Sunnova Energy International (NOVA) 10-Q 29 Apr 21 2021 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2021	Apr. 26, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
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 Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		111,970,130
Entity Central Index Key	0001772695
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false
Current Fiscal Year End Date	--12-31

UNAUDITED CONDENSED CONSOLIDATE

UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands		Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash		$ 150,892	$ 209,859
Accounts receivable—trade, net		11,802	10,243
Accounts receivable—other		21,536	21,378
Other current assets, net of allowance of $837 and $707 as of March 31, 2021 and December 31, 2020, respectively		192,580	215,175
Total current assets		376,810	456,655
Property and equipment, net		2,446,103	2,323,169
Customer notes receivable, net of allowance of $20,082 and $16,961 as of March 31, 2021 and December 31, 2020, respectively		622,901	513,386
Other assets		310,794	294,372
Total assets	[1]	3,756,608	3,587,582
Current liabilities:
Accounts payable		33,903	39,908
Accrued expenses		44,309	34,049
Current portion of long-term debt		116,205	110,883
Other current liabilities		22,932	26,013
Total current liabilities		217,349	210,853
Long-term debt, net		1,994,734	1,924,653
Other long-term liabilities		183,618	171,395
Total liabilities	[1]	2,395,701	2,306,901
Commitments and contingencies (Note 14)
Redeemable noncontrolling interests		137,122	136,124
Stockholders' equity:
Common stock, 108,553,802 and 100,412,036 shares issued as of March 31, 2021 and December 31, 2020, respectively, at $0.0001 par value		11	10
Additional paid-in capital—common stock		1,547,375	1,482,716
Accumulated deficit		(524,511)	(530,995)
Total stockholders' equity		1,022,875	951,731
Noncontrolling interests		200,910	192,826
Total equity		1,223,785	1,144,557
Total liabilities, redeemable noncontrolling interests and equity		$ 3,756,608	$ 3,587,582
[1]	The consolidated assets as of March 31, 2021 and December 31, 2020 include $1,510,026 and $1,471,796, respectively, of assets of variable interest entities ("VIEs") that can only be used to settle obligations of the VIEs. These assets include cash of $15,532 and $13,407 as of March 31, 2021 and December 31, 2020, respectively; accounts receivable—trade, net of $3,822 and $2,953 as of March 31, 2021 and December 31, 2020, respectively; accounts receivable—other of $813 and $583 as of March 31, 2021 and December 31, 2020, respectively; other current assets of $121,832 and $182,646 as of March 31, 2021 and December 31, 2020, respectively; property and equipment, net of $1,349,815 and $1,257,953 as of March 31, 2021 and December 31, 2020, respectively; and other assets of $18,212 and $14,254 as of March 31, 2021 and December 31, 2020, respectively. The consolidated liabilities as of March 31, 2021 and December 31, 2020 include $35,959 and $32,345, respectively, of liabilities of VIEs whose creditors have no recourse to Sunnova Energy International Inc. These liabilities include accounts payable of $3,303 and $2,744 as of March 31, 2021 and December 31, 2020, respectively; accrued expenses of $886 and $827 as of March 31, 2021 and December 31, 2020, respectively; other current liabilities of $3,740 and $3,284 as of March 31, 2021 and December 31, 2020, respectively; and other long-term liabilities of $28,030 and $25,490 as of March 31, 2021 and December 31, 2020, respectively.

UNAUDITED CONDENSED CONSOLIDA_2

UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands		Mar. 31, 2021	Dec. 31, 2020
Other current asset, allowance		$ 837	$ 707
Customer notes receivable, allowance		$ 20,082	$ 16,961
Common stock, issued (in shares)		108,553,802	100,412,036
Common stock, par value (in USD per share)		$ 0.0001	$ 0.0001
Assets	[1]	$ 3,756,608	$ 3,587,582
Cash		150,892	209,859
Accounts receivable—trade, net		11,802	10,243
Accounts receivable—other		21,536	21,378
Other current assets		192,580	215,175
Property and equipment, net		2,446,103	2,323,169
Other assets		310,794	294,372
Liabilities	[1]	2,395,701	2,306,901
Accounts payable		33,903	39,908
Accrued expenses		44,309	34,049
Other current liabilities		22,932	26,013
Other long-term liabilities		183,618	171,395
Primary beneficiary
Assets		1,510,026	1,471,796
Cash		15,532	13,407
Accounts receivable—trade, net		3,822	2,953
Accounts receivable—other		813	583
Other current assets		121,832	182,646
Property and equipment, net		1,349,815	1,257,953
Other assets		18,212	14,254
Liabilities		35,959	32,345
Accounts payable		3,303	2,744
Accrued expenses		886	827
Other current liabilities		3,740	3,284
Other long-term liabilities		$ 28,030	$ 25,490
[1]	The consolidated assets as of March 31, 2021 and December 31, 2020 include $1,510,026 and $1,471,796, respectively, of assets of variable interest entities ("VIEs") that can only be used to settle obligations of the VIEs. These assets include cash of $15,532 and $13,407 as of March 31, 2021 and December 31, 2020, respectively; accounts receivable—trade, net of $3,822 and $2,953 as of March 31, 2021 and December 31, 2020, respectively; accounts receivable—other of $813 and $583 as of March 31, 2021 and December 31, 2020, respectively; other current assets of $121,832 and $182,646 as of March 31, 2021 and December 31, 2020, respectively; property and equipment, net of $1,349,815 and $1,257,953 as of March 31, 2021 and December 31, 2020, respectively; and other assets of $18,212 and $14,254 as of March 31, 2021 and December 31, 2020, respectively. The consolidated liabilities as of March 31, 2021 and December 31, 2020 include $35,959 and $32,345, respectively, of liabilities of VIEs whose creditors have no recourse to Sunnova Energy International Inc. These liabilities include accounts payable of $3,303 and $2,744 as of March 31, 2021 and December 31, 2020, respectively; accrued expenses of $886 and $827 as of March 31, 2021 and December 31, 2020, respectively; other current liabilities of $3,740 and $3,284 as of March 31, 2021 and December 31, 2020, respectively; and other long-term liabilities of $28,030 and $25,490 as of March 31, 2021 and December 31, 2020, respectively.

UNAUDITED CONDENSED CONSOLIDA_3

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue	$ 41,276	$ 29,829
Operating expense:
Cost of revenue—depreciation	17,408	12,986
Cost of revenue—other	1,234	1,043
Operations and maintenance	3,620	2,219
General and administrative	42,320	27,893
Other operating income	0	(6)
Total operating expense, net	64,582	44,135
Operating loss	(23,306)	(14,306)
Interest expense, net	8,051	67,318
Interest income	(7,180)	(4,620)
Other income	(113)	0
Loss before income tax	(24,064)	(77,004)
Income tax	0	0
Net loss	(24,064)	(77,004)
Net income (loss) attributable to redeemable noncontrolling interests and noncontrolling interests	8,919	(5,929)
Net loss attributable to stockholders	$ (32,983)	$ (71,075)
Net loss per share attributable to common stockholders—basic and diluted (in USD per share)	$ (0.31)	$ (0.85)
Weighted average common shares outstanding—basic and diluted (in shares)	106,359,220	84,001,151

UNAUDITED CONDENSED CONSOLIDA_4

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (24,064)	$ (77,004)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	19,543	14,946
Impairment and loss on disposals, net	326	331
Amortization of deferred financing costs	2,164	3,494
Amortization of debt discount	1,720	4,663
Non-cash effect of equity-based compensation plans	7,924	2,690
Unrealized (gain) loss on derivatives	(18,705)	7,596
Unrealized gain on fair value option instruments	(113)	0
Other non-cash items	(3,644)	3,424
Changes in components of operating assets and liabilities:
Accounts receivable	(1,771)	(2,755)
Other current assets	(26,808)	4,124
Other assets	(7,501)	(8,682)
Accounts payable	(756)	13,768
Accrued expenses	10,626	(17,227)
Other current liabilities	(6,869)	(6,446)
Other long-term liabilities	(1,980)	(1,034)
Net cash used in operating activities	(49,908)	(58,112)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of property and equipment	(117,459)	(141,231)
Payments for investments and customer notes receivable	(122,532)	(50,448)
Proceeds from customer notes receivable	13,459	6,940
State utility rebates and tax credits	111	135
Other, net	208	289
Net cash used in investing activities	(226,213)	(184,315)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from long-term debt	311,280	583,681
Payments of long-term debt	(174,800)	(408,695)
Payments on notes payable	(2,254)	(2,398)
Payments of deferred financing costs	(6,273)	(10,619)
Payments of debt discounts	(20)	(229)
Proceeds from issuance of common stock, net	(1,037)	(41)
Contributions from redeemable noncontrolling interests and noncontrolling interests	40,802	102,342
Distributions to redeemable noncontrolling interests and noncontrolling interests	(2,833)	(1,373)
Payments of costs related to redeemable noncontrolling interests and noncontrolling interests	(3,146)	(1,295)
Other, net	(28)	(1)
Net cash provided by financing activities	161,691	261,372
Net increase (decrease) in cash and restricted cash	(114,430)	18,945
Cash and restricted cash at beginning of period	377,893	150,291
Cash and restricted cash at end of period	263,463	169,236
Restricted cash included in other current assets	(43,603)	(30,502)
Restricted cash included in other assets	(68,968)	(65,298)
Cash at end of period	150,892	73,436
Non-cash investing and financing activities:
Change in accounts payable and accrued expenses related to purchases of property and equipment	3,272	9,357
Change in accounts payable and accrued expenses related to payments for investments and customer notes receivable	(9,107)	(4,523)
Non-cash conversion of convertible senior notes for common stock	95,648	0
Supplemental cash flow information:
Cash paid for interest	28,180	25,369
Cash paid for income taxes	$ 0	$ 0

