain attributes associated with our solar energy systems. The typical condition for a controlling financial interest is holding a majority of the voting interests of an entity. However, a controlling financial interest may also exist in entities, such as VIEs, through arrangements that do not involve holding a majority of the voting interests. We consolidate any VIE of which we are the primary beneficiary, which is defined as the party that has (a) the power to direct the activities of a VIE that most significantly impact the VIE's economic performance and (b) the obligation to absorb losses or receive benefits from the VIE that could potentially be significant to the VIE. We do not consolidate a VIE in which we have a majority ownership interest when we are not considered the primary beneficiary. We have considered the provisions within the contractual arrangements that grant us power to manage and make decisions that affect the operation of our VIEs, including determining the solar energy systems contributed to the VIEs, and the installation, operation and maintenance of the solar energy systems. We consider the rights granted to the other investors under the contractual arrangements to be more protective in nature rather than substantive participating rights. As such, we have determined we are the primary beneficiary of our VIEs and evaluate our relationships with our VIEs on an ongoing basis to determine whether we continue to be the primary beneficiary. We have eliminated all intercompany transactions in consolidation. Adoption of ASU In June 2016, the FASB issued Accounting Standards Update ("ASU") No. 2016-13, Financial Instruments—Credit Losses , which requires entities to use a forward-looking expected loss approach, referred to as the current expected credit loss ("CECL") methodology, in accordance with ASC 326, Financial Instruments—Credit Losses , instead of the incurred loss approach previously in effect when estimating the allowance for credit losses. Under CECL, financial assets measured at amortized cost are presented at the net amount expected to be collected by using an estimate of credit losses for the remaining estimated life of the financial asset based on historical experience, current conditions and reasonable and supportable forecasts. This ASU is effective for annual and interim reporting periods in 2020. In 2018 and 2019, the FASB issued the following ASUs related to ASU 2016-13: ASU No. 2018-19, Codification Improvements to Topic 326, Financial Instruments—Credit Losses , ASU 2019-05, Financial Instruments—Credit Losses: Targeted Transition Relief and ASU 2019-11, Codification Improvements to Topic 326, Financial Instruments—Credit Losses . The supplemental ASUs must be adopted simultaneously with ASU 2016-13. We adopted this ASU in January 2020 using the modified retrospective approach for our trade accounts receivable, customer notes receivable and long-term receivable for leases, which resulted in a cumulative-effect adjustment to stockholders' equity of approximately $9.9 million. Results for reporting periods prior to 2020 continue to be presented in accordance with previously applicable GAAP while results for subsequent reporting periods are presented under ASC 326. See Note 2, Significant Accounting Policies, and Note 7, Customer Notes Receivable. The following table presents the impact of the adoption of ASU No. 2016-13 on the consolidated balance sheet: As of January 1, 2020 As Reported Impact of ASC Pre-ASC 326 (in thousands) Accounts receivable—trade, net $ 10,912 $ 240 $ 10,672 Other current assets 173,565 (451) 174,016 Customer notes receivable 289,191 (8,784) 297,975 Other assets 168,799 (913) 169,712 Accumulated deficit (371,732) (9,908) (361,824) Revisions We have revised our previously issued annual audited consolidated financial statements to correct immaterial classification errors pertaining to the Class A members' interests in certain of our tax equity funds. We incorrectly classified the Class A members' interests as redeemable noncontrolling interests whereas these interests should have been classified as noncontrolling interests. These misclassifications impacted our consolidated balance sheets and consolidated statements of redeemable noncontrolling interests and equity. The following tables present the impact of these revisions on our consolidated financial statements: As of December 31, 2019 As Previously Revisions As (in thousands) Redeemable noncontrolling interests $ 172,305 $ (45,176) $ 127,129 Noncontrolling interests — 45,176 45,176 Redeemable Noncontrolling As Previously Revisions As As Previously Revisions As (in thousands) December 31, 2018 $ 85,680 $ — $ 85,680 $ — $ — $ — Net income 10,917 (2,396) 8,521 — 2,396 2,396 Contributions from redeemable noncontrolling interests and noncontrolling interests 157,149 (79,570) 77,579 — 79,570 79,570 Distributions to redeemable noncontrolling interests (7,559) — (7,559) — — — Costs related to redeemable noncontrolling interests and noncontrolling interests (7,392) 5,054 (2,338) — (5,054) (5,054) Equity in subsidiaries attributable to parent (68,848) 31,736 (37,112) — (31,736) (31,736) Other, net 2,358 — 2,358 — — — December 31, 2019 $ 172,305 $ (45,176) $ 127,129 $ — $ 45,176 $ 45,176 Reclassifications Certain other prior period amounts have been reclassified to conform to the current period presentation. These reclassifications did not have a significant impact on our consolidated financial statements. Coronavirus ("COVID-19") Pandemic The ongoing COVID-19 pandemic has resulted and may continue to result in widespread adverse impacts on the global economy. Our first priority in our response to this pandemic has been the health and safety of our employees, customers and dealers. To that end, we quickly implemented preventative measures to minimize unnecessary risk of exposure, which we have continued to follow. We have experienced some resulting disruptions to our business operations as the COVID-19 pandemic has continued to spread through the states and U.S. territories in which we operate. To adjust to federal social distancing guidelines, stay-at-home orders and similar government measures, our dealers expanded the use of digital tools and origination channels and created new methods that offset restrictions on their ability to meet with potential new customers in person. The service and installation of solar energy systems has continued during the COVID-19 pandemic. This reflects residential solar services' designation as an essential service in all of our service territories. In order to adhere to all applicable state and federal health and safety guidelines, we and our dealers have moved to a contact-free process for installers and service technicians. In addition, an increasing number of jurisdictional authorities, as well as local utilities, are accepting electronic submissions for permits, and inspections are being performed in many locations through video calls and other electronic means. Throughout the COVID-19 pandemic, we have seen minimal impact to our supply chain as our technicians and dealers have largely been able to successfully procure the equipment needed to service and install solar energy systems. We cannot predict the full impact the COVID-19 pandemic or the significant disruption and volatility currently being experienced in the capital markets will have on our business, cash flows, liquidity, financial condition and results of operations at this time due to numerous uncertainties. The ultimate impact will depend on future developments, including, among other things, the ultimate duration of the COVID-19 virus, the distribution, acceptance and efficacy of the vaccine, the depth and duration of the economic downturn and other economic effects of the COVID-19 pandemic, the consequences of governmental and other measures designed to prevent the spread of the COVID-19 virus, actions taken by governmental authorities, customers, suppliers, dealers and other third parties, our ability and the ability of our customers, potential customers and dealers to adapt to operating in a changed environment and the timing and extent to which normal economic and operating conditions resume.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Use of Estimates The application of GAAP in the preparation of the consolidated financial statements requires us to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. We base our estimates on historical experience and on various other assumptions believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results could differ materially from those estimates. Cash We maintain cash, which consists principally of demand deposits, with investment-grade financial institutions. We are exposed to credit risk to the extent cash balances exceed amounts covered by the Federal Deposit Insurance Corporation ("FDIC"). As of December 31, 2020 and 2019, we had cash deposits of $199.6 million and $72.4 million, respectively, in excess of the FDIC's current insured limit of $250,000. We have not experienced any losses on our deposits of cash. Restricted Cash We record cash that is restricted as to withdrawal or use under the terms of certain contractual agreements as restricted cash. Our restricted cash primarily represents cash held to service certain payments under the Helios Issuer, LLC ("HELI"), Sunnova LAP Holdings, LLC ("LAPH"), Sunnova EZ-Own Portfolio, LLC ("EZOP"), Sunnova TEP IV-A, LLC ("TEPIVA"), Sunnova TEP IV-B, LLC ("TEPIVB"), Sunnova TEP Holdings, LLC ("TEPH"), Sunnova TEP II Holdings, LLC ("TEPIIH"), Helios II Issuer, LLC ("HELII"), Helios III Issuer, LLC ("HELIII"), Sunnova RAYS I Issuer, LLC ("RAYSI"), Sunnova TEP Inventory, LLC ("TEPINV"), Sunnova Sol Issuer, LLC ("SOLI"), Sunnova TEP IV-C, LLC ("TEPIVC"), Sunnova TEP IV-D, LLC ("TEPIVD"), Sunnova Helios IV Issuer, LLC ("HELIV"), Sunnova TEP IV-E, LLC ("TEPIVE"), Sunnova TEP IV-G, LLC ("TEPIVG"), Sunnova Asset Portfolio 8, LLC ("AP8") and Sunnova Sol II Issuer, LLC ("SOLII") financing arrangements (see Note 8, Long-Term Debt and Note 12, Redeemable Noncontrolling Interests and Noncontrolling Interests) and balances collateralizing outstanding letters of credit related to one of our operating leases for office space (see Note 16, Commitments and Contingencies). The following table presents the detail of restricted cash as recorded in other current assets and other assets in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Debt and inverter reserves $ 93,889 $ 55,407 Tax equity reserves 72,426 9,904 Letters of credit for office lease 375 725 Other 1,344 770 Total (1) $ 168,034 $ 66,806 (1) Of this amount, $73.0 million and $10.5 million is recorded in other current assets as of December 31, 2020 and 2019, respectively. We are exposed to credit risk to the extent restricted cash balances exceed amounts covered by the FDIC. As of December 31, 2020 and 2019, we had restricted cash deposits of $163.8 million and $63.6 million, respectively, in excess of the FDIC's current insured limit of $250,000. We have not experienced any losses on our deposits of restricted cash. Accounts Receivable Accounts Receivable — Trade. Accounts receivable — trade primarily represents trade receivables from residential customers that are generally collected in the subsequent month. Accounts receivable — trade is recorded net of an allowance for credit losses, which is based on our assessment of the collectability of customer accounts based on the best available data at the time. We review the allowance by considering factors such as historical experience, customer credit rating, contractual term, aging category and current economic conditions that may affect a customer's ability to pay to identify customers with potential disputes or collection issues. We write off accounts receivable when we deem them uncollectible. As of December 31, 2020, we have not experienced a significant increase in delinquent customer accounts and have not made any significant adjustments to our allowance for credit losses related to accounts receivable — trade as a result of the COVID-19 pandemic. The following table presents the changes in the allowance for credit losses recorded against accounts receivable — trade, net in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Balance at beginning of period $ 960 $ 723 Impact of ASC 326 adoption (240) — Provision for current expected credit losses 1,878 — Bad debt expense — 1,645 Write off of uncollectible accounts (1,741) (1,498) Recoveries 55 90 Balance at end of period $ 912 $ 960 Accounts Receivable — Other. Accounts receivable — other primarily represents receivables related to the sale of inventory. Inventory Inventory is stated at the lower of cost and net realizable value using the first-in, first-out method. Inventory primarily represents raw materials, such as energy storage systems, photovoltaic modules, inverters, meters and other associated equipment purchased. These materials are typically sold to dealers or held for use as original parts on new solar energy systems or replacement parts on existing solar energy systems. We remove these items from inventory and record the transaction in typically one of these manners: (a) expense to operations and maintenance expense when installed as a replacement part for a solar energy system, (b) expense to cost of sales if sold directly or (c) capitalize to property and equipment when installed as an original part on a solar energy system. We periodically evaluate our inventory for unusable and obsolete items based on assumptions about future demand and market conditions. Based on this evaluation, provisions are made to write inventory down to market value. The following table presents the detail of inventory as recorded in other current assets in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Energy storage systems and components $ 18,122 $ 33,443 Modules and inverters 83,904 10,137 Meters 563 169 Total $ 102,589 $ 43,749 As of December 31, 2020 and 2019, we recorded accrued expenses of $8.9 million and $15.2 million, respectively, for inventory purchases. Concentrations of Risk Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash, restricted cash, accounts receivable and notes receivable. The concentrated risk associated with cash and restricted cash is mitigated by our policy of banking with creditworthy institutions. Typically, amounts on deposit with certain banking institutions exceed FDIC insurance limits. We do not generally require collateral or other security to support accounts receivable. To reduce credit risk related to our relationship with our dealers, management performs periodic credit evaluations and ongoing assessments of our dealers' financial condition. Concentration of Services and Equipment from Dealers We utilize a network of approximately 150 dealers as of December 31, 2020. During the year ended December 31, 2020, two dealers accounted for approximately 34% and 13%, respectively, of our total expenditures to dealers relating to costs incurred for solar energy systems. During the year ended December 31, 2019, two dealers accounted for approximately 49% and 10%, respectively, of our total expenditures to dealers. During the year ended December 31, 2018, one dealer accounted for approximately 58% of our total expenditures to dealers. No other dealer accounted for more than 10% of our expenditures for solar energy systems during the years ended December 31, 2020, 2019 and 2018. Dealer Commitments We enter into exclusivity and other similar agreements with certain key dealers pursuant to which we agree to pay an incentive if such dealers install a certain minimum number of solar energy systems within specified periods. These incentives are recorded in other assets in the consolidated balance sheets and are amortized to general and administrative expense in the consolidated statements of operations generally over the term of the customer agreements, which is estimated at an average of 23 years. See Note 16, Commitments and Contingencies. Fair Value of Financial Instruments Fair value is an exit price representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions market participants would use in pricing an asset or a liability. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. ASC 820 establishes a three-tier fair value hierarchy, which prioritizes inputs that may be used to measure fair value as follows: • Level 1—Observable inputs that reflect unadjusted quoted market prices in active markets for identical assets or liabilities that are accessible at the measurement date. • Level 2—Observable inputs other than Level 1 prices, such as quoted market prices for similar assets or liabilities in active markets, quoted market prices in markets that are not active or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the level in the fair value hierarchy must be determined based on the lowest level input that is significant to the fair value measurement. An assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and consideration of factors specific to the asset or liability. Our financial instruments include accounts receivable, notes receivable, accounts payable, accrued expenses, long-term debt and interest rate swaps. The carrying values of accounts receivable, accounts payable and accrued expenses approximate the fair values due to the fact that they are short-term in nature (Level 1). We estimate the fair value of our customer notes receivable based on interest rates currently offered under the loan program with similar maturities and terms (Level 3). We estimate the fair value of our fixed-rate long-term debt based on interest rates currently offered for debt with similar maturities and terms (Level 3). We determine the fair values of the interest rate derivative transactions based on a discounted cash flow method using contractual terms of the transactions. The floating interest rate is based on observable rates consistent with the frequency of the interest cash flows (Level 2). See Note 7, Customer Notes Receivable, Note 8, Long-Term Debt and Note 9, Derivative Instruments. Derivative Instruments Our derivative instruments consist of interest rate swaps that are not designated as cash flow hedges or fair value hedges under accounting guidance. We use interest rate swaps to manage our net exposure to interest rate changes. We record the derivatives in other current assets, other assets, other current liabilities and other long-term liabilities, as appropriate, in the consolidated balance sheets and the changes in fair value are recorded in interest expense, net in the consolidated statements of operations. We include unrealized gains and losses on derivatives as a non-cash reconciling item in operating activities in the consolidated statements of cash flows. We include realized gains and losses on derivatives as a change in components of operating assets and liabilities in operating activities in the consolidated statements of cash flows. See Note 9, Derivative Instruments. Revenue The following table presents the detail of revenue as recorded in the consolidated statements of operations: Year Ended 2020 2019 2018 (in thousands) PPA revenue $ 65,760 $ 48,041 $ 38,950 Lease revenue 51,650 40,191 33,079 Solar renewable energy certificate revenue 35,747 38,453 30,630 Loan revenue 3,032 1,645 933 Other revenue 4,631 3,226 790 Total $ 160,820 $ 131,556 $ 104,382 We recognize revenue from contracts with customers as we satisfy our performance obligations at a transaction price reflecting an amount of consideration based upon an estimated rate of return. We express this rate of return as the solar rate per kilowatt hour ("kWh") in the customer contract. The amount of revenue we recognize does not equal customer cash payments because we satisfy performance obligations ahead of cash receipt or evenly as we provide continuous access on a stand-ready basis to the solar energy system. We reflect the differences between revenue recognition and cash payments received in accounts receivable, other assets or deferred revenue, as appropriate. Revenue allocated to remaining performance obligations represents contracted revenue we have not yet recognized and includes deferred revenue as well as amounts that will be invoiced and recognized as revenue in future periods. Contracted but not yet recognized revenue was approximately $1.6 billion as of December 31, 2020, of which we expect to recognize approximately 4% over the next 12 months. We do not expect the annual recognition to vary significantly over approximately the next 20 years as the vast majority of existing solar service agreements have at least 20 years remaining, given the average age of the fleet of solar energy systems under contract is less than three years. PPAs. Customers purchase electricity from us under PPAs. Pursuant to ASC 606, we recognize revenue based upon the amount of electricity delivered as determined by remote monitoring equipment at solar rates specified under the PPAs. All customers must pass our credit evaluation process. The PPAs generally have a term of 25 years with an opportunity for customers to renew for up to an additional 10 years, via two five-year renewal options. Leases . We are the lessor under lease agreements for solar energy systems and energy storage systems, which do not meet the definition of a lease under ASC 842 and are accounted for as contracts with customers under ASC 606. We recognize revenue on a straight-line basis over the contract term as we satisfy our obligation to provide continuous access to the solar energy system. All customers must pass our credit evaluation process. The lease agreements generally have a term of 25 years with an opportunity for customers to renew for up to an additional 10 years, via two five-year renewal options. We provide customers under our lease agreements a performance guarantee that each solar energy system will achieve a certain specified minimum solar energy production output, which is a significant proportion of its expected output. The specified minimum solar energy production output may not be achieved due to natural fluctuations in the weather or equipment failures from exposure and wear and tear outside of our control, among other factors. We determine the amount of the guaranteed output based on a number of different factors, including: (a) the specific site information relating to the tilt of the panels, azimuth (a horizontal angle measured clockwise in degrees from a reference direction) of the panels, size of the system, and shading on site; (b) the calculated amount of available irradiance (amount of energy for a given flat surface facing a specific direction) based on historical average weather data and (c) the calculated amount of energy output of the solar energy system. While actual irradiance levels can significantly change year over year due to natural fluctuations in the weather, we expect the levels to average out over the term of a 25-year lease and to approximate the levels used in determining the amount of the performance guarantee. Generally, weather fluctuations are the most likely reason a solar energy system may not achieve a certain specified minimum solar energy production output. If the solar energy system does not produce the guaranteed production amount, we are required to refund a portion of the previously remitted customer payments, where the repayment is calculated as the product of (a) the shortfall production amount and (b) the dollar amount (guaranteed rate) per kWh that is fixed throughout the term of the contract. These remittances of a customer's payments, if needed, are payable in January following the end of the first three years of the solar energy system's placed in service date and then every annual period thereafter. See Note 16, Commitments and Contingencies. Solar Renewable Energy Certificates. Each solar renewable energy certificate ("SREC") represents one megawatt hour (1,000 kWh) generated by a solar energy system. SRECs can be sold with or without the actual electricity associated with the renewable-based generation source. We account for the SRECs we generate from our solar energy systems as governmental incentives with no costs incurred to obtain them and do not consider those SRECs output of the underlying solar energy systems. We classify these SRECs as inventory held until sold and delivered to third parties. As we did not incur costs to obtain these governmental incentives, the inventory carrying value for the SRECs was $0 as of December 31, 2020 and 2019. We enter into economic hedges related to expected production of SRECs through forward contracts. The contracts require us to physically deliver the SRECs upon settlement. We recognize the related revenue under ASC 606 upon satisfaction of the performance obligation to transfer the SRECs to the stated counterparty. Payments are typically received within one month of transferring the SREC to the counterparty. The costs related to the sales of SRECs are generally limited to broker fees (recorded in cost of revenue—other), which are only paid in connection with certain transactions. In certain circumstances we are required to purchase SRECs on the open market to fulfill minimum delivery requirements under our forward contracts. Loans. See discussion of loan revenue in the " Loans " section below. Other Revenue. Other revenue includes certain state and utility incentives, revenue from the direct sale of energy storage systems to customers and sales of service plans. We recognize revenue from state and utility incentives in the periods in which they are earned. We recognize revenue from the direct sale of energy storage systems in the period in which the storage components are placed in service. Service plans are available to customers whose solar energy system was not originally sold by Sunnova. We recognize revenue from service plan contracts over the life of the contract, which is typically five years or ten years. Loans We offer a loan program, under which the customer finances the purchase of a solar energy system or energy storage system through a solar service agreement, typically for a term of 10, 15 or 25 years. We recognize cash payments received from customers on a monthly basis under our loan program (a) as interest income, to the extent attributable to earned interest on the contract that financed the customer's purchase of the solar energy system or energy storage system; (b) as a reduction of a note receivable on the balance sheet, to the extent attributable to a return of principal (whether scheduled or prepaid) on the contract that financed the customer's purchase of the solar energy system or energy storage system; and (c) as revenue, to the extent attributable to payments for operations and maintenance services provided by us. To qualify for the loan program, a customer must pass our credit evaluation process, which requires the customer to have a minimum FICO ® score of 650 to 720 depending on certain circumstances, and we secure the loans with the solar energy systems or energy storage systems financed. The credit evaluation process is performed once for each customer at the time the customer is entering into the solar service agreement with us. Our investments in solar energy systems and energy storage systems related to the loan program that are not yet placed in service are recorded in other assets in the consolidated balance sheets and are transferred to customer notes receivable upon being placed in service. Customer notes receivable are recorded at amortized cost, net of an allowance for credit losses (as described below), in other current assets and customer notes receivable in the consolidated balance sheets. Accrued interest receivable related to our customer notes receivable is recorded in accounts receivable—trade, net in the consolidated balance sheets. Interest income from customer notes receivable is recorded in interest income in the consolidated statements of operations. The amortized cost of our customer notes receivable is equal to the principal balance of customer notes receivable outstanding and does not include accrued interest receivable. Customer notes receivable continue to accrue interest until they are written off against the allowance, which occurs when the balance is 180 days or more past due unless the balance is in the process of collection. Customer notes receivable are considered past due one day after the due date based on the contractual terms of the loan agreement. In all cases, customer notes receivable balances are placed on a nonaccrual status or written off at an earlier date when they are deemed uncollectible. Expected recoveries do not exceed the aggregate of amounts previously written off and expected to be written off. Accrued interest receivable for customer notes receivable placed on a nonaccrual status is recorded as a reduction to interest income. Interest received on such customer notes receivable is accounted for on a cash basis until the customer notes receivable qualifies for the return to accrual status. Customer notes receivable are returned to accrual status when there is no longer any principal or interest amounts past due and future payments are reasonably assured. The allowance for credit losses is deducted from the customer notes receivable amortized cost to present the net amount expected to be collected. It is measured on a collective (pool) basis when similar risk characteristics (such as financial asset type, customer credit rating, contractual term and vintage) exist. In determining the allowance for credit losses, we identify customers with potential disputes or collection issues and consider our historical level of credit losses and current economic trends that might impact the level of future credit losses. Adjustments to historical loss information are made for differences in current loan-specific risk characteristics, such as differences in underwriting standards. Expected credit losses are estimated over the contractual term of the loan agreements based on the best available data at the time, and adjusted for expected prepayments when appropriate. The contractual term excludes expected extensions, renewals and modifications unless either of the following applies: (a) we have a reasonable expectation at the reporting date that a troubled debt restructuring will be executed with an individual customer or (b) the extension or renewal options are included in the original or modified contract at the reporting date and are not unconditionally cancelable by us. As of December 31, 2020, we have not experienced a significant increase in delinquent customer notes receivable and have not made any significant adjustments to our allowance for credit losses related to loans as a result of the COVID-19 pandemic. See Note 7, Customer Notes Receivable. Deferred Revenue Deferred revenue consists of amounts for which the criteria for revenue recognition have not yet been met and includes (a) down payments and partial or full prepayments from customers, (b) differences due to the timing of energy production versus billing for certain types of PPAs and (c) payments for unfulfilled performance obligations from the loan program which will be recognized on a straight-line basis over the remaining term of the respective solar service agreements. Deferred revenue was $34.0 million as of December 31, 2018. The following table presents the detail of deferred revenue as recorded in other current liabilities and other long-term liabilities in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Loans $ 93,859 $ 46,958 PPAs and leases 11,787 8,895 SRECs 1,163 3,000 Total (1) $ 106,809 $ 58,853 (1) Of this amount, $3.8 million and $2.1 million is recorded in other current liabilities as of December 31, 2020 and 2019, respectively. During the years ended December 31, 2020 and 2019, we recognized revenue of $7.3 million and $3.0 million, respectively, from amounts recorded in deferred revenue at the beginning of the respective years. Performance Guarantee Obligations We guarantee certain specified minimum solar energy production output under our leases and loan agreements, generally over a term of 10, 15 or 25 years. The amounts are generally measured and credited to the customer's account in January following the end of the first three years of the solar energy system's placed in service date and then every annual period thereafter. We monitor the solar energy systems to ensure these outputs are achieved. We evaluate if any amounts are due to our customers based upon not meeting the guaranteed solar energy production outputs at each reporting period end. For leases, these estimated amounts are recorded as a reduction to revenues from customers and a current or long-term liability, as applicable. For loans, these estimated amounts are recorded as an increase to cost of revenue—other and a current or long-term liability, as applicable. See Note 16, Commitments and Contingencies. Property and Equipment Solar Energy Systems. Depreciation and amortization of solar energy systems are calculated using the straight-line method over the estimated useful lives of the solar energy systems and are recorded in cost of revenue—depreciation. While solar energy systems are in the design, construction and installation stages prior to being placed in service, the development of the systems is accounted for through construction in progress. The components of the design, construction and installation of the solar energy systems, which are installed on or near residential rooftops, are as follows: • Dealer's costs (engineering, procurement and construction) • Direct costs (costs directly related to a solar energy system) • Indirect costs (costs incurred in the design, construction and installation of the solar energy system but not directly associated with a particular asset) Solar energy systems are carried at the cost of acquisition or construction (including design and installation) less certain utility rebates and federal and state tax incentives (including federal investment tax credits, known as "Section 48(a) ITCs") and are depreciated over the useful lives of the assets. We account for the Section 48(a) ITCs in accordance with the deferral gross up method, thus reducing the cost basis of the qualifying solar energy systems by the rate applicable to Section 48(a) ITCs. However, as discussed in Note 10, Income Taxes, we have a full valuation allowance, which is recorded against deferred income taxes and requires the gross up of the basis of the qualifying solar energy systems back to the full value. Depreciation begins when a solar energy system is placed in service. Costs associated with repair and maintenance of a solar energy system are expensed as incurred. Costs associated with improvements to a solar energy system, which extend the life, increase the capacity or improve the efficiency of the systems, are capitalized and depreciated over the remaining life of the asset. Property and Equipment, Excluding Solar Energy Systems . Property and equipment, including information technology system projects, computers and equipment, leasehold improvements, furniture and fixtures, vehicles and other property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization are calculated using the straight-line method over the estimated useful lives of the respective assets and are recorded in general and administrative expense. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful lives. Upon disposition, the cost and related accumulated depreciation of the assets are removed from property and equipment and the resulting gain or loss is reflected in the consolidated statements of operations. Repair and maintenance costs are expensed as incurred. Intangibles Our intangible assets primarily consist of a software license and a trademark related to the design process of solar energy systems and are stated at cost less accumulated amortization. We amortize intangible assets to general and administrative expense over a useful life of three years using the straight-line method. The following table presents the detail of intangible assets as recorded in other assets in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Software license $ 331 $ 331 Trademark 68 68 Other 88 88 Intangibles, gross 487 487 Less: accumulated amortization (449) (420) Intangibles, net $ 38 $ 67 As of December 31, 2020, amortization expense related to intangible assets to be recognized is $29,000 for 2021, $9,000 for 2022 and $0 thereafter. Deferred Financing Costs Deferred financing costs are capitalized and amortized to interest expense, net over the term of the related debt using the effective interest method for term loans or the straight-line method for revolving credit facilities. The unamortized balance of deferred financing costs is recorded in current portion of long-term debt, current portion of long-term debt—affiliates, long-term debt, net and long-term debt, net—affiliates (see Note 8, Long-Term Debt) for term loans or in other current assets and other assets for revolving credit facilities and debt and equity transactions not yet completed, in the consolidated balance sheets. The following table presents the changes in net deferred financing costs: As of December 31, 2020 2019 (in thousands) Balance at beginning of period $ 25,621 $ 22,712 Capitalized 23,202 12,731 Amortized (9,031) (9,822) Balance at end of period $ 39,792 $ 25,621 Asset Retirement Obligation ("ARO") We have AROs arising from contractual requirements to perform certain asset retirement activities at the time the solar energy systems are disposed. We recognize an ARO at the point an obligating event takes place, typically when the solar energy system is placed in service. An asset is considered retired when it is permanently taken out of service, such as through a sale or disposal. The liability is initially measured at fair value (as a Level 3 measurement) based on the present value of estimated removal and restoration costs and subsequently adjusted for changes in the underlying assumptions and for accretion expense. The accretion expense is recognized in general and administrative expense in the consolidated statements of operations. The corresponding asset retirement costs are capitalized as part of the carrying amount of the solar energy system and depreciated (for which the expense is recorded in cost of revenue — depreciation) over the solar energy system's remaining useful life. See Note 6, AROs. Warranty Obligations In connection with our solar service agreements, we warrant the solar energy systems against defects in workmanship, against component or materials breakdowns and against any damages to rooftops during the installation process. The dealers' warranties on the workmanship, including work during the installation process, and the manufacturers' warranties over component parts have a range of warranty periods which are generally 10 to 25 years. As of December 31, 2020 and 2019, we recorded a warranty reserve of $0 and an insignificant amount, respectively. Advertising Costs We expense advertising costs as they are incurred to general and administrative expense in the consolidated statements of operations. We recognized advertising expense of $195,000, $1.0 million and $191,000 during the years ended December 31, 2020, 2019 and 2018, respectively. Defined Contribution Plan In April 2015, we established the Sunnova Energy Corporation 401(k) Profit Sharing Plan ("401(k) plan") available to employees who meet the 401(k) plan's eligibility requirements. The 401(k) plan allows participants to contribute a pe

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment The following table presents the detail of property and equipment, net as recorded in the consolidated balance sheets: As of December 31, Useful Lives 2020 2019 (in years) (in thousands) Solar energy systems 35 $ 2,298,427 $ 1,689,457 Construction in progress 160,618 143,449 Asset retirement obligations 30 35,532 26,967 Information technology systems 3 35,077 28,320 Computers and equipment 3-5 1,727 1,499 Leasehold improvements 3-6 2,770 1,014 Furniture and fixtures 7 811 735 Vehicles 4-5 1,638 1,632 Other 5-6 157 146 Property and equipment, gross 2,536,757 1,893,219 Less: accumulated depreciation (213,588) (148,159) Property and equipment, net $ 2,323,169 $ 1,745,060 Solar Energy Systems. The amounts included in the above table for solar energy systems and substantially all the construction in progress relate to our customer contracts (including PPAs and leases). These assets had accumulated depreciation of $188.8 million and $130.9 million as of December 31, 2020 and 2019, respectively.