UNAUDITED CONDENSED CONSOLIDA_5

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF REDEEMABLE NONCONTROLLING INTERESTS AND EQUITY - USD ($) $ in Thousands	Total	Cumulative-effect adjustment	Total Stockholders' Equity	Total Stockholders' EquityCumulative-effect adjustment	Common Stock	Additional Paid-in Capital - Common Stock	Accumulated Deficit	Accumulated DeficitCumulative-effect adjustment	Noncontrolling Interests
Redeemable noncontrolling interest, beginning balance at Dec. 31, 2019	$ 127,129
Increase (Decrease) in Redeemable Noncontrolling Interests [Roll Forward]
Net income (loss)	1,576
Contributions from redeemable noncontrolling interests and noncontrolling interests	3,170
Distributions to redeemable noncontrolling interests and noncontrolling interests	(1,373)
Costs related to redeemable noncontrolling interests and noncontrolling interests	(187)
Equity in subsidiaries attributable to parent	145
Other, net	(44)
Redeemable noncontrolling interest, ending balance at Mar. 31, 2020	130,790
Stockholders' equity, beginning balance (in shares) at Dec. 31, 2019					83,980,885
Stockholders' equity, beginning balance at Dec. 31, 2019	691,111	$ (9,908)	$ 645,935	$ (9,908)	$ 8	$ 1,007,751	$ (361,824)	$ (9,908)	$ 45,176
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(78,580)		(71,075)				(71,075)		(7,505)
Issuance of stock, net (in shares)					45,405
Issuance of common stock, net	214		214			214
Contributions from redeemable noncontrolling interests and noncontrolling interests	99,172								99,172
Distributions to redeemable noncontrolling interests and noncontrolling interests									0
Costs related to redeemable noncontrolling interests and noncontrolling interests	(894)								(894)
Equity in subsidiaries attributable to parent	(145)		24,164				24,164		(24,309)
Equity-based compensation expense	2,690		2,690			2,690
Other, net	(3)								(3)
Stockholders' equity, ending balance (in shares) at Mar. 31, 2020					84,026,290
Stockholders' equity, ending balance at Mar. 31, 2020	703,657		592,020		$ 8	1,010,655	(418,643)		111,637
Redeemable noncontrolling interest, beginning balance at Dec. 31, 2019	127,129
Redeemable noncontrolling interest, ending balance at Dec. 31, 2020	136,124
Stockholders' equity, beginning balance (in shares) at Dec. 31, 2019					83,980,885
Stockholders' equity, beginning balance at Dec. 31, 2019	$ 691,111	(9,908)	645,935	(9,908)	$ 8	1,007,751	(361,824)	(9,908)	45,176
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	nova:AccountingStandardsUpdate202006Member
Stockholders' equity, ending balance (in shares) at Dec. 31, 2020					100,412,036
Stockholders' equity, ending balance at Dec. 31, 2020	$ 1,144,557	$ 2,254	951,731	$ 2,254	$ 10	1,482,716	(530,995)	$ 2,254	192,826
Increase (Decrease) in Redeemable Noncontrolling Interests [Roll Forward]
Net income (loss)	2,110
Distributions to redeemable noncontrolling interests and noncontrolling interests	(1,090)
Equity in subsidiaries attributable to parent	40
Other, net	(62)
Redeemable noncontrolling interest, ending balance at Mar. 31, 2021	137,122
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(26,174)		(32,983)				(32,983)		6,809
Issuance of stock, net (in shares)					8,141,766
Issuance of common stock, net	65,542		65,542		$ 1	65,541
Equity component of debt instrument	(8,807)		(8,807)			(8,807)
Contributions from redeemable noncontrolling interests and noncontrolling interests	40,802								40,802
Distributions to redeemable noncontrolling interests and noncontrolling interests	(1,743)								(1,743)
Costs related to redeemable noncontrolling interests and noncontrolling interests	(55)								(55)
Equity in subsidiaries attributable to parent	(40)		37,213				37,213		(37,253)
Equity-based compensation expense	7,924		7,924			7,924
Other, net	(475)		1			1			(476)
Stockholders' equity, ending balance (in shares) at Mar. 31, 2021					108,553,802
Stockholders' equity, ending balance at Mar. 31, 2021	$ 1,223,785		$ 1,022,875		$ 11	$ 1,547,375	$ (524,511)		$ 200,910

Description of Business and Bas

Description of Business and Basis of Presentation	3 Months Ended
	Mar. 31, 2021
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 116,000 customers in more than 25 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 March 31, 2021, we have raised more than $6.9 billion in total capital commitments from equity, debt and tax equity investors. Basis of Presentation The accompanying interim unaudited condensed consolidated financial statements ("interim 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. We have condensed or omitted certain information and note disclosures normally included in the financial statements prepared in accordance with GAAP pursuant to the applicable rules and regulations of the Securities and Exchange Commission ("SEC") regarding interim financial reporting. As such, these interim financial statements should be read in conjunction with our 2020 annual audited consolidated financial statements and accompanying notes included in our Annual Report on Form 10-K filed with the SEC on February 25, 2021. Our interim financial statements reflect all normal recurring adjustments necessary, in our opinion, to state fairly our financial position and results of operations for the reported periods. Amounts reported for interim periods may not be indicative of a full year period because of our continual growth, seasonal fluctuations in demand for power, timing of maintenance and other expenditures, changes in interest expense and other factors. Our interim 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. A primary beneficiary 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. Revisions We have revised our previously issued interim 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 statements of redeemable noncontrolling interests and equity. The following table presents the impact of these revisions on the financial statements: Redeemable Noncontrolling As Previously Revisions As As Previously Revisions As (in thousands) December 31, 2019 $ 172,305 $ (45,176) $ 127,129 $ — $ 45,176 $ 45,176 Net income (loss) (5,929) 7,505 1,576 — (7,505) (7,505) Contributions from redeemable noncontrolling interests and noncontrolling interests 102,342 (99,172) 3,170 — 99,172 99,172 Distributions to redeemable noncontrolling interests (1,373) — (1,373) — — — Costs related to redeemable noncontrolling interests and noncontrolling interests (707) 894 187 — (894) (894) Equity in subsidiaries attributable to parent (24,164) 24,309 145 — (24,309) (24,309) Other, net (47) 3 (44) — (3) (3) March 31, 2020 $ 242,427 $ (111,637) $ 130,790 $ — $ 111,637 $ 111,637 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 virus has continued to circulate 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