Natural Disaster Losses

Natural Disaster Losses	12 Months Ended
	Dec. 31, 2020
Unusual or Infrequent Items, or Both [Abstract]
Natural Disaster Losses	Natural Disaster Losses We have insurance coverage related to property damage and business interruption. When a solar energy system is damaged by a natural disaster, we impair all or a portion of the net book value to operations and maintenance expense in the period for which the amount is probable and can be reasonably estimated. Insurance proceeds for property damage, up to the amount of impairment expense recorded for property damage, are estimated and recorded as a receivable (recorded in accounts receivable—other in the consolidated balance sheet) and a reduction to operations and maintenance expense when the receipt of the proceeds is deemed probable. Insurance proceeds for property damage that exceed the amount of impairment expense recorded and insurance proceeds related to business interruption are recorded when received, as a reduction to operations and maintenance expense. Costs incurred to repair or replace a solar energy system are capitalized (recorded in property and equipment, net in the consolidated balance sheet) and are classified as an investing cash outflow in the consolidated statement of cash flows. Insurance proceeds received for property damage are classified as an investing cash inflow in the consolidated statement of cash flows. Insurance proceeds received for business interruption are classified as an operating cash inflow in the consolidated statement of cash flows. Hurricane Maria in Puerto Rico . In September 2017, Hurricane Maria made landfall in Puerto Rico causing catastrophic wind and water damage to the island's infrastructure, residences and businesses. A majority of Puerto Rico was left without electrical power. In addition, other basic utility and infrastructure services (such as water, communications, ports and other transportation networks) were severely curtailed and the government imposed a mandatory curfew. Prior to the hurricane, we implemented certain business continuity measures. Although our critical business systems experienced minimal outages from the hurricane, our physical operations in Puerto Rico were significantly disrupted primarily due to the lack of electricity and communications and limited accessibility. Throughout 2017 and 2018, we completed assessments of solar energy systems in Puerto Rico and submitted requests to the insurance company for recoveries for damage to solar energy systems and business interruption. However, we did not complete all reasonable estimates until December 2018 due to the overall impact of the hurricane on Puerto Rico. Although our solar energy systems are distributed energy sources, most are dependent upon complementary grid power to operate and all are dependent upon cellular communication services for operations and monitoring and evaluation. The outage was the largest and longest in U.S. history. As such, many repairs and estimates of damages and lost customers lagged the restoration of these services. Given the loss of grid power and cellular communication and the fact that much of Puerto Rico was not navigable, assessment of our solar energy systems and status of our customers continued through the fourth quarter of 2018. The final settlement with the insurance company for property damage was completed and those funds were received in the fourth quarter of 2018. As of December 31, 2018, we received $9.8 million of insurance proceeds, of which $5.8 million represented recoveries for damage to solar energy systems and $4.0 million represented recoveries for business interruption. During 2017 and 2018, we reassessed the collectability of the receivables related to the solar energy systems in Puerto Rico and determined there were no significant write-offs or allowances needed. Wildfires in California . In October 2017 and November 2018, major wildfires burned throughout California and damaged several customers' homes and solar energy systems. These wildfires did not have a significant impact on our results of operations or financial position. The related impairments and insurance recoveries are included in the table below. Typhoon Yutu in Saipan . In October 2018, typhoon Yutu impacted Saipan causing massive wind and water damage to the island's infrastructure, residences and businesses. Several customer homes and solar energy systems were damaged; however, typhoon Yutu did not have a significant impact on our results of operations or financial position. The related impairments and insurance recoveries are included in the table below. As of December 31, 2019, substantially all solar energy systems damaged by a natural disaster that were deemed economical to repair had been repaired. The impact of the natural disaster losses as recorded in the consolidated statements of operations for the years ended December 31, 2020, 2019 and 2018 is as follows: Year Ended 2020 2019 2018 (in thousands) Operations and maintenance expense: Impairment of solar energy systems due to natural disaster losses $ — $ — $ 5,840 Insurance proceeds received/expected to be received—property damage 31 54 (53) Insurance proceeds received—business interruption — — (2,693) Other natural disaster-related charges — — 1,679 General and administrative expense: Other natural disaster-related charges — — 750 Total $ 31 $ 54 $ 5,523

Detail of Certain Balance Sheet

Detail of Certain Balance Sheet Captions	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Detail of Certain Balance Sheet Captions	Detail of Certain Balance Sheet Captions The following table presents the detail of other current assets as recorded in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Inventory $ 102,589 $ 43,749 Restricted cash 73,020 10,474 Current portion of customer notes receivable 24,035 13,758 Other prepaid assets 8,645 7,380 Prepaid inventory 3,352 96,167 Deferred receivables 2,678 1,506 Current portion of other notes receivable 853 982 Other 3 — Total $ 215,175 $ 174,016 The following table presents the detail of other assets as recorded in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Restricted cash $ 95,014 $ 56,332 Construction in progress - customer notes receivable 85,604 37,137 Exclusivity and other bonus arrangements with dealers, net 55,709 32,791 Straight-line revenue adjustment, net 33,411 24,852 Other 24,634 18,600 Total $ 294,372 $ 169,712 The following table presents the detail of other current liabilities as recorded in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Interest payable $ 17,718 $ 14,680 Deferred revenue 3,754 2,086 Current portion of performance guarantee obligations 3,308 4,067 Current portion of lease liability 1,206 561 Other 27 410 Total $ 26,013 $ 21,804

AROs

AROs	12 Months Ended
	Dec. 31, 2020
Asset Retirement Obligation Disclosure [Abstract]
AROs	AROsAROs consist primarily of costs to remove solar energy system assets and costs to restore the solar energy system sites to the original condition, which we estimate based on current market rates. For each solar energy system, we recognize the fair value of the ARO as a liability and capitalize that cost as part of the cost basis of the related solar energy system. The related assets are depreciated on a straight-line basis over 30 years, which is the estimated average time a solar energy system will be installed in a location before being removed, and the related liabilities are accreted to the full value over the same period of time. We revise our estimated future liabilities based on recent actual experiences, including third party cost estimates, average size of solar energy systems and inflation rates, which we evaluate at least annually. Changes in our estimated future liabilities are recorded as either a reduction or addition in the carrying amount of the remaining unamortized asset and the ARO and either decrease or increase our depreciation and accretion expense amounts prospectively. The following table presents the changes in AROs as recorded in other long-term liabilities in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Balance at beginning of period $ 31,053 $ 20,033 Additional obligations incurred 8,633 4,641 Accretion expense 2,186 1,443 Change in estimate — 4,983 Other (84) (47) Balance at end of period $ 41,788 $ 31,053

Customer Notes Receivable

Customer Notes Receivable	12 Months Ended
	Dec. 31, 2020
Receivables [Abstract]
Customer Notes Receivable	Customer Notes Receivable We offer a loan program, under which the customer finances the purchase of a solar energy system or energy storage system through a solar service agreement for a term of 10, 15 or 25 years. The following table presents the detail of customer notes receivable as recorded in the consolidated balance sheets and the corresponding fair values: As of December 31, 2020 2019 (in thousands) Customer notes receivable $ 555,089 $ 312,823 Allowance for credit losses (17,668) (1,091) Customer notes receivable, net (1) $ 537,421 $ 311,732 Estimated fair value, net $ 548,238 $ 314,222 (1) Of this amount, $24.0 million and $13.8 million is recorded in other current assets as of December 31, 2020 and 2019, respectively. The following table presents the changes in the allowance for credit losses related to customer notes receivable as recorded in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Balance at beginning of period $ 1,091 $ 710 Impact of ASC 326 adoption 9,235 — Provision for current expected credit losses (1) 7,785 — Bad debt expense — 419 Write off of uncollectible accounts (443) (38) Balance at end of period $ 17,668 $ 1,091 (1) In addition, we recognized $184,000 of provision for current expected credit losses during the year ended December 31, 2020 related to our long-term receivables for our leases. As of December 31, 2020 and 2019, we invested $85.6 million and $37.1 million, respectively, in loan solar energy systems and energy storage systems not yet placed in service. For the years ended December 31, 2020 and 2019, interest income related to our customer notes receivable was $23.2 million and $11.6 million, respectively. As of December 31, 2020 and 2019, accrued interest receivable related to our customer notes receivable was $1.2 million and $869,000, respectively. As of December 31, 2020 and 2019, there were no customer notes receivable not accruing interest and thus, there was no allowance recorded for loans on nonaccrual status. For the years ended December 31, 2020 and 2019, interest income of $0 was recognized for loans on nonaccrual status and accrued interest receivable of $0 was written off by reversing interest income. We consider the performance of our customer notes receivable portfolio and its impact on our allowance for credit losses. We also evaluate the credit quality based on the aging status and payment activity. The following table presents the aging of the amortized cost of customer notes receivable as of December 31, 2020: As of December 31, 2020 2019 (in thousands) 1-90 days past due $ 8,504 $ 5,741 91-180 days past due 1,733 1,714 Greater than 180 days past due 6,855 3,331 Total past due 17,092 10,786 Not past due 537,997 302,037 Total $ 555,089 $ 312,823 As of December 31, 2020 and 2019, the amortized cost of our customer notes receivable more than 90 days past due but not on nonaccrual status was $8.6 million and $5.0 million, respectively. The following table presents the amortized cost by origination year of our customer notes receivable based on payment activity. Amortized Cost by Origination Year 2020 2019 2018 2017 2016 Prior Total (in thousands) Payment performance: Performing $ 266,756 $ 134,152 $ 86,815 $ 31,042 $ 19,522 $ 9,947 $ 548,234 Nonperforming (1) 280 1,275 1,910 1,972 1,215 203 $ 6,855 Total $ 267,036 $ 135,427 $ 88,725 $ 33,014 $ 20,737 $ 10,150 $ 555,089 (1) A nonperforming loan is a loan in which the customer is in default and has not made any scheduled principal or interest payments for 181 days or more.

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Our subsidiaries with long-term debt include SEI, Sunnova Energy Corporation, Sunnova Asset Portfolio 4, LLC ("AP4"), HELI, LAPH, EZOP, TEPIIH, HELII, RAYSI, HELIII, TEPH, TEPINV, SOLI, HELIV, AP8 and SOLII. The following table presents the detail of long-term debt, net as recorded in the consolidated balance sheets: Year Ended As of December 31, 2020 Year Ended As of December 31, 2019 Long-term Current Long-term Current (in thousands, except interest rates) SEI 7.75% convertible senior notes 17.41 % $ — $ — 7.75 % $ 55,000 $ — 9.75% convertible senior notes 14.53 % 95,648 — — — Debt discount, net (37,394) — (16,913) — Deferred financing costs, net (239) — (480) — Sunnova Energy Corporation Notes payable 7.14 % — 2,254 3.22 % — 2,428 AP4 Secured term loan 10.81 % — — 5.61 % 86,369 6,109 Debt discount, net — — (452) — Deferred financing costs, net — — (196) — HELI Solar asset-backed notes 6.55 % 205,395 6,329 6.56 % 213,632 8,673 Debt discount, net (2,241) — (3,169) — Deferred financing costs, net (4,004) — (5,586) — LAPH Secured term loan 11.34 % — — 7.71 % 41,484 1,392 Debt discount, net — — (401) — Deferred financing costs, net — — (356) — EZOP Warehouse credit facility 4.39 % 171,600 — 6.60 % 121,400 — Debt discount, net (1,431) — (2,178) — TEPIIH Revolving credit facility 19.47 % — — 6.36 % 234,650 — Debt discount, net — — (2,219) — HELII Solar asset-backed notes 5.71 % 227,574 11,707 5.77 % 241,309 13,005 Debt discount, net (42) — (49) — Deferred financing costs, net (5,085) — (5,873) — RAYSI Solar asset-backed notes 5.49 % 120,391 5,836 5.47 % 126,828 6,327 Debt discount, net (1,376) — (1,547) — Deferred financing costs, net (4,334) — (4,759) — HELIII Solar loan-backed notes 4.01 % 122,047 13,065 4.03 % 135,543 19,030 Debt discount, net (2,423) — (2,532) — Deferred financing costs, net (2,326) — (2,410) — TEPH Revolving credit facility 5.81 % 239,570 — 6.70 % 90,325 — Debt discount, net (3,815) — (645) — TEPINV Revolving credit facility 10.80 % 25,240 29,464 7.95 % 54,707 40,500 Debt discount, net (1,322) — (2,856) — Deferred financing costs, net (1,758) — (2,207) — SOLI Solar asset-backed notes 3.91 % 384,258 15,416 — — Debt discount, net (113) — — — Deferred financing costs, net (8,915) — — — HELIV Solar loan-backed notes 3.97 % 129,648 16,515 — — Debt discount, net (885) — — — Deferred financing costs, net (3,905) — — — AP8 Revolving credit facility 5.31 % 42,047 4,386 — — SOLII Solar asset-backed notes 3.18 % 248,789 5,911 — — Debt discount, net (80) — — — Deferred financing costs, net (5,866) — — — Total $ 1,924,653 $ 110,883 $ 1,346,419 $ 97,464 Availability. As of December 31, 2020, we had $402.4 million of available borrowing capacity under our various financing arrangements, consisting of $28.4 million under the EZOP warehouse credit facility, $360.4 million under the TEPH revolving credit facility and $13.6 million under the AP8 revolving credit facility. There was no available borrowing capacity under any of our other financing arrangements. As of December 31, 2020, we were in compliance with all debt covenants under our financing arrangements. Weighted Average Effective Interest Rates. The weighted average effective interest rates disclosed in the table above are the weighted average stated interest rates for each debt instrument plus the effect on interest expense for other items classified as interest expense, such as the amortization of deferred financing costs, amortization of debt discounts and commitment fees on unused balances for the period of time the debt was outstanding during the indicated periods. SEI Debt . In December 2019, we issued and sold an aggregate principal amount of $55.0 million of our 7.75% convertible senior notes ("7.75% convertible senior notes") in a private placement at an issue price of 95%, for an aggregate purchase price of $52.3 million. In May 2020, we issued and sold an aggregate principal amount of $130.0 million of our 9.75% convertible senior notes ("9.75% convertible senior notes") in a private placement at an issue price of 95%, for an aggregate purchase price of $123.5 million. The 9.75% convertible senior notes mature in April 2025 unless earlier redeemed, repurchased or converted. We granted the investors of the 9.75% convertible senior notes an option to purchase up to an additional $60.0 million aggregate principal amount of 9.75% convertible senior notes on the same terms and conditions, and the investors exercised this option and completed the purchase of such additional 9.75% convertible senior notes in June 2020. In May 2020, we also exchanged all $55.0 million aggregate principal amount outstanding of our 7.75% convertible senior notes for an equal principal amount of our 9.75% convertible senior notes. During the year ended December 31, 2020, certain holders of our 9.75% convertible senior notes converted approximately $150.8 million aggregate principal amount, including accrued and unpaid interest to the date of each conversion, of our 9.75% convertible senior notes into common stock. See Note 13, Stockholders' Equity. The investors in our 9.75% convertible senior notes may, at their option, convert all or any portion of their 9.75% convertible senior notes. Upon conversion, we may satisfy our conversion obligation by paying and/or delivering, as the case may be, cash, shares of common stock, or a combination of cash and shares of common stock, at our option, subject to certain terms and conditions. The conversion rate for the 9.75% convertible senior notes is 74.0741 shares of common stock per $1,000 principal amount of 9.75% convertible senior notes, plus accrued and unpaid interest, which is equivalent to an initial conversion price (excluding interest) of approximately $13.50 per share of common stock. The conversion rate is subject to adjustment under certain circumstances in accordance with the terms of the related indenture. On and after May 14, 2023, we have the right to cause the conversion of the 9.75% convertible senior notes if certain specified conditions are met, including minimum common stock price and minimum volume conditions. At any time prior to May 14, 2022, we may, at our option, redeem for cash up to 33.33% aggregate principal amount of the then outstanding 9.75% convertible senior notes (after giving effect to any conversions on or prior to such redemption date) at a redemption price equal to 115% of aggregate principal amount of 9.75% convertible senior notes so redeemed, plus any accrued and unpaid interest to, but excluding, the redemption date, using the net cash proceeds of one or more equity offerings by us, provided the redemption occurs within 180 days of the date of the closing of such equity offering. At any time on or after May 14, 2023, we may, at our option, redeem for cash all (but not less than all) of the 9.75% convertible senior notes at the redemption price (expressed as percentages of principal amount) set forth below, plus any accrued and unpaid interest, if any, to, but excluding, the redemption date: Period Percentage At any time on and after May 14, 2023 but prior to May 14, 2024 115% At any time on and after May 14, 2024 110% On and after September 23, 2024, the holders of the 9.75% convertible senior notes have the option to require us to repurchase their 9.75% convertible senior notes for cash at a purchase price of 110% of the aggregate principal amount repurchased, plus accrued and unpaid interest to the date of repurchase. For accounting purposes and in accordance with GAAP, the exchange of our 7.75% convertible senior notes for our 9.75% convertible senior notes was treated as a debt modification and we separated the 9.75% convertible senior notes into liability and equity components. As of December 31, 2020, the carrying amount of the liability component for the 9.75% convertible senior notes of approximately $58.0 million (net of an unamortized debt discount of $37.4 million and unamortized issuance costs of $239,000) was determined based on a discounted cash flow analysis and a binomial lattice model. The valuation required the use of Level 3 unobservable inputs and subjective assumptions, including but not limited to, the stock price volatility and bond yield. The use of alternative market assumptions and estimation methodologies could have had an effect on these estimates of fair value. As of December 31, 2020, the carrying amount of the equity component for the 9.75% convertible senior notes of approximately $8.8 million (net of unamortized issuance costs of $545,000), representing the conversion option, was determined by deducting the carrying amount of the liability components from the principal amount of the 9.75% convertible senior notes. This difference between the principal amount of the 9.75% convertible senior notes and the liability component represents the debt discount, presented as a reduction to the 9.75% convertible senior notes in the consolidated balance sheets and is amortized to interest expense, net using the effective interest method over the remaining term of the 9.75% convertible senior notes. The equity component of the 9.75% convertible senior notes is included in additional paid-in-capital—common stock in the consolidated balance sheets and is not remeasured as long as it continues to meet the conditions for equity classification. See Note 17, Subsequent Events. Sunnova Energy Corporation Notes Payable . In May 2019, we entered into an arrangement to finance $1.9 million in property insurance premiums at an annual interest rate of 5.50% over ten months. In July 2019, we entered into an arrangement to finance $4.7 million in directors and officers insurance premiums at an annual interest rate of 4.94% over eight months. In August 2020, we entered into an arrangement to finance $2.8 million in directors and officers insurance premiums at an annual interest rate of 4.25% over seven months. In October 2020, we entered into an arrangement to finance $1.4 million in property insurance premiums at an annual interest rate of 4.25% over five months. AP4 Debt . In July 2014, we entered into a collateral-based financing agreement with Texas Capital Bank, as administrative agent, and the lenders party thereto, to obtain funding for solar energy systems, working capital and general and administrative expenses of Sunnova Energy Corporation and AP4. The initial aggregate principal amount of the commitments under the AP4 financing agreement was $90.0 million, which was increased to $110.0 million in October 2015 and then reduced to $107.1 million in December 2017. Borrowings under the AP4 financing agreement were secured by the assets of AP4, which include certain solar energy systems and the related solar service agreements, accounts receivable and note receivable. The loans under the AP4 financing agreement bore interest at an annual rate of either LIBOR plus 3.00% or a base rate (defined as, for any day, a rate of interest per annum equal to the highest of (a) the prime rate for such day; (b) the sum of the federal funds rate for such day plus 0.50%; and (c) adjusted LIBOR for such day plus 1.00%) plus 2.00%. In addition, through December 2016, the AP4 debt accrued a commitment fee at a rate equal to 0.50% per year of the daily unused amount of the commitment. In December 2016, the loans converted to an amortizing term loan and began amortizing quarterly based on a modified mortgage style amortization schedule. The terms under the AP4 financing agreement contained certain covenants and restrictions, including a ratio of consolidated EBITDA (as defined in the AP4 financing agreement) to debt service (as defined in the AP4 financing agreement) that could not be less than 1.25 to 1.00 for any four-quarter period ending as of the end of any fiscal quarter. Furthermore, the borrowers were permitted to pay distributions so long as after giving effect thereto, the debt service coverage ratio was at least 1.0 to 1.0. In March 2017, the AP4 financing agreement was amended to, among other things, extend the maturity date from July 2019 to July 2020. In December 2017, the AP4 financing agreement was amended to, among other things, admit into the collateral pool and borrow against certain assets previously financed under another subsidiary's financing agreement, the proceeds of which were used to repay a substantial portion of the aggregate outstanding principal amount under the subsidiary's financing agreement. In December 2018, the AP4 financing agreement was amended to, among other things, extend the start date of required excess cash flow payments from January 2019 to June 2019 and add a minimum net worth requirement. As of March 31, 2019, AP4 was not in compliance with the debt covenant regarding the ratio of consolidated EBITDA to debt service, which is an event of default. In April 2019, AP4 exercised its right to an equity cure, which allowed Sunnova Energy Corporation to contribute approximately $106,000 to AP4 and allowed AP4 to add such amount to consolidated EBITDA for purposes of recalculating the ratio as of March 31, 2019. Subsequent to the equity cure, AP4 was in compliance with the debt covenants under the AP4 financing agreement. In June 2019, we amended the AP4 financing agreement to, among other things, (a) extend the maturity date from July 2020 to January 2021, (b) decrease the applicable margin for LIBOR loans to 2.50% and (c) change the debt covenant regarding the ratio of consolidated EBITDA to debt service to be calculated based on collections from customers and other cash receipts and disbursements (instead of consolidated EBITDA). In connection with this amendment we repaid $5.0 million of outstanding borrowings under this facility. In August 2019, AP4 conveyed its ownership interest in Sunnova Lease Vehicle 3-HI, LLC to Sunnova Energy Corporation and the security interest on the assets of Sunnova Lease Vehicle 3-HI, LLC that were previously collateral securing the borrowings under the AP4 financing agreement was released. In February 2020 , the aggregate principal amount outstanding under the AP4 financing agreement of $92.0 million was fully repaid using proceeds from the SOLI Notes (as defined below), all related interest rate swaps were unwound and the debt facility was terminated. HELI Debt . In April 2017, we pooled and transferred eligible solar energy systems and the related asset receivables into HELI, a special purpose entity, that issued $191.8 million in aggregate principal amount of Series 2017-1 Class A solar asset-backed notes, $18.0 million in aggregate principal amount of Series 2017-1 Class B solar asset-backed notes and $45.0 million in aggregate principal amount of Series 2017-1 Class C solar asset-backed notes (collectively, the "Notes") with a maturity date of September 2049. The Notes were issued at a discount of 0.05% for Class A, 9.28% for Class B and 8.65% for Class C and bear interest at an annual rate equal to 4.94%, 6.00% and 8.00%, respectively. The cash flows generated by these solar energy systems are used to service the semi-annual principal and interest payments on the Notes and satisfy HELI's expenses, and any remaining cash can be distributed to Helios Depositor, LLC, HELI's sole member. In connection with the Notes, certain of our affiliates receive a fee for managing and servicing the solar energy systems pursuant to management and servicing agreements. In addition, Sunnova Energy Corporation has guaranteed (a) the manager's obligations to manage the solar energy systems pursuant to the management agreement, (b) the servicer's obligations to service the solar energy systems pursuant to the servicing agreement and (c) Sunnova Asset Portfolio 5, LLC's obligations to repurchase or substitute certain ineligible solar energy systems eventually sold to HELI pursuant to the sale and contribution agreement. HELI is also required to maintain a liquidity reserve account and an inverter replacement reserve account for the benefit of the holders of the Notes, each of which must remain funded at all times to the levels specified in the Notes (see Note 2, Significant Accounting Policies). The indenture requires HELI to track the debt service coverage ratio (such ratio, the "DSCR") of (a) the amount of certain payments received from customers, certain performance based incentives, certain energy credits and any applicable insurance proceeds as of a specific date to (b) interest and scheduled principal due on the Notes as of such date with the potential to enter into an early amortization period if the DSCR drops below a certain threshold. The holders of the Notes have no recourse to our other assets except as expressly set forth in the Notes. LAPH Debt . In April 2017, LAPH and its wholly-owned subsidiaries Sunnova LAP I, LLC and Sunnova LAP II, LLC, entered into a term loan agreement with Credit Suisse AG, New York Branch, as administrative agent, and the lenders party thereto, for an initial aggregate committed principal amount of $260.0 million with a maturity date of December 2018, which was amended (see below). The proceeds of the loans were available to purchase or otherwise acquire solar energy systems (which we originated) directly from Sunnova Asset Portfolio 7 Holdings, LLC ("AP7H"), the sole member of LAPH, pursuant to a sale and contribution agreement, fund certain reserve accounts that are required to be maintained by the borrowers in accordance with the loan agreement and pay fees and expenses incurred in connection with the loan agreement. The amount available for borrowings at any one time under the loan agreement was limited to a borrowing base amount determined at each borrowing and calculated based on the aggregate discounted present value of remaining payments owed to LAPH and its wholly-owned subsidiaries in respect of the solar energy systems transferred to LAPH and its wholly-owned subsidiaries. Interest on the borrowings under the LAPH loan agreement was due monthly; however, it was amended to be due quarterly in November 2018 (see below). Class A advances under the LAPH loan agreement initially bore interest at an annual rate equal to the weighted-average cost to the lender of any commercial paper (to the extent the lender funds an advance by issuing commercial paper) plus 3.30%. Class B advances bore interest at an annual rate equal to 11.00%. The loan agreement required the borrowers to pay a fee based on the daily unused portion of the commitments under the loan agreement. Revenues from the solar energy systems were deposited into accounts established pursuant to the loan agreement and applied in accordance with a cash waterfall in the manner specified in the loan agreement. The borrowers were also required to maintain a liquidity reserve account and an inverter replacement reserve account for the benefit of the lenders under the loan agreement, each of which had to be funded at all times to the levels specified in the loan agreement (see Note 2, Significant Accounting Policies). In connection with the LAPH loan agreement, certain of our affiliates received a fee for managing and servicing the solar energy systems pursuant to management and servicing agreements. In addition, Sunnova Energy Corporation had guaranteed (a) the manager's obligations to manage the solar energy systems pursuant to the management agreement, (b) the servicer's obligations to service the solar energy systems pursuant to the servicing agreement, (c) AP7H's obligations to repurchase or substitute certain ineligible solar energy systems sold to LAPH and its wholly-owned subsidiaries pursuant to certain sale and contribution agreements and (d) certain indemnification obligations related to its affiliates in connection with the LAPH loan agreement, but did not provide a general guarantee of the creditworthiness of the assets of LAPH and its wholly-owned subsidiaries pledged as the collateral for the loan agreement. Under the limited guarantee, Sunnova Energy Corporation was subject to certain financial covenants regarding tangible net worth, working capital and restrictions on the use of proceeds from the loan agreement. In April 2018, the LAPH loan agreement was amended to, among other things, extend the maturity date from December 2018 to May 2019. In November 2018, the LAPH loan agreement was amended to, among other things, decrease the maximum commitment amount of Class A advances to $44.2 million and of Class B advances to $0, extend the maturity date to November 2022, change the interest on Class A advances to an annual rate equal to LIBOR plus 4.50% and change the interest collection period from monthly to quarterly. In February 2020 , proceeds from the SOLI Notes (as defined below) were used to repay $32.0 million in aggregate principal amount outstanding of LAPH debt. In November 2020 , the aggregate principal amount outstanding under the LAPH loan agreement of $10.6 million was fully repaid using proceeds from the SOLII Notes (as defined below), all related interest rates swaps were unwound and the debt facility was terminated. EZOP Debt . In April 2017, EZOP, a special purpose entity, entered into a secured revolving warehouse credit facility with Credit Suisse AG, New York Branch, as administrative agent, and the lenders party thereto, for an aggregate committed amount of $100.0 million with a maturity date of April 2019. In August 2017, the aggregate committed amount was reduced to $70.0 million and in March 2019, the aggregate committed amount was increased to $200.0 million. The warehouse credit facility allows for the pooling and transfer of eligible loans on a non-recourse basis subject to certain limited exceptions. The proceeds of the loans under the warehouse credit facility are available to purchase or otherwise acquire loans (which we originated) directly from AP7H pursuant to a sale and contribution agreement, fund certain reserve accounts that are required to be maintained by EZOP in accordance with the credit agreement and pay fees and expenses incurred in connection with the warehouse credit facility. The amount available for borrowings at any one time under the warehouse credit facility is limited to a borrowing base amount determined at each borrowing and calculated based on the aggregate discounted present value of remaining payments owed to EZOP in respect of the loans transferred to EZOP. Interest on the borrowings under the warehouse credit facility is due monthly. Borrowings under the EZOP warehouse credit facility bear interest at an annual rate equal to the weighted-average cost to the lender of any commercial paper (to the extent the lender funds an advance by issuing commercial paper) plus 3.50% during the commitment availability period and 4.50% after the commitment availability period. In March 2019, we amended the EZOP warehouse credit facility to, among other things, adjust the interest rate on borrowings to an annual rate of adjusted LIBOR plus either 2.15% or 3.15% per annum depending on the date of the most recent takeout transaction in respect of assets securing the credit facility and extend the maturity date from April 2019 to November 2022 . In December 2019, we further amended the EZOP warehouse credit facility to, among other things, adjust the interest rate on borrowings to an annual rate of adjusted LIBOR plus either 2.35% or 3.35% per annum depending on the date of the most recent takeout transaction in respect of assets securing the credit facility. The warehouse credit facility requires EZOP to pay a fee based on the daily unused portion of the commitments under the warehouse credit facility. Revenues from the solar energy systems will be deposited into accounts established pursuant to the warehouse credit facility and applied in accordance with a cash waterfall in the manner specified in the warehouse credit facility. EZOP is also required to maintain a liquidity reserve account and an equipment replacement reserve account for the benefit of the lenders under the warehouse credit facility, each of which must remain funded at all times to the levels specified in the credit agreement (see Note 2, Significant Accounting Policies). In connection with the EZOP warehouse credit facility, certain of our affiliates receive a fee for managing and servicing the solar loan agreements and related solar energy systems pursuant to management and servicing agreements. In addition, Sunnova Energy Corporation has guaranteed (a) the manager's obligations to manage the solar loan agreements and related solar energy systems pursuant to the management agreement, (b) the servicer's obligations to service the solar loan agreements and related solar energy systems pursuant to the servicing agreement, (c) AP7H's obligations to repurchase or substitute certain ineligible solar loans sold to EZOP pursuant to certain sale and contribution agreements and (d) certain indemnification obligations related to its affiliates in connection with the EZOP warehouse credit facility, but does not provide a general guarantee of the creditworthiness of the assets of EZOP pledged as the collateral for the warehouse credit facility. Under the limited guarantee, Sunnova Energy Corporation is subject to certain financial covenants regarding tangible net worth, working capital and restrictions on the use of proceeds from the warehouse credit facility. In June 2020, proceeds from the HELIV Notes (as defined below) were used to repay $149.3 million in aggregate principal amount outstanding of EZOP debt. In October 2020, proceeds from the AP8 revolving credit facility were used to repay $28.0 million in aggregate principal amount outstanding of EZOP debt. See Note 17, Subsequent Events. TEPIIH Debt . In August 2018, TEPIIH entered into a revolving credit facility with Credit Suisse AG, New York Branch, as administrative agent, and the lenders party thereto. The TEPIIH revolving credit facility allowed for borrowings based on the aggregate value of solar assets owned by subsidiaries of TEPIIH subject to certain excess concentration limitations. Under the TEPIIH revolving credit facility, TEPIIH could borrow up to an initial aggregate committed amount of $125.0 million with a maximum commitment amount of $175.0 million. The proceeds from the revolving credit facility were available for funding certain reserve accounts required by the revolving credit facility, making distributions to the parent of TEPIIH and paying fees incurred in connection with closing the revolving credit facility. The TEPIIH revolving credit facility had a maturity date of August 2022. In March 2019, we amended the TEPIIH revolving credit facility to, among other things, extend the maturity date from August 2022 to November 2022, increase the aggregate committed amount to $150.0 million and increase the maximum commitment amount to $250.0 million. In September 2019, we further amended the TEPIIH revolving credit facility to, among other things, cross-collateralize the TEPIIH revolving credit facility with the TEPH revolving credit facility and implement corresponding cross-default provisions. In February 2020 , the aggregate principal amount outstanding under the TEPIIH revolving credit facility of $226.6 million was fully repaid using proceeds from the SOLI Notes (as defined below), all related interest rate swaps were unwound and the debt facility was terminated. HELII Debt . In November 2018, we pooled and transferred eligible solar energy systems and the related asset receivables into HELII, a special purpose entity, that issued $202.0 million in aggregate principal amount of Series 2018-1 Class A solar asset-backed notes and $60.7 million in aggregate principal amount of Series 2018-1 Class B solar asset-backed notes (collectively, the "Notes II") with a maturity date of July 2048. The Notes II were issued at a discount of 0.02% for Class A and 0.02% for Class B and bear interest at an annual rate equal to 4.87% and 7.71%, respectively. The cash flows generated by these solar energy systems are used to service the semi-annual principal and interest payments on the Notes II and satisfy HELII's expenses, and any remaining cash can be distributed to Helios Depositor II, LLC, HELII's sole member. In connection with the Notes II, certain of our affiliates receive a fee for managing and servicing the solar energy systems pursuant to management and servicing agreements. In addition, Sunnova Energy Corporation has guaranteed (a) the manager's obligations to manage the solar energy systems pursuant to the management agreement, (b) the servicer's obligations to service the solar energy systems pursuant to the servicing agreement and (c) Sunnova ABS Holdings, LLC's obligations to repurchase or substitute certain ineligible solar energy systems eventually sold to HELII pursuant to the sale and contribution agreement. HELII is also required to maintain a liquidity reserve account, an inverter replacement reserve account and a cash trap reserve account for the benefit of the holders of the Notes II, each of which must remain funded at all times to the levels specified in the Notes II (see Note 2, Significant Accounting Policies). The indenture requires HELII to track the DSCR of (a) the amount of certain payments received from customers, certain performance based incentives, certain energy credits and any applicable insurance proceeds as of a specific date to (b) interest and scheduled principal due on the Notes II as of such date with the potential to enter into an early amortization period if the DSCR drops below a certain threshold. The holders of the Notes II have no recourse to our other assets except as expressly set forth in the Notes II. RAYSI Debt . In March 2019, we pooled and transferred eligible solar energy systems and the related asset receivables into RAYSI, a special purpose entity, that issued $118.1 million in aggregate principal amount of Series 2019-1 Class A solar asset-backed notes with a maturity date of April 2044 and $15.0 million in aggregate principal amount of Series 2019-1 Class B solar asset-backed notes with a maturity date of April 2034. The notes were issued with no discount for Class A and at a discount of 6.50% for Class B and bear interest at an annual rate equal to 4.95% and 6.35%, respectively. In June 2019, RAYSI issued $6.4 million in aggregate principal amount of 2019-2 Class B solar asset-backed notes with a maturity date of April 2034 pursuant to a supplemental note purchase agreement at a discount rate of 10.50% and bear interest at an annual rate equal to 6.35%. The notes issued by RAYSI are referred to as the "RAYSI Notes". The cash flows generated by these solar energy systems are used to service the semi-annual principal and interest payments on the RAYSI Notes and satisfy RAYSI's expenses, and any remaining cash can be distributed to Sunnova RAYS Depositor II, LLC, RAYSI's sole member. In connection with the RAYSI Notes, certain of our affiliates receive a fee for managing and servicing the solar energy systems pursuant to management, servicing, facility administration and asset management agreements. In addition, Sunnova Energy Corporation has guaranteed, among other things, (a) the obligations of certain of our subsidiaries to manage and service the solar energy systems pursuant to management, servicing, facility administration and asset management agreements, (b) the managing member's obligations, in such capacity, under the related financing fund's limited liability company agreement and (c) certain of our subsidiaries' obligations to repurchase or substitute certain ineligible solar energy systems eventually sold to RAYSI pursuant to the related sale and contribution agreement. RAYSI is also required to maintain a liquidity reserve account, a supplemental reserve account for inverter replacement and financing fund purchase option exercises, a storage system reserve account and a cash trap reserve account for the benefit of the holders of the RAYSI Notes, each of which must remain funded at all times to the levels specified in the RAYSI Notes. The indenture requires RAYSI to track the DSCR of (a) the amount of certain payments received from customers, certain performance based incentives, certain energy credits and any applicable insurance proceeds as of a specific date to (b) interest and scheduled principal due on the RAYSI Notes as of such date with the potential to enter into an early amortization period if the DSCR drops below a certain threshold. The indenture contains cross-default provisions under which a material default by (a) RAYSI or (b) a tax equity fund under the applicable tax equity transaction documents

Derivative Instruments

Derivative Instruments	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments Interest Rate Swaps on AP4 Debt . During the year ended December 31, 2020, the aggregate outstanding principal amount under the AP4 financing agreement was fully repaid, AP4 unwound all outstanding interest rate swaps with an aggregate notional amount of $105.2 million and recorded a realized loss of $484,000. Interest Rate Swaps on LAPH Debt. During the year ended December 31, 2020, the aggregate outstanding principal amount under the LAPH loan agreement was fully repaid, LAPH unwound all outstanding interest rate swaps with an aggregate notional amount of $44.2 million and recorded a realized loss of $9.1 million. Interest Rate Swaps on EZOP Debt. During the years ended December 31, 2020 and 2019, EZOP entered into interest rate swaps for an aggregate notional amount of $155.8 million and $255.8 million, respectively, to economically hedge its exposure to the variable interest rates on a portion of the outstanding EZOP debt. No collateral was posted for the interest rate swaps as they are secured under the EZOP warehouse credit facility. In October 2020, the notional amount of the interest rate swaps began decreasing to match EZOP's estimated monthly principal payments on the debt. During the years ended December 31, 2020 and 2019, EZOP unwound interest rate swaps with a notional amount of $126.1 million and $264.6 million, respectively, and recorded a realized loss of $6.4 million and $81,000, respectively. Interest Rate Swaps on TEPIIH Debt. During the year ended December 31, 2019, TEPIIH entered into interest rate swaps for an aggregate notional amount of $171.2 million to economically hedge its exposure to the variable interest rates on a portion of the outstanding TEPIIH debt. No collateral was posted for the interest rate swaps as they are secured under the TEPIIH revolving credit facility. During the year ended December 31, 2020, the aggregate outstanding principal amount under the TEPIIH revolving credit facility was fully repaid, TEPIIH unwound all outstanding interest rate swaps with an aggregate notional amount of $181.4 million and recorded a realized loss of $25.1 million. Interest Rate Swaps on TEPH Debt. During the years ended December 31, 2020 and 2019, TEPH entered into interest rate swaps for an aggregate notional amount of $260.8 million and $103.1 million, respectively, to economically hedge its exposure to the variable interest rates on a portion of the outstanding TEPH debt. No collateral was posted for the interest rate swaps as they are secured under the TEPH revolving credit facility. In October 2020, the notional amount of the interest rate swaps began decreasing to match TEPH's estimated quarterly principal payments on the debt. Interest Rate Cap on TEPINV Debt. During the year ended December 31, 2020, TEPINV entered into an interest rate cap for an aggregate notional amount of $95.2 million to economically hedge its exposure to the variable interest rates on a portion of the outstanding TEPINV debt. No collateral was posted for the interest rate cap as it is secured under the TEPINV revolving credit facility. In January 2020, the notional amount of the interest rate cap began decreasing to match TEPINV's estimated monthly principal payments on the debt. The following table presents a summary of the outstanding derivative instruments: As of December 31, 2020 2019 Effective Termination Fixed Aggregate Effective Termination Fixed Aggregate (in thousands, except interest rates) AP4 —% $ — March 2018 July 2020 2.338% $ 99,762 LAPH —% — November 2018 October 2036 3.409% 43,298 EZOP June 2020 - September 2029 - 0.483% - 2.620% 130,373 June 2019 - July 2029 - 1.631% - 2.620% 100,083 TEPIIH —% — September 2018 - July 2031 - 1.909% - 3.383% 225,845 TEPH September 2018 - January 2023 - 0.528% - 2.114% 202,272 September 2019 January 2023 1.620% - 1.928% 55,115 TEPINV December 2019 December 2022 2.500% 51,025 —% — Total $ 383,670 $ 524,103 The following table presents the fair value of the interest rate swaps as recorded in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Other assets $ — $ 360 Other current liabilities — (397) Other long-term liabilities (13,407) (27,092) Total, net $ (13,407) $ (27,129) We did not designate the interest rate swaps as hedging instruments for accounting purposes. As a result, we recognize changes in fair value immediately in interest expense, net. The following table presents the impact of the interest rate swaps as recorded in the consolidated statements of operations: Year Ended 2020 2019 2018 (in thousands) Realized (gain) loss $ 51,326 $ 13,195 $ (17,004) Unrealized (gain) loss (13,768) 19,237 6,100 Total $ 37,558 $ 32,432 $ (10,904)

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Our effective income tax rate is 0% for the years ended December 31, 2020, 2019 and 2018. Total income tax differs from the amounts computed by applying the statutory income tax rate to loss before income tax primarily as a result of our valuation allowance. The sources of these differences are as follows: Year Ended 2020 2019 2018 (in thousands) Loss before income tax $ (307,637) $ (133,434) $ (68,409) Statutory federal tax rate 21 % 21 % 21 % Tax benefit computed at statutory rate (64,604) (28,021) (14,366) State income tax, net of federal benefit (16,862) (8,344) (4,308) Adjustments from permanent differences: Redeemable noncontrolling interests 11,662 (2,293) (1,226) ITC recapture 232 296 989 Other 475 852 234 Increase in valuation allowance, net 69,278 37,510 18,677 Total income tax expense $ 181 $ — $ — State, federal and foreign income taxes are $181,000, $0 and $0 for the years ended December 31, 2020, 2019 and 2018, respectively. The tax effects of temporary differences that give rise to significant portions of the deferred tax assets (liabilities) are as follows: As of December 31, 2020 2019 (tax effected, in thousands) Federal net operating loss carryforward $ 242,732 $ 169,379 State net operating loss carryforward 76,281 49,565 ITC carryforward 267,522 246,828 Federal unused interest deduction carryforward 39,036 22,559 Investment in certain financing arrangements 44,337 36,999 Other deferred tax assets 23,010 20,801 Deferred tax assets 692,918 546,131 Fixed asset basis difference (298,032) (235,510) Investment in certain financing arrangements (57,222) (22,826) Other deferred tax liabilities (3,427) (2,819) Deferred tax liabilities (358,681) (261,155) Valuation allowance (334,237) (284,976) Net deferred tax asset $ — $ — A full valuation allowance of $334.2 million and $285.0 million was recorded against our net deferred tax assets as of December 31, 2020 and 2019, respectively. We believe it is not more likely than not that future taxable income and the reversal of deferred tax liabilities will be sufficient to realize our net deferred tax assets. Our estimated federal tax net operating loss carryforward as of December 31, 2020 is approximately $1.2 billion, which will begin to expire in 2032 if not utilized. We also generated $20.7 million of Section 48(a) ITCs in 2020 for a net $267.5 million through December 31, 2020, which will begin to expire in 2033 if not utilized. We assessed whether we had any significant uncertain tax positions taken in a filed tax return, planned to be taken in a future tax return or claim, or otherwise subject to interpretation and determined there were none not more likely than not to be sustained upon examination, including resolution of any related appeals or litigation processes, based on the technical merits of the position, or prospectively approved when such approval may be sought in advance. Accordingly, we recorded no reserve for uncertain tax positions. Should a provision for any interest or penalties relative to unrecognized tax benefits be necessary, it is our policy to accrue for such in our income tax accounts. There were no such accruals as of December 31, 2020 and 2019 and we do not expect a significant change in gross unrecognized tax benefits in the next twelve months. Our tax years after 2011 remain subject to examination by the IRS and by the taxing authorities in the states and territories in which we operate. Under the provisions of the Internal Revenue Code and similar state provisions, our net operating loss carryforwards and tax credit carryforwards are subject to review and possible adjustment by the IRS and state tax authorities. Under Sections 382 and 383 of the Internal Revenue Code, as well as similar state provisions, our net operating loss and tax credit carryforwards may be subject to an annual limitation in the event of certain cumulative changes in the ownership interest of certain significant shareholders over a three-year period in excess of 50%. This could limit the amount of tax attributes that can be utilized annually to offset future taxable income or tax liabilities. The amount of the annual limitation is determined based on the value of our company immediately prior to the ownership change. Subsequent ownership changes may further affect the limitation in future years. We experienced an ownership change in August 2020 as defined by Sections 382 and 383 of the Internal Revenue Code. While we are presently evaluating the impact of Sections 382 and 383 on our deferred tax assets as a result of the aforementioned ownership change, we maintain a full valuation allowance to reduce our deferred tax assets to the amount expected to be realized. We conduct operations in the U.S. territories of Puerto Rico, Guam and the Commonwealth of the Northern Mariana Islands. As a result, our income tax expense includes the effects of taxes incurred in such jurisdictions where the tax code for the respective jurisdiction may have separate tax-reporting requirements. Jurisdiction-specific income taxes, in aggregate, do not adjust our effective income tax rate of 0%. In March 2020, the U.S. enacted the Coronavirus Aid, Relief, and Economic Security Act ("CARES Act"), featuring significant tax provisions and relief measures to assist individuals and businesses impacted by the economic effects of the COVID-19 pandemic. Relief measures intended to aid businesses in employee retention include payroll tax relief and a refundable tax credit for employers who retain employees during the COVID-19 pandemic. In addition, among other things, the CARES Act establishes (a) a five-year carryback of net operating losses generated in 2018, 2019 and 2020, (b) a temporary suspension of the 80% limitation on the use of net operating losses in 2018, 2019 and 2020 and (c) an increase to the adjusted taxable income limitation from 30% to 50% for business interest deductions under Section 163(j) of the U.S. Internal Revenue Code of 1986, as amended, for 2019 and 2020. We have historically maintained, and continue to maintain, a full valuation allowance against deferred tax assets. Due to our aggregate amount of net operating losses, we cannot utilize the carryback or limitation suspension provisions pertaining to the usage of net operating losses. However, the increase to the adjusted taxable income limitation for business interest deductions resulted in a decrease to our deferred tax assets for unused business interest deductions and an offsetting increase to our net operating loss carryforward. In December 2020, the U.S. enacted the Continued Assistance for Unemployment Workers Act of 2020 ("CARES Act II"), which provided an extension of the CARES Act's unemployment benefits. It also extended unemployment benefits to independent contractors and provided independent contractors with paid sick and family leave benefits through March 2021. Neither the CARES Act nor the CARES Act II has any impact on our valuation allowance.

Related-Party Transactions

Related-Party Transactions	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related-Party Transactions	Related-Party Transactions SEI Debt . During 2020, certain of our affiliates who have representatives on our Board were holders of more than 10% of our common stock and were also holders of our 9.75% convertible senior notes. For the year ended December 31, 2020, we recorded expense related to such holders of approximately $1.3 million in interest expense, net in the consolidated statement of operations while the holders were classified as a related party . As of December 31, 2020, such holders no longer own more than 10% of our common stock. Sunnova Energy Corporation Debt . During 2019 and 2018, c ertain of our affiliates who have representatives on our Board were holders of certain senior secured notes and convertible notes. In connection with our IPO, we redeemed the senior secured notes for cash and the holders of the convertible notes converted the principal amount plus accrued and unpaid interest into shares of common stock. We have classified these related transactions as such in the consolidated statements of operations and consolidated statements of cash flows for the years ended December 31, 2019 and 2018. Promissory Notes . In March 2018 , we entered into a bonus agreement with an executive officer providing that each year beginning in January 2019, one-fourth of the outstanding loan balance (and related accrued and unpaid interest) under the promissory notes executed by that officer and an entity controlled by that officer, in favor of Sunnova Energy Corporation, in combined aggregate principal amounts totaling $1.7 million (the "Officer Notes"), was to be forgiven provided that officer remained employed through the applicable forgiveness date, such that the full amount of the Officer Notes would be forgiven as of January 2022 . In January 2019 , one-fourth of the balance of the Officer Notes was forgiven. In June 2019 , as additional bonus compensation, the remaining principal and interest in the amount of $1.4 million associated with the Officer Notes was forgiven and Sunnova Energy Corporation agreed to pay the officer a bonus to reimburse the officer for the expected tax liability associated with such forgiveness of $892,000, which was paid in August 2019 .

Redeemable Noncontrolling Inter

Redeemable Noncontrolling Interests and Noncontrolling Interests	12 Months Ended
	Dec. 31, 2020
Noncontrolling Interest [Abstract]
Redeemable Noncontrolling Interests and Noncontrolling Interests	Redeemable Noncontrolling Interests and Noncontrolling Interests The following table summarizes our redeemable noncontrolling interests and noncontrolling interests as of December 31, 2020: Tax Equity Entity Balance Sheet Classification Date Class A Sunnova TEP I, LLC Redeemable noncontrolling interests March 2017 Sunnova TEP II, LLC Redeemable noncontrolling interests December 2017 Sunnova TEP II-B, LLC Redeemable noncontrolling interests December 2017 Sunnova TEP III, LLC Redeemable noncontrolling interests January 2019 TEPIVA Noncontrolling interests August 2019 TEPIVB Noncontrolling interests December 2019 TEPIVC Noncontrolling interests February 2020 TEPIVD Noncontrolling interests May 2020 Sunnova TEP IV-F, LLC Noncontrolling interests July 2020 TEPIVE Noncontrolling interests September 2020 TEPIVG Noncontrolling interests November 2020 The purpose of the tax equity entities is to own and operate a portfolio of residential solar energy systems and energy storage systems. The terms of the tax equity entities' operating agreements contain allocations of income (loss), Section 48(a) ITCs and cash distributions that vary over time and adjust between the members on an agreed date (referred to as the flip date). The operating agreements specify either a date certain flip date or an internal rate of return ("IRR") flip date. The date certain flip date is based on the passage of a fixed period of time that generally corresponds to the expiration of the recapture period associated with Section 48(a) ITCs or a year thereafter. The IRR flip date is the date on which the tax equity investor has achieved a contractual rate of return. From inception through the flip date, the Class A members' allocation of taxable income (loss) and Section 48(a) ITCs is generally 99% and the Class B members' allocation of taxable income (loss) and Section 48(a) ITCs is generally 1%. TEPIVA, TEPIVB, TEPIVC, TEPIVD, TEPIVE and TEPIVG also have a step-down period prior to the flip date in which the Class A members' allocation of certain items within taxable income (loss) and Section 48(a) ITCs become 67% and the Class B members' allocation of certain items within taxable income (loss) and Section 48(a) ITCs become 33%. After the related flip date (or, if the tax equity investor has a deficit capital account, typically after such deficit has been eliminated), the Class A members' allocation of taxable income (loss) will typically decrease to 5% (or, in some cases, a higher percentage if required by the tax equity investor) and the Class B members' allocation of taxable income (loss) will increase by an inverse amount. The redeemable noncontrolling interests and noncontrolling interests are comprised of Class A units, which represent the tax equity investors' interest in the tax equity entities. Both the Class A members and Class B members have call options to allow either member to redeem the other member's interest in the tax equity entities upon the occurrence of certain contingent events, such as bankruptcy, dissolution/liquidation and forced divestitures of the tax equity entities. Additionally, except for TEPIVG, the Class B members have the option to purchase all Class A units, which is typically exercisable at any time during the periods specified under their respective governing documents, and, in regards to the tax equity entities classified as redeemable noncontrolling interests, also have the contingent obligation to purchase all Class A units if the Class A members exercise their right to withdraw, which is typically exercisable at any time during the nine-month period commencing upon the applicable flip date. The carrying values of the redeemable noncontrolling interests were equal to or greater than the redemption values as of December 31, 2020 and 2019. Guarantees . We are contractually obligated to make certain Class A members whole for losses they may suffer in certain limited circumstances resulting from the disallowance or recapture of Section 48(a) ITCs. We have concluded the likelihood of a significant recapture event is remote and consequently have not recorded a liability for any potential recapture exposure. The maximum potential future payments we could be required to make under this obligation would depend on the IRS successfully asserting upon audit the fair market values of the solar energy systems sold or transferred to the tax equity entities as determined by us exceed the allowable basis for the systems for purposes of claiming Section 48(a) ITCs. The fair market values of the solar energy systems and related Section 48(a) ITCs are determined, and the Section 48(a) ITCs are allocated to the Class A members, in accordance with the tax equity entities' operating agreements. Due to uncertainties associated with estimating the timing and amounts of distributions, the likelihood of an event that may trigger repayment, forfeiture or recapture of Section 48(a) ITCs to such Class A members, and the fact that we cannot determine how the IRS will evaluate system values used in claiming Section 48(a) ITCs, we cannot determine the potential maximum future payments that are required under these guarantees. From time to time, we incur non-performance fees, which may include, but is not limited to, delays in the installation process and interconnection to the power grid of solar energy systems and other factors. The non-performance fees are settled by either a return of a portion of the Class A members' capital contributions or an additional payment to the Class A members. During the years ended December 31, 2020 and 2019, we paid $2.1 million and $1.3 million, respectively, related to non-performance fees. During the year ended December 31, 2018, we did not make any reimbursements or payments related to non-performance fees. As of December 31, 2020 and 2019, we recorded a liability of $1.5 million and $566,000, respectively, related to non-performance fees.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2020
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity Series A and Series C Convertible Preferred Stock The Series A and Series C convertible preferred stock was convertible into our Series A common stock at an initial conversion ratio of 1:1, subject to appropriate adjustment in the event of any stock dividend, stock split, combination or other similar recapitalization with respect to any of our common stock and to broad-based weighted average anti-dilution protection. The Series A and Series C convertible preferred stock was mandatorily convertible into our Series A common stock upon either (a) the closing of a public offering of shares of our common stock with aggregate gross proceeds, net of underwriting discounts and commissions, of not less than $175.0 million at a per share offering price of at least 1.25 times the original purchase price of our Series A convertible preferred stock or (b) the affirmative vote of at least 80% of the shares of Series A and Series C convertible preferred stock voting as a single class and on an "as converted basis". The holders of Series A and Series C convertible preferred stock were entitled to cast the number of votes equal to the number of whole shares of Series A common stock into which the Series A and Series C convertible preferred stock held by such holders is convertible as of the record date for determining stockholders entitled to vote on such matter. In March 2018, we increased the number of authorized voting shares of our convertible preferred stock to 64,294,899 shares, of which 47,149,592 shares were designated as Series A convertible preferred stock and 17,145,306 shares were designated as Series C convertible preferred stock. During the year ended December 31, 2018, we issued 13,006,780 shares of Series C convertible preferred stock at $13.53 per share in exchange for $176.0 million in cash. In connection with our IPO, we converted 46,351,877 shares of our Series A convertible preferred stock and 14,127,140 shares of our Series C convertible preferred stock, which represented all the outstanding shares of our Series A convertible preferred stock and Series C convertible preferred stock, into 60,479,017 shares of our common stock. Series B Convertible Preferred Stock The Series B convertible preferred stock was convertible into our Series A common stock at a rate determined by dividing the original issue price by the conversion price of $8.70 at or after the earlier of (a) November 9, 2018 or (b) immediately prior to the consummation of a sale of Sunnova, subject to appropriate adjustment in the event of any stock dividend, stock split, combination or other similar recapitalization with respect to any of our common stock and to broad-based weighted average anti-dilution protection. The Series B convertible preferred stock was mandatorily convertible into our Series A common stock upon either (a) the closing of the sale of shares of any of our common stock to the public at a price of at least approximately $6.6558 per share (subject to appropriate adjustments) or (b) the affirmative vote of at least 75% of the shares of Series A and Series B convertible preferred stock. Each holder of Series B convertible preferred stock was entitled to cast the number of votes equal to the number of whole shares of Series A common stock into which the Series B convertible preferred stock held by such holder were convertible as of the record date for determining stockholders entitled to vote on such matter. In January 2018, we issued 13,013 shares of Series B convertible preferred stock at $8.70 per share in exchange for $113,000 in cash. In March 2018, we exchanged all outstanding shares of Series B convertible preferred stock, plus accrued paid-in-kind interest thereon, for 4,763,086 shares of Series A convertible preferred stock. Immediately following the exchange, we canceled all shares of Series B convertible preferred stock. As of December 31, 2018, there was no Series B convertible preferred stock outstanding. Series A Common Stock In March 2018, we increased the number of authorized voting shares of Series A common stock to 77,153,879 shares, of which 64,294,899 shares were reserved for the issuance of Series A common stock upon the conversion of Series A or Series C convertible preferred stock. In connection with our IPO, our Series A common stock was redesignated as common stock. Series B Common Stock Our Series B non-voting common stock related to our equity-based compensation plans (see Note 14, Equity-Based Compensation). In connection with our IPO, we converted 23,870 shares of our non-voting Series B common stock, which represented all the outstanding shares of our Series B common stock, into 23,870 shares of our voting Series A common stock, which was subsequently redesignated as common stock. Common Stock On July 24, 2019, we priced 14,000,000 shares of common stock in our IPO at a public offering price of $12.00 per share and on July 25, 2019 our common stock began trading on the New York Stock Exchange under the symbol "NOVA". On August 19, 2019, we issued and sold an additional 865,267 shares of our common stock at a public offering price of $12.00 per share pursuant to the underwriters' exercise of their option to purchase additional shares. We received aggregate net proceeds from our IPO of approximately $162.3 million, after deducting underwriting discounts and commissions of approximately $10.7 million and offering expenses of approximately $5.4 million. We used the proceeds from our IPO to repay indebtedness and for working capital purposes. In December 2020, we sold 4,025,000 shares of common stock at a public offering price of $37.00 per share. We received aggregate net proceeds of approximately $142.7 million, after deducting underwriting discounts and commissions of approximately $6.0 million and offering expenses of approximately $300,000. We used the net proceeds from the offering to acquire solar equipment, repay indebtedness and for working capital purposes. During the year ended December 31, 2020, certain of the holders of our 9.75% convertible senior notes converted approximately $150.8 million aggregate principal amount, including accrued and unpaid interest to the date of each conversion, of our 9.75% convertible senior notes into 11,168,874 shares of our common stock. Such conversions resulted in a loss on extinguishment of debt under GAAP of $142.8 million for the year ended December 31, 2020 . See Note 17, Subsequent Events.

Equity-Based Compensation

Equity-Based Compensation	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Equity-Based Compensation	Equity-Based Compensation Effective December 2013 and January 2015, we established and adopted two stock option plans (collectively, the "Prior Plans") after approval by our Board. The Prior Plans provided the aggregate number of shares of common stock that may be issued pursuant to stock options shall not exceed 26,032 shares. No further awards may be made under the Prior Plans. Effective March 2016, we established and adopted a new stock option plan (the "2016 Plan") after approval by our Board. The 2016 Plan allowed for the issuance of non-qualified and incentive stock options. The 2016 Plan provided the aggregate number of shares of common stock that may be issued pursuant to stock options shall not exceed 4,288,950 shares. No further awards may be made under the 2016 Plan. In connection with our IPO, approximately 50% of the non-vested stock options outstanding at that time, or 995,517 stock options, became exercisable and the vesting terms for all remaining stock options were amended so all stock options would be fully vested on the first anniversary of the closing date of our IPO. We recorded an additional $3.2 million of expense in July 2019 related to the accelerated vesting periods. In connection with our IPO, our Board adopted the 2019 Long-Term Incentive Plan (the "LTIP") to incentivize employees, officers, directors and other service providers of SEI and its affiliates. The LTIP provides for the grant, from time to time, at the discretion of our Board or a committee thereof, of stock options, stock appreciation rights, stock awards, including restricted stock and restricted stock units, performance awards and cash awards. The LTIP provides the aggregate number of shares of common stock that may be issued pursuant to awards shall not exceed 5,229,318 shares. The number of shares available for issuance under the LTIP will be increased on the first day of each fiscal year beginning in 2020, in an amount equal to the lesser of (a) a number of shares such that the total number of shares that remain available for additional grants under the LTIP equals five percent of the outstanding shares of our common stock on the last day of the immediately preceding fiscal year or (b) such number of shares determined by our Board. Awards granted under the LTIP contain a service condition and cease vesting for employees, consultants and directors upon termination of employment or service. During the year ended December 31, 2020, we granted 1,141,413 restricted stock units to certain employees, consultants and directors with a grant date fair value of $13.7 million, which will be recognized ratably over the applicable vesting period of each award (either one year, three years or seven years). The Prior Plans and the 2016 Plan will only allow for settlement of stock options by the issuance of common stock and restricted stock units issued under the LTIP can generally only be settled by the issuance of common stock. Therefore, we classify the stock options and restricted stock units as equity awards. We recognize the fair value of equity-based compensation awards as compensation cost in the financial statements, beginning on the grant date. We base compensation expense on the fair value of the awards we expect to vest, recognized over the service period, and adjusted for actual forfeitures that occur before vesting. Stock Options During 2018, we granted 1,810,016 stock options to employees and 24,860 stock options to non-employee consultants. During 2018, 1,393 stock options were net exercised (and thus, no cash was received) resulting in the issuance of 644 shares of common stock. During 2019, we granted 94,295 stock options to employees. During 2019, 2,143 stock options were exercised resulting in the issuance of 2,143 shares of common stock in exchange for an insignificant amount of cash. During 2020, no stock options were granted and 922,770 stock options were exercised resulting in the issuance of 922,770 shares of common stock in exchange for $13.6 million. We used the following assumptions to apply the Black-Scholes option-pricing model to stock options granted during the years ended December 31, 2019 and 2018: Year Ended 2019 2018 Expected dividend yield 0.00% 0.00% Risk-free interest rate 2.62% 2.62% Expected term (in years) 7.94 7.94 Volatility 81% 81% The expected volatility was calculated based on the average historical volatilities of publicly traded peer companies determined by us. The risk-free interest rate used was based on the U.S. treasury yield curve in effect at the time of grant for the expected term of the stock options to be valued. The expected dividend yield is zero as we do not anticipate paying common stock dividends within the relevant time frame. The expected term has been estimated using the average of the contractual term and weighted average life of the stock options. The following table summarizes stock option activity: Number Weighted Weighted Weighted Aggregate (in thousands) Outstanding, December 31, 2018 4,808,390 $ 15.90 8.09 $ 129 Granted 94,295 $ 13.58 9.07 $ 3.11 Exercised (2,143) $ 1.85 $ 20 Forfeited (596,233) $ 15.85 $ 3.48 Outstanding, December 31, 2019 4,304,309 $ 15.86 7.08 $ 242 Exercised (922,770) $ 14.76 $ 28,022 Forfeited (115,191) $ 19.19 $ 3.54 Outstanding, December 31, 2020 3,266,348 $ 16.06 5.82 $ 94,962 Exercisable, December 31, 2020 3,266,348 $ 16.06 5.82 $ 94,962 Vested, December 31, 2020 3,266,348 $ 16.06 5.82 $ 94,962 Non-vested, December 31, 2019 964,396 $ 3.52 Non-vested, December 31, 2020 — $ — The number of stock options that vested during the years ended December 31, 2020 and 2019 was 915,501 and 1,765,410, respectively. The grant date fair value of stock options that vested during the years ended December 31, 2020 and 2019 was $3.2 million and $6.0 million, respectively. As of December 31, 2020, there was no unrecognized compensation expense related to stock options. Restricted Stock Units The following table summarizes restricted stock unit activity: Number of Weighted Outstanding, December 31, 2018 — $ — Granted 1,431,555 $ 11.93 Forfeited (5,416) $ 12.00 Outstanding, December 31, 2019 1,426,139 $ 11.93 Granted 1,141,413 $ 11.98 Vested (463,762) $ 11.89 Forfeited (44,606) $ 12.31 Outstanding, December 31, 2020 2,059,184 $ 11.95 The number of restricted stock units that vested during the years ended December 31, 2020 and 2019 was 463,762 and 0, respectively. The grant date fair value of restricted stock units that vested during the years ended December 31, 2020 and 2019 was $5.5 million and $0, respectively. As of December 31, 2020, there was $17.9 million of total unrecognized compensation expense related to restricted stock units, which is expected to be recognized over the weighted average period of 1.79 years.