Significant Accounting Policies

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Included below are updates to significant accounting policies disclosed in our 2020 annual audited consolidated financial statements. Use of Estimates The application of GAAP in the preparation of the interim financial statements requires us to make estimates and assumptions that affect the amounts reported in the interim 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. 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 March 31, 2021, 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 unaudited condensed consolidated balance sheets: As of March 31, 2021 2020 (in thousands) Balance at beginning of period $ 912 $ 960 Impact of ASC 326 adoption — (240) Provision for current expected credit losses 396 402 Write off of uncollectible accounts (496) (385) Recoveries 36 9 Other, net — 1 Balance at end of period $ 848 $ 747 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 unaudited condensed consolidated balance sheets: As of As of (in thousands) Energy storage systems and components $ 29,769 $ 18,122 Modules and inverters 77,277 83,904 Meters 638 563 Total $ 107,684 $ 102,589 As of March 31, 2021 and December 31, 2020, we recorded accrued expenses of $13.5 million and $8.9 million, respectively, for inventory purchases. 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 6, Customer Notes Receivable, Note 7, Long-Term Debt and Note 8, Derivative Instruments. Revenue The following table presents the detail of revenue as recorded in the unaudited condensed consolidated statements of operations: Three Months Ended 2021 2020 (in thousands) PPA revenue $ 16,834 $ 12,633 Lease revenue 16,397 11,542 Solar renewable energy certificate revenue 5,957 4,363 Loan revenue 1,195 599 Other revenue 893 692 Total $ 41,276 $ 29,829 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 $1.7 billion as of March 31, 2021, 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 four 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 14, 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 March 31, 2021 and December 31, 2020. 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 March 31, 2021, 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 6, 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 $58.9 million as of December 31, 2019. The following table presents the detail of deferred revenue as recorded in other current liabilities and other long-term liabilities in the unaudited condensed consolidated balance sheets: As of As of (in thousands) Loans $ 122,583 $ 93,859 PPAs and leases 13,599 11,787 SRECs 290 1,163 Total (1) $ 136,472 $ 106,809 (1) Of this amount, $9.0 million and $3.8 million is recorded in other current liabilities as of March 31, 2021 and December 31, 2020, respectively. During the three months ended March 31, 2021 and 2020, we recognized revenue of $2.5 million and $997,000, respectively, from amounts recorded in deferred revenue at the beginning of the respective years. 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 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 adopted this ASU in January 2021 using the modified retrospective approach, which resulted in a cumulative-effect adjustment to stockholders' equity of $2.3 million.

Property and Equipment

Property and Equipment	3 Months Ended
	Mar. 31, 2021
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 unaudited condensed consolidated balance sheets: Useful Lives As of As of (in years) (in thousands) Solar energy systems 35 $ 2,447,218 $ 2,298,427 Construction in progress 151,166 160,618 Asset retirement obligations 30 37,811 35,532 Information technology systems 3 35,649 35,077 Computers and equipment 3-5 1,913 1,727 Leasehold improvements 3-6 2,776 2,770 Furniture and fixtures 7 811 811 Vehicles 4-5 1,638 1,638 Other 5-6 157 157 Property and equipment, gross 2,679,139 2,536,757 Less: accumulated depreciation (233,036) (213,588) Property and equipment, net $ 2,446,103 $ 2,323,169 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 $206.1 million and $188.8 million as of March 31, 2021 and December 31, 2020, respectively.

Detail of Certain Balance Sheet

Detail of Certain Balance Sheet Captions	3 Months Ended
	Mar. 31, 2021
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 unaudited condensed consolidated balance sheets: As of As of (in thousands) Inventory $ 107,684 $ 102,589 Restricted cash 43,603 73,020 Current portion of customer notes receivable 29,077 24,035 Other prepaid assets 9,318 8,645 Prepaid inventory — 3,352 Deferred receivables 2,075 2,678 Current portion of other notes receivable 820 853 Other 3 3 Total $ 192,580 $ 215,175 The following table presents the detail of other assets as recorded in the unaudited condensed consolidated balance sheets: As of As of (in thousands) Restricted cash $ 68,968 $ 95,014 Construction in progress - customer notes receivable 102,242 85,604 Exclusivity and other bonus arrangements with dealers, net 62,600 55,709 Straight-line revenue adjustment, net 35,877 33,411 Derivative assets 14,291 — Other 26,816 24,634 Total $ 310,794 $ 294,372 The following table presents the detail of other current liabilities as recorded in the unaudited condensed consolidated balance sheets: As of As of (in thousands) Interest payable $ 10,318 $ 17,718 Deferred revenue 9,026 3,754 Current portion of performance guarantee obligations 2,349 3,308 Current portion of operating and finance lease liability 1,217 1,206 Other 22 27 Total $ 22,932 $ 26,013

Asset Retirement Obligations ("

Asset Retirement Obligations ("ARO")	3 Months Ended
	Mar. 31, 2021
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations ("ARO")	Asset Retirement Obligations ("ARO") AROs 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 unaudited condensed consolidated balance sheets: As of March 31, 2021 2020 (in thousands) Balance at beginning of period $ 41,788 $ 31,053 Additional obligations incurred 2,290 2,067 Accretion expense 652 489 Other (16) (15) Balance at end of period $ 44,714 $ 33,594