Basic and Diluted Net Loss Per

Basic and Diluted Net Loss Per Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Basic and Diluted Net Loss Per Share	Basic and Diluted Net Loss Per Share The following table sets forth the computation of our basic and diluted net loss per share: Year Ended 2020 2019 2018 (in thousands, except share and per share amounts) Net loss attributable to stockholders $ (252,284) $ (144,351) $ (74,246) Dividends earned on Series A convertible preferred stock — (19,271) (36,346) Dividends earned on Series C convertible preferred stock — (5,454) (5,948) Deemed dividends on convertible preferred stock exchange — — (19,332) Net loss attributable to common stockholders—basic and diluted $ (252,284) $ (169,076) $ (135,872) Net loss per share attributable to common stockholders—basic and diluted $ (2.87) $ (4.14) $ (15.74) Weighted average common shares outstanding—basic and diluted 87,871,457 40,797,976 8,634,477 The following table presents the weighted average shares of common stock equivalents that were excluded from the computation of diluted net loss per share for the periods presented because including them would have been anti-dilutive: Year Ended 2020 2019 2018 Equity-based compensation awards 6,013,797 4,954,286 4,307,614 Convertible preferred stock — 33,960,624 53,112,246 Convertible senior notes 9,606,157 104,320 —

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal. We are a party to a number of lawsuits, claims and governmental proceedings which are ordinary, routine matters incidental to our business. In addition, in the ordinary course of business, we periodically have disputes with dealers and customers. We do not expect the outcomes of these matters to have, either individually or in the aggregate, a material adverse effect on our financial position or results of operations. Performance Guarantee Obligations. As of December 31, 2020, we recorded $5.7 million relating to our guarantee of certain specified minimum solar energy production output under our leases and loans, of which $3.3 million is recorded in other current liabilities and $2.4 million is recorded in other long-term liabilities in the consolidated balance sheet. As of December 31, 2019, we recorded $6.5 million relating to these guarantees, of which $4.1 million is recorded in other current liabilities and $2.4 million is recorded in other long-term liabilities in the consolidated balance sheet. The changes in our aggregate performance guarantee obligations are as follows: As of December 31, 2020 2019 (in thousands) Balance at beginning of period $ 6,468 $ 6,044 Accruals for obligations issued 3,155 3,101 Settlements made in cash (3,905) (2,677) Balance at end of period $ 5,718 $ 6,468 Operating and Finance Leases . We lease real estate and certain office equipment under operating leases and vehicles and certain other office equipment under finance leases. The following table presents the detail of lease expense and lease income as recorded in general and administrative expense and other operating income, respectively, in the consolidated statements of operations: Year Ended 2020 2019 2018 (in thousands) Operating lease expense $ 1,342 $ 1,248 $ 972 Finance lease amortization expense 3 8 — Short-term lease expense 49 48 50 Variable lease expense 696 1,037 704 Sublease income — (73) (70) Total $ 2,090 $ 2,268 $ 1,656 The following table presents the detail of right-of-use assets and lease liabilities as recorded in other assets and other current liabilities As of December 31, 2020 2019 (in thousands) Right-of-use assets: Operating leases $ 8,779 $ 9,668 Finance leases 391 5 Total right-of-use assets $ 9,170 $ 9,673 Current lease liabilities: Operating leases $ 1,094 $ 556 Finance leases 112 5 Long-term leases liabilities: Operating leases 9,742 9,389 Finance leases 203 — Total lease liabilities $ 11,151 $ 9,950 Other information related to leases was as follows: Year Ended 2020 2019 2018 (in thousands) Cash paid (received) for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases (1) $ (439) $ 1,254 $ 875 Financing cash flows from finance leases 2 8 — Right-of-use assets obtained in exchange for lease obligations: Operating leases — 8,087 — Finance leases 392 13 — (1) Includes reimbursements in 2020 of approximately $1.5 million for leasehold improvements. As of December 31, 2020 2019 Weighted average remaining lease term (years): Operating leases 8.47 9.41 Finance leases 3.99 0.68 Weighted average discount rate: Operating leases 3.93 % 3.94 % Finance leases 3.39 % 4.26 % Future minimum lease payments under our non-cancelable leases as of December 31, 2020 were as follows: Operating Finance (in thousands) 2021 $ 1,536 $ 122 2022 1,559 88 2023 1,594 69 2024 1,616 55 2025 1,633 — 2026 and thereafter 5,984 — Total 13,922 334 Amount representing interest (2,136) (19) Amount representing leasehold incentives (950) — Present value of future payments 10,836 315 Current portion of lease liability (1,094) (112) Long-term portion of lease liability $ 9,742 $ 203 Letters of Credit . In connection with various security arrangements for an office lease, we have a letter of credit outstanding of $375,000 and $725,000 as of December 31, 2020 and 2019, respectively. The letter of credit is cash collateralized for the same amount or a lesser amount and this cash is classified as restricted cash recorded in other current assets and other assets in the consolidated balance sheets. Guarantees or Indemnifications . We enter into contracts that include indemnifications and guarantee provisions. In general, we enter into contracts with indemnities for matters such as breaches of representations and warranties and covenants contained in the contract and/or against certain specified liabilities. Examples of these contracts include dealer agreements, debt agreements, asset purchases and sales agreements, service agreements and procurement agreements. We are unable to estimate our maximum potential exposure under these agreements until an event triggering payment occurs. We do not expect to make any material payments under these agreements. Dealer Commitments. As of December 31, 2020 and 2019, the net unamortized balance of payments to dealers for exclusivity and other similar arrangements was $55.7 million and $32.8 million, respectively. Under these agreements, we paid $25.8 million and $31.7 million during the years ended December 31, 2020 and 2019, respectively. We could be obligated to make maximum payments, excluding additional amounts payable on a per watt basis if even higher thresholds are met, as follows: Dealer (in thousands) 2021 $ 28,982 2022 35,844 2023 12,520 2024 12,515 2025 2,191 2026 and thereafter — Total $ 92,052 Purchase Commitments. In August 2019, we amended an agreement with a supplier in which we agreed to purchase a minimum amount of energy storage systems and components for five years. In December 2020, we amended an agreement with a supplier in which we agreed to purchase a certain amount of energy storage systems and components for one year. These purchases are recorded to inventory in other current assets in the consolidated balance sheets. Under these agreements, we could be obligated to make minimum purchases as follows: Purchase (in thousands) 2021 $ 28,497 2022 26,810 2023 26,605 2024 19,807 2025 — 2026 and thereafter — Total $ 101,719 Information Technology Commitments. We have certain long-term contractual commitments related to information technology software services and licenses. Future commitments as of December 31, 2020 were as follows: Information (in thousands) 2021 $ 7,976 2022 2,112 2023 26 2024 26 2025 7 2026 and thereafter — Total $ 10,147 Restricted Net Assets . Our various financing agreements contain provisions that restrict the ability of certain of our consolidated subsidiaries to transfer their net assets to SEI. Such restricted net assets amounted to approximately $863.2 million as of December 31, 2020.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Common Stock. In January and February 2021, the remaining holders of our 9.75% convertible senior notes converted approximately $97.1 million aggregate principal amount, including accrued and unpaid interest to the date of each conversion, of our 9.75% convertible senior notes into 7,196,035 shares of our common stock. TEPH Debt . In January 2021 , we amended the TEPH revolving credit facility to, among other things, (a) permit certain transactions in SRECs (or proceeds therefrom) and related hedging arrangements and exclude certain of such amounts from the calculation of net cash flow available to service the indebtedness and (b) allow for borrowings with respect to certain ancillary components. HELV Debt. In February 2021, we pooled and transferred eligible solar loans and the related receivables into Sunnova Helios V Issuer, LLC ("HELV"), a special purpose entity, that issued $150.1 million in aggregate principal amount of Series 2021-A Class A solar loan-backed notes and $38.6 million in aggregate principal amount of Series 2021-A Class B solar loan-backed notes (collectively, the "HELV Notes") with a maturity date of February 2048. The HELV Notes were issued at a discount of 0.001% for Class A and 2.487% for Class B and bear interest at an annual rate of 1.80% and 3.15%, respectively. The cash flows generated by these solar loans are used to service the monthly principal and interest payments on the HELV Notes and satisfy HELV's expenses, and any remaining cash can be distributed to Sunnova Helios V Depositor, LLC, HELV's sole member. In connection with the HELV Notes, certain of our affiliates receive a fee for managing and servicing the solar energy systems pursuant to management and service agreements. In addition, Sunnova Energy Corporation has guaranteed, among other things, (a) the obligations of certain of our subsidiaries to manage and service the solar energy systems pursuant to management and servicing agreements and (b) certain of our subsidiaries' obligations to repurchase or substitute certain ineligible solar loans eventually sold to HELV pursuant to the related sale and contribution agreement. HELV is also required to maintain certain reserve accounts for the benefit of the holders of the HELV Notes, each of which must be funded at all times to the levels specified in the HELV Notes. The holders of the HELV Notes have no recourse to our other assets except as expressly set forth in the HELV Notes. EZOP and AP8 Debt. In February 2021, proceeds from the HELV Notes were used to repay $107.3 million and $29.5 million in aggregate principal amount of outstanding EZOP and AP8 debt, respectively. Acquisition of SunStreet . In February 2021, we entered into an Agreement and Plan of Merger (the "Merger Agreement") with certain of our subsidiaries, SunStreet Energy Group, LLC, a Delaware limited liability company ("SunStreet"), and LEN X, LLC, a Florida limited liability company, the sole member of SunStreet and a wholly owned subsidiary of Lennar Corporation. Pursuant to the Merger Agreement, we will acquire SunStreet, Lennar Corporation's residential solar platform, in exchange for up to 7,222,229 shares of our common stock (the "Acquisition"), comprised of 3,333,333 shares in initial consideration to be issued at closing, subject to purchase price adjustment, and up to 3,888,896 shares issuable as earnout consideration after closing of the Acquisition. The Acquisition is expected to provide a new strategic path to further scale our business and develop clean and resilient residential microgrids across the U.S. The Merger Agreement contains termination rights if, among other things, the Acquisition does not close on or before September 1, 2021. The Acquisition is expected to close in the second quarter of 2021. We are currently in the process of determining the accounting treatment of the Acquisition.

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (Unaudited)	Selected Quarterly Financial Data (Unaudited) The following tables present the selected quarterly financial data for the years ended December 31, 2020 and 2019. Three Months Ended December 31, 2020 September 30, 2020 June 30, 2020 March 31, 2020 (in thousands, except per share amounts) Revenue (1)(2) $ 38,024 $ 50,177 $ 42,790 $ 29,829 Total operating expenses, net (2) $ 56,002 $ 48,528 $ 47,933 $ 44,135 Operating income (loss) (1)(2) $ (17,978) $ 1,649 $ (5,143) $ (14,306) Net loss (1)(2)(3)(4) $ (128,791) $ (73,294) $ (28,729) $ (77,004) Net loss attributable to common stockholders—basic and diluted (1)(2)(3)(4) $ (91,770) $ (64,181) $ (25,258) $ (71,075) Net loss per share attributable to common stockholders—basic and diluted (1)(2)(3)(4) $ (0.96) $ (0.73) $ (0.30) $ (0.85) Three Months Ended December 31, 2019 September 30, 2019 June 30, 2019 March 31, 2019 (in thousands, except per share amounts) Revenue (1)(2) $ 33,614 $ 36,615 $ 34,612 $ 26,715 Total operating expenses, net (2) $ 42,769 $ 42,513 $ 37,322 $ 31,222 Operating loss (1)(2) $ (9,155) $ (5,898) $ (2,710) $ (4,507) Net loss (1)(2)(3) $ (13,762) $ (34,369) $ (49,807) $ (35,496) Net loss attributable to common stockholders—basic and diluted (1)(2)(3) $ (17,509) $ (37,590) $ (63,260) $ (50,717) Net loss per share attributable to common stockholders—basic and diluted (1)(2)(3) $ (0.21) $ (0.62) $ (7.32) $ (5.87) (1) Fluctuations are primarily due to seasonality. (2) Fluctuations are primarily due to growth. (3) Fluctuations are primarily due to unrealized gains and losses on derivative instruments. (4) Fluctuations are primarily due to losses on conversions of debt into common stock.

Schedule I Parent Company Finan

Schedule I Parent Company Financial Statements	12 Months Ended
	Dec. 31, 2020
Condensed Financial Information Disclosure [Abstract]
Schedule I Parent Company Financial Statements	SUNNOVA ENERGY INTERNATIONAL INC. CONDENSED BALANCE SHEETS (in thousands, except share amounts and share par values) As of December 31, 2020 2019 Assets Current assets: Cash $ 4,917 $ 696 Total current assets 4,917 696 Investments in subsidiaries 1,076,299 891,330 Total assets $ 1,081,216 $ 892,026 Liabilities and Stockholders' Equity Current liabilities: Accounts payable, including affiliates $ 437 $ — Other current liabilities 1,314 83 Total current liabilities 1,751 83 Long-term debt, net 58,015 37,607 Total liabilities 59,766 37,690 Stockholders' equity: Common stock, 100,412,036 and 83,980,885 shares issued as of December 31, 2020 and 2019, respectively, at $0.0001 par value 10 8 Additional paid-in capital—common stock 1,462,690 987,760 Accumulated deficit (441,250) (133,432) Total stockholders' equity 1,021,450 854,336 Total liabilities and stockholders' equity $ 1,081,216 $ 892,026 See accompanying notes to parent company condensed financial statements. SUNNOVA ENERGY INTERNATIONAL INC. CONDENSED STATEMENTS OF OPERATIONS (in thousands) Year Ended 2020 2019 2018 Revenue $ — $ — $ — General and administrative expense 2,972 418 — Operating loss (2,972) (418) — Interest expense, net 19,578 83 — Loss on extinguishment of long-term debt, net 142,772 — — Equity in losses of subsidiaries 142,496 132,933 — Loss before income tax (307,818) (133,434) — Income tax — — — Net loss $ (307,818) $ (133,434) $ — See accompanying notes to parent company condensed financial statements. SUNNOVA ENERGY INTERNATIONAL INC. CONDENSED STATEMENTS OF CASH FLOWS (in thousands) Year Ended 2020 2019 2018 CASH FLOWS FROM OPERATING ACTIVITIES Net cash used in operating activities $ (7,762) $ — $ — CASH FLOWS FROM INVESTING ACTIVITIES Investments in subsidiaries (334,471) (219,206) — Distributions from subsidiaries 10,547 2 — Net cash used in investing activities (323,924) (219,204) — CASH FLOWS FROM FINANCING ACTIVITIES Proceeds from long-term debt 106,400 38,087 — Payments of deferred financing costs (1,155) (377) — Proceeds from issuance of common stock, net 157,005 168,204 — Proceeds from equity component of debt instrument, net 73,657 13,984 — Other, net — 2 — Net cash provided by financing activities 335,907 219,900 — Net increase in cash 4,221 696 — Cash at beginning of period 696 — — Cash at end of period $ 4,917 $ 696 $ — Non-cash investing and financing activities: Non-cash conversion of convertible senior notes for common stock $ 149,352 $ — $ — Supplemental cash flow information: Cash paid for interest $ 9,191 $ — $ — Cash paid for income taxes $ — $ — $ — See accompanying notes to parent company condensed financial statements.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying annual audited consolidated financial statements ("consolidated financial statements") include our consolidated balance sheets, statements of operations, statements of redeemable noncontrolling interests and equity and statements of cash flows and have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") from records maintained by us. Our consolidated financial statements include our accounts and those of our subsidiaries in which we have a controlling financial interest. In accordance with the provisions of the Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") 810, Consolidation , we consolidate any VIE of which we are the primary beneficiary. We form VIEs with our investors in the ordinary course of business to facilitate the funding and monetization of certain attributes associated with our solar energy systems. The typical condition for a controlling financial interest is holding a majority of the voting interests of an entity. However, a controlling financial interest may also exist in entities, such as VIEs, through arrangements that do not involve holding a majority of the voting interests. We consolidate any VIE of which we are the primary beneficiary, which is defined as the party that has (a) the power to direct the activities of a VIE that most significantly impact the VIE's economic performance and (b) the obligation to absorb losses or receive benefits from the VIE that could potentially be significant to the VIE. We do not consolidate a VIE in which we have a majority ownership interest when we are not considered the primary beneficiary. We have considered the provisions within the contractual arrangements that grant us power to manage and make decisions that affect the operation of our VIEs, including determining the solar energy systems contributed to the VIEs, and the installation, operation and maintenance of the solar energy systems. We consider the rights granted to the other investors under the contractual arrangements to be more protective in nature rather than substantive participating rights. As such, we have determined we are the primary beneficiary of our VIEs and evaluate our relationships with our VIEs on an ongoing basis to determine whether we continue to be the primary beneficiary. We have eliminated all intercompany transactions in consolidation.
Adoption of ASU and New Accounting Guidance	Adoption of ASU In June 2016, the FASB issued Accounting Standards Update ("ASU") No. 2016-13, Financial Instruments—Credit Losses , which requires entities to use a forward-looking expected loss approach, referred to as the current expected credit loss ("CECL") methodology, in accordance with ASC 326, Financial Instruments—Credit Losses , instead of the incurred loss approach previously in effect when estimating the allowance for credit losses. Under CECL, financial assets measured at amortized cost are presented at the net amount expected to be collected by using an estimate of credit losses for the remaining estimated life of the financial asset based on historical experience, current conditions and reasonable and supportable forecasts. This ASU is effective for annual and interim reporting periods in 2020. In 2018 and 2019, the FASB issued the following ASUs related to ASU 2016-13: ASU No. 2018-19, Codification Improvements to Topic 326, Financial Instruments—Credit Losses , ASU 2019-05, Financial Instruments—Credit Losses: Targeted Transition Relief and ASU 2019-11, Codification Improvements to Topic 326, Financial Instruments—Credit Losses New Accounting Guidance New accounting pronouncements are issued by the FASB or other standard setting bodies and are adopted as of the specified effective date. In December 2019, the FASB issued ASU No. 2019-12, Income Taxes: Simplifying the Accounting for Income Taxes , to remove certain exceptions and clarify and amend the existing guidance. This ASU is effective for annual and interim reporting periods in 2021. We adopted this ASU in January 2021 and determined it did not have a significant impact on our consolidated financial statements and related disclosures. In March 2020, the FASB issued ASU No. 2020-03, Codification Improvements to Financial Instruments , to clarify and amend the existing guidance. The amendments in this ASU are effective either upon issuance of this ASU or for annual and interim reporting periods in 2020. We adopted this ASU in January 2020 and determined it did not have a significant impact on our consolidated financial statements and related disclosures. In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform: Facilitation of the Effects of Reference Rate Reform on Financial Reporting , to provide temporary optional expedients and exceptions for applying GAAP to contracts, hedging relationships and other transactions affected by reference rate reform. In 2021, the FASB issued ASU No. 2021-01, Reference Rate Reform: Scope , to refine the scope of ASC 848, Reference Rate Reform , and clarify guidance related to certain optional expedients and exceptions. This ASU and the supplemental ASU are effective beginning in March 2020 or prospectively from a date through December 2022. We adopted this ASU in October 2020 and determined it did not have a significant impact on our consolidated financial statements and related disclosures. In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options and Derivatives and Hedging—Contracts in Entity's Own Equity: Accounting for Convertible Instruments and Contracts in an Entity's Own Equity , to simplify the accounting for certain financial instruments with characteristics of liabilities and equity by removing the separation models for convertible debt with a cash conversion feature and convertible instruments with a beneficial conversion feature. This ASU also expands the required disclosures related to the terms and features of convertible instruments, how the instruments have been reported and information about events, conditions and circumstances that can affect how to assess the amount or timing of an entity's future cash flows related to those instruments. This ASU is effective for annual and interim reporting periods in 2022. We are currently evaluating the impact of this ASU on our consolidated financial statements and related disclosures. In October 2020, the FASB issued ASU No. 2020-10, Codification Improvements , to clarify and amend the existing guidance. This ASU is effective for annual and interim reporting periods in 2021. We adopted this ASU in January 2021 and determined it did not have a significant impact on our consolidated financial statements and related disclosures.
Reclassifications	Reclassifications Certain other prior period amounts have been reclassified to conform to the current period presentation. These reclassifications did not have a significant impact on our consolidated financial statements.
Use of Estimates	Use of Estimates The application of GAAP in the preparation of the consolidated financial statements requires us to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. We base our estimates on historical experience and on various other assumptions believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results could differ materially from those estimates.
Cash	Cash We maintain cash, which consists principally of demand deposits, with investment-grade financial institutions. We are exposed to credit risk to the extent cash balances exceed amounts covered by the Federal Deposit Insurance Corporation ("FDIC"). As of December 31, 2020 and 2019, we had cash deposits of $199.6 million and $72.4 million, respectively, in excess of the FDIC's current insured limit of $250,000. We have not experienced any losses on our deposits of cash.
Restricted Cash	Restricted CashWe record cash that is restricted as to withdrawal or use under the terms of certain contractual agreements as restricted cash. Our restricted cash primarily represents cash held to service certain payments under the Helios Issuer, LLC ("HELI"), Sunnova LAP Holdings, LLC ("LAPH"), Sunnova EZ-Own Portfolio, LLC ("EZOP"), Sunnova TEP IV-A, LLC ("TEPIVA"), Sunnova TEP IV-B, LLC ("TEPIVB"), Sunnova TEP Holdings, LLC ("TEPH"), Sunnova TEP II Holdings, LLC ("TEPIIH"), Helios II Issuer, LLC ("HELII"), Helios III Issuer, LLC ("HELIII"), Sunnova RAYS I Issuer, LLC ("RAYSI"), Sunnova TEP Inventory, LLC ("TEPINV"), Sunnova Sol Issuer, LLC ("SOLI"), Sunnova TEP IV-C, LLC ("TEPIVC"), Sunnova TEP IV-D, LLC ("TEPIVD"), Sunnova Helios IV Issuer, LLC ("HELIV"), Sunnova TEP IV-E, LLC ("TEPIVE"), Sunnova TEP IV-G, LLC ("TEPIVG"), Sunnova Asset Portfolio 8, LLC ("AP8") and Sunnova Sol II Issuer, LLC ("SOLII") financing arrangements (see Note 8, Long-Term Debt and Note 12, Redeemable Noncontrolling Interests and Noncontrolling Interests) and balances collateralizing outstanding letters of credit related to one of our operating leases for office space (see Note 16, Commitments and Contingencies).
Accounts Receivable	Accounts Receivable Accounts Receivable — Trade. Accounts receivable — trade primarily represents trade receivables from residential customers that are generally collected in the subsequent month. Accounts receivable — Accounts Receivable — Other. Accounts receivable — other primarily represents receivables related to the sale of inventory.
Inventory	InventoryInventory is stated at the lower of cost and net realizable value using the first-in, first-out method. Inventory primarily represents raw materials, such as energy storage systems, photovoltaic modules, inverters, meters and other associated equipment purchased. These materials are typically sold to dealers or held for use as original parts on new solar energy systems or replacement parts on existing solar energy systems. We remove these items from inventory and record the transaction in typically one of these manners: (a) expense to operations and maintenance expense when installed as a replacement part for a solar energy system, (b) expense to cost of sales if sold directly or (c) capitalize to property and equipment when installed as an original part on a solar energy system. We periodically evaluate our inventory for unusable and obsolete items based on assumptions about future demand and market conditions.
Concentrations of Risk	Concentrations of Risk Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash, restricted cash, accounts receivable and notes receivable. The concentrated risk associated with cash and restricted cash is mitigated by our policy of banking with creditworthy institutions. Typically, amounts on deposit with certain banking institutions exceed FDIC insurance limits. We do not generally require collateral or other security to support accounts receivable. To reduce credit risk related to our relationship with our dealers, management performs periodic credit evaluations and ongoing assessments of our dealers' financial condition.
Dealer Commitments	Dealer Commitments We enter into exclusivity and other similar agreements with certain key dealers pursuant to which we agree to pay an incentive if such dealers install a certain minimum number of solar energy systems within specified periods. These incentives are recorded in other assets in the consolidated balance sheets and are amortized to general and administrative expense in the consolidated statements of operations generally over the term of the customer agreements, which is estimated at an average of 23 years. See Note 16, Commitments and Contingencies.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value is an exit price representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions market participants would use in pricing an asset or a liability. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. ASC 820 establishes a three-tier fair value hierarchy, which prioritizes inputs that may be used to measure fair value as follows: • Level 1—Observable inputs that reflect unadjusted quoted market prices in active markets for identical assets or liabilities that are accessible at the measurement date. • Level 2—Observable inputs other than Level 1 prices, such as quoted market prices for similar assets or liabilities in active markets, quoted market prices in markets that are not active or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the level in the fair value hierarchy must be determined based on the lowest level input that is significant to the fair value measurement. An assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and consideration of factors specific to the asset or liability. Our financial instruments include accounts receivable, notes receivable, accounts payable, accrued expenses, long-term debt and interest rate swaps. The carrying values of accounts receivable, accounts payable and accrued expenses approximate the fair values due to the fact that they are short-term in nature (Level 1). We estimate the fair value of our customer notes receivable based on interest rates currently offered under the loan program with similar maturities and terms (Level 3). We estimate the fair value of our fixed-rate long-term debt based on interest rates currently offered for debt with similar maturities and terms (Level 3). We determine the fair values of the interest rate derivative transactions based on a discounted cash flow method using contractual terms of the transactions. The floating interest rate is based on observable rates consistent with the frequency of the interest cash flows (Level 2). See Note 7, Customer Notes Receivable, Note 8, Long-Term Debt and Note 9, Derivative Instruments.
Derivative Instruments	Derivative Instruments Our derivative instruments consist of interest rate swaps that are not designated as cash flow hedges or fair value hedges under accounting guidance. We use interest rate swaps to manage our net exposure to interest rate changes. We record the derivatives in other current assets, other assets, other current liabilities and other long-term liabilities, as appropriate, in the consolidated balance sheets and the changes in fair value are recorded in interest expense, net in the consolidated statements of operations. We include unrealized gains and losses on derivatives as a non-cash reconciling item in operating activities in the consolidated statements of cash flows. We include realized gains and losses on derivatives as a change in components of operating assets and liabilities in operating activities in the consolidated statements of cash flows. See Note 9, Derivative Instruments.
Revenue / Loans / Deferred Revenue	Revenue We recognize revenue from contracts with customers as we satisfy our performance obligations at a transaction price reflecting an amount of consideration based upon an estimated rate of return. We express this rate of return as the solar rate per kilowatt hour ("kWh") in the customer contract. The amount of revenue we recognize does not equal customer cash payments because we satisfy performance obligations ahead of cash receipt or evenly as we provide continuous access on a stand-ready basis to the solar energy system. We reflect the differences between revenue recognition and cash payments received in accounts receivable, other assets or deferred revenue, as appropriate. Revenue allocated to remaining performance obligations represents contracted revenue we have not yet recognized and includes deferred revenue as well as amounts that will be invoiced and recognized as revenue in future periods. Contracted but not yet recognized revenue was approximately $1.6 billion as of December 31, 2020, of which we expect to recognize approximately 4% over the next 12 months. We do not expect the annual recognition to vary significantly over approximately the next 20 years as the vast majority of existing solar service agreements have at least 20 years remaining, given the average age of the fleet of solar energy systems under contract is less than three years. PPAs. Customers purchase electricity from us under PPAs. Pursuant to ASC 606, we recognize revenue based upon the amount of electricity delivered as determined by remote monitoring equipment at solar rates specified under the PPAs. All customers must pass our credit evaluation process. The PPAs generally have a term of 25 years with an opportunity for customers to renew for up to an additional 10 years, via two five-year renewal options. Leases . We are the lessor under lease agreements for solar energy systems and energy storage systems, which do not meet the definition of a lease under ASC 842 and are accounted for as contracts with customers under ASC 606. We recognize revenue on a straight-line basis over the contract term as we satisfy our obligation to provide continuous access to the solar energy system. All customers must pass our credit evaluation process. The lease agreements generally have a term of 25 years with an opportunity for customers to renew for up to an additional 10 years, via two five-year renewal options. We provide customers under our lease agreements a performance guarantee that each solar energy system will achieve a certain specified minimum solar energy production output, which is a significant proportion of its expected output. The specified minimum solar energy production output may not be achieved due to natural fluctuations in the weather or equipment failures from exposure and wear and tear outside of our control, among other factors. We determine the amount of the guaranteed output based on a number of different factors, including: (a) the specific site information relating to the tilt of the panels, azimuth (a horizontal angle measured clockwise in degrees from a reference direction) of the panels, size of the system, and shading on site; (b) the calculated amount of available irradiance (amount of energy for a given flat surface facing a specific direction) based on historical average weather data and (c) the calculated amount of energy output of the solar energy system. While actual irradiance levels can significantly change year over year due to natural fluctuations in the weather, we expect the levels to average out over the term of a 25-year lease and to approximate the levels used in determining the amount of the performance guarantee. Generally, weather fluctuations are the most likely reason a solar energy system may not achieve a certain specified minimum solar energy production output. If the solar energy system does not produce the guaranteed production amount, we are required to refund a portion of the previously remitted customer payments, where the repayment is calculated as the product of (a) the shortfall production amount and (b) the dollar amount (guaranteed rate) per kWh that is fixed throughout the term of the contract. These remittances of a customer's payments, if needed, are payable in January following the end of the first three years of the solar energy system's placed in service date and then every annual period thereafter. See Note 16, Commitments and Contingencies. Solar Renewable Energy Certificates. Each solar renewable energy certificate ("SREC") represents one megawatt hour (1,000 kWh) generated by a solar energy system. SRECs can be sold with or without the actual electricity associated with the renewable-based generation source. We account for the SRECs we generate from our solar energy systems as governmental incentives with no costs incurred to obtain them and do not consider those SRECs output of the underlying solar energy systems. We classify these SRECs as inventory held until sold and delivered to third parties. As we did not incur costs to obtain these governmental incentives, the inventory carrying value for the SRECs was $0 as of December 31, 2020 and 2019. We enter into economic hedges related to expected production of SRECs through forward contracts. The contracts require us to physically deliver the SRECs upon settlement. We recognize the related revenue under ASC 606 upon satisfaction of the performance obligation to transfer the SRECs to the stated counterparty. Payments are typically received within one month of transferring the SREC to the counterparty. The costs related to the sales of SRECs are generally limited to broker fees (recorded in cost of revenue—other), which are only paid in connection with certain transactions. In certain circumstances we are required to purchase SRECs on the open market to fulfill minimum delivery requirements under our forward contracts. Loans. See discussion of loan revenue in the " Loans " section below. Other Revenue. Other revenue includes certain state and utility incentives, revenue from the direct sale of energy storage systems to customers and sales of service plans. We recognize revenue from state and utility incentives in the periods in which they are earned. We recognize revenue from the direct sale of energy storage systems in the period in which the storage components are placed in service. Service plans are available to customers whose solar energy system was not originally sold by Sunnova. We recognize revenue from service plan contracts over the life of the contract, which is typically five years or ten years. Loans We offer a loan program, under which the customer finances the purchase of a solar energy system or energy storage system through a solar service agreement, typically for a term of 10, 15 or 25 years. We recognize cash payments received from customers on a monthly basis under our loan program (a) as interest income, to the extent attributable to earned interest on the contract that financed the customer's purchase of the solar energy system or energy storage system; (b) as a reduction of a note receivable on the balance sheet, to the extent attributable to a return of principal (whether scheduled or prepaid) on the contract that financed the customer's purchase of the solar energy system or energy storage system; and (c) as revenue, to the extent attributable to payments for operations and maintenance services provided by us. To qualify for the loan program, a customer must pass our credit evaluation process, which requires the customer to have a minimum FICO ® score of 650 to 720 depending on certain circumstances, and we secure the loans with the solar energy systems or energy storage systems financed. The credit evaluation process is performed once for each customer at the time the customer is entering into the solar service agreement with us. Our investments in solar energy systems and energy storage systems related to the loan program that are not yet placed in service are recorded in other assets in the consolidated balance sheets and are transferred to customer notes receivable upon being placed in service. Customer notes receivable are recorded at amortized cost, net of an allowance for credit losses (as described below), in other current assets and customer notes receivable in the consolidated balance sheets. Accrued interest receivable related to our customer notes receivable is recorded in accounts receivable—trade, net in the consolidated balance sheets. Interest income from customer notes receivable is recorded in interest income in the consolidated statements of operations. The amortized cost of our customer notes receivable is equal to the principal balance of customer notes receivable outstanding and does not include accrued interest receivable. Customer notes receivable continue to accrue interest until they are written off against the allowance, which occurs when the balance is 180 days or more past due unless the balance is in the process of collection. Customer notes receivable are considered past due one day after the due date based on the contractual terms of the loan agreement. In all cases, customer notes receivable balances are placed on a nonaccrual status or written off at an earlier date when they are deemed uncollectible. Expected recoveries do not exceed the aggregate of amounts previously written off and expected to be written off. Accrued interest receivable for customer notes receivable placed on a nonaccrual status is recorded as a reduction to interest income. Interest received on such customer notes receivable is accounted for on a cash basis until the customer notes receivable qualifies for the return to accrual status. Customer notes receivable are returned to accrual status when there is no longer any principal or interest amounts past due and future payments are reasonably assured. The allowance for credit losses is deducted from the customer notes receivable amortized cost to present the net amount expected to be collected. It is measured on a collective (pool) basis when similar risk characteristics (such as financial asset type, customer credit rating, contractual term and vintage) exist. In determining the allowance for credit losses, we identify customers with potential disputes or collection issues and consider our historical level of credit losses and current economic trends that might impact the level of future credit losses. Adjustments to historical loss information are made for differences in current loan-specific risk characteristics, such as differences in underwriting standards. Expected credit losses are estimated over the contractual term of the loan agreements based on the best available data at the time, and adjusted for expected prepayments when appropriate. The contractual term excludes expected extensions, renewals and modifications unless either of the following applies: (a) we have a reasonable expectation at the reporting date that a troubled debt restructuring will be executed with an individual customer or (b) the extension or renewal options are included in the original or modified contract at the reporting date and are not unconditionally cancelable by us. As of December 31, 2020, we have not experienced a significant increase in delinquent customer notes receivable and have not made any significant adjustments to our allowance for credit losses related to loans as a result of the COVID-19 pandemic. See Note 7, Customer Notes Receivable. Deferred Revenue
Performance Guarantee Obligations	Performance Guarantee Obligations We guarantee certain specified minimum solar energy production output under our leases and loan agreements, generally over a term of 10, 15 or 25 years. The amounts are generally measured and credited to the customer's account in January following the end of the first three years of the solar energy system's placed in service date and then every annual period thereafter. We monitor the solar energy systems to ensure these outputs are achieved. We evaluate if any amounts are due to our customers based upon not meeting the guaranteed solar energy production outputs at each reporting period end. For leases, these estimated amounts are recorded as a reduction to revenues from customers and a current or long-term liability, as applicable. For loans, these estimated amounts are recorded as an increase to cost of revenue—other and a current or long-term liability, as applicable. See Note 16, Commitments and Contingencies.
Property and Equipment	Property and Equipment Solar Energy Systems. Depreciation and amortization of solar energy systems are calculated using the straight-line method over the estimated useful lives of the solar energy systems and are recorded in cost of revenue—depreciation. While solar energy systems are in the design, construction and installation stages prior to being placed in service, the development of the systems is accounted for through construction in progress. The components of the design, construction and installation of the solar energy systems, which are installed on or near residential rooftops, are as follows: • Dealer's costs (engineering, procurement and construction) • Direct costs (costs directly related to a solar energy system) • Indirect costs (costs incurred in the design, construction and installation of the solar energy system but not directly associated with a particular asset) Solar energy systems are carried at the cost of acquisition or construction (including design and installation) less certain utility rebates and federal and state tax incentives (including federal investment tax credits, known as "Section 48(a) ITCs") and are depreciated over the useful lives of the assets. We account for the Section 48(a) ITCs in accordance with the deferral gross up method, thus reducing the cost basis of the qualifying solar energy systems by the rate applicable to Section 48(a) ITCs. However, as discussed in Note 10, Income Taxes, we have a full valuation allowance, which is recorded against deferred income taxes and requires the gross up of the basis of the qualifying solar energy systems back to the full value. Depreciation begins when a solar energy system is placed in service. Costs associated with repair and maintenance of a solar energy system are expensed as incurred. Costs associated with improvements to a solar energy system, which extend the life, increase the capacity or improve the efficiency of the systems, are capitalized and depreciated over the remaining life of the asset. Property and Equipment, Excluding Solar Energy Systems . Property and equipment, including information technology system projects, computers and equipment, leasehold improvements, furniture and fixtures, vehicles and other property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization are calculated using the straight-line method over the estimated useful lives of the respective assets and are recorded in general and administrative expense. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful lives. Upon disposition, the cost and related accumulated depreciation of the assets are removed from property and equipment and the resulting gain or loss is reflected in the consolidated statements of operations. Repair and maintenance costs are expensed as incurred.
Intangibles	IntangiblesOur intangible assets primarily consist of a software license and a trademark related to the design process of solar energy systems and are stated at cost less accumulated amortization. We amortize intangible assets to general and administrative expense over a useful life of three years using the straight-line method.
Deferred Financing Costs	Deferred Financing CostsDeferred financing costs are capitalized and amortized to interest expense, net over the term of the related debt using the effective interest method for term loans or the straight-line method for revolving credit facilities. The unamortized balance of deferred financing costs is recorded in current portion of long-term debt, current portion of long-term debt—affiliates, long-term debt, net and long-term debt, net—affiliates (see Note 8, Long-Term Debt) for term loans or in other current assets and other assets for revolving credit facilities and debt and equity transactions not yet completed, in the consolidated balance sheets.
Asset Retirement Obligation	Asset Retirement Obligation ("ARO") We have AROs arising from contractual requirements to perform certain asset retirement activities at the time the solar energy systems are disposed. We recognize an ARO at the point an obligating event takes place, typically when the solar energy system is placed in service. An asset is considered retired when it is permanently taken out of service, such as through a sale or disposal. The liability is initially measured at fair value (as a Level 3 measurement) based on the present value of estimated removal and restoration costs and subsequently adjusted for changes in the underlying assumptions and for accretion expense. The accretion expense is recognized in general and administrative expense in the consolidated statements of operations. The corresponding asset retirement costs are capitalized as part of the carrying amount of the solar energy system and depreciated (for which the expense is recorded in cost of revenue — depreciation) over the solar energy system's remaining useful life. See Note 6, AROs.
Warranty Obligations	Warranty Obligations In connection with our solar service agreements, we warrant the solar energy systems against defects in workmanship, against component or materials breakdowns and against any damages to rooftops during the installation process. The dealers' warranties on the workmanship, including work during the installation process, and the manufacturers' warranties over component parts have a range of warranty periods which are generally 10 to 25 years. As of December 31, 2020 and 2019, we recorded a warranty reserve of $0 and an insignificant amount, respectively.
Advertising Costs	Advertising Costs We expense advertising costs as they are incurred to general and administrative expense in the consolidated statements of operations. We recognized advertising expense of $195,000, $1.0 million and $191,000 during the years ended December 31, 2020, 2019 and 2018, respectively.
Defined Contribution Plan	Defined Contribution Plan In April 2015, we established the Sunnova Energy Corporation 401(k) Profit Sharing Plan ("401(k) plan") available to employees who meet the 401(k) plan's eligibility requirements. The 401(k) plan allows participants to contribute a percentage of their compensation to the 401(k) plan up to the limits set forth in the Internal Revenue Code. We may make additional discretionary contributions to the 401(k) plan as a percentage of total participant contributions, subject to established limits. Participants are fully vested in their contributions and any safe harbor matching contributions we make. We made safe harbor matching contributions of $820,000, $736,000 and $551,000 during the years ended December 31, 2020, 2019 and 2018, respectively, which are recorded in general and administrative expense in the consolidated statements of operations.
Income Taxes	Income Taxes We account for income taxes under an asset and liability approach. Deferred income taxes reflect the impact of temporary differences between assets and liabilities recognized for financial reporting purposes and the amounts recognized for income tax reporting purposes, net operating loss, carryforwards, and other tax credits measured by applying currently enacted tax laws. A valuation allowance is provided when necessary to reduce deferred tax assets to an amount that is more likely than not to be realized. We determine whether a tax position taken in a filed tax return, planned to be taken in a future tax return or claim, or otherwise subject to interpretation, is more likely than not to be sustained upon examination, including resolution of any related appeals or litigation processes, based on the technical merits of the position, or prospectively approved when such approval may be sought in advance. We use a two-step approach to recognize and measure uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the available evidence indicates it is more likely than not the position will be sustained upon tax authority examination, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit or obligation as the largest amount that is more than 50% likely of being realized upon ultimate settlement. See Note 10, Income Taxes.
Comprehensive Income (Loss)	Comprehensive Income (Loss) We are required to report comprehensive income (loss), which includes net income (loss) as well as other comprehensive income (loss). There were no differences between comprehensive loss and net loss as reported in the consolidated statements of operations for the periods presented.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets Long-lived assets, such as property and equipment, are reviewed for impairment whenever events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset be tested for possible impairment, we first compare undiscounted cash flows expected to be generated by that asset or asset group to its carrying value. If the carrying value of the long-lived asset or asset group is not recoverable on an undiscounted cash flow basis, impairment is recognized to the extent the carrying value exceeds its fair value. Fair value is determined through various valuation techniques including discounted cash flow models, quoted market values and third-party independent appraisals as considered necessary. Impairment charges are recorded in operations and maintenance expense for solar energy systems that relate to revenue from contracts with customers and general and administrative expense for all other property and equipment and other long-lived assets. During the years ended December 31, 2020, 2019 and 2018, we recognized net losses on disposals and impairment expense of $5.8 million, $1.8 million and $7.6 million, respectively, of which $5.8 million, $1.8 million and $7.4 million, respectively, is recorded in operations and maintenance expense and an insignificant amount is recorded in general and administrative expense. Of the total amount of net losses on disposals and impairment expense for the years ended December 31, 2020, 2019 and 2018, $31,000, $54,000 and $5.8 million, respectively, is related to natural disaster losses. See Note 4, Natural Disaster Losses.
Segment Information	Segment Information Operating segments are defined as components of a company about which separate financial information is available that is evaluated regularly by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. Our chief operating decision maker is the chief executive officer. Based on the financial information presented to and reviewed by our chief operating decision maker in deciding how to allocate resources and in assessing performance, we have determined we have a single reportable segment: solar energy products and services. Our principal operations, revenue and decision-making functions are located in the U.S.
Basic and Diluted Net Income (Loss) Per Share	Basic and Diluted Net Income (Loss) Per Share Our basic net income (loss) per share attributable to common stockholders is calculated by dividing the net income (loss) attributable to the common stockholders by the weighted-average number of shares of common stock outstanding for the period. Cumulative dividends owed to convertible preferred stockholders (as defined in Note 13, Stockholders' Equity) decrease (increase) the income (loss) available to common stockholders. The diluted net income (loss) per share attributable to common stockholders is computed by giving effect to all potential common stock equivalents outstanding for the period determined using the treasury stock method or the if-converted method, as applicable. During periods in which we incur a net loss attributable to common stockholders, stock options are considered to be common stock equivalents but are excluded from the calculation of diluted net loss per share attributable to common stockholders as the effect is antidilutive. See Note 15, Basic and Diluted Net Loss Per Share.
Equity-Based Compensation	Equity-Based Compensation We account for equity-based compensation, which requires the measurement and recognition of compensation expense related to the fair value of equity-based compensation awards. Equity-based compensation expense includes the compensation cost for all share-based awards granted to employees, consultants and members of our board of directors (our "Board") based on the grant date fair value estimate. This also applies to awards modified, repurchased or canceled during the periods reported. We use the Black-Scholes option-pricing model to measure the fair value of stock options at the measurement date. We use the closing price of our common stock on the grant date to measure the fair value of restricted stock units at the measurement date. We account for forfeitures as they occur. Equity-based compensation expense is recorded in general and administrative expense in the consolidated statements of operations. See Note 14, Equity-Based Compensation.
Redeemable Noncontrolling Interests and Noncontrolling Interests	Redeemable Noncontrolling Interests and Noncontrolling Interests Noncontrolling interests represent third-party interests in the net assets of certain consolidated subsidiaries (the "tax equity entities"). For these tax equity entities, we have determined the appropriate methodology for calculating the noncontrolling interest balances that reflects the substantive economic arrangements in the operating agreements is a balance sheet approach using the hypothetical liquidation at book value ("HLBV") method. Under the HLBV method, the amounts reported as noncontrolling interests in the consolidated balance sheets represent the amounts third-party investors would hypothetically receive at each balance sheet date under the liquidation provisions of the operating agreements, assuming the net assets of the subsidiaries were liquidated at amounts determined in accordance with GAAP and distributed to the investors. The noncontrolling interest balances in these subsidiaries are reported as a component of equity in the consolidated balance sheets. The amount of income or loss allocated to noncontrolling interests in the results of operations for the subsidiaries using HLBV are determined as the difference in the noncontrolling interest balances in the consolidated balance sheets at the start and end of each reporting period, after taking into account any capital transactions between the subsidiaries and the third-party investors. Factors used in the HLBV calculation include GAAP income (loss), taxable income (loss), capital contributions, investment tax credits, distributions and the stipulated targeted investor return specified in the subsidiaries' operating agreements. Changes in these factors could have a significant impact on the amounts that investors would receive upon a hypothetical liquidation. The use of the HLBV method to allocate income (loss) to the noncontrolling interest holders may create volatility in the consolidated statements of operations as the application of HLBV can drive changes in net income or loss attributable to noncontrolling interests from period to period. We classify certain noncontrolling interests with redemption features that are not solely within our control outside of permanent equity in the consolidated balance sheets. Redeemable noncontrolling interests are reported using the greater of the carrying value at each reporting date as determined by the HLBV method or the estimated redemption value at the end of each reporting period. Estimating the redemption value of the redeemable noncontrolling interests requires the use of significant assumptions and estimates, such as projected future cash flows at the time the redemption feature can be exercised. The redeemable noncontrolling interests and noncontrolling interests are recorded net of related issuance costs and net of the basis difference in the solar energy systems transferred to the tax equity entities in the consolidated balance sheets. This basis difference is reflected as equity in subsidiaries attributable to parent in the consolidated statements of redeemable noncontrolling interests and equity.

Description of Business and B_2

Description of Business and Basis of Presentation (Tables)	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of new accounting pronouncements and changes in accounting principles	The following table presents the impact of the adoption of ASU No. 2016-13 on the consolidated balance sheet: As of January 1, 2020 As Reported Impact of ASC Pre-ASC 326 (in thousands) Accounts receivable—trade, net $ 10,912 $ 240 $ 10,672 Other current assets 173,565 (451) 174,016 Customer notes receivable 289,191 (8,784) 297,975 Other assets 168,799 (913) 169,712 Accumulated deficit (371,732) (9,908) (361,824)
Schedule of accounting revisions	The following tables present the impact of these revisions on our consolidated financial statements: As of December 31, 2019 As Previously Revisions As (in thousands) Redeemable noncontrolling interests $ 172,305 $ (45,176) $ 127,129 Noncontrolling interests — 45,176 45,176 Redeemable Noncontrolling As Previously Revisions As As Previously Revisions As (in thousands) December 31, 2018 $ 85,680 $ — $ 85,680 $ — $ — $ — Net income 10,917 (2,396) 8,521 — 2,396 2,396 Contributions from redeemable noncontrolling interests and noncontrolling interests 157,149 (79,570) 77,579 — 79,570 79,570 Distributions to redeemable noncontrolling interests (7,559) — (7,559) — — — Costs related to redeemable noncontrolling interests and noncontrolling interests (7,392) 5,054 (2,338) — (5,054) (5,054) Equity in subsidiaries attributable to parent (68,848) 31,736 (37,112) — (31,736) (31,736) Other, net 2,358 — 2,358 — — — December 31, 2019 $ 172,305 $ (45,176) $ 127,129 $ — $ 45,176 $ 45,176

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Details of restricted cash	The following table presents the detail of restricted cash as recorded in other current assets and other assets in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Debt and inverter reserves $ 93,889 $ 55,407 Tax equity reserves 72,426 9,904 Letters of credit for office lease 375 725 Other 1,344 770 Total (1) $ 168,034 $ 66,806 (1) Of this amount, $73.0 million and $10.5 million is recorded in other current assets as of December 31, 2020 and 2019, respectively.
Changes in the allowance for doubtful accounts	The following table presents the changes in the allowance for credit losses recorded against accounts receivable — trade, net in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Balance at beginning of period $ 960 $ 723 Impact of ASC 326 adoption (240) — Provision for current expected credit losses 1,878 — Bad debt expense — 1,645 Write off of uncollectible accounts (1,741) (1,498) Recoveries 55 90 Balance at end of period $ 912 $ 960 The following table presents the changes in the allowance for credit losses related to customer notes receivable as recorded in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Balance at beginning of period $ 1,091 $ 710 Impact of ASC 326 adoption 9,235 — Provision for current expected credit losses (1) 7,785 — Bad debt expense — 419 Write off of uncollectible accounts (443) (38) Balance at end of period $ 17,668 $ 1,091 (1) In addition, we recognized $184,000 of provision for current expected credit losses during the year ended December 31, 2020 related to our long-term receivables for our leases.
Schedule of inventory	The following table presents the detail of inventory as recorded in other current assets in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Energy storage systems and components $ 18,122 $ 33,443 Modules and inverters 83,904 10,137 Meters 563 169 Total $ 102,589 $ 43,749
Disaggregation of revenue	The following table presents the detail of revenue as recorded in the consolidated statements of operations: Year Ended 2020 2019 2018 (in thousands) PPA revenue $ 65,760 $ 48,041 $ 38,950 Lease revenue 51,650 40,191 33,079 Solar renewable energy certificate revenue 35,747 38,453 30,630 Loan revenue 3,032 1,645 933 Other revenue 4,631 3,226 790 Total $ 160,820 $ 131,556 $ 104,382
Deferred revenue schedule	The following table presents the detail of deferred revenue as recorded in other current liabilities and other long-term liabilities in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Loans $ 93,859 $ 46,958 PPAs and leases 11,787 8,895 SRECs 1,163 3,000 Total (1) $ 106,809 $ 58,853 (1) Of this amount, $3.8 million and $2.1 million is recorded in other current liabilities as of December 31, 2020 and 2019, respectively.
Schedule of Intangible Assets	The following table presents the detail of intangible assets as recorded in other assets in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Software license $ 331 $ 331 Trademark 68 68 Other 88 88 Intangibles, gross 487 487 Less: accumulated amortization (449) (420) Intangibles, net $ 38 $ 67
Changes in deferred financing costs	The following table presents the changes in net deferred financing costs: As of December 31, 2020 2019 (in thousands) Balance at beginning of period $ 25,621 $ 22,712 Capitalized 23,202 12,731 Amortized (9,031) (9,822) Balance at end of period $ 39,792 $ 25,621

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Property and equipment	The following table presents the detail of property and equipment, net as recorded in the consolidated balance sheets: As of December 31, Useful Lives 2020 2019 (in years) (in thousands) Solar energy systems 35 $ 2,298,427 $ 1,689,457 Construction in progress 160,618 143,449 Asset retirement obligations 30 35,532 26,967 Information technology systems 3 35,077 28,320 Computers and equipment 3-5 1,727 1,499 Leasehold improvements 3-6 2,770 1,014 Furniture and fixtures 7 811 735 Vehicles 4-5 1,638 1,632 Other 5-6 157 146 Property and equipment, gross 2,536,757 1,893,219 Less: accumulated depreciation (213,588) (148,159) Property and equipment, net $ 2,323,169 $ 1,745,060

Natural Disaster Losses (Tables

Natural Disaster Losses (Tables)	12 Months Ended
	Dec. 31, 2020
Unusual or Infrequent Items, or Both [Abstract]
Schedule of disaster losses	The impact of the natural disaster losses as recorded in the consolidated statements of operations for the years ended December 31, 2020, 2019 and 2018 is as follows: Year Ended 2020 2019 2018 (in thousands) Operations and maintenance expense: Impairment of solar energy systems due to natural disaster losses $ — $ — $ 5,840 Insurance proceeds received/expected to be received—property damage 31 54 (53) Insurance proceeds received—business interruption — — (2,693) Other natural disaster-related charges — — 1,679 General and administrative expense: Other natural disaster-related charges — — 750 Total $ 31 $ 54 $ 5,523

Detail of Certain Balance She_2

Detail of Certain Balance Sheet Captions (Tables)	12 Months Ended
	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of other current assets	The following table presents the detail of other current assets as recorded in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Inventory $ 102,589 $ 43,749 Restricted cash 73,020 10,474 Current portion of customer notes receivable 24,035 13,758 Other prepaid assets 8,645 7,380 Prepaid inventory 3,352 96,167 Deferred receivables 2,678 1,506 Current portion of other notes receivable 853 982 Other 3 — Total $ 215,175 $ 174,016
Schedule of other assets	The following table presents the detail of other assets as recorded in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Restricted cash $ 95,014 $ 56,332 Construction in progress - customer notes receivable 85,604 37,137 Exclusivity and other bonus arrangements with dealers, net 55,709 32,791 Straight-line revenue adjustment, net 33,411 24,852 Other 24,634 18,600 Total $ 294,372 $ 169,712
Schedule of other current liabilities	The following table presents the detail of other current liabilities as recorded in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Interest payable $ 17,718 $ 14,680 Deferred revenue 3,754 2,086 Current portion of performance guarantee obligations 3,308 4,067 Current portion of lease liability 1,206 561 Other 27 410 Total $ 26,013 $ 21,804

AROs (Tables)

AROs (Tables)	12 Months Ended
	Dec. 31, 2020
Asset Retirement Obligation Disclosure [Abstract]
Schedule of changes in AROs	The following table presents the changes in AROs as recorded in other long-term liabilities in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Balance at beginning of period $ 31,053 $ 20,033 Additional obligations incurred 8,633 4,641 Accretion expense 2,186 1,443 Change in estimate — 4,983 Other (84) (47) Balance at end of period $ 41,788 $ 31,053

Customer Notes Receivable (Tabl

Customer Notes Receivable (Tables)	12 Months Ended
	Dec. 31, 2020
Receivables [Abstract]
Fair values of notes receivable and corresponding carrying amounts	The following table presents the detail of customer notes receivable as recorded in the consolidated balance sheets and the corresponding fair values: As of December 31, 2020 2019 (in thousands) Customer notes receivable $ 555,089 $ 312,823 Allowance for credit losses (17,668) (1,091) Customer notes receivable, net (1) $ 537,421 $ 311,732 Estimated fair value, net $ 548,238 $ 314,222 (1) Of this amount, $24.0 million and $13.8 million is recorded in other current assets as of December 31, 2020 and 2019, respectively.
Changes in the allowance for doubtful accounts	The following table presents the changes in the allowance for credit losses recorded against accounts receivable — trade, net in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Balance at beginning of period $ 960 $ 723 Impact of ASC 326 adoption (240) — Provision for current expected credit losses 1,878 — Bad debt expense — 1,645 Write off of uncollectible accounts (1,741) (1,498) Recoveries 55 90 Balance at end of period $ 912 $ 960 The following table presents the changes in the allowance for credit losses related to customer notes receivable as recorded in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Balance at beginning of period $ 1,091 $ 710 Impact of ASC 326 adoption 9,235 — Provision for current expected credit losses (1) 7,785 — Bad debt expense — 419 Write off of uncollectible accounts (443) (38) Balance at end of period $ 17,668 $ 1,091 (1) In addition, we recognized $184,000 of provision for current expected credit losses during the year ended December 31, 2020 related to our long-term receivables for our leases.
Financing receivable, past due	The following table presents the aging of the amortized cost of customer notes receivable as of December 31, 2020: As of December 31, 2020 2019 (in thousands) 1-90 days past due $ 8,504 $ 5,741 91-180 days past due 1,733 1,714 Greater than 180 days past due 6,855 3,331 Total past due 17,092 10,786 Not past due 537,997 302,037 Total $ 555,089 $ 312,823
Financing receivable amortized cost of customer notes receivable	The following table presents the amortized cost by origination year of our customer notes receivable based on payment activity. Amortized Cost by Origination Year 2020 2019 2018 2017 2016 Prior Total (in thousands) Payment performance: Performing $ 266,756 $ 134,152 $ 86,815 $ 31,042 $ 19,522 $ 9,947 $ 548,234 Nonperforming (1) 280 1,275 1,910 1,972 1,215 203 $ 6,855 Total $ 267,036 $ 135,427 $ 88,725 $ 33,014 $ 20,737 $ 10,150 $ 555,089 (1) A nonperforming loan is a loan in which the customer is in default and has not made any scheduled principal or interest payments for 181 days or more.