Customer Notes Receivable

Customer Notes Receivable	3 Months Ended
	Mar. 31, 2021
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 unaudited condensed consolidated balance sheets and the corresponding fair values: As of As of (in thousands) Customer notes receivable $ 672,897 $ 555,089 Allowance for credit losses (20,919) (17,668) Customer notes receivable, net (1) $ 651,978 $ 537,421 Estimated fair value, net $ 664,534 $ 548,238 (1) Of this amount, $29.1 million and $24.0 million is recorded in other current assets as of March 31, 2021 and December 31, 2020, respectively. The following table presents the changes in the allowance for credit losses related to customer notes receivable as recorded in the unaudited condensed consolidated balance sheets: As of March 31, 2021 2020 (in thousands) Balance at beginning of period $ 17,668 $ 1,091 Impact of ASC 326 adoption — 9,235 Provision for current expected credit losses (1) 3,251 1,811 Other, net — (1) Balance at end of period $ 20,919 $ 12,136 (1) In addition, we recognized $62,000 and $53,000 of provision for current expected credit losses during the three months ended March 31, 2021 and 2020, respectively, related to our long-term receivables for our customer leases. As of March 31, 2021 and December 31, 2020, we invested $102.2 million and $85.6 million, respectively, in loan solar energy systems and energy storage systems not yet placed in service. For the three months ended March 31, 2021 and 2020, interest income related to our customer notes receivable was $7.1 million and $4.4 million, respectively. As of March 31, 2021 and December 31, 2020, accrued interest receivable related to our customer notes receivable was $1.8 million and $1.2 million, respectively. As of March 31, 2021 and December 31, 2020, there were no customer notes receivable not accruing interest and thus, there was no allowance recorded for loans on nonaccrual status. For the three months ended March 31, 2021 and 2020, 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 As of (in thousands) 1-90 days past due $ 9,202 $ 8,504 91-180 days past due 1,815 1,733 Greater than 180 days past due 6,780 6,855 Total past due 17,797 17,092 Not past due 655,100 537,997 Total $ 672,897 $ 555,089 As of March 31, 2021 and December 31, 2020, the amortized cost of our customer notes receivable more than 90 days past due but not on nonaccrual status was $8.6 million. The following table presents the amortized cost by origination year of our customer notes receivable based on payment activity. Amortized Cost by Origination Year 2021 2020 2019 2018 2017 Prior Total (in thousands) Payment performance: Performing $ 129,799 $ 261,183 $ 131,093 $ 84,994 $ 30,426 $ 28,622 $ 666,117 Nonperforming (1) — 267 1,319 1,874 1,931 1,389 $ 6,780 Total $ 129,799 $ 261,450 $ 132,412 $ 86,868 $ 32,357 $ 30,011 $ 672,897 (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	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term DebtOur subsidiaries with long-term debt include SEI, Sunnova Energy Corporation, Helios Issuer, LLC ("HELI"), Sunnova EZ-Own Portfolio, LLC ("EZOP"), Sunnova Helios II Issuer, LLC ("HELII"), Sunnova RAYS I Issuer, LLC ("RAYSI"), Sunnova Helios III Issuer, LLC ("HELIII"), Sunnova TEP Holdings, LLC ("TEPH"), Sunnova TEP Inventory, LLC ("TEPINV"), Sunnova Sol Issuer, LLC ("SOLI"), Sunnova Helios IV Issuer, LLC ("HELIV"), Sunnova Asset Portfolio 8, LLC ("AP8"), Sunnova Sol II Issuer, LLC ("SOLII") and Sunnova Helios V Issuer, LLC ("HELV"). The following table presents the detail of long-term debt, net as recorded in the unaudited condensed consolidated balance sheets: Three Months Ended As of March 31, 2021 Year Ended As of December 31, 2020 Long-term Current Long-term Current (in thousands, except interest rates) SEI 9.75% convertible senior notes 21.70 % $ — $ — 14.53 % $ 95,648 $ — Debt discount, net — — (37,394) — Deferred financing costs, net — — (239) — Sunnova Energy Corporation Notes payable 8.39 % — — 7.14 % — 2,254 HELI Solar asset-backed notes 6.65 % 201,759 6,538 6.55 % 205,395 6,329 Debt discount, net (2,020) — (2,241) — Deferred financing costs, net (3,607) — (4,004) — EZOP Revolving credit facility 3.65 % 109,400 — 4.39 % 171,600 — Debt discount, net (1,266) — (1,431) — HELII Solar asset-backed notes 5.80 % 221,668 10,606 5.71 % 227,574 11,707 Debt discount, net (40) — (42) — Deferred financing costs, net (4,896) — (5,085) — RAYSI Solar asset-backed notes 5.57 % 119,281 5,744 5.49 % 120,391 5,836 Debt discount, net (1,334) — (1,376) — Deferred financing costs, net (4,229) — (4,334) — HELIII Solar loan-backed notes 4.06 % 119,044 12,295 4.01 % 122,047 13,065 Debt discount, net (2,395) — (2,423) — Deferred financing costs, net (2,298) — (2,326) — TEPH Revolving credit facility 5.73 % 304,570 — 5.81 % 239,570 — Debt discount, net (3,332) — (3,815) — TEPINV Revolving credit facility 12.19 % 27,434 22,302 10.80 % 25,240 29,464 Debt discount, net (997) — (1,322) — Deferred financing costs, net (1,442) — (1,758) — SOLI Solar asset-backed notes 3.94 % 379,771 15,383 3.91 % 384,258 15,416 Debt discount, net (110) — (113) — Deferred financing costs, net (8,660) — (8,915) — HELIV Solar loan-backed notes 4.10 % 125,659 16,127 3.97 % 129,648 16,515 Debt discount, net (849) — (885) — Deferred financing costs, net (3,754) — (3,905) — AP8 Revolving credit facility 5.56 % 21,205 4,395 5.31 % 42,047 4,386 SOLII Solar asset-backed notes 3.28 % 246,872 5,853 3.18 % 248,789 5,911 Debt discount, net (79) — (80) — Deferred financing costs, net (5,825) — (5,866) — HELV Solar loan-backed notes 2.31 % 169,760 16,962 — — Debt discount, net (949) — — — Deferred financing costs, net (3,607) — — — Total $ 1,994,734 $ 116,205 $ 1,924,653 $ 110,883 Availability. As of March 31, 2021, we had $281.1 million of available borrowing capacity under our various financing arrangements, consisting of $90.6 million under the EZOP revolving credit facility, $156.1 million under the TEPH revolving credit facility and $34.4 million under the AP8 revolving credit facility. There was no available borrowing capacity under any of our other financing arrangements. As of March 31, 2021, 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 . During the three months ended March 31, 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 common stock. See Note 11, Stockholders' Equity. 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 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. In March 2021, we amended the EZOP revolving credit facility to, among other things, (a) extend the maturity date to November 2023 and (b) increase the maximum facility amount from $200.0 million to $350.0 million. Fair Values of Long-Term Debt . The fair values of our long-term debt and the corresponding carrying amounts are as follows: As of March 31, 2021 As of December 31, 2020 Carrying Estimated Carrying Estimated (in thousands) SEI 9.75% convertible senior notes $ — $ — $ 95,648 $ 100,482 Sunnova Energy Corporation notes payable — — 2,254 2,254 HELI solar asset-backed notes 208,297 216,578 211,724 220,941 EZOP revolving credit facility 109,400 109,400 171,600 171,600 HELII solar asset-backed notes 232,274 266,817 239,281 286,579 RAYSI solar asset-backed notes 125,025 138,191 126,227 146,506 HELIII solar loan-backed notes 131,339 139,181 135,112 149,489 TEPH revolving credit facility 304,570 304,570 239,570 239,570 TEPINV revolving credit facility 49,736 49,736 54,704 54,704 SOLI solar asset-backed notes 395,154 404,116 399,674 427,511 HELIV solar loan-backed notes 141,786 136,672 146,163 145,433 AP8 revolving credit facility 25,600 25,600 46,433 46,433 SOLII solar asset-backed notes 252,725 241,066 254,700 254,674 HELV solar loan-backed notes 186,722 182,359 — — Total (1) $ 2,162,628 $ 2,214,286 $ 2,123,090 $ 2,246,176 (1) Amounts exclude the net deferred financing costs (classified in debt) and net debt discounts of $51.7 million and $87.6 million as of March 31, 2021 and December 31, 2020, respectively. For the EZOP, TEPH, TEPINV and AP8 debt, the estimated fair values approximate the carrying amounts due primarily to the variable nature of the interest rates of the underlying instruments. For the notes payable, the estimated fair value approximates the carrying amount due primarily to the short-term nature of the instruments. For the convertible senior notes and the HELI, HELII, RAYSI, HELIII, SOLI, HELIV, SOLII and HELV debt, we determined the estimated fair values based on a yield analysis of similar type debt.

Derivative Instruments

Derivative Instruments	3 Months Ended
	Mar. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments Interest Rate Swaps on EZOP Debt. During the three months ended March 31, 2021 and 2020, EZOP unwound interest rate swaps with a notional amount of $131.7 million and $0, respectively, and recorded a realized loss of $68,000 and $59,000, respectively. The following table presents a summary of the outstanding derivative instruments: As of March 31, 2021 As of December 31, 2020 Effective Termination Fixed Aggregate Effective Termination Fixed Aggregate (in thousands, except interest rates) EZOP March 2021 July 2033 1.000% $ 180,181 June 2020 - September 2029 - 0.483% - 2.620% $ 130,373 TEPH September 2018 - January 2023 - 0.121% - 2.534% 270,170 September 2018 - January 2023 - 0.528% - 2.114% 202,272 TEPINV December 2019 December 2022 2.500% 40,132 December 2019 December 2022 2.500% 51,025 Total $ 490,483 $ 383,670 The following table presents the fair value of the interest rate swaps as recorded in the unaudited condensed consolidated balance sheets: As of As of (in thousands) Other assets $ 14,291 $ — Other long-term liabilities — (13,407) Total, net $ 14,291 $ (13,407) 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 unaudited condensed consolidated statements of operations: Three Months Ended 2021 2020 (in thousands) Realized loss $ 591 $ 31,898 Unrealized (gain) loss (18,705) 7,596 Total $ (18,114) $ 39,494

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income TaxesOur effective income tax rate is 0% for the three months ended March 31, 2021 and 2020. 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. 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 March 31, 2021 and December 31, 2020 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.

Redeemable Noncontrolling Inter

Redeemable Noncontrolling Interests and Noncontrolling Interests	3 Months Ended
	Mar. 31, 2021
Noncontrolling Interest [Abstract]
Redeemable Noncontrolling Interests and Noncontrolling Interests	Redeemable Noncontrolling Interests and Noncontrolling InterestsThe carrying values of the redeemable noncontrolling interests were equal to or greater than the redemption values as of March 31, 2021 and December 31, 2020. See Note 15, Subsequent Events.

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2021
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity Common Stock During the three months ended March 31, 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.

Equity-Based Compensation

Equity-Based Compensation	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Equity-Based Compensation	Equity-Based CompensationIn March 2021, the aggregate number of shares of common stock that may be issued pursuant to awards under the 2019 Long-Term Incentive Plan (the "LTIP") was increased by 2,214,561, an amount which, together with the shares remaining available for grant under the LTIP, is equal to 5,020,602, or 5% of the number of shares of common stock outstanding as of December 31, 2020. Stock Options The following table summarizes stock option activity: Number Weighted Weighted Weighted Aggregate (in thousands) Outstanding, December 31, 2020 3,266,348 $ 16.06 5.82 $ 94,962 Granted 75,031 $ 40.50 9.97 $ 18.35 Exercised (491,125) $ 16.30 $ 15,549 Outstanding, March 31, 2021 2,850,254 $ 16.66 5.69 $ 68,865 Exercisable, March 31, 2021 2,775,223 $ 16.01 5.57 $ 68,841 Vested and expected to vest, March 31, 2021 2,850,254 $ 16.66 5.69 $ 68,865 Non-vested, March 31, 2021 75,031 $ 18.35 The number of stock options that vested during the three months ended March 31, 2021 and 2020 was 0 and 265,207, respectively. The grant date fair value of stock options that vested during the three months ended March 31, 2021 and 2020 was $0 and $791,000, respectively. As of March 31, 2021, there was $1.4 million of total unrecognized compensation expense related to stock options, which is expected to be recognized over the weighted average period of 2.23 years. Restricted Stock Units The following table summarizes restricted stock unit activity: Number of Weighted Outstanding, December 31, 2020 2,059,184 $ 11.95 Granted 426,243 $ 38.95 Vested (657,484) $ 18.50 Forfeited (11,294) $ 16.22 Outstanding, March 31, 2021 1,816,649 $ 15.89 The number of restricted stock units that vested during the three months ended March 31, 2021 and 2020 was 657,484 and 27,083, respectively. The grant date fair value of restricted stock units that vested during the three months ended March 31, 2021 and 2020 was $12.2 million and $325,000, respectively. As of March 31, 2021, there was $26.4 million of total unrecognized compensation expense related to restricted stock units, which is expected to be recognized over the weighted average period of 1.99 years.