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Schedule of long-term debt instruments	The following table presents the detail of long-term debt, net as recorded in the consolidated balance sheets: Year Ended As of December 31, 2020 Year Ended As of December 31, 2019 Long-term Current Long-term Current (in thousands, except interest rates) SEI 7.75% convertible senior notes 17.41 % $ — $ — 7.75 % $ 55,000 $ — 9.75% convertible senior notes 14.53 % 95,648 — — — Debt discount, net (37,394) — (16,913) — Deferred financing costs, net (239) — (480) — Sunnova Energy Corporation Notes payable 7.14 % — 2,254 3.22 % — 2,428 AP4 Secured term loan 10.81 % — — 5.61 % 86,369 6,109 Debt discount, net — — (452) — Deferred financing costs, net — — (196) — HELI Solar asset-backed notes 6.55 % 205,395 6,329 6.56 % 213,632 8,673 Debt discount, net (2,241) — (3,169) — Deferred financing costs, net (4,004) — (5,586) — LAPH Secured term loan 11.34 % — — 7.71 % 41,484 1,392 Debt discount, net — — (401) — Deferred financing costs, net — — (356) — EZOP Warehouse credit facility 4.39 % 171,600 — 6.60 % 121,400 — Debt discount, net (1,431) — (2,178) — TEPIIH Revolving credit facility 19.47 % — — 6.36 % 234,650 — Debt discount, net — — (2,219) — HELII Solar asset-backed notes 5.71 % 227,574 11,707 5.77 % 241,309 13,005 Debt discount, net (42) — (49) — Deferred financing costs, net (5,085) — (5,873) — RAYSI Solar asset-backed notes 5.49 % 120,391 5,836 5.47 % 126,828 6,327 Debt discount, net (1,376) — (1,547) — Deferred financing costs, net (4,334) — (4,759) — HELIII Solar loan-backed notes 4.01 % 122,047 13,065 4.03 % 135,543 19,030 Debt discount, net (2,423) — (2,532) — Deferred financing costs, net (2,326) — (2,410) — TEPH Revolving credit facility 5.81 % 239,570 — 6.70 % 90,325 — Debt discount, net (3,815) — (645) — TEPINV Revolving credit facility 10.80 % 25,240 29,464 7.95 % 54,707 40,500 Debt discount, net (1,322) — (2,856) — Deferred financing costs, net (1,758) — (2,207) — SOLI Solar asset-backed notes 3.91 % 384,258 15,416 — — Debt discount, net (113) — — — Deferred financing costs, net (8,915) — — — HELIV Solar loan-backed notes 3.97 % 129,648 16,515 — — Debt discount, net (885) — — — Deferred financing costs, net (3,905) — — — AP8 Revolving credit facility 5.31 % 42,047 4,386 — — SOLII Solar asset-backed notes 3.18 % 248,789 5,911 — — Debt discount, net (80) — — — Deferred financing costs, net (5,866) — — — Total $ 1,924,653 $ 110,883 $ 1,346,419 $ 97,464
Debt instrument redemption	At any time on or after May 14, 2023, we may, at our option, redeem for cash all (but not less than all) of the 9.75% convertible senior notes at the redemption price (expressed as percentages of principal amount) set forth below, plus any accrued and unpaid interest, if any, to, but excluding, the redemption date: Period Percentage At any time on and after May 14, 2023 but prior to May 14, 2024 115% At any time on and after May 14, 2024 110%
Schedule of carrying values and estimated fair values of debt instruments	Fair Values of Long-Term Debt . The fair values of our long-term debt and the corresponding carrying amounts are as follows: As of December 31, 2020 2019 Carrying Estimated Carrying Estimated (in thousands) SEI 7.75% convertible senior notes $ — $ — $ 55,000 $ 37,964 SEI 9.75% convertible senior notes 95,648 100,482 — — Sunnova Energy Corporation notes payable 2,254 2,254 2,428 2,428 AP4 secured term loan — — 92,478 92,478 HELI solar asset-backed notes 211,724 220,941 222,305 223,895 LAPH secured term loan — — 42,876 42,876 EZOP warehouse credit facility 171,600 171,600 121,400 121,400 TEPIIH revolving credit facility — — 234,650 234,650 HELII solar asset-backed notes 239,281 286,579 254,314 281,850 RAYSI solar asset-backed notes 126,227 146,506 133,155 139,004 HELIII solar loan-backed notes 135,112 149,489 154,573 155,701 TEPH revolving credit facility 239,570 239,570 90,325 90,325 TEPINV revolving credit facility 54,704 54,704 95,207 95,207 SOLI solar asset-backed notes 399,674 427,511 — — HELIV solar loan-backed notes 146,163 145,433 — — AP8 revolving credit facility 46,433 46,433 — — SOLII solar asset-backed notes 254,700 254,674 — — Total (1) $ 2,123,090 $ 2,246,176 $ 1,498,711 $ 1,517,778 (1) Amounts exclude the net deferred financing costs and net debt discounts of $87.6 million and $54.8 million as of December 31, 2020 and 2019, respectively.
Schedule of principal maturities of our long-term debt	Principal Maturities of Long-Term Debt. As of December 31, 2020, the principal maturities of our long-term debt were as follows: Principal Maturities (in thousands) 2021 $ 110,883 2022 505,674 2023 107,401 2024 63,536 2025 161,088 2026 and thereafter 1,174,508 Total $ 2,123,090

Derivative Instruments (Tables)

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2020
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Outstanding derivative instruments	The following table presents a summary of the outstanding derivative instruments: As of December 31, 2020 2019 Effective Termination Fixed Aggregate Effective Termination Fixed Aggregate (in thousands, except interest rates) AP4 —% $ — March 2018 July 2020 2.338% $ 99,762 LAPH —% — November 2018 October 2036 3.409% 43,298 EZOP June 2020 - September 2029 - 0.483% - 2.620% 130,373 June 2019 - July 2029 - 1.631% - 2.620% 100,083 TEPIIH —% — September 2018 - July 2031 - 1.909% - 3.383% 225,845 TEPH September 2018 - January 2023 - 0.528% - 2.114% 202,272 September 2019 January 2023 1.620% - 1.928% 55,115 TEPINV December 2019 December 2022 2.500% 51,025 —% — Total $ 383,670 $ 524,103
Fair value of interest rate swaps	The following table presents the fair value of the interest rate swaps as recorded in the consolidated balance sheets: As of December 31, 2020 2019 (in thousands) Other assets $ — $ 360 Other current liabilities — (397) Other long-term liabilities (13,407) (27,092) Total, net $ (13,407) $ (27,129) Year Ended 2020 2019 2018 (in thousands) Realized (gain) loss $ 51,326 $ 13,195 $ (17,004) Unrealized (gain) loss (13,768) 19,237 6,100 Total $ 37,558 $ 32,432 $ (10,904)

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of effective income tax rate reconciliation	Total income tax differs from the amounts computed by applying the statutory income tax rate to loss before income tax primarily as a result of our valuation allowance. The sources of these differences are as follows: Year Ended 2020 2019 2018 (in thousands) Loss before income tax $ (307,637) $ (133,434) $ (68,409) Statutory federal tax rate 21 % 21 % 21 % Tax benefit computed at statutory rate (64,604) (28,021) (14,366) State income tax, net of federal benefit (16,862) (8,344) (4,308) Adjustments from permanent differences: Redeemable noncontrolling interests 11,662 (2,293) (1,226) ITC recapture 232 296 989 Other 475 852 234 Increase in valuation allowance, net 69,278 37,510 18,677 Total income tax expense $ 181 $ — $ —
Schedule of deferred tax assets and liabilities	The tax effects of temporary differences that give rise to significant portions of the deferred tax assets (liabilities) are as follows: As of December 31, 2020 2019 (tax effected, in thousands) Federal net operating loss carryforward $ 242,732 $ 169,379 State net operating loss carryforward 76,281 49,565 ITC carryforward 267,522 246,828 Federal unused interest deduction carryforward 39,036 22,559 Investment in certain financing arrangements 44,337 36,999 Other deferred tax assets 23,010 20,801 Deferred tax assets 692,918 546,131 Fixed asset basis difference (298,032) (235,510) Investment in certain financing arrangements (57,222) (22,826) Other deferred tax liabilities (3,427) (2,819) Deferred tax liabilities (358,681) (261,155) Valuation allowance (334,237) (284,976) Net deferred tax asset $ — $ —

Redeemable Noncontrolling Int_2

Redeemable Noncontrolling Interest and Noncontrolling Interests (Tables)	12 Months Ended
	Dec. 31, 2020
Noncontrolling Interest [Abstract]
Redeemable noncontrolling interests	The following table summarizes our redeemable noncontrolling interests and noncontrolling interests as of December 31, 2020: Tax Equity Entity Balance Sheet Classification Date Class A Sunnova TEP I, LLC Redeemable noncontrolling interests March 2017 Sunnova TEP II, LLC Redeemable noncontrolling interests December 2017 Sunnova TEP II-B, LLC Redeemable noncontrolling interests December 2017 Sunnova TEP III, LLC Redeemable noncontrolling interests January 2019 TEPIVA Noncontrolling interests August 2019 TEPIVB Noncontrolling interests December 2019 TEPIVC Noncontrolling interests February 2020 TEPIVD Noncontrolling interests May 2020 Sunnova TEP IV-F, LLC Noncontrolling interests July 2020 TEPIVE Noncontrolling interests September 2020 TEPIVG Noncontrolling interests November 2020

Equity-Based Compensation (Tabl

Equity-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock option assumptions	We used the following assumptions to apply the Black-Scholes option-pricing model to stock options granted during the years ended December 31, 2019 and 2018: Year Ended 2019 2018 Expected dividend yield 0.00% 0.00% Risk-free interest rate 2.62% 2.62% Expected term (in years) 7.94 7.94 Volatility 81% 81%
Stock option activity	The following table summarizes stock option activity: Number Weighted Weighted Weighted Aggregate (in thousands) Outstanding, December 31, 2018 4,808,390 $ 15.90 8.09 $ 129 Granted 94,295 $ 13.58 9.07 $ 3.11 Exercised (2,143) $ 1.85 $ 20 Forfeited (596,233) $ 15.85 $ 3.48 Outstanding, December 31, 2019 4,304,309 $ 15.86 7.08 $ 242 Exercised (922,770) $ 14.76 $ 28,022 Forfeited (115,191) $ 19.19 $ 3.54 Outstanding, December 31, 2020 3,266,348 $ 16.06 5.82 $ 94,962 Exercisable, December 31, 2020 3,266,348 $ 16.06 5.82 $ 94,962 Vested, December 31, 2020 3,266,348 $ 16.06 5.82 $ 94,962 Non-vested, December 31, 2019 964,396 $ 3.52 Non-vested, December 31, 2020 — $ —
Restricted stock unit activity	The following table summarizes restricted stock unit activity: Number of Weighted Outstanding, December 31, 2018 — $ — Granted 1,431,555 $ 11.93 Forfeited (5,416) $ 12.00 Outstanding, December 31, 2019 1,426,139 $ 11.93 Granted 1,141,413 $ 11.98 Vested (463,762) $ 11.89 Forfeited (44,606) $ 12.31 Outstanding, December 31, 2020 2,059,184 $ 11.95

Basic and Diluted Net Loss Pe_2

Basic and Diluted Net Loss Per Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Schedule of basic and diluted net loss per share	The following table sets forth the computation of our basic and diluted net loss per share: Year Ended 2020 2019 2018 (in thousands, except share and per share amounts) Net loss attributable to stockholders $ (252,284) $ (144,351) $ (74,246) Dividends earned on Series A convertible preferred stock — (19,271) (36,346) Dividends earned on Series C convertible preferred stock — (5,454) (5,948) Deemed dividends on convertible preferred stock exchange — — (19,332) Net loss attributable to common stockholders—basic and diluted $ (252,284) $ (169,076) $ (135,872) Net loss per share attributable to common stockholders—basic and diluted $ (2.87) $ (4.14) $ (15.74) Weighted average common shares outstanding—basic and diluted 87,871,457 40,797,976 8,634,477
Schedule of antidilutive weighted average shares	The following table presents the weighted average shares of common stock equivalents that were excluded from the computation of diluted net loss per share for the periods presented because including them would have been anti-dilutive: Year Ended 2020 2019 2018 Equity-based compensation awards 6,013,797 4,954,286 4,307,614 Convertible preferred stock — 33,960,624 53,112,246 Convertible senior notes 9,606,157 104,320 —

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Schedule of performance guarantee obligations	The changes in our aggregate performance guarantee obligations are as follows: As of December 31, 2020 2019 (in thousands) Balance at beginning of period $ 6,468 $ 6,044 Accruals for obligations issued 3,155 3,101 Settlements made in cash (3,905) (2,677) Balance at end of period $ 5,718 $ 6,468
Lease expense	The following table presents the detail of lease expense and lease income as recorded in general and administrative expense and other operating income, respectively, in the consolidated statements of operations: Year Ended 2020 2019 2018 (in thousands) Operating lease expense $ 1,342 $ 1,248 $ 972 Finance lease amortization expense 3 8 — Short-term lease expense 49 48 50 Variable lease expense 696 1,037 704 Sublease income — (73) (70) Total $ 2,090 $ 2,268 $ 1,656 Other information related to leases was as follows: Year Ended 2020 2019 2018 (in thousands) Cash paid (received) for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases (1) $ (439) $ 1,254 $ 875 Financing cash flows from finance leases 2 8 — Right-of-use assets obtained in exchange for lease obligations: Operating leases — 8,087 — Finance leases 392 13 — (1) Includes reimbursements in 2020 of approximately $1.5 million for leasehold improvements. As of December 31, 2020 2019 Weighted average remaining lease term (years): Operating leases 8.47 9.41 Finance leases 3.99 0.68 Weighted average discount rate: Operating leases 3.93 % 3.94 % Finance leases 3.39 % 4.26 %
Lease assets and liabilities	The following table presents the detail of right-of-use assets and lease liabilities as recorded in other assets and other current liabilities As of December 31, 2020 2019 (in thousands) Right-of-use assets: Operating leases $ 8,779 $ 9,668 Finance leases 391 5 Total right-of-use assets $ 9,170 $ 9,673 Current lease liabilities: Operating leases $ 1,094 $ 556 Finance leases 112 5 Long-term leases liabilities: Operating leases 9,742 9,389 Finance leases 203 — Total lease liabilities $ 11,151 $ 9,950
Operating lease, future minimum lease payments	Future minimum lease payments under our non-cancelable leases as of December 31, 2020 were as follows: Operating Finance (in thousands) 2021 $ 1,536 $ 122 2022 1,559 88 2023 1,594 69 2024 1,616 55 2025 1,633 — 2026 and thereafter 5,984 — Total 13,922 334 Amount representing interest (2,136) (19) Amount representing leasehold incentives (950) — Present value of future payments 10,836 315 Current portion of lease liability (1,094) (112) Long-term portion of lease liability $ 9,742 $ 203
Other commitments	Dealer Commitments. As of December 31, 2020 and 2019, the net unamortized balance of payments to dealers for exclusivity and other similar arrangements was $55.7 million and $32.8 million, respectively. Under these agreements, we paid $25.8 million and $31.7 million during the years ended December 31, 2020 and 2019, respectively. We could be obligated to make maximum payments, excluding additional amounts payable on a per watt basis if even higher thresholds are met, as follows: Dealer (in thousands) 2021 $ 28,982 2022 35,844 2023 12,520 2024 12,515 2025 2,191 2026 and thereafter — Total $ 92,052
Future commitments	Purchase Commitments. In August 2019, we amended an agreement with a supplier in which we agreed to purchase a minimum amount of energy storage systems and components for five years. In December 2020, we amended an agreement with a supplier in which we agreed to purchase a certain amount of energy storage systems and components for one year. These purchases are recorded to inventory in other current assets in the consolidated balance sheets. Under these agreements, we could be obligated to make minimum purchases as follows: Purchase (in thousands) 2021 $ 28,497 2022 26,810 2023 26,605 2024 19,807 2025 — 2026 and thereafter — Total $ 101,719 Information (in thousands) 2021 $ 7,976 2022 2,112 2023 26 2024 26 2025 7 2026 and thereafter — Total $ 10,147

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Quarterly financial data	The following tables present the selected quarterly financial data for the years ended December 31, 2020 and 2019. Three Months Ended December 31, 2020 September 30, 2020 June 30, 2020 March 31, 2020 (in thousands, except per share amounts) Revenue (1)(2) $ 38,024 $ 50,177 $ 42,790 $ 29,829 Total operating expenses, net (2) $ 56,002 $ 48,528 $ 47,933 $ 44,135 Operating income (loss) (1)(2) $ (17,978) $ 1,649 $ (5,143) $ (14,306) Net loss (1)(2)(3)(4) $ (128,791) $ (73,294) $ (28,729) $ (77,004) Net loss attributable to common stockholders—basic and diluted (1)(2)(3)(4) $ (91,770) $ (64,181) $ (25,258) $ (71,075) Net loss per share attributable to common stockholders—basic and diluted (1)(2)(3)(4) $ (0.96) $ (0.73) $ (0.30) $ (0.85) Three Months Ended December 31, 2019 September 30, 2019 June 30, 2019 March 31, 2019 (in thousands, except per share amounts) Revenue (1)(2) $ 33,614 $ 36,615 $ 34,612 $ 26,715 Total operating expenses, net (2) $ 42,769 $ 42,513 $ 37,322 $ 31,222 Operating loss (1)(2) $ (9,155) $ (5,898) $ (2,710) $ (4,507) Net loss (1)(2)(3) $ (13,762) $ (34,369) $ (49,807) $ (35,496) Net loss attributable to common stockholders—basic and diluted (1)(2)(3) $ (17,509) $ (37,590) $ (63,260) $ (50,717) Net loss per share attributable to common stockholders—basic and diluted (1)(2)(3) $ (0.21) $ (0.62) $ (7.32) $ (5.87) (1) Fluctuations are primarily due to seasonality. (2) Fluctuations are primarily due to growth. (3) Fluctuations are primarily due to unrealized gains and losses on derivative instruments. (4) Fluctuations are primarily due to losses on conversions of debt into common stock.

Description of Business and B_3

Description of Business and Basis of Presentation - Narrative (Details) customer in Thousands, $ in Thousands	12 Months Ended	17 Months Ended
	Dec. 31, 2020USD ($)customerstaterenewal_option	Dec. 31, 2020USD ($)state	Dec. 31, 2019USD ($)
Subsidiary, Sale of Stock [Line Items]
Number of customers | customer	107
Number of states in which entity operates (more than) | state	20	20
Maximum renewal term	10 years
Capital contribution received		$ 6,700,000
Stockholders' equity	$ (951,731)	$ (951,731)	$ (645,935)
Impact of ASC 326 Adoption
Subsidiary, Sale of Stock [Line Items]
Stockholders' equity			$ 9,900
Lease and Power Purchase Agreement (PPA)
Subsidiary, Sale of Stock [Line Items]
Number of options to renew term | renewal_option	2
Renewal term	5 years
Minimum
Subsidiary, Sale of Stock [Line Items]
Agreement term	10 years
Median
Subsidiary, Sale of Stock [Line Items]
Agreement term	15 years
Maximum
Subsidiary, Sale of Stock [Line Items]
Agreement term	25 years

Description of Business and B_4

Description of Business and Basis of Presentation Schedule of New Accounting Pronouncement (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable—trade, net	$ 10,243	$ 10,672	$ 10,672
Other current assets	215,175	174,016	174,016
Customer notes receivable	513,386	297,975	297,975
Other assets	294,372	169,712	169,712
Accumulated deficit	$ (530,995)	(361,824)	$ (361,824)
As Reported Under ASC 326
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable—trade, net		10,912
Other current assets		173,565
Customer notes receivable		289,191
Other assets		168,799
Accumulated deficit		(371,732)
Impact of ASC 326 Adoption
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accounts receivable—trade, net		240
Other current assets		(451)
Customer notes receivable		(8,784)
Other assets		(913)
Accumulated deficit		$ (9,908)

Description of Business and B_5

Description of Business and Basis of Presentation - Revision of Interim Financials (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Redeemable Noncontrolling Interests
Redeemable noncontrolling interest, beginning balance	$ 127,129	$ 85,680	$ 38,590
Net income	10,164	8,521	5,837
Contributions from redeemable noncontrolling interests and noncontrolling interests	3,449	77,579	79,017
Distributions to redeemable noncontrolling interests and noncontrolling interests	(4,802)	(7,559)	(2,017)
Costs related to redeemable noncontrolling interests and noncontrolling interests	187	(2,338)	(1,062)
Equity in subsidiaries attributable to parent	(883)	(37,112)	(30,697)
Other, net	880	2,358	(3,988)
Redeemable noncontrolling interest, ending balance	136,124	127,129	85,680
Noncontrolling Interests
Stockholders' equity, beginning balance	691,111	501,118	371,183
Net income	(317,982)	(141,955)	(74,246)
Contributions from redeemable noncontrolling interests and noncontrolling interests	316,796	79,570	0
Distributions to redeemable noncontrolling interests and noncontrolling interests	(1,725)	0	0
Costs related to redeemable noncontrolling interests and noncontrolling interests	(7,895)	(5,054)	0
Equity in subsidiaries attributable to parent	883	37,112	30,697
Other, net	(1,690)	492	0
Stockholders' equity, ending balance	1,144,557	691,111	501,118
Noncontrolling Interests
Noncontrolling Interests
Stockholders' equity, beginning balance	45,176	0	0
Net income	(65,698)	2,396
Contributions from redeemable noncontrolling interests and noncontrolling interests	316,796	79,570
Distributions to redeemable noncontrolling interests and noncontrolling interests	(1,725)	0
Costs related to redeemable noncontrolling interests and noncontrolling interests	(7,895)	(5,054)
Equity in subsidiaries attributable to parent	(92,138)	(31,736)
Other, net	(1,690)	0
Stockholders' equity, ending balance	192,826	45,176	0
As Previously Reported
Redeemable Noncontrolling Interests
Redeemable noncontrolling interest, beginning balance	172,305	85,680
Net income		10,917
Contributions from redeemable noncontrolling interests and noncontrolling interests		157,149
Distributions to redeemable noncontrolling interests and noncontrolling interests		(7,559)
Costs related to redeemable noncontrolling interests and noncontrolling interests		(7,392)
Equity in subsidiaries attributable to parent		(68,848)
Other, net		2,358
Redeemable noncontrolling interest, ending balance		172,305	85,680
As Previously Reported | Noncontrolling Interests
Noncontrolling Interests
Stockholders' equity, beginning balance	0	0
Net income		0
Contributions from redeemable noncontrolling interests and noncontrolling interests		0
Distributions to redeemable noncontrolling interests and noncontrolling interests		0
Costs related to redeemable noncontrolling interests and noncontrolling interests		0
Equity in subsidiaries attributable to parent		0
Other, net		0
Stockholders' equity, ending balance		0	0
Revisions
Redeemable Noncontrolling Interests
Redeemable noncontrolling interest, beginning balance	(45,176)	0
Net income		(2,396)
Contributions from redeemable noncontrolling interests and noncontrolling interests		(79,570)
Distributions to redeemable noncontrolling interests and noncontrolling interests		0
Costs related to redeemable noncontrolling interests and noncontrolling interests		5,054
Equity in subsidiaries attributable to parent		31,736
Other, net		0
Redeemable noncontrolling interest, ending balance		(45,176)	0
Revisions | Noncontrolling Interests
Noncontrolling Interests
Stockholders' equity, beginning balance	$ 45,176	0
Net income		2,396
Contributions from redeemable noncontrolling interests and noncontrolling interests		79,570
Distributions to redeemable noncontrolling interests and noncontrolling interests		0
Costs related to redeemable noncontrolling interests and noncontrolling interests		(5,054)
Equity in subsidiaries attributable to parent		(31,736)
Other, net		0
Stockholders' equity, ending balance		$ 45,176	$ 0

Significant Accounting Polici_4

Significant Accounting Policies - Narrative (Details)	12 Months Ended
	Dec. 31, 2020USD ($)kWhrenewal_optionFICO_scoredealer	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Disaggregation of Revenue [Line Items]
Cash deposits in excess of FDIC insured limit	$ 199,600,000	$ 72,400,000
Restricted cash deposits in excess of FDIC insured limit	163,800,000	63,600,000
Accrued expenses for inventory purchases	$ 8,900,000	15,200,000
Number of dealers | dealer	150
Customer agreement, average term	23 years
Contracted but not yet recognized revenue	$ 1,600,000,000
Average age of solar systems	3 years
SREC inventory	$ 102,589,000	43,749,000
Threshold period past due, writeoff	180 days
Deferred revenue	$ 106,809,000	58,853,000	$ 34,000,000
Revenue recognized	$ 7,300,000	3,000,000
Intangible assets, useful lives	3 years
Amortization, 2021	$ 29,000
Amortization, 2022	9,000
Amortization, thereafter	0
Warranty reserve	0	0
Advertising expense	195,000	1,000,000	191,000
Defined contribution plan, employer contribution	820,000	736,000	551,000
Net losses on disposals and impairment expense	5,824,000	1,772,000	7,565,000
Operations And Maintenance Expense
Disaggregation of Revenue [Line Items]
Net losses on disposals and impairment expense	5,800,000	1,800,000	7,400,000
Operations And Maintenance Expense | Natural Disaster Losses
Disaggregation of Revenue [Line Items]
Net losses on disposals and impairment expense	31,000	54,000	$ 5,800,000
Solar Renewable Energy Certificates
Disaggregation of Revenue [Line Items]
SREC inventory	$ 0	0
Minimum
Disaggregation of Revenue [Line Items]
Agreement term	10 years
Product warranty obligations, term	10 years
Median
Disaggregation of Revenue [Line Items]
Agreement term	15 years
Maximum
Disaggregation of Revenue [Line Items]
Agreement term	25 years
Product warranty obligations, term	25 years
PPA revenue
Disaggregation of Revenue [Line Items]
Agreement term	25 years
Renewal term	5 years
Number of options to renew term | renewal_option	2
PPA revenue | Maximum
Disaggregation of Revenue [Line Items]
Renewal term	10 years
Lease revenue
Disaggregation of Revenue [Line Items]
Agreement term	25 years
Renewal term	5 years
Number of options to renew term | renewal_option	2
Remittances of customer payments, period after placed in service date	3 years
Lease revenue | Maximum
Disaggregation of Revenue [Line Items]
Renewal term	10 years
Solar renewable energy certificate revenue
Disaggregation of Revenue [Line Items]
Energy per certificate (in kWhs) | kWh	1,000
Typical period for receiving payment	1 month
Other revenue | Minimum
Disaggregation of Revenue [Line Items]
Agreement term	5 years
Other revenue | Maximum
Disaggregation of Revenue [Line Items]
Agreement term	10 years
Loan revenue
Disaggregation of Revenue [Line Items]
Deferred revenue	$ 93,859,000	$ 46,958,000
Loan revenue | Minimum
Disaggregation of Revenue [Line Items]
Agreement term	10 years
Minimum FICO score required for customer to qualify for program | FICO_score	650
Loan revenue | Median
Disaggregation of Revenue [Line Items]
Agreement term	15 years
Loan revenue | Maximum
Disaggregation of Revenue [Line Items]
Agreement term	25 years
Minimum FICO score required for customer to qualify for program | FICO_score	720
Dealer One | Expenditures To Dealers | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk	34.00%	49.00%	58.00%
Dealer Two | Expenditures To Dealers | Customer Concentration Risk
Disaggregation of Revenue [Line Items]
Concentration risk	13.00%	10.00%

Significant Accounting Polici_5

Significant Accounting Policies - Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	$ 168,034	$ 66,806
Restricted cash included in other current assets	73,020	10,474	$ 5,190
Debt and inverter reserves
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	93,889	55,407
Tax equity reserves
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	72,426	9,904
Letters of credit for office lease
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	375	725
Other
Restricted Cash and Cash Equivalents Items [Line Items]
Restricted cash	$ 1,344	$ 770

Significant Accounting Polici_6

Significant Accounting Policies - Allowance for Credit Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 960	$ 723
Provision for current expected credit losses	1,878	1,645
Write off of uncollectible accounts	(1,741)	(1,498)
Recoveries	55	90
Balance at end of period	912	960
Impact of ASC 326 Adoption
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ (240)
Balance at end of period		$ (240)

Significant Accounting Polici_7

Significant Accounting Policies - Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Inventory [Line Items]
Inventory	$ 102,589	$ 43,749
Energy storage systems and components
Inventory [Line Items]
Inventory	18,122	33,443
Modules and inverters
Inventory [Line Items]
Inventory	83,904	10,137
Meters
Inventory [Line Items]
Inventory	$ 563	$ 169

Significant Accounting Polici_8

Significant Accounting Policies - Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 38,024	$ 50,177	$ 42,790	$ 29,829	$ 33,614	$ 36,615	$ 34,612	$ 26,715	$ 160,820	$ 131,556	$ 104,382
PPA revenue
Disaggregation of Revenue [Line Items]
Revenue									65,760	48,041	38,950
Lease revenue
Disaggregation of Revenue [Line Items]
Revenue									51,650	40,191	33,079
Solar renewable energy certificate revenue
Disaggregation of Revenue [Line Items]
Revenue									35,747	38,453	30,630
Loan revenue
Disaggregation of Revenue [Line Items]
Revenue									3,032	1,645	933
Other revenue
Disaggregation of Revenue [Line Items]
Revenue									$ 4,631	$ 3,226	$ 790

Significant Accounting Polici_9

Significant Accounting Policies - Performance Obligations (Details) $ in Billions	12 Months Ended
	Dec. 31, 2020USD ($)
Accounting Policies [Abstract]
Contracted but not yet recognized revenue	$ 1.6
Performance obligation, description of timing	We do not expect the annual recognition to vary significantly over approximately the next 20 years as the vast majority of existing solar service agreements have at least 20 years remaining
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Contracted but not yet recognized revenue, percentage	4.00%
Contracted but not yet recognized revenue, expected timing of satisfaction	12 months

Significant Accounting Polic_10

Significant Accounting Policies - Deferred Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Deferred revenue	$ 106,809	$ 58,853	$ 34,000
Deferred revenue included in other current liabilities	3,754	2,086
Loans
Disaggregation of Revenue [Line Items]
Deferred revenue	93,859	46,958
PPAs and leases
Disaggregation of Revenue [Line Items]
Deferred revenue	11,787	8,895
SRECs
Disaggregation of Revenue [Line Items]
Deferred revenue	$ 1,163	$ 3,000

Significant Accounting Polic_11

Significant Accounting Policies - Intangibles Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 487	$ 487
Less: accumulated amortization	(449)	(420)
Intangibles, net	38	67
Software license
Finite-Lived Intangible Assets [Line Items]
Intangible assets	331	331
Trademark
Finite-Lived Intangible Assets [Line Items]
Intangible assets	68	68
Other
Finite-Lived Intangible Assets [Line Items]
Intangible assets	$ 88	$ 88

Significant Accounting Polic_12

Significant Accounting Policies - Deferred Financing Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Issuance Costs [Roll Forward]
Balance at beginning of period	$ 25,621	$ 22,712
Capitalized	23,202	12,731
Amortized	(9,031)	(9,822)	$ (9,074)
Balance at end of period	$ 39,792	$ 25,621	$ 22,712

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 2,536,757	$ 1,893,219
Less: accumulated depreciation	(213,588)	(148,159)
Property and equipment, net	$ 2,323,169	1,745,060
Solar energy systems
Property, Plant and Equipment [Line Items]
Useful Lives	35 years
Property and equipment, gross	$ 2,298,427	1,689,457
Less: accumulated depreciation	(188,800)	(130,900)
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 160,618	143,449
Asset retirement obligations
Property, Plant and Equipment [Line Items]
Useful Lives	30 years
Property and equipment, gross	$ 35,532	26,967
Information technology systems
Property, Plant and Equipment [Line Items]
Useful Lives	3 years
Property and equipment, gross	$ 35,077	28,320
Computers and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,727	1,499
Computers and equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful Lives	3 years
Computers and equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful Lives	5 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 2,770	1,014
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Useful Lives	3 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Useful Lives	6 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Useful Lives	7 years
Property and equipment, gross	$ 811	735
Vehicles
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,638	1,632
Vehicles | Minimum
Property, Plant and Equipment [Line Items]
Useful Lives	4 years
Vehicles | Maximum
Property, Plant and Equipment [Line Items]
Useful Lives	5 years
Other
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 157	$ 146
Other | Minimum
Property, Plant and Equipment [Line Items]
Useful Lives	5 years
Other | Maximum
Property, Plant and Equipment [Line Items]
Useful Lives	6 years

Natural Disaster Losses (Detail

Natural Disaster Losses (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018USD ($)
Business Interruption Loss [Line Items]
Insurance proceeds	$ 9.8
Solar Energy System Damage
Business Interruption Loss [Line Items]
Insurance proceeds	5.8
Recoveries for Business Interruption
Business Interruption Loss [Line Items]
Insurance proceeds	$ 4

Natural Disaster Losses - Sched

Natural Disaster Losses - Schedule of Disaster Losses (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Interruption Loss [Line Items]
Operations and maintenance									$ 16,313	$ 8,588	$ 14,035
General and administrative									115,148	97,986	67,430
Total operating expense, net	$ 56,002	$ 48,528	$ 47,933	$ 44,135	$ 42,769	$ 42,513	$ 37,322	$ 31,222	196,598	153,826	118,112
Natural disaster losses
Business Interruption Loss [Line Items]
Total operating expense, net									31	54	5,523
Impairment of solar energy systems due to natural disaster losses
Business Interruption Loss [Line Items]
Operations and maintenance									0	0	5,840
Insurance proceeds received/expected to be received—property damage
Business Interruption Loss [Line Items]
Operations and maintenance									31	54	(53)
Insurance proceeds received—business interruption
Business Interruption Loss [Line Items]
Operations and maintenance									0	0	(2,693)
Other natural disaster-related charges
Business Interruption Loss [Line Items]
Operations and maintenance									0	0	1,679
General and administrative									$ 0	$ 0	$ 750

Detail of Certain Balance She_3

Detail of Certain Balance Sheet Captions - Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Inventory	$ 102,589		$ 43,749
Restricted cash	73,020		10,474	$ 5,190
Current portion of customer notes receivable	24,035		13,758
Other prepaid assets	8,645		7,380
Prepaid inventory	3,352		96,167
Deferred receivables	2,678		1,506
Current portion of other notes receivable	853		982
Other	3		0
Total	$ 215,175	$ 174,016	$ 174,016

Detail of Certain Balance She_4

Detail of Certain Balance Sheet Captions - Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019	Dec. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Restricted cash	$ 95,014		$ 56,332	$ 29,150
Construction in progress - customer notes receivable	85,604		37,137
Exclusivity and other bonus arrangements with dealers, net	55,709		32,791
Straight-line revenue adjustment, net	33,411		24,852
Other	24,634		18,600
Total	$ 294,372	$ 169,712	$ 169,712

Detail of Certain Balance She_5

Detail of Certain Balance Sheet Captions - Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Interest payable	$ 17,718	$ 14,680
Deferred revenue	3,754	2,086
Current portion of performance guarantee obligations	3,308	4,067
Current portion of lease liability	1,206	561
Other	27	410
Total	$ 26,013	$ 21,804

AROs (Details)

AROs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Asset Retirement Obligation Disclosure [Abstract]
Asset retirement obligation, useful life	30 years
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at beginning of period	$ 31,053	$ 20,033
Additional obligations incurred	8,633	4,641
Accretion expense	2,186	1,443
Change in estimate	0	4,983
Other	(84)	(47)
Balance at end of period	$ 41,788	$ 31,053