Basic and Diluted Net Loss Per

Basic and Diluted Net Loss Per Share	3 Months Ended
	Mar. 31, 2021
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: Three Months Ended 2021 2020 (in thousands, except share and per share amounts) Net loss attributable to common stockholders—basic and diluted $ (32,983) $ (71,075) Net loss per share attributable to common stockholders—basic and diluted $ (0.31) $ (0.85) Weighted average common shares outstanding—basic and diluted 106,359,220 84,001,151 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: Three Months Ended 2021 2020 Equity-based compensation awards 4,902,790 5,872,563 Convertible senior notes 1,682,132 4,230,768

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
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 March 31, 2021, we recorded $2.9 million relating to our guarantee of certain specified minimum solar energy production output under our leases and loans, of which $2.3 million is recorded in other current liabilities and $556,000 is recorded in other long-term liabilities in the unaudited condensed consolidated balance sheet. As of December 31, 2020, we recorded $5.7 million relating to these guarantees, of which $3.3 million is recorded in other current liabilities and $2.4 million is recorded in other long-term liabilities in the unaudited condensed consolidated balance sheet. The changes in our aggregate performance guarantee obligations are as follows: As of March 31, 2021 2020 (in thousands) Balance at beginning of period $ 5,718 $ 6,468 Accruals for obligations issued 433 683 Settlements made in cash (3,246) (3,844) Balance at end of period $ 2,905 $ 3,307 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 unaudited condensed consolidated statements of operations: Three Months Ended 2021 2020 (in thousands) Operating lease expense $ 336 $ 336 Finance lease expense: Finance lease amortization expense 25 2 Interest on lease liabilities 3 — Short-term lease expense 10 16 Variable lease expense 261 7 Total $ 635 $ 361 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 As of (in thousands) Right-of-use assets: Operating leases $ 8,558 $ 8,779 Finance leases 367 391 Total right-of-use assets $ 8,925 $ 9,170 Current lease liabilities: Operating leases $ 1,108 $ 1,094 Finance leases 110 112 Long-term leases liabilities: Operating leases 9,885 9,742 Finance leases 178 203 Total lease liabilities $ 11,281 $ 11,151 Other information related to leases was as follows: Three Months Ended 2021 2020 (in thousands) Cash paid (received) for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases (1) $ (42) $ 11 Operating cash flows from finance leases 3 — Financing cash flows from finance leases 28 1 Right-of-use assets obtained in exchange for lease obligations: Operating leases — — Finance leases — — (1) Includes reimbursements in 2021 of $423,000 for leasehold improvements. As of As of Weighted average remaining lease term (years): Operating leases 8.23 8.47 Finance leases 3.74 3.99 Weighted average discount rate: Operating leases 3.93 % 3.93 % Finance leases 3.38 % 3.39 % Future minimum lease payments under our non-cancelable leases as of March 31, 2021 were as follows: Operating Finance (in thousands) Remaining 2021 $ 1,155 $ 91 2022 1,559 88 2023 1,594 69 2024 1,616 55 2025 1,633 — 2026 and thereafter 5,984 — Total 13,541 303 Amount representing interest (2,021) (15) Amount representing leasehold incentives (527) — Present value of future payments 10,993 288 Current portion of lease liability (1,108) (110) Long-term portion of lease liability $ 9,885 $ 178 Letters of Credit . In connection with various security arrangements for an office lease, we have a letter of credit outstanding of $375,000 as of March 31, 2021 and December 31, 2020. 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 unaudited condensed 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 March 31, 2021 and December 31, 2020, the net unamortized balance of payments to dealers for exclusivity and other similar arrangements was $62.6 million and $55.7 million, respectively. Under these agreements, we paid $3.7 million and $5.3 million during the three months ended March 31, 2021 and 2020, 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) Remaining 2021 $ 31,530 2022 40,118 2023 18,110 2024 7,970 2025 938 2026 and thereafter — Total $ 98,666 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) Remaining 2021 $ 15,642 2022 26,810 2023 26,605 2024 19,807 2025 — 2026 and thereafter — Total $ 88,864 Information Technology Commitments. We have certain long-term contractual commitments related to information technology software services and licenses. Future commitments as of March 31, 2021 were as follows: Information (in thousands) Remaining 2021 $ 8,026 2022 2,216 2023 26 2024 26 2025 7 2026 and thereafter — Total $ 10,301

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2021
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events 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, in April 2021,we acquired SunStreet, Lennar Corporation's residential solar platform, in exchange for up to 6,984,225 shares of our common stock (the "Acquisition"), comprised of 3,095,329 shares in initial consideration issued at closing, subject to purchase price adjustment, and up to 3,888,896 shares issuable as earnout consideration after closing of the Acquisition. Noncontrolling Interests. In April 2021, we admitted a tax equity investor as the Class A member of Sunnova TEP V-D, LLC ("TEPVD"), a subsidiary of Sunnova TEP V-D Manager, LLC, which is the Class B member of TEPVD. The Class A member of TEPVD made a total capital commitment of approximately $50.0 million.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying interim unaudited condensed consolidated financial statements ("interim 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. We have condensed or omitted certain information and note disclosures normally included in the financial statements prepared in accordance with GAAP pursuant to the applicable rules and regulations of the Securities and Exchange Commission ("SEC") regarding interim financial reporting. As such, these interim financial statements should be read in conjunction with our 2020 annual audited consolidated financial statements and accompanying notes included in our Annual Report on Form 10-K filed with the SEC on February 25, 2021. Our interim financial statements reflect all normal recurring adjustments necessary, in our opinion, to state fairly our financial position and results of operations for the reported periods. Amounts reported for interim periods may not be indicative of a full year period because of our continual growth, seasonal fluctuations in demand for power, timing of maintenance and other expenditures, changes in interest expense and other factors. Our interim 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. A primary beneficiary 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
Use of Estimates	Use of Estimates The application of GAAP in the preparation of the interim financial statements requires us to make estimates and assumptions that affect the amounts reported in the interim 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.
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	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
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 6, Customer Notes Receivable, Note 7, Long-Term Debt and Note 8, 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 $1.7 billion as of March 31, 2021, 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 four 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 14, 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 March 31, 2021 and December 31, 2020. 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 March 31, 2021, 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 6, Customer Notes Receivable. Deferred Revenue
New Accounting Guidance	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 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 adopted this ASU in January 2021 using the modified retrospective approach, which resulted in a cumulative-effect adjustment to stockholders' equity of $2.3 million.

Description of Business and B_2

Description of Business and Basis of Presentation (Tables)	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of accounting revisions	The following table presents the impact of these revisions on the financial statements: Redeemable Noncontrolling As Previously Revisions As As Previously Revisions As (in thousands) December 31, 2019 $ 172,305 $ (45,176) $ 127,129 $ — $ 45,176 $ 45,176 Net income (loss) (5,929) 7,505 1,576 — (7,505) (7,505) Contributions from redeemable noncontrolling interests and noncontrolling interests 102,342 (99,172) 3,170 — 99,172 99,172 Distributions to redeemable noncontrolling interests (1,373) — (1,373) — — — Costs related to redeemable noncontrolling interests and noncontrolling interests (707) 894 187 — (894) (894) Equity in subsidiaries attributable to parent (24,164) 24,309 145 — (24,309) (24,309) Other, net (47) 3 (44) — (3) (3) March 31, 2020 $ 242,427 $ (111,637) $ 130,790 $ — $ 111,637 $ 111,637

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Changes in the allowance for credit losses	The following table presents the changes in the allowance for credit losses recorded against accounts receivable — trade, net in the unaudited condensed consolidated balance sheets: As of March 31, 2021 2020 (in thousands) Balance at beginning of period $ 912 $ 960 Impact of ASC 326 adoption — (240) Provision for current expected credit losses 396 402 Write off of uncollectible accounts (496) (385) Recoveries 36 9 Other, net — 1 Balance at end of period $ 848 $ 747 The following table presents the changes in the allowance for credit losses related to customer notes receivable as recorded in the unaudited condensed consolidated balance sheets: As of March 31, 2021 2020 (in thousands) Balance at beginning of period $ 17,668 $ 1,091 Impact of ASC 326 adoption — 9,235 Provision for current expected credit losses (1) 3,251 1,811 Other, net — (1) Balance at end of period $ 20,919 $ 12,136 (1) In addition, we recognized $62,000 and $53,000 of provision for current expected credit losses during the three months ended March 31, 2021 and 2020, respectively, related to our long-term receivables for our customer leases.
Schedule of inventory	The following table presents the detail of inventory as recorded in other current assets in the unaudited condensed consolidated balance sheets: As of As of (in thousands) Energy storage systems and components $ 29,769 $ 18,122 Modules and inverters 77,277 83,904 Meters 638 563 Total $ 107,684 $ 102,589
Disaggregation of revenue	The following table presents the detail of revenue as recorded in the unaudited condensed consolidated statements of operations: Three Months Ended 2021 2020 (in thousands) PPA revenue $ 16,834 $ 12,633 Lease revenue 16,397 11,542 Solar renewable energy certificate revenue 5,957 4,363 Loan revenue 1,195 599 Other revenue 893 692 Total $ 41,276 $ 29,829
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 unaudited condensed consolidated balance sheets: As of As of (in thousands) Loans $ 122,583 $ 93,859 PPAs and leases 13,599 11,787 SRECs 290 1,163 Total (1) $ 136,472 $ 106,809 (1) Of this amount, $9.0 million and $3.8 million is recorded in other current liabilities as of March 31, 2021 and December 31, 2020, respectively.

Property and Equipment (Tables)

Property and Equipment (Tables)	3 Months Ended
	Mar. 31, 2021
Property, Plant and Equipment [Abstract]
Property and equipment	The following table presents the detail of property and equipment, net as recorded in the unaudited condensed consolidated balance sheets: Useful Lives As of As of (in years) (in thousands) Solar energy systems 35 $ 2,447,218 $ 2,298,427 Construction in progress 151,166 160,618 Asset retirement obligations 30 37,811 35,532 Information technology systems 3 35,649 35,077 Computers and equipment 3-5 1,913 1,727 Leasehold improvements 3-6 2,776 2,770 Furniture and fixtures 7 811 811 Vehicles 4-5 1,638 1,638 Other 5-6 157 157 Property and equipment, gross 2,679,139 2,536,757 Less: accumulated depreciation (233,036) (213,588) Property and equipment, net $ 2,446,103 $ 2,323,169

Detail of Certain Balance She_2

Detail of Certain Balance Sheet Captions (Tables)	3 Months Ended
	Mar. 31, 2021
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 unaudited condensed consolidated balance sheets: As of As of (in thousands) Inventory $ 107,684 $ 102,589 Restricted cash 43,603 73,020 Current portion of customer notes receivable 29,077 24,035 Other prepaid assets 9,318 8,645 Prepaid inventory — 3,352 Deferred receivables 2,075 2,678 Current portion of other notes receivable 820 853 Other 3 3 Total $ 192,580 $ 215,175
Schedule of other assets	The following table presents the detail of other assets as recorded in the unaudited condensed consolidated balance sheets: As of As of (in thousands) Restricted cash $ 68,968 $ 95,014 Construction in progress - customer notes receivable 102,242 85,604 Exclusivity and other bonus arrangements with dealers, net 62,600 55,709 Straight-line revenue adjustment, net 35,877 33,411 Derivative assets 14,291 — Other 26,816 24,634 Total $ 310,794 $ 294,372
Schedule of other current liabilities	The following table presents the detail of other current liabilities as recorded in the unaudited condensed consolidated balance sheets: As of As of (in thousands) Interest payable $ 10,318 $ 17,718 Deferred revenue 9,026 3,754 Current portion of performance guarantee obligations 2,349 3,308 Current portion of operating and finance lease liability 1,217 1,206 Other 22 27 Total $ 22,932 $ 26,013

Asset Retirement Obligations _2

Asset Retirement Obligations ("ARO") (Tables)	3 Months Ended
	Mar. 31, 2021
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 unaudited condensed consolidated balance sheets: As of March 31, 2021 2020 (in thousands) Balance at beginning of period $ 41,788 $ 31,053 Additional obligations incurred 2,290 2,067 Accretion expense 652 489 Other (16) (15) Balance at end of period $ 44,714 $ 33,594

Customer Notes Receivable (Tabl

Customer Notes Receivable (Tables)	3 Months Ended
	Mar. 31, 2021
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 unaudited condensed consolidated balance sheets and the corresponding fair values: As of As of (in thousands) Customer notes receivable $ 672,897 $ 555,089 Allowance for credit losses (20,919) (17,668) Customer notes receivable, net (1) $ 651,978 $ 537,421 Estimated fair value, net $ 664,534 $ 548,238 (1) Of this amount, $29.1 million and $24.0 million is recorded in other current assets as of March 31, 2021 and December 31, 2020, respectively.
Changes in the allowance for credit losses	The following table presents the changes in the allowance for credit losses recorded against accounts receivable — trade, net in the unaudited condensed consolidated balance sheets: As of March 31, 2021 2020 (in thousands) Balance at beginning of period $ 912 $ 960 Impact of ASC 326 adoption — (240) Provision for current expected credit losses 396 402 Write off of uncollectible accounts (496) (385) Recoveries 36 9 Other, net — 1 Balance at end of period $ 848 $ 747 The following table presents the changes in the allowance for credit losses related to customer notes receivable as recorded in the unaudited condensed consolidated balance sheets: As of March 31, 2021 2020 (in thousands) Balance at beginning of period $ 17,668 $ 1,091 Impact of ASC 326 adoption — 9,235 Provision for current expected credit losses (1) 3,251 1,811 Other, net — (1) Balance at end of period $ 20,919 $ 12,136 (1) In addition, we recognized $62,000 and $53,000 of provision for current expected credit losses during the three months ended March 31, 2021 and 2020, respectively, related to our long-term receivables for our customer leases.
Financing receivable, past due	The following table presents the aging of the amortized cost of customer notes receivable: As of As of (in thousands) 1-90 days past due $ 9,202 $ 8,504 91-180 days past due 1,815 1,733 Greater than 180 days past due 6,780 6,855 Total past due 17,797 17,092 Not past due 655,100 537,997 Total $ 672,897 $ 555,089
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 2021 2020 2019 2018 2017 Prior Total (in thousands) Payment performance: Performing $ 129,799 $ 261,183 $ 131,093 $ 84,994 $ 30,426 $ 28,622 $ 666,117 Nonperforming (1) — 267 1,319 1,874 1,931 1,389 $ 6,780 Total $ 129,799 $ 261,450 $ 132,412 $ 86,868 $ 32,357 $ 30,011 $ 672,897 (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)	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Schedule of long-term debt instruments	The following table presents the detail of long-term debt, net as recorded in the unaudited condensed consolidated balance sheets: Three Months Ended As of March 31, 2021 Year Ended As of December 31, 2020 Long-term Current Long-term Current (in thousands, except interest rates) SEI 9.75% convertible senior notes 21.70 % $ — $ — 14.53 % $ 95,648 $ — Debt discount, net — — (37,394) — Deferred financing costs, net — — (239) — Sunnova Energy Corporation Notes payable 8.39 % — — 7.14 % — 2,254 HELI Solar asset-backed notes 6.65 % 201,759 6,538 6.55 % 205,395 6,329 Debt discount, net (2,020) — (2,241) — Deferred financing costs, net (3,607) — (4,004) — EZOP Revolving credit facility 3.65 % 109,400 — 4.39 % 171,600 — Debt discount, net (1,266) — (1,431) — HELII Solar asset-backed notes 5.80 % 221,668 10,606 5.71 % 227,574 11,707 Debt discount, net (40) — (42) — Deferred financing costs, net (4,896) — (5,085) — RAYSI Solar asset-backed notes 5.57 % 119,281 5,744 5.49 % 120,391 5,836 Debt discount, net (1,334) — (1,376) — Deferred financing costs, net (4,229) — (4,334) — HELIII Solar loan-backed notes 4.06 % 119,044 12,295 4.01 % 122,047 13,065 Debt discount, net (2,395) — (2,423) — Deferred financing costs, net (2,298) — (2,326) — TEPH Revolving credit facility 5.73 % 304,570 — 5.81 % 239,570 — Debt discount, net (3,332) — (3,815) — TEPINV Revolving credit facility 12.19 % 27,434 22,302 10.80 % 25,240 29,464 Debt discount, net (997) — (1,322) — Deferred financing costs, net (1,442) — (1,758) — SOLI Solar asset-backed notes 3.94 % 379,771 15,383 3.91 % 384,258 15,416 Debt discount, net (110) — (113) — Deferred financing costs, net (8,660) — (8,915) — HELIV Solar loan-backed notes 4.10 % 125,659 16,127 3.97 % 129,648 16,515 Debt discount, net (849) — (885) — Deferred financing costs, net (3,754) — (3,905) — AP8 Revolving credit facility 5.56 % 21,205 4,395 5.31 % 42,047 4,386 SOLII Solar asset-backed notes 3.28 % 246,872 5,853 3.18 % 248,789 5,911 Debt discount, net (79) — (80) — Deferred financing costs, net (5,825) — (5,866) — HELV Solar loan-backed notes 2.31 % 169,760 16,962 — — Debt discount, net (949) — — — Deferred financing costs, net (3,607) — — — Total $ 1,994,734 $ 116,205 $ 1,924,653 $ 110,883
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 March 31, 2021 As of December 31, 2020 Carrying Estimated Carrying Estimated (in thousands) SEI 9.75% convertible senior notes $ — $ — $ 95,648 $ 100,482 Sunnova Energy Corporation notes payable — — 2,254 2,254 HELI solar asset-backed notes 208,297 216,578 211,724 220,941 EZOP revolving credit facility 109,400 109,400 171,600 171,600 HELII solar asset-backed notes 232,274 266,817 239,281 286,579 RAYSI solar asset-backed notes 125,025 138,191 126,227 146,506 HELIII solar loan-backed notes 131,339 139,181 135,112 149,489 TEPH revolving credit facility 304,570 304,570 239,570 239,570 TEPINV revolving credit facility 49,736 49,736 54,704 54,704 SOLI solar asset-backed notes 395,154 404,116 399,674 427,511 HELIV solar loan-backed notes 141,786 136,672 146,163 145,433 AP8 revolving credit facility 25,600 25,600 46,433 46,433 SOLII solar asset-backed notes 252,725 241,066 254,700 254,674 HELV solar loan-backed notes 186,722 182,359 — — Total (1) $ 2,162,628 $ 2,214,286 $ 2,123,090 $ 2,246,176 (1) Amounts exclude the net deferred financing costs (classified in debt) and net debt discounts of $51.7 million and $87.6 million as of March 31, 2021 and December 31, 2020, respectively.