Customer Notes Receivable - Nar

Customer Notes Receivable - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan systems not yet placed in service	$ 85,600,000	$ 37,100,000
Interest income	23,741,000	12,483,000	$ 6,450,000
Customer notes receivable not accruing interest	0	0
Interest income for nonaccrual loans	0
Amortized cost	8,600,000	5,000,000
Customer notes receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest income	23,200,000	11,600,000
Accrued investment income receivable	1,200,000	$ 869,000
Accrued investment income receivable, written off	$ 0
Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Agreement term	10 years
Median
Accounts, Notes, Loans and Financing Receivable [Line Items]
Agreement term	15 years
Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Agreement term	25 years
Loan revenue | Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Agreement term	10 years
Loan revenue | Median
Accounts, Notes, Loans and Financing Receivable [Line Items]
Agreement term	15 years
Loan revenue | Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Agreement term	25 years

Customer Notes Receivable - Sch

Customer Notes Receivable - Schedule of Customer Notes Receivables (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Customer notes receivable	$ 555,089	$ 312,823
Allowance for credit losses	(17,668)	(1,091)	$ (710)
Current portion of customer notes receivable	24,035	13,758
Customer Notes Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current portion of customer notes receivable	24,000	13,800
Carrying Value
Accounts, Notes, Loans and Financing Receivable [Line Items]
Customer notes receivable	537,421	311,732
Estimated Fair Value
Accounts, Notes, Loans and Financing Receivable [Line Items]
Customer notes receivable	$ 548,238	$ 314,222

Customer Notes Receivable - S_2

Customer Notes Receivable - Schedule of Changes in Allowances for Credit Losses Related to Customer Notes Receivable (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Balance at beginning of period	$ 1,091	$ 710
Provision for current expected credit loss/Bad debt expense	7,785	419
Write off of uncollectible accounts	(443)	(38)
Balance at end of period	17,668	1,091
Provision for expected credit losses	184
Impact of ASC 326 Adoption
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Balance at beginning of period	$ 9,235
Balance at end of period		$ 9,235

Customer Notes Receivable - S_3

Customer Notes Receivable - Schedule of Aged Receivables (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	$ 17,092	$ 10,786
Financing receivable, not past due	537,997	302,037
Total	555,089	312,823
1-90 days past due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	8,504	5,741
91-180 days past due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	1,733	1,714
Greater than 180 days past due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	$ 6,855	$ 3,331

Customer Notes Receivable - S_4

Customer Notes Receivable - Schedule of Amortized cost of Customer Notes Receivable (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
2020	$ 267,036
2019	135,427
2018	88,725
2017	33,014
2016	20,737
Prior	10,150
Total	555,089	$ 312,823
Performing
Financing Receivable, Credit Quality Indicator [Line Items]
2020	266,756
2019	134,152
2018	86,815
2017	31,042
2016	19,522
Prior	9,947
Total	548,234
Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
2020	280
2019	1,275
2018	1,910
2017	1,972
2016	1,215
Prior	203
Total	$ 6,855

Long-Term Debt - Schedule of Lo

Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Oct. 31, 2020	Aug. 31, 2020	Jul. 31, 2019	May 31, 2019
Debt Instrument [Line Items]
Long-term debt, non-current	$ 1,924,653	$ 1,346,419
Long-term debt, current	$ 110,883	$ 97,464
SEI | Convertible senior notes | 7.75% convertible senior notes
Debt Instrument [Line Items]
Stated interest rate		7.75%
Weighted average effective interest rates	17.41%	7.75%
Long-term debt, gross, non-current	$ 0	$ 55,000
Long-term debt, gross, current	$ 0	0
SEI | Convertible senior notes | 9.75% convertible senior notes
Debt Instrument [Line Items]
Stated interest rate	9.75%
Weighted average effective interest rates	14.53%
Long-term debt, gross, non-current	$ 95,648	0
Debt discount, net, non-current	(37,394)	(16,913)
Deferred financing costs, net, non-current	(239)	(480)
Long-term debt, gross, current	0	0
Debt discount, net, current	0	0
Deferred financing costs, net, current	$ 0	$ 0
Sunnova Energy Corporation | Notes payable
Debt Instrument [Line Items]
Stated interest rate			4.25%	4.25%	4.94%	5.50%
Weighted average effective interest rates	7.14%	3.22%
Long-term debt, gross, non-current	$ 0	$ 0
Long-term debt, gross, current	2,254	2,428
AP4
Debt Instrument [Line Items]
Debt discount, net, non-current	0	(452)
Deferred financing costs, net, non-current	0	(196)
Debt discount, net, current	0	0
Deferred financing costs, net, current	$ 0	$ 0
AP4 | Secured term loan
Debt Instrument [Line Items]
Weighted average effective interest rates	10.81%	5.61%
Long-term debt, gross, non-current	$ 0	$ 86,369
Long-term debt, gross, current	0	6,109
HELI
Debt Instrument [Line Items]
Debt discount, net, non-current	(2,241)	(3,169)
Deferred financing costs, net, non-current	(4,004)	(5,586)
Debt discount, net, current	0	0
Deferred financing costs, net, current	$ 0	$ 0
HELI | Solar asset-backed notes
Debt Instrument [Line Items]
Weighted average effective interest rates	6.55%	6.56%
Long-term debt, gross, non-current	$ 205,395	$ 213,632
Long-term debt, gross, current	6,329	8,673
LAPH
Debt Instrument [Line Items]
Debt discount, net, non-current	0	(401)
Deferred financing costs, net, non-current	0	(356)
Debt discount, net, current	0	0
Deferred financing costs, net, current	$ 0	$ 0
LAPH | Secured term loan
Debt Instrument [Line Items]
Weighted average effective interest rates	11.34%	7.71%
Long-term debt, gross, non-current	$ 0	$ 41,484
Long-term debt, gross, current	0	1,392
EZOP
Debt Instrument [Line Items]
Debt discount, net, non-current	(1,431)	(2,178)
Debt discount, net, current	$ 0	$ 0
EZOP | Warehouse credit facility
Debt Instrument [Line Items]
Weighted average effective interest rates	4.39%	6.60%
Long-term debt, gross, non-current	$ 171,600	$ 121,400
Long-term debt, gross, current	0	0
TEPIIH
Debt Instrument [Line Items]
Debt discount, net, non-current	0	(2,219)
Debt discount, net, current	$ 0	$ 0
TEPIIH | Revolving credit facility | Revolving credit facility
Debt Instrument [Line Items]
Weighted average effective interest rates	19.47%	6.36%
Long-term debt, gross, non-current	$ 0	$ 234,650
Long-term debt, gross, current	0	0
HELII
Debt Instrument [Line Items]
Debt discount, net, non-current	(42)	(49)
Deferred financing costs, net, non-current	(5,085)	(5,873)
Debt discount, net, current	0	0
Deferred financing costs, net, current	$ 0	$ 0
HELII | Solar asset-backed notes
Debt Instrument [Line Items]
Weighted average effective interest rates	5.71%	5.77%
Long-term debt, gross, non-current	$ 227,574	$ 241,309
Long-term debt, gross, current	11,707	13,005
RAYSI
Debt Instrument [Line Items]
Debt discount, net, non-current	(1,376)	(1,547)
Deferred financing costs, net, non-current	(4,334)	(4,759)
Debt discount, net, current	0	0
Deferred financing costs, net, current	$ 0	$ 0
RAYSI | Solar asset-backed notes
Debt Instrument [Line Items]
Weighted average effective interest rates	5.49%	5.47%
Long-term debt, gross, non-current	$ 120,391	$ 126,828
Long-term debt, gross, current	5,836	6,327
HELIII
Debt Instrument [Line Items]
Debt discount, net, non-current	(2,423)	(2,532)
Deferred financing costs, net, non-current	(2,326)	(2,410)
Debt discount, net, current	0	0
Deferred financing costs, net, current	$ 0	$ 0
HELIII | Solar loan-backed notes
Debt Instrument [Line Items]
Weighted average effective interest rates	4.01%	4.03%
Long-term debt, gross, non-current	$ 122,047	$ 135,543
Long-term debt, gross, current	13,065	19,030
TEPH
Debt Instrument [Line Items]
Debt discount, net, non-current	(3,815)	(645)
Debt discount, net, current	$ 0	$ 0
TEPH | Revolving credit facility | Revolving credit facility
Debt Instrument [Line Items]
Weighted average effective interest rates	5.81%	6.70%
Long-term debt, gross, non-current	$ 239,570	$ 90,325
Long-term debt, gross, current	0	0
TEPINV
Debt Instrument [Line Items]
Debt discount, net, non-current	(1,322)	(2,856)
Deferred financing costs, net, non-current	(1,758)	(2,207)
Debt discount, net, current	0	0
Deferred financing costs, net, current	$ 0	$ 0
TEPINV | Revolving credit facility | Revolving credit facility
Debt Instrument [Line Items]
Weighted average effective interest rates	10.80%	7.95%
Long-term debt, gross, non-current	$ 25,240	$ 54,707
Long-term debt, gross, current	29,464	40,500
SOLI
Debt Instrument [Line Items]
Debt discount, net, non-current	(113)	0
Deferred financing costs, net, non-current	(8,915)	0
Debt discount, net, current	0	0
Deferred financing costs, net, current	$ 0	0
SOLI | Solar asset-backed notes
Debt Instrument [Line Items]
Weighted average effective interest rates	3.91%
Long-term debt, gross, non-current	$ 384,258	0
Long-term debt, gross, current	15,416	0
HELIV
Debt Instrument [Line Items]
Debt discount, net, non-current	(885)	0
Deferred financing costs, net, non-current	(3,905)	0
Debt discount, net, current	0	0
Deferred financing costs, net, current	$ 0	0
HELIV | Solar loan-backed notes
Debt Instrument [Line Items]
Weighted average effective interest rates	3.97%
Long-term debt, gross, non-current	$ 129,648	0
Long-term debt, gross, current	$ 16,515	$ 0
AP8 | Revolving credit facility | Revolving credit facility
Debt Instrument [Line Items]
Weighted average effective interest rates	5.31%
Long-term debt, gross, non-current	$ 42,047	$ 0
Long-term debt, gross, current	4,386	0
SOLII
Debt Instrument [Line Items]
Debt discount, net, non-current	(80)	0
Deferred financing costs, net, non-current	(5,866)	0
Debt discount, net, current	0	0
Deferred financing costs, net, current	$ 0	0
SOLII | Solar asset-backed notes
Debt Instrument [Line Items]
Weighted average effective interest rates	3.18%
Long-term debt, gross, non-current	$ 248,789	0
Long-term debt, gross, current	$ 5,911	$ 0

Long-Term Debt - Narrative (Det

Long-Term Debt - Narrative (Details)	1 Months Ended																12 Months Ended			17 Months Ended
	Nov. 30, 2020USD ($)	Oct. 31, 2020USD ($)	Aug. 31, 2020USD ($)	Jun. 30, 2020USD ($)	May 31, 2020USD ($)$ / shares	Feb. 29, 2020USD ($)	Dec. 31, 2019USD ($)	Jul. 31, 2019USD ($)	Jun. 30, 2019USD ($)	May 31, 2019USD ($)	Apr. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Nov. 30, 2018USD ($)	Dec. 31, 2017USD ($)	Apr. 30, 2017USD ($)	Dec. 31, 2016	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2020USD ($)	Oct. 29, 2020USD ($)	Mar. 31, 2020USD ($)	Sep. 30, 2019USD ($)	Aug. 31, 2018USD ($)	Aug. 31, 2017USD ($)	Oct. 31, 2015USD ($)	Jul. 31, 2014USD ($)
Debt Instrument [Line Items]
Borrowing capacity																	$ 402,400,000			$ 402,400,000
Debt conversion																	149,352,000	$ 0	$ 0
Long-term debt																	2,123,090,000			2,123,090,000
Equity cure contribution																				6,700,000,000
EZOP
Debt Instrument [Line Items]
Unamortized debt discount							$ 2,178,000										1,431,000	2,178,000		1,431,000
Repayments of debt		$ 28,000,000		$ 149,300,000
EZOP | Warehouse credit facility
Debt Instrument [Line Items]
Borrowing capacity																	28,400,000			28,400,000
Maximum borrowing capacity												$ 200,000,000			$ 100,000,000										$ 70,000,000
EZOP | Warehouse credit facility | LIBOR | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate							2.35%					2.15%
EZOP | Warehouse credit facility | LIBOR | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate							3.35%					3.15%
EZOP | Warehouse credit facility | Weighted-Average Cost To Lender Rate | During Commitment Availability Period
Debt Instrument [Line Items]
Basis spread on variable rate															3.50%
EZOP | Warehouse credit facility | Weighted-Average Cost To Lender Rate | After Commitment Availability Period
Debt Instrument [Line Items]
Basis spread on variable rate															4.50%
TEPH
Debt Instrument [Line Items]
Unamortized debt discount							$ 645,000										3,815,000	645,000		3,815,000
TEPH | Revolving credit facility | Revolving credit facility
Debt Instrument [Line Items]
Borrowing capacity																	$ 360,400,000			360,400,000
Repayments of debt	$ 211,500,000
Maximum borrowing capacity				437,500,000		$ 200,000,000															$ 600,000,000	$ 400,000,000	$ 150,000,000
Aggregate committed amount		460,700,000		437,500,000	$ 390,000,000	200,000,000																	$ 100,000,000
TEPH | Revolving credit facility | Revolving credit facility | Solar Projects Before Construction
Debt Instrument [Line Items]
Advanced rate																	60.00%
TEPH | Revolving credit facility | Revolving credit facility | Solar Projects Under Construction
Debt Instrument [Line Items]
Advanced rate																	80.00%
TEPH | Revolving credit facility | Revolving credit facility | Minimum
Debt Instrument [Line Items]
Basis spread on variable rate																	2.90%
TEPH | Revolving credit facility | Revolving credit facility | Maximum
Debt Instrument [Line Items]
Basis spread on variable rate																	4.30%
TEPH | Revolving credit facility | Revolving credit facility | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate																	4.15%
TEPH | Revolving credit facility | Revolving credit facility | Federal Funds Rate
Debt Instrument [Line Items]
Variable rate basis adjustment																	0.50%
TEPH | Revolving credit facility | Revolving credit facility | TEPH Class A
Debt Instrument [Line Items]
Stated interest rate, increase																						0.40%
TEPH | Revolving credit facility | Revolving credit facility | TEPH Class B
Debt Instrument [Line Items]
Stated interest rate, increase																						0.40%
AP8 | Revolving credit facility | Revolving credit facility
Debt Instrument [Line Items]
Borrowing capacity																	$ 13,600,000			13,600,000
Maximum borrowing capacity																	$ 60,000,000			$ 60,000,000
SEI | Convertible senior notes | At any time prior to May 14, 2022
Debt Instrument [Line Items]
Redemption price																	115.00%
SEI | Convertible senior notes | At any time on and after September 23, 2024
Debt Instrument [Line Items]
Redemption price																	110.00%
SEI | Convertible senior notes | 7.75% convertible senior notes
Debt Instrument [Line Items]
Principal amount of debt issued							$ 55,000,000											$ 55,000,000
Stated interest rate							7.75%											7.75%
Purchase price							$ 52,300,000											$ 52,300,000
Issue price percentage					95.00%
Long-term debt exchanged					$ 55,000,000
SEI | Convertible senior notes | 9.75% convertible senior notes
Debt Instrument [Line Items]
Principal amount of debt issued					130,000,000
Stated interest rate																	9.75%			9.75%
Purchase price					$ 123,500,000
Issue price percentage					95.00%
Additional principal available to purchase					$ 60,000,000
Debt conversion																	$ 150,800,000
Conversion ratio					0.0740741
Conversion price (in USD per share) | $ / shares					$ 13.50
Redemption period																	180 days
Long-term debt																	$ 58,000,000			$ 58,000,000
Unamortized debt discount							16,913,000										37,394,000	16,913,000		37,394,000
Unamortized issuance costs							480,000										239,000	480,000		239,000
Carrying amount of equity component																	8,800,000			8,800,000
Unamortized issuance costs, equity component																	$ 545,000			545,000
SEI | Convertible senior notes | 9.75% convertible senior notes | At any time prior to May 14, 2022
Debt Instrument [Line Items]
Percentage of principal amount redeemed																	33.33%
Sunnova Energy Corporation | Notes payable
Debt Instrument [Line Items]
Principal amount of debt issued		$ 1,400,000	$ 2,800,000					$ 4,700,000		$ 1,900,000
Stated interest rate		4.25%	4.25%					4.94%		5.50%
Debt instrument term		5 months	7 months					8 months		10 months
AP4
Debt Instrument [Line Items]
Unamortized debt discount							452,000										$ 0	452,000		0
Unamortized issuance costs							196,000										0	196,000		0
Equity cure contribution											$ 106,000
AP4 | Secured term loan
Debt Instrument [Line Items]
Principal amount of debt issued														$ 107,100,000												$ 110,000,000	$ 90,000,000
Commitment fee																0.50%
Debt service coverage ratio, minimum																1.25
Debt service coverage ratio, minimum for distributions																1
Repayments of debt						92,000,000			$ 5,000,000
AP4 | Secured term loan | Variable Rate Component, Adjusted
Debt Instrument [Line Items]
Basis spread on variable rate														2.00%
AP4 | Secured term loan | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate									2.50%					3.00%
AP4 | Secured term loan | LIBOR | Variable Rate Component, Adjusted
Debt Instrument [Line Items]
Basis spread on variable rate														1.00%
AP4 | Secured term loan | Federal Funds Rate | Variable Rate Component, Adjusted
Debt Instrument [Line Items]
Basis spread on variable rate														0.50%
HELI
Debt Instrument [Line Items]
Unamortized debt discount							3,169,000										2,241,000	3,169,000		2,241,000
Unamortized issuance costs							5,586,000										4,004,000	5,586,000		4,004,000
HELI | Solar asset-backed notes | Solar Loan-Backed Notes, 2017-1 Class A
Debt Instrument [Line Items]
Principal amount of debt issued															$ 191,800,000
Stated interest rate															4.94%
Discount percent															0.05%
HELI | Solar asset-backed notes | Solar Loan-Backed Notes, 2017-1 Class B
Debt Instrument [Line Items]
Principal amount of debt issued															$ 18,000,000
Stated interest rate															6.00%
Discount percent															9.28%
HELI | Solar asset-backed notes | Solar Loan-Backed Notes, 2017-1 Class C
Debt Instrument [Line Items]
Principal amount of debt issued															$ 45,000,000
Stated interest rate															8.00%
Discount percent															8.65%
LAPH
Debt Instrument [Line Items]
Unamortized debt discount							401,000										0	401,000		0
Unamortized issuance costs							356,000										0	356,000		0
Repayments of debt	10,600,000					32,000,000
LAPH | Secured term loan
Debt Instrument [Line Items]
Principal amount of debt issued															$ 260,000,000
LAPH | Secured term loan | Secured Debt Class A
Debt Instrument [Line Items]
Principal amount of debt issued													$ 44,200,000
Basis spread on variable rate															3.30%
LAPH | Secured term loan | Secured Debt Class A | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate													4.50%
LAPH | Secured term loan | Secured Debt Class B
Debt Instrument [Line Items]
Principal amount of debt issued													$ 0
Basis spread on variable rate															11.00%
TEPIIH
Debt Instrument [Line Items]
Unamortized debt discount							2,219,000										0	2,219,000		0
Repayments of debt						226,600,000
TEPIIH | Revolving credit facility | Revolving credit facility
Debt Instrument [Line Items]
Maximum borrowing capacity												$ 250,000,000												$ 175,000,000
Aggregate committed amount												150,000,000												$ 125,000,000
HELII
Debt Instrument [Line Items]
Unamortized debt discount							49,000										42,000	49,000		42,000
Unamortized issuance costs							5,873,000										5,085,000	5,873,000		5,085,000
HELII | Solar asset-backed notes | Asset-backed Securities, 2019-01 Class A
Debt Instrument [Line Items]
Principal amount of debt issued													$ 202,000,000
Stated interest rate													4.87%
Discount percent													0.02%
HELII | Solar asset-backed notes | Asset-backed Securities, 2019-01 Class B
Debt Instrument [Line Items]
Principal amount of debt issued													$ 60,700,000
Stated interest rate													7.71%
Discount percent													0.02%
RAYSI
Debt Instrument [Line Items]
Unamortized debt discount							1,547,000										1,376,000	1,547,000		1,376,000
Unamortized issuance costs							4,759,000										4,334,000	4,759,000		4,334,000
RAYSI | Solar asset-backed notes | Asset-backed Securities, 2019-01 Class A
Debt Instrument [Line Items]
Principal amount of debt issued												$ 118,100,000
Stated interest rate												4.95%
RAYSI | Solar asset-backed notes | Asset-backed Securities, 2019-01 Class B
Debt Instrument [Line Items]
Principal amount of debt issued												$ 15,000,000
Stated interest rate												6.35%
Discount percent												6.50%
RAYSI | Solar asset-backed notes | Asset-backed Securities, 2019-02 Class B
Debt Instrument [Line Items]
Principal amount of debt issued									$ 6,400,000
Stated interest rate									6.35%
Discount percent									10.50%
HELIII
Debt Instrument [Line Items]
Unamortized debt discount							2,532,000										2,423,000	2,532,000		2,423,000
Unamortized issuance costs							2,410,000										2,326,000	2,410,000		2,326,000
HELIII | Asset-backed Securities, 2019-A Class A
Debt Instrument [Line Items]
Principal amount of debt issued									$ 139,700,000
Stated interest rate									3.75%
Discount percent									0.03%
HELIII | Asset-backed securities 2019-A Class B
Debt Instrument [Line Items]
Principal amount of debt issued									$ 14,900,000
Stated interest rate									4.49%
Discount percent									0.01%
HELIII | Asset-backed securities 2019-A Class C
Debt Instrument [Line Items]
Principal amount of debt issued									$ 13,000,000
Stated interest rate									5.32%
Discount percent									0.03%
TEPINV
Debt Instrument [Line Items]
Unamortized debt discount							2,856,000										1,322,000	2,856,000		1,322,000
Unamortized issuance costs							2,207,000										$ 1,758,000	2,207,000		1,758,000
TEPINV | Revolving credit facility | Revolving credit facility
Debt Instrument [Line Items]
Basis spread on variable rate																	0.00%
Maximum borrowing capacity							137,600,000											137,600,000
Aggregate committed amount							$ 95,200,000											95,200,000
Line of credit facility, maturity							27 months
TEPINV | Revolving credit facility | Revolving credit facility | Eligible Projects
Debt Instrument [Line Items]
Advanced rate																	85.00%
Obligation cap																	$ 9,500,000			9,500,000
TEPINV | Revolving credit facility | Revolving credit facility | Federal Funds Rate
Debt Instrument [Line Items]
Basis spread on variable rate																	0.50%
Obligation cap, percent																	10.00%
TEPINV | Revolving credit facility | Revolving credit facility | Class A Loans | Federal Funds Rate
Debt Instrument [Line Items]
Basis spread on variable rate																	5.99%
SOLI
Debt Instrument [Line Items]
Unamortized debt discount							$ 0										$ 113,000	0		113,000
Unamortized issuance costs							0										8,915,000	0		8,915,000
SOLI | Solar asset-backed notes | SOLI Series 2020-1 Class A
Debt Instrument [Line Items]
Principal amount of debt issued						$ 337,100,000
Stated interest rate						3.35%
Discount percent						0.89%
SOLI | Solar asset-backed notes | SOLI Series 2020-1 Class B
Debt Instrument [Line Items]
Principal amount of debt issued						$ 75,400,000
Stated interest rate						5.54%
Discount percent						0.85%
HELIV
Debt Instrument [Line Items]
Unamortized debt discount							0										885,000	0		885,000
Unamortized issuance costs							0										3,905,000	0		3,905,000
HELIV | Solar loan-backed notes | HELIV Series 2020-A Class A
Debt Instrument [Line Items]
Principal amount of debt issued				$ 135,900,000
Stated interest rate				2.98%
Discount percent				0.01%
HELIV | Solar loan-backed notes | HELIV Series 2020-A Class B
Debt Instrument [Line Items]
Principal amount of debt issued				$ 22,600,000
Stated interest rate				7.25%
Discount percent				4.18%
SOLII
Debt Instrument [Line Items]
Unamortized debt discount							0										80,000	0		80,000
Unamortized issuance costs							$ 0										$ 5,866,000	$ 0		$ 5,866,000
SOLII | Solar asset-backed notes | SOLII Series 2020-2 Class A
Debt Instrument [Line Items]
Principal amount of debt issued	$ 209,100,000
Stated interest rate	2.73%
Discount percent	0.03%
SOLII | Solar asset-backed notes | SOLII Series 2020-2 Class B
Debt Instrument [Line Items]
Principal amount of debt issued	$ 45,600,000
Stated interest rate	5.47%
Discount percent	0.05%

Long-Term Debt - Redemption Rat

Long-Term Debt - Redemption Rate (Details) - SEI - Convertible senior notes	12 Months Ended
	Dec. 31, 2020
At any time on and after May 14, 2023 but prior to May 14, 2024
Debt Instrument, Redemption [Line Items]
Redemption price	115.00%
At any time on and after May 14, 2024
Debt Instrument, Redemption [Line Items]
Redemption price	110.00%

Long-Term Debt - Schedule of Fa

Long-Term Debt - Schedule of Fair Value of Long-term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Oct. 31, 2020	Aug. 31, 2020	Dec. 31, 2019	Jul. 31, 2019	May 31, 2019
Debt Instrument [Line Items]
Net deferred financing costs and debt discounts	$ 87,600			$ 54,800
Carrying Value
Debt Instrument [Line Items]
Long-term debt	2,123,090			1,498,711
Estimated Fair Value
Debt Instrument [Line Items]
Long-term debt	$ 2,246,176			$ 1,517,778
SEI | Convertible senior notes | 7.75% convertible senior notes
Debt Instrument [Line Items]
Stated interest rate				7.75%
SEI | Convertible senior notes | 9.75% convertible senior notes
Debt Instrument [Line Items]
Stated interest rate	9.75%
SEI | Carrying Value | Convertible senior notes | 7.75% convertible senior notes
Debt Instrument [Line Items]
Long-term debt	$ 0			$ 55,000
SEI | Carrying Value | Convertible senior notes | 9.75% convertible senior notes
Debt Instrument [Line Items]
Long-term debt	95,648			0
SEI | Estimated Fair Value | Convertible senior notes | 7.75% convertible senior notes
Debt Instrument [Line Items]
Long-term debt	0			37,964
SEI | Estimated Fair Value | Convertible senior notes | 9.75% convertible senior notes
Debt Instrument [Line Items]
Long-term debt	100,482			0
Sunnova Energy Corporation | Notes payable
Debt Instrument [Line Items]
Stated interest rate		4.25%	4.25%		4.94%	5.50%
Sunnova Energy Corporation | Carrying Value | Notes payable
Debt Instrument [Line Items]
Long-term debt	2,254			2,428
Sunnova Energy Corporation | Estimated Fair Value | Notes payable
Debt Instrument [Line Items]
Long-term debt	2,254			2,428
AP4 | Carrying Value | Secured term loan
Debt Instrument [Line Items]
Long-term debt	0			92,478
AP4 | Estimated Fair Value | Secured term loan
Debt Instrument [Line Items]
Long-term debt	0			92,478
HELI | Carrying Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	211,724			222,305
HELI | Estimated Fair Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	220,941			223,895
LAPH | Carrying Value | Secured term loan
Debt Instrument [Line Items]
Long-term debt	0			42,876
LAPH | Estimated Fair Value | Secured term loan
Debt Instrument [Line Items]
Long-term debt	0			42,876
EZOP | Carrying Value | Warehouse credit facility
Debt Instrument [Line Items]
Long-term debt	171,600			121,400
EZOP | Estimated Fair Value | Warehouse credit facility
Debt Instrument [Line Items]
Long-term debt	171,600			121,400
HELII | Carrying Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	239,281			254,314
HELII | Estimated Fair Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	286,579			281,850
RAYSI | Carrying Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	126,227			133,155
RAYSI | Estimated Fair Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	146,506			139,004
HELIII | Carrying Value | Solar loan-backed notes
Debt Instrument [Line Items]
Long-term debt	135,112			154,573
HELIII | Estimated Fair Value | Solar loan-backed notes
Debt Instrument [Line Items]
Long-term debt	149,489			155,701
SOLI | Carrying Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	399,674			0
SOLI | Estimated Fair Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	427,511			0
HELIV | Carrying Value | Solar loan-backed notes
Debt Instrument [Line Items]
Long-term debt	146,163			0
HELIV | Estimated Fair Value | Solar loan-backed notes
Debt Instrument [Line Items]
Long-term debt	145,433			0
SOLII | Carrying Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	254,700			0
SOLII | Estimated Fair Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	254,674			0
Revolving credit facility | TEPIIH | Carrying Value | Revolving credit facility
Debt Instrument [Line Items]
Long-term debt	0			234,650
Revolving credit facility | TEPIIH | Estimated Fair Value | Revolving credit facility
Debt Instrument [Line Items]
Long-term debt	0			234,650
Revolving credit facility | TEPH | Carrying Value | Revolving credit facility
Debt Instrument [Line Items]
Long-term debt	239,570			90,325
Revolving credit facility | TEPH | Estimated Fair Value | Revolving credit facility
Debt Instrument [Line Items]
Long-term debt	239,570			90,325
Revolving credit facility | TEPINV | Carrying Value | Revolving credit facility
Debt Instrument [Line Items]
Long-term debt	54,704			95,207
Revolving credit facility | TEPINV | Estimated Fair Value | Revolving credit facility
Debt Instrument [Line Items]
Long-term debt	54,704			95,207
Revolving credit facility | AP8 | Carrying Value | Revolving credit facility
Debt Instrument [Line Items]
Long-term debt	46,433			0
Revolving credit facility | AP8 | Estimated Fair Value | Revolving credit facility
Debt Instrument [Line Items]
Long-term debt	$ 46,433			$ 0

Long-Term Debt - Schedule of _2

Long-Term Debt - Schedule of Long-term Debt Maturities (Details) $ in Thousands	Dec. 31, 2020USD ($)
Debt Disclosure [Abstract]
2021	$ 110,883
2022	505,674
2023	107,401
2024	63,536
2025	161,088
2026 and thereafter	1,174,508
Total	$ 2,123,090

Derivative Instruments - Narrat

Derivative Instruments - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Interest Rate Swap
Derivative [Line Items]
Aggregate notional amount of derivative	$ 383,670	$ 524,103
AP4 | Interest Rate Swap
Derivative [Line Items]
Aggregate notional amount of derivative	105,200
Realized loss	484
LAPH | Interest Rate Swap
Derivative [Line Items]
Realized loss	9,100
Aggregate notional amount of unwound derivative	44,200
EZOP | Interest Rate Swap
Derivative [Line Items]
Aggregate notional amount of derivative	155,800	255,800
Realized loss	6,400	81
Aggregate notional amount of unwound derivative	126,100	264,600
TEPIIH | Interest Rate Swap
Derivative [Line Items]
Aggregate notional amount of derivative		171,200
Realized loss	25,100
Aggregate notional amount of unwound derivative	181,400
TEPH | Interest Rate Swap
Derivative [Line Items]
Aggregate notional amount of derivative	260,800	$ 103,100
TEPINV | Interest Rate Cap
Derivative [Line Items]
Aggregate notional amount of derivative	$ 95,200