Derivative Instruments (Tables)

Derivative Instruments (Tables)	3 Months Ended
	Mar. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Outstanding derivative instruments	The following table presents a summary of the outstanding derivative instruments: As of March 31, 2021 As of December 31, 2020 Effective Termination Fixed Aggregate Effective Termination Fixed Aggregate (in thousands, except interest rates) EZOP March 2021 July 2033 1.000% $ 180,181 June 2020 - September 2029 - 0.483% - 2.620% $ 130,373 TEPH September 2018 - January 2023 - 0.121% - 2.534% 270,170 September 2018 - January 2023 - 0.528% - 2.114% 202,272 TEPINV December 2019 December 2022 2.500% 40,132 December 2019 December 2022 2.500% 51,025 Total $ 490,483 $ 383,670
Fair value of interest rate swaps	The following table presents the fair value of the interest rate swaps as recorded in the unaudited condensed consolidated balance sheets: As of As of (in thousands) Other assets $ 14,291 $ — Other long-term liabilities — (13,407) Total, net $ 14,291 $ (13,407) Three Months Ended 2021 2020 (in thousands) Realized loss $ 591 $ 31,898 Unrealized (gain) loss (18,705) 7,596 Total $ (18,114) $ 39,494

Equity-Based Compensation (Tabl

Equity-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Stock option activity	The following table summarizes stock option activity: Number Weighted Weighted Weighted Aggregate (in thousands) Outstanding, December 31, 2020 3,266,348 $ 16.06 5.82 $ 94,962 Granted 75,031 $ 40.50 9.97 $ 18.35 Exercised (491,125) $ 16.30 $ 15,549 Outstanding, March 31, 2021 2,850,254 $ 16.66 5.69 $ 68,865 Exercisable, March 31, 2021 2,775,223 $ 16.01 5.57 $ 68,841 Vested and expected to vest, March 31, 2021 2,850,254 $ 16.66 5.69 $ 68,865 Non-vested, March 31, 2021 75,031 $ 18.35
Restricted stock unit activity	The following table summarizes restricted stock unit activity: Number of Weighted Outstanding, December 31, 2020 2,059,184 $ 11.95 Granted 426,243 $ 38.95 Vested (657,484) $ 18.50 Forfeited (11,294) $ 16.22 Outstanding, March 31, 2021 1,816,649 $ 15.89

Basic and Diluted Net Loss Pe_2

Basic and Diluted Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2021
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: Three Months Ended 2021 2020 (in thousands, except share and per share amounts) Net loss attributable to common stockholders—basic and diluted $ (32,983) $ (71,075) Net loss per share attributable to common stockholders—basic and diluted $ (0.31) $ (0.85) Weighted average common shares outstanding—basic and diluted 106,359,220 84,001,151
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: Three Months Ended 2021 2020 Equity-based compensation awards 4,902,790 5,872,563 Convertible senior notes 1,682,132 4,230,768

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Schedule of performance guarantee obligations	The changes in our aggregate performance guarantee obligations are as follows: As of March 31, 2021 2020 (in thousands) Balance at beginning of period $ 5,718 $ 6,468 Accruals for obligations issued 433 683 Settlements made in cash (3,246) (3,844) Balance at end of period $ 2,905 $ 3,307
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 unaudited condensed consolidated statements of operations: Three Months Ended 2021 2020 (in thousands) Operating lease expense $ 336 $ 336 Finance lease expense: Finance lease amortization expense 25 2 Interest on lease liabilities 3 — Short-term lease expense 10 16 Variable lease expense 261 7 Total $ 635 $ 361 Other information related to leases was as follows: Three Months Ended 2021 2020 (in thousands) Cash paid (received) for amounts included in the measurement of lease liabilities: Operating cash flows from operating leases (1) $ (42) $ 11 Operating cash flows from finance leases 3 — Financing cash flows from finance leases 28 1 Right-of-use assets obtained in exchange for lease obligations: Operating leases — — Finance leases — — (1) Includes reimbursements in 2021 of $423,000 for leasehold improvements. As of As of Weighted average remaining lease term (years): Operating leases 8.23 8.47 Finance leases 3.74 3.99 Weighted average discount rate: Operating leases 3.93 % 3.93 % Finance leases 3.38 % 3.39 %
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 As of (in thousands) Right-of-use assets: Operating leases $ 8,558 $ 8,779 Finance leases 367 391 Total right-of-use assets $ 8,925 $ 9,170 Current lease liabilities: Operating leases $ 1,108 $ 1,094 Finance leases 110 112 Long-term leases liabilities: Operating leases 9,885 9,742 Finance leases 178 203 Total lease liabilities $ 11,281 $ 11,151
Operating lease, future minimum lease payments	Future minimum lease payments under our non-cancelable leases as of March 31, 2021 were as follows: Operating Finance (in thousands) Remaining 2021 $ 1,155 $ 91 2022 1,559 88 2023 1,594 69 2024 1,616 55 2025 1,633 — 2026 and thereafter 5,984 — Total 13,541 303 Amount representing interest (2,021) (15) Amount representing leasehold incentives (527) — Present value of future payments 10,993 288 Current portion of lease liability (1,108) (110) Long-term portion of lease liability $ 9,885 $ 178
Other commitments	Dealer Commitments. As of March 31, 2021 and December 31, 2020, the net unamortized balance of payments to dealers for exclusivity and other similar arrangements was $62.6 million and $55.7 million, respectively. Under these agreements, we paid $3.7 million and $5.3 million during the three months ended March 31, 2021 and 2020, 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) Remaining 2021 $ 31,530 2022 40,118 2023 18,110 2024 7,970 2025 938 2026 and thereafter — Total $ 98,666
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) Remaining 2021 $ 15,642 2022 26,810 2023 26,605 2024 19,807 2025 — 2026 and thereafter — Total $ 88,864 Information (in thousands) Remaining 2021 $ 8,026 2022 2,216 2023 26 2024 26 2025 7 2026 and thereafter — Total $ 10,301