Derivative Instruments - Outsta

Derivative Instruments - Outstanding Derivative Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Interest Rate Swap
Derivative [Line Items]
Aggregate Notional Amount	$ 383,670	$ 524,103
AP4 | Interest Rate Swap One
Derivative [Line Items]
Fixed Interest Rate	0.00%	2.338%
Aggregate Notional Amount	$ 0	$ 99,762
AP4 | Interest Rate Swap
Derivative [Line Items]
Aggregate Notional Amount	$ 105,200
LAPH | Interest Rate Swap Two
Derivative [Line Items]
Fixed Interest Rate	0.00%	3.409%
Aggregate Notional Amount	$ 0	$ 43,298
EZOP | Interest Rate Swap Three
Derivative [Line Items]
Aggregate Notional Amount	$ 130,373	$ 100,083
EZOP | Interest Rate Swap Three | Minimum
Derivative [Line Items]
Fixed Interest Rate	0.483%	1.631%
EZOP | Interest Rate Swap Three | Maximum
Derivative [Line Items]
Fixed Interest Rate	2.62%	2.62%
EZOP | Interest Rate Swap
Derivative [Line Items]
Aggregate Notional Amount	$ 155,800	$ 255,800
TEPIIH | Interest Rate Swap Four
Derivative [Line Items]
Fixed Interest Rate	0.00%
Aggregate Notional Amount	$ 0	$ 225,845
TEPIIH | Interest Rate Swap Four | Minimum
Derivative [Line Items]
Fixed Interest Rate		1.909%
TEPIIH | Interest Rate Swap Four | Maximum
Derivative [Line Items]
Fixed Interest Rate		3.383%
TEPIIH | Interest Rate Swap
Derivative [Line Items]
Aggregate Notional Amount		$ 171,200
TEPH | Interest Rate Swap Five
Derivative [Line Items]
Aggregate Notional Amount	$ 202,272	$ 55,115
TEPH | Interest Rate Swap Five | Minimum
Derivative [Line Items]
Fixed Interest Rate	0.528%	1.62%
TEPH | Interest Rate Swap Five | Maximum
Derivative [Line Items]
Fixed Interest Rate	2.114%	1.928%
TEPH | Interest Rate Swap
Derivative [Line Items]
Aggregate Notional Amount	$ 260,800	$ 103,100
TEPINV | Interest Rate Swap Six
Derivative [Line Items]
Fixed Interest Rate	2.50%	0.00%
Aggregate Notional Amount	$ 51,025	$ 0

Derivative Instruments - Balanc

Derivative Instruments - Balance Sheet (Details) - Not designated as hedging instrument - Interest rate swap - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Total, net	$ (13,407)	$ (27,129)
Other assets
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	0	360
Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	0	(397)
Other long-term liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	$ (13,407)	$ (27,092)

Derivative Instruments - Intere

Derivative Instruments - Interest Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized (gain) loss	$ (13,768)	$ 19,237	$ 6,100
Interest Rate Swap | Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Realized (gain) loss	51,326	13,195	(17,004)
Unrealized (gain) loss	(13,768)	19,237	6,100
Total	$ 37,558	$ 32,432	$ (10,904)

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Tax Credit Carryforward [Line Items]
Effective income tax rate	0.00%	0.00%	0.00%
Income tax	$ 181,000	$ 0	$ 0
Valuation allowance	334,237,000	284,976,000
Tax credit carryforward	267,500,000
Income tax penalties and interest accrued	0	$ 0
Investment Tax Credit Carryforward
Tax Credit Carryforward [Line Items]
Tax credit carryforward	20,700,000
Domestic Tax Authority
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	$ 1,200,000,000

Income Taxes - Effective Income

Income Taxes - Effective Income Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Loss before income tax	$ (307,637)	$ (133,434)	$ (68,409)
Statutory federal tax rate	21.00%	21.00%	21.00%
Tax benefit computed at statutory rate	$ (64,604)	$ (28,021)	$ (14,366)
State income tax, net of federal benefit	(16,862)	(8,344)	(4,308)
Redeemable noncontrolling interests	11,662	(2,293)	(1,226)
ITC recapture	232	296	989
Other	475	852	234
Increase in valuation allowance, net	69,278	37,510	18,677
Total income tax expense	$ 181	$ 0	$ 0

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Federal net operating loss carryforward	$ 242,732	$ 169,379
State net operating loss carryforward	76,281	49,565
ITC carryforward	267,522	246,828
Federal unused interest deduction carryforward	39,036	22,559
Investment in certain financing arrangements	44,337	36,999
Other deferred tax assets	23,010	20,801
Deferred tax assets	692,918	546,131
Fixed asset basis difference	(298,032)	(235,510)
Investment in certain financing arrangements	(57,222)	(22,826)
Other deferred tax liabilities	(3,427)	(2,819)
Deferred tax liabilities	(358,681)	(261,155)
Valuation allowance	(334,237)	(284,976)
Net deferred tax asset	$ 0	$ 0

Related-Party Transactions - Re

Related-Party Transactions - Related Party (Details) - USD ($) $ in Thousands	1 Months Ended		12 Months Ended
	Aug. 31, 2019	Jun. 30, 2019	Dec. 31, 2020	Jan. 31, 2019
Debt Instrument [Line Items]
Notes receivable forgiven			$ 1,300
Promissory notes | Executive officer
Debt Instrument [Line Items]
Notes receivable forgiven		$ 1,400
Annual forgiveness, notes receivable			0.25%
Notes receivable, related party				$ 1,700
Bonus for tax liability reimbursement	$ 892

Redeemable Noncontrolling Int_3

Redeemable Noncontrolling Interests and Noncontrolling Interests - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Noncontrolling Interest [Line Items]
Non-performance fees paid	$ 2,100,000	$ 1,300,000	$ 0
Non-Performance Fee	$ 1,500,000	$ 566,000
Class A members | Flip Date
Noncontrolling Interest [Line Items]
Allocation of income (loss)	5.00%
Class A members | TEPIVA, TEPIVB, TEPIVC, TEPIVD, TEPIVE and TEPIVG
Noncontrolling Interest [Line Items]
Allocation of income (loss)	67.00%
Class B Members | TEPIVA, TEPIVB, TEPIVC, TEPIVD, TEPIVE and TEPIVG
Noncontrolling Interest [Line Items]
Allocation of income (loss)	33.00%
Minimum | Class B Members
Noncontrolling Interest [Line Items]
Allocation of income (loss)	1.00%
Maximum | Class A members
Noncontrolling Interest [Line Items]
Allocation of income (loss)	99.00%

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($)	Aug. 19, 2019	Jul. 24, 2019	Dec. 31, 2020	Aug. 19, 2019	Jan. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Repayments of Debt [Line Items]
Non-cash conversion of convertible senior notes for common stock						$ 149,352,000	$ 0	$ 0
Debt conversion, shares issued (in shares)						11,168,874
Loss on extinguishment of debt						$ 142,772,000	$ 0	$ 0
9.75% convertible senior notes | Convertible senior notes | SEI
Repayments of Debt [Line Items]
Stated interest rate			9.75%			9.75%
Non-cash conversion of convertible senior notes for common stock						$ 150,800,000
IPO
Repayments of Debt [Line Items]
Shares issued (in shares)		14,000,000
Common stock offering price (in USD per share)		$ 12
Sale of stock, net proceeds				$ 162,300,000
Underwriting discounts and commissions				10,700,000
Issuance costs on offering expenses				$ 5,400,000
Over-Allotment Option
Repayments of Debt [Line Items]
Shares issued (in shares)	865,267
Common stock offering price (in USD per share)	$ 12			$ 12
Public Stock Offering
Repayments of Debt [Line Items]
Shares issued (in shares)			4,025,000
Common stock offering price (in USD per share)			$ 37			$ 37
Sale of stock, net proceeds			$ 142,700,000
Underwriting discounts and commissions			6,000,000
Issuance costs on offering expenses			$ 300,000
Common Stock
Repayments of Debt [Line Items]
Issuance of stock, net (in shares)						16,431,151	14,865,267
Conversion of stock, shares issued (in shares)								60,479,017
Series A and Series C Convertible Preferred Stock
Repayments of Debt [Line Items]
Conversion terms, public offering aggregate gross proceeds, net						$ 175,000,000
Conversion terms, offering price ratio						125.00%
Conversion terms, affirmative vote						80.00%
Series A Convertible Preferred Stock
Repayments of Debt [Line Items]
Convertible preferred stock, authorized (in shares)									47,149,592
Series A Convertible Preferred Stock | Pro Forma
Repayments of Debt [Line Items]
Convertible preferred stock, authorized (in shares)									64,294,899
Stock converted (in shares)								46,351,877
Series C Convertible Preferred Stock
Repayments of Debt [Line Items]
Stock issuance price (in USD per share)								$ 13.53
Proceeds from issuance of redeemable convertible preferred stock								$ 176,000,000
Stock converted (in shares)								14,127,140
Series C Convertible Preferred Stock | Pro Forma
Repayments of Debt [Line Items]
Convertible preferred stock, authorized (in shares)									17,145,306
Issuance of stock, net (in shares)								13,006,780
Series B Convertible Preferred Stock
Repayments of Debt [Line Items]
Conversion terms, affirmative vote					75.00%
Stock issuance price (in USD per share)					$ 8.70
Sale of stock price threshold (in USD per share)					$ 6.6558
Proceeds from preferred stock					$ 113,000
Series B Convertible Preferred Stock | Pro Forma
Repayments of Debt [Line Items]
Issuance of stock, net (in shares)					13,013
Preferred stock, exchange of shares (in shares)					4,763,086
Series A Common Stock
Repayments of Debt [Line Items]
Conversion of stock, shares issued (in shares)								23,870
Shares authorized (in shares)									64,294,899
Series A Common Stock | Pro Forma
Repayments of Debt [Line Items]
Shares authorized (in shares)									77,153,879
Series B Common Stock
Repayments of Debt [Line Items]
Stock converted (in shares)								23,870

Equity-Based Compensation - Sch

Equity-Based Compensation - Schedule of Stock Options Assumptions (Details) - Stock Options	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected dividend yield	0.00%	0.00%	0.00%
Risk-free interest rate		2.62%	2.62%
Expected term		7 years 11 months 8 days	7 years 11 months 8 days
Volatility		81.00%	81.00%

Equity-Based Compensation - Sto

Equity-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number of Stock Options
Outstanding, beginning balance (in shares)	4,304,309	4,808,390
Granted (in shares)		94,295
Exercised (in shares)	(922,770)	(2,143)
Forfeited (in shares)	(115,191)	(596,233)
Outstanding, ending balance (in shares)	3,266,348	4,304,309	4,808,390
Number of options, exercisable (in shares)	3,266,348
Number of options, vested (in shares)	3,266,348
Number of options, non-vested (in shares)	0	964,396
Weighted Average Exercise Price
Outstanding, beginning balance (in USD per share)	$ 15.86	$ 15.90
Granted (in USD per share)		13.58
Exercised (in USD per share)	14.76	1.85
Forfeited (in USD per share)	19.19	15.85
Outstanding, ending balance (in USD per share)	16.06	$ 15.86	$ 15.90
Weighted average exercise price, exercisable (in USD per share)	16.06
Weighted average exercise price, vested (in USD per share)	$ 16.06
Weighted Average Remaining Contractual Term (Years)
Outstanding	5 years 9 months 25 days	7 years 29 days	8 years 1 month 2 days
Granted		9 years 25 days
Exercisable	5 years 9 months 25 days
Vested	5 years 9 months 25 days
Weighted Average Grant Date Fair Value
Granted (in USD per share)		$ 3.11
Forfeited (in USD per share)	$ 3.54	3.48
Non-vested (in USD per share)	$ 0	$ 3.52
Aggregate Intrinsic Value
Outstanding, beginning balance	$ 242	$ 129
Exercised	28,022	20
Outstanding, ending balance	94,962	$ 242	$ 129
Exercisable	94,962
Vested	$ 94,962

Equity-Based Compensation - Nar

Equity-Based Compensation - Narrative (Details)	Jul. 29, 2019USD ($)shares	Dec. 31, 2020USD ($)planshares	Dec. 31, 2019USD ($)shares	Dec. 31, 2018USD ($)shares	Mar. 31, 2016shares	Jan. 31, 2015shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock option plans | plan		2
Granted (in shares)			94,295
Stock options exercised (in shares)		922,770	2,143
Proceeds from issuance of common stock, net | $		$ 152,277,000	$ 164,452,000	$ 0
Stock options vested (in shares)		915,501	1,765,410
Stock options vested | $		$ 3,200,000	$ 6,000,000
Total unrecognized compensation expense | $		$ 0
Long-Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized (in shares)	5,229,318
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted (in shares)		1,141,413	1,431,555
Stock units vested (in shares)		463,762	0
Restricted stock units, vested | $		$ 5,500,000	$ 0
Unrecognized compensation expense | $		$ 17,900,000
Weighted average period		1 year 9 months 14 days
Restricted Stock Units | Long-Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted (in shares)		1,141,413
Awards granted, fair value | $		$ 13,700,000
Restricted Stock Units | Long-Term Incentive Plan | Share-based Payment Arrangement, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		1 year
Restricted Stock Units | Long-Term Incentive Plan | Share-based Payment Arrangement, Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		3 years
Restricted Stock Units | Long-Term Incentive Plan | Share-based Payment Arrangement, Tranche Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		7 years
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of non-vested awards becoming exercisable	50.00%
Awards becoming exercisable (in shares)	995,517
Accelerated vesting expense | $	$ 3,200,000
Granted (in shares)		0	94,295	24,860
Shares net exercised (in shares)				1,393
Issued (in shares)		922,770	2,143	644
Stock options exercised (in shares)		922,770	2,143
Proceeds from issuance of common stock, net | $		$ 13,600,000
Expected dividend yield		0.00%	0.00%	0.00%
Stock Options | Prior Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized (in shares)						26,032
Stock Options | 2016 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized (in shares)					4,288,950
Stock Options | Pro Forma
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)				1,810,016

Equity-Based Compensation - Res

Equity-Based Compensation - Restricted Stock Activity (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number of Restricted Stock Units
Forfeited (in shares)	(44,606)	(5,416)
Weighted Average Grant Date Fair Value
Forfeited (in USD per share)	$ 12.31	$ 12
Restricted Stock Units
Number of Restricted Stock Units
Outstanding, beginning balance (in shares)	1,426,139	0
Granted (in shares)	1,141,413	1,431,555
Vested (in shares)	(463,762)	0
Outstanding, ending balance (in shares)	2,059,184	1,426,139
Weighted Average Grant Date Fair Value
Outstanding (in USD per share)	$ 11.95	$ 11.93	$ 0
Granted (in USD per share)	11.98	$ 11.93
Vested (in USD per share)	$ 11.89

Basic and Diluted Net Loss Pe_3

Basic and Diluted Net Loss Per Share - Schedule of Basic and Diluted Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net loss attributable to stockholders									$ (252,284)	$ (144,351)	$ (74,246)
Deemed dividends on convertible preferred stock exchange									0	0	(19,332)
Net loss attributable to common stockholders—basic	$ (91,770)	$ (64,181)	$ (25,258)	$ (71,075)	$ (17,509)	$ (37,590)	$ (63,260)	$ (50,717)	(252,284)	(169,076)	(135,872)
Net loss attributable to common stockholders - diluted	$ (91,770)	$ (64,181)	$ (25,258)	$ (71,075)	$ (17,509)	$ (37,590)	$ (63,260)	$ (50,717)	$ (252,284)	$ (169,076)	$ (135,872)
Net loss per share attributable to common stockholders—basic and diluted (in USD per share)	$ (0.96)	$ (0.73)	$ (0.30)	$ (0.85)	$ (0.21)	$ (0.62)	$ (7.32)	$ (5.87)	$ (2.87)	$ (4.14)	$ (15.74)
Weighted average common shares outstanding—basic and diluted (in shares)									87,871,457	40,797,976	8,634,477
Series A Convertible Preferred Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Dividends earned on convertible preferred stock									$ 0	$ (19,271)	$ (36,346)
Series C Convertible Preferred Stock
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Dividends earned on convertible preferred stock									$ 0	$ (5,454)	$ (5,948)

Basic and Diluted Net Loss Pe_4

Basic and Diluted Net Loss Per Share - Anti-Dilutive Weighted Average Shares (Details) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Equity-based compensation awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	6,013,797	4,954,286	4,307,614
Convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	33,960,624	53,112,246
Convertible senior notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share (in shares)	9,606,157	104,320	0

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Loss Contingencies [Line Items]
Current portion of performance guarantee obligations	$ 3,308	$ 4,067
Letter of credit outstanding	375	725
Other commitment	55,700	32,800
Payments for dealer commitments	25,800	31,700
Subsidiary restricted net assets	863,200
Performance Guarantee Obligations
Loss Contingencies [Line Items]
Performance guarantee obligations	5,718	6,468	$ 6,044
Current portion of performance guarantee obligations	3,300	4,100
Long-term portion of performance guarantee obligations	$ 2,400	$ 2,400

Commitments and Contingencies_2

Commitments and Contingencies - Performance Guarantee Obligations (Details) - Performance Guarantee Obligations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Performance Guarantee Obligations [Roll Forward]
Balance at beginning of period	$ 6,468	$ 6,044
Accruals for obligations issued	3,155	3,101
Settlements made in cash	(3,905)	(2,677)
Balance at end of period	$ 5,718	$ 6,468

Commitments and Contingencies_3

Commitments and Contingencies - Lease Expenses and Other Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Operating lease expense	$ 1,342	$ 1,248	$ 972
Finance lease amortization expense	3	8	0
Short-term lease expense	49	48	50
Variable lease expense	696	1,037	704
Sublease income	0	(73)	(70)
Total	$ 2,090	$ 2,268	$ 1,656

Commitments and Contingencies_4

Commitments and Contingencies - Lease Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Right-of-use assets:
Operating leases	$ 8,779	$ 9,668
Finance leases	391	5
Total right-of-use assets	9,170	9,673
Current lease liabilities:
Operating leases	1,094	556
Finance leases	112	5
Long-term leases liabilities:
Operating leases	9,742	9,389
Long-term portion of lease liability	203	0
Total lease liabilities	$ 11,151	$ 9,950
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:OtherAssetsNoncurrent	us-gaap:OtherAssetsNoncurrent
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesCurrent	us-gaap:OtherLiabilitiesCurrent
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:LiabilitiesOtherThanLongtermDebtNoncurren	us-gaap:LiabilitiesOtherThanLongtermDebtNoncurren

Commitments and Contingencies_5

Commitments and Contingencies - Other Lease Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash paid (received) for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ (439)	$ 1,254	$ 875
Financing cash flows from finance leases	2	8	0
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	0	8,087	0
Finance leases	392	$ 13	$ 0
Leasehold improvements reimbursements	$ 1,500
Weighted average remaining lease term (years):
Operating leases	8 years 5 months 19 days	9 years 4 months 28 days
Finance leases	3 years 11 months 26 days	8 months 4 days
Weighted average discount rate:
Operating leases	3.93%	3.94%
Finance leases	3.39%	4.26%

Commitments and Contingencies_6

Commitments and Contingencies - Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Operating Leases
2021	$ 1,536
2022	1,559
2023	1,594
2024	1,616
2025	1,633
2026 and thereafter	5,984
Total	13,922
Amount representing interest	(2,136)
Amount representing leasehold incentives	(950)
Present value of future payments	10,836
Current portion of lease liability	(1,094)	$ (556)
Long-term portion of lease liability	9,742	9,389
Finance Leases
2021	122
2022	88
2023	69
2024	55
2025	0
2026 and thereafter	0
Total	334
Amount representing interest	(19)
Amount representing leasehold incentives	0
Present value of future payments	315
Current portion of lease liability	(112)	(5)
Long-term portion of lease liability	$ 203	$ 0

Commitments and Contingencies_7

Commitments and Contingencies - Dealer Commitments (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Long-term Purchase Commitment [Line Items]
Total	$ 55,700	$ 32,800
Long-Term Dealer Commitments
Long-term Purchase Commitment [Line Items]
2021	28,982
2022	35,844
2023	12,520
2024	12,515
2025	2,191
2026 and thereafter	0
Total	$ 92,052

Commitments and Contingencies_8

Commitments and Contingencies - Purchase Commitments (Details) $ in Thousands	Dec. 31, 2020USD ($)
Commitments and Contingencies Disclosure [Abstract]
2021	$ 28,497
2022	26,810
2023	26,605
2024	19,807
2025	0
2026 and thereafter	0
Total	$ 101,719

Commitments and Contingencies_9

Commitments and Contingencies - Future Commitments (Details) $ in Thousands	Dec. 31, 2020USD ($)
Commitments and Contingencies Disclosure [Abstract]
2021	$ 7,976
2022	2,112
2023	26
2024	26
2025	7
2026 and thereafter	0
Total	$ 10,147

Subsequent Events (Details)

Subsequent Events (Details) - USD ($)	1 Months Ended			2 Months Ended	12 Months Ended
	Feb. 25, 2021	Oct. 31, 2020	Jun. 30, 2020	Feb. 25, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	May 31, 2020
Subsequent Event [Line Items]
Non-cash conversion of convertible senior notes for common stock					$ 149,352,000	$ 0	$ 0
Debt conversion, shares issued (in shares)					11,168,874
Subsequent Event | SunStreet Energy Group, LLC
Subsequent Event [Line Items]
Business acquisition, shares issued in exchange (in shares)	7,222,229
Business acquisition, shares issued at closing (in shares)	3,333,333
Business acquisition, shares issuable as earnout (in shares)	3,888,896
SEI | 9.75% convertible senior notes | Convertible senior notes
Subsequent Event [Line Items]
Stated interest rate					9.75%
Non-cash conversion of convertible senior notes for common stock					$ 150,800,000
Principal amount of debt issued								$ 130,000,000
SEI | Subsequent Event | 9.75% convertible senior notes | Convertible senior notes
Subsequent Event [Line Items]
Non-cash conversion of convertible senior notes for common stock				$ 97,100,000
Debt conversion, shares issued (in shares)				7,196,035
HELV | Subsequent Event | HELV Series 2021-A Class A | Solar loan-backed notes
Subsequent Event [Line Items]
Stated interest rate	1.80%			1.80%
Principal amount of debt issued	$ 150,100,000			$ 150,100,000
Discount percent	0.001%
HELV | Subsequent Event | HELV Series 2021-A Class B | Solar loan-backed notes
Subsequent Event [Line Items]
Stated interest rate	3.15%			3.15%
Principal amount of debt issued	$ 38,600,000			$ 38,600,000
Discount percent	2.487%
EZOP
Subsequent Event [Line Items]
Repayments of debt		$ 28,000,000	$ 149,300,000
EZOP | Subsequent Event | Warehouse credit facility
Subsequent Event [Line Items]
Repayments of debt	$ 107,300,000
AP8 | Subsequent Event | Revolving credit facility | Revolving credit facility
Subsequent Event [Line Items]
Repayments of debt	$ 29,500,000

Selected Quarterly Financial _3

Selected Quarterly Financial Data (Unaudited) Statements of Operation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 38,024	$ 50,177	$ 42,790	$ 29,829	$ 33,614	$ 36,615	$ 34,612	$ 26,715	$ 160,820	$ 131,556	$ 104,382
Total operating expenses, net	56,002	48,528	47,933	44,135	42,769	42,513	37,322	31,222	196,598	153,826	118,112
Operating income (loss)	(17,978)	1,649	(5,143)	(14,306)	(9,155)	(5,898)	(2,710)	(4,507)	(35,778)	(22,270)	(13,730)
Net loss	(128,791)	(73,294)	(28,729)	(77,004)	(13,762)	(34,369)	(49,807)	(35,496)	(307,818)	(133,434)	(68,409)
Net loss attributable to common stockholders—basic	(91,770)	(64,181)	(25,258)	(71,075)	(17,509)	(37,590)	(63,260)	(50,717)	(252,284)	(169,076)	(135,872)
Net loss attributable to common stockholders - diluted	$ (91,770)	$ (64,181)	$ (25,258)	$ (71,075)	$ (17,509)	$ (37,590)	$ (63,260)	$ (50,717)	$ (252,284)	$ (169,076)	$ (135,872)
Net loss per share attributable to common stockholders—basic and diluted (in USD per share)	$ (0.96)	$ (0.73)	$ (0.30)	$ (0.85)	$ (0.21)	$ (0.62)	$ (7.32)	$ (5.87)	$ (2.87)	$ (4.14)	$ (15.74)

Schedule I Parent Company Fin_2

Schedule I Parent Company Financial Statements - Condensed Balance Sheets (Details) - USD ($) $ in Thousands		Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash		$ 209,859		$ 83,485	$ 52,706
Total current assets		456,655		274,320
Total assets	[1]	3,587,582		2,487,067
Current liabilities:
Accounts payable		39,908		36,190
Other current liabilities		26,013		21,804
Total current liabilities		210,853		195,002
Total liabilities	[1]	2,306,901		1,668,827
Stockholders' equity:
Common stock		10		8
Additional paid-in capital—common stock		1,482,716		1,007,751
Accumulated deficit		(530,995)	$ (361,824)	(361,824)
Total stockholders' equity		951,731		645,935
Total liabilities, redeemable noncontrolling interests and equity		3,587,582		2,487,067
Parent Company
Current assets:
Cash		4,917		696
Total current assets		4,917		696
Investments in subsidiaries		1,076,299		891,330
Total assets		1,081,216		892,026
Current liabilities:
Accounts payable		437		0
Other current liabilities		1,314		83
Total current liabilities		1,751		83
Long-term debt, net		58,015		37,607
Total liabilities		59,766		37,690
Stockholders' equity:
Common stock		10		8
Additional paid-in capital—common stock		1,462,690		987,760
Accumulated deficit		(441,250)		(133,432)
Total stockholders' equity		1,021,450		854,336
Total liabilities, redeemable noncontrolling interests and equity		$ 1,081,216		$ 892,026
[1]	The consolidated assets as of December 31, 2020 and 2019 include $1,471,796 and $790,211, respectively, of assets of variable interest entities ("VIEs") that can only be used to settle obligations of the VIEs. These assets include cash of $13,407 and $7,347 as of December 31, 2020 and 2019, respectively; accounts receivable—trade, net of $2,953 and $1,460 as of December 31, 2020 and 2019, respectively; accounts receivable—other of $583 and $4 as of December 31, 2020 and 2019, respectively; other current assets of $182,646 and $47,606 as of December 31, 2020 and 2019, respectively; property and equipment, net of $1,257,953 and $726,415 as of December 31, 2020 and 2019, respectively; and other assets of $14,254 and $7,379 as of December 31, 2020 and 2019, respectively. The consolidated liabilities as of December 31, 2020 and 2019 include $32,345 and $13,440, respectively, of liabilities of VIEs whose creditors have no recourse to Sunnova Energy International Inc. These liabilities include accounts payable of $2,744 and $1,926 as of December 31, 2020 and 2019, respectively; accrued expenses of $827 and $35 as of December 31, 2020 and 2019, respectively; other current liabilities of $3,284 and $612 as of December 31, 2020 and 2019, respectively; and other long-term liabilities of $25,490 and $10,867 as of December 31, 2020 and 2019, respectively.

Schedule I Parent Company Fin_3

Schedule I Parent Company Financial Statements - Condensed Balance Sheets Additional Information (Details) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Condensed Financial Statements, Captions [Line Items]
Common stock, issued (in shares)	100,412,036	83,980,885
Common stock, par value (in USD per share)	$ 0.0001	$ 0.0001
Parent Company
Condensed Financial Statements, Captions [Line Items]
Common stock, issued (in shares)	100,412,036	83,980,885
Common stock, par value (in USD per share)	$ 0.0001	$ 0.0001

Schedule I Parent Company Fin_4

Schedule I Parent Company Financial Statements - Condensed Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Condensed Financial Statements, Captions [Line Items]
Revenue	$ 38,024	$ 50,177	$ 42,790	$ 29,829	$ 33,614	$ 36,615	$ 34,612	$ 26,715	$ 160,820	$ 131,556	$ 104,382
General and administrative									115,148	97,986	67,430
Operating loss	(17,978)	1,649	(5,143)	(14,306)	(9,155)	(5,898)	(2,710)	(4,507)	(35,778)	(22,270)	(13,730)
Interest expense, net									154,580	108,024	51,582
Loss on extinguishment of long-term debt, net									142,772	0	0
Loss before income tax									(307,637)	(133,434)	(68,409)
Income tax expense									181	0	0
Net loss	$ (128,791)	$ (73,294)	$ (28,729)	$ (77,004)	$ (13,762)	$ (34,369)	$ (49,807)	$ (35,496)	(307,818)	(133,434)	(68,409)
Parent Company
Condensed Financial Statements, Captions [Line Items]
Revenue									0	0	0
General and administrative									2,972	418	0
Operating loss									(2,972)	(418)	0
Interest expense, net									19,578	83	0
Loss on extinguishment of long-term debt, net									142,772	0	0
Equity in losses of subsidiaries									142,496	132,933	0
Loss before income tax									(307,818)	(133,434)	0
Income tax expense									0	0	0
Net loss									$ (307,818)	$ (133,434)	$ 0

Schedule I Parent Company Fin_5

Schedule I Parent Company Financial Statements - Condensed Statements of Cash Flow (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
CASH FLOWS FROM OPERATING ACTIVITIES
Net cash used in operating activities	$ (131,466)	$ (170,262)	$ (11,570)
CASH FLOWS FROM INVESTING ACTIVITIES
Net cash used in investing activities	(829,519)	(568,316)	(348,849)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from long-term debt	1,651,765	883,360	445,586
Payments of deferred financing costs	(24,084)	(12,110)	(8,598)
Proceeds from issuance of common stock, net	152,277	164,452	0
Other, net	(2)	(16)	(6)
Net cash provided by financing activities	1,188,587	801,823	365,687
Net increase in cash and restricted cash	227,602	63,245	5,268
Cash and restricted cash at beginning of period	150,291	87,046	81,778
Cash and restricted cash at end of period	377,893	150,291	87,046
Non-cash investing and financing activities:
Non-cash conversion of convertible senior notes for common stock	149,352	0	0
Supplemental cash flow information:
Cash paid for interest	87,829	58,060	57,887
Cash paid for income taxes	181	0	0
Parent Company
CASH FLOWS FROM OPERATING ACTIVITIES
Net cash used in operating activities	(7,762)	0	0
CASH FLOWS FROM INVESTING ACTIVITIES
Investments in subsidiaries	(334,471)	(219,206)	0
Distributions from subsidiaries	10,547	2	0
Net cash used in investing activities	(323,924)	(219,204)	0
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from long-term debt	106,400	38,087	0
Payments of deferred financing costs	(1,155)	(377)	0
Proceeds from issuance of common stock, net	157,005	168,204	0
Proceeds from equity component of debt instrument, net	73,657	13,984	0
Other, net	0	2	0
Net cash provided by financing activities	335,907	219,900	0
Net increase in cash and restricted cash	4,221	696	0
Cash and restricted cash at beginning of period	696	0	0
Cash and restricted cash at end of period	4,917	696	0
Non-cash investing and financing activities:
Non-cash conversion of convertible senior notes for common stock	149,352	0	0
Supplemental cash flow information:
Cash paid for interest	9,191	0	0
Cash paid for income taxes	$ 0	$ 0	$ 0

Schedule I Parent Company Fin_6

Schedule I Parent Company Financial Statements - Basis of Presentation (Details) - IPO	Jul. 24, 2019$ / sharesshares
Subsidiary, Sale of Stock [Line Items]
Shares issued (in shares) | shares	14,000,000
Common stock offering price (in USD per share) | $ / shares	$ 12
Parent Company
Subsidiary, Sale of Stock [Line Items]
Shares issued (in shares) | shares	14,000,000
Common stock offering price (in USD per share) | $ / shares	$ 12