Description of Business and B_3

Description of Business and Basis of Presentation - Narrative (Details) customer in Thousands, $ in Billions	3 Months Ended	20 Months Ended
	Mar. 31, 2021staterenewal_optioncustomer	Mar. 31, 2021USD ($)state
Subsidiary, Sale of Stock [Line Items]
Number of customers | customer	116
Number of states in which entity operates (more than) | state	25	25
Maximum renewal term	10 years
Equity cure contribution | $		$ 6.9
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 - Revision of Interim Financials (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Redeemable Noncontrolling Interests
Redeemable noncontrolling interest, beginning balance	$ 136,124	$ 127,129
Net income (loss)	2,110	1,576
Contributions from redeemable noncontrolling interests and noncontrolling interests		3,170
Distributions to redeemable noncontrolling interests and noncontrolling interests	(1,090)	(1,373)
Costs related to redeemable noncontrolling interests and noncontrolling interests		187
Equity in subsidiaries attributable to parent	40	145
Other, net	(62)	(44)
Redeemable noncontrolling interest, ending balance	137,122	130,790
Noncontrolling Interests
Stockholders' equity, beginning balance	1,144,557	691,111
Net income (loss)	(26,174)	(78,580)
Contributions from redeemable noncontrolling interests and noncontrolling interests	40,802	99,172
Distributions to redeemable noncontrolling interests and noncontrolling interests	(1,743)
Costs related to redeemable noncontrolling interests and noncontrolling interests	(55)	(894)
Equity in subsidiaries attributable to parent	(40)	(145)
Other, net	(475)	(3)
Stockholders' equity, ending balance	1,223,785	703,657
Noncontrolling Interests
Noncontrolling Interests
Stockholders' equity, beginning balance	192,826	45,176
Net income (loss)	6,809	(7,505)
Contributions from redeemable noncontrolling interests and noncontrolling interests	40,802	99,172
Distributions to redeemable noncontrolling interests and noncontrolling interests	(1,743)	0
Costs related to redeemable noncontrolling interests and noncontrolling interests	(55)	(894)
Equity in subsidiaries attributable to parent	(37,253)	(24,309)
Other, net	(476)	(3)
Stockholders' equity, ending balance	$ 200,910	111,637
As Previously Reported
Redeemable Noncontrolling Interests
Redeemable noncontrolling interest, beginning balance		172,305
Net income (loss)		(5,929)
Contributions from redeemable noncontrolling interests and noncontrolling interests		102,342
Distributions to redeemable noncontrolling interests and noncontrolling interests		(1,373)
Costs related to redeemable noncontrolling interests and noncontrolling interests		(707)
Equity in subsidiaries attributable to parent		(24,164)
Other, net		(47)
Redeemable noncontrolling interest, ending balance		242,427
As Previously Reported | Noncontrolling Interests
Noncontrolling Interests
Stockholders' equity, beginning balance		0
Net income (loss)		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
Revisions
Redeemable Noncontrolling Interests
Redeemable noncontrolling interest, beginning balance		(45,176)
Net income (loss)		7,505
Contributions from redeemable noncontrolling interests and noncontrolling interests		(99,172)
Distributions to redeemable noncontrolling interests and noncontrolling interests		0
Costs related to redeemable noncontrolling interests and noncontrolling interests		894
Equity in subsidiaries attributable to parent		24,309
Other, net		3
Redeemable noncontrolling interest, ending balance		(111,637)
Revisions | Noncontrolling Interests
Noncontrolling Interests
Stockholders' equity, beginning balance		45,176
Net income (loss)		(7,505)
Contributions from redeemable noncontrolling interests and noncontrolling interests		99,172
Distributions to redeemable noncontrolling interests and noncontrolling interests		0
Costs related to redeemable noncontrolling interests and noncontrolling interests		(894)
Equity in subsidiaries attributable to parent		(24,309)
Other, net		(3)
Stockholders' equity, ending balance		$ 111,637

Significant Accounting Polici_4

Significant Accounting Policies - Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 912	$ 960
Provision for current expected credit losses	396	402
Write off of uncollectible accounts	(496)	(385)
Recoveries	36	9
Other, net	0	1
Balance at end of period	$ 848	747
Impact of ASC 326 adoption
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period		$ (240)

Significant Accounting Polici_5

Significant Accounting Policies - Inventories (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Inventory [Line Items]
Inventory	$ 107,684	$ 102,589
Energy storage systems and components
Inventory [Line Items]
Inventory	29,769	18,122
Modules and inverters
Inventory [Line Items]
Inventory	77,277	83,904
Meters
Inventory [Line Items]
Inventory	$ 638	$ 563

Significant Accounting Polici_6

Significant Accounting Policies - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)kWhFICO_scorerenewal_option	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Disaggregation of Revenue [Line Items]
Accrued expenses for inventory purchases	$ 13,500		$ 8,900
Contracted but not yet recognized revenue	$ 1,700,000
Average age of solar systems	4 years
SREC inventory	$ 107,684		102,589
Threshold period past due, writeoff	180 days
Deferred revenue	$ 136,472		106,809	$ 58,900
Revenue recognized	2,500	$ 997
Solar Renewable Energy Certificates
Disaggregation of Revenue [Line Items]
SREC inventory	$ 0		0
Minimum
Disaggregation of Revenue [Line Items]
Agreement term	10 years
Median
Disaggregation of Revenue [Line Items]
Agreement term	15 years
Maximum
Disaggregation of Revenue [Line Items]
Agreement 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	$ 122,583		$ 93,859
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

Significant Accounting Polici_7

Significant Accounting Policies - Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 41,276	$ 29,829
PPA revenue
Disaggregation of Revenue [Line Items]
Revenue	16,834	12,633
Lease revenue
Disaggregation of Revenue [Line Items]
Revenue	16,397	11,542
Solar renewable energy certificate revenue
Disaggregation of Revenue [Line Items]
Revenue	5,957	4,363
Loan revenue
Disaggregation of Revenue [Line Items]
Revenue	1,195	599
Other revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 893	$ 692

Significant Accounting Polici_8

Significant Accounting Policies - Performance Obligations (Details) $ in Billions	3 Months Ended
	Mar. 31, 2021USD ($)
Accounting Policies [Abstract]
Contracted but not yet recognized revenue	$ 1.7
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]: 2021-04-01
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 Polici_9

Significant Accounting Policies - Deferred Revenue (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Deferred revenue	$ 136,472	$ 106,809	$ 58,900
Deferred revenue included in other current liabilities	9,026	3,754
Loans
Disaggregation of Revenue [Line Items]
Deferred revenue	122,583	93,859
PPAs and leases
Disaggregation of Revenue [Line Items]
Deferred revenue	13,599	11,787
SRECs
Disaggregation of Revenue [Line Items]
Deferred revenue	$ 290	$ 1,163

Significant Accounting Polic_10

Significant Accounting Policies - New Accounting Guidance (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity	$ 1,223,785	$ 1,144,557	$ 703,657	$ 691,111
Total Stockholders' Equity
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity	$ 1,022,875	951,731	$ 592,020	645,935
Impact of ASC 326 adoption
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity		2,254		(9,908)
Impact of ASC 326 adoption | Total Stockholders' Equity
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Total equity		$ 2,254		$ (9,908)

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 2,679,139	$ 2,536,757
Less: accumulated depreciation	(233,036)	(213,588)
Property and equipment, net	$ 2,446,103	2,323,169
Solar energy systems
Property, Plant and Equipment [Line Items]
Useful Lives	35 years
Property and equipment, gross	$ 2,447,218	2,298,427
Less: accumulated depreciation	(206,100)	(188,800)
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 151,166	160,618
Asset retirement obligations
Property, Plant and Equipment [Line Items]
Useful Lives	30 years
Property and equipment, gross	$ 37,811	35,532
Information technology systems
Property, Plant and Equipment [Line Items]
Useful Lives	3 years
Property and equipment, gross	$ 35,649	35,077
Computers and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,913	1,727
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	$ 2,776	2,770
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	811
Vehicles
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,638	1,638
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	$ 157
Other | Minimum
Property, Plant and Equipment [Line Items]
Useful Lives	5 years
Other | Maximum
Property, Plant and Equipment [Line Items]
Useful Lives	6 years

Detail of Certain Balance She_3

Detail of Certain Balance Sheet Captions - Other Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Inventory	$ 107,684	$ 102,589
Restricted cash	43,603	73,020	$ 30,502
Current portion of customer notes receivable	29,077	24,035
Other prepaid assets	9,318	8,645
Prepaid inventory	0	3,352
Deferred receivables	2,075	2,678
Current portion of other notes receivable	820	853
Other	3	3
Total	$ 192,580	$ 215,175

Detail of Certain Balance She_4

Detail of Certain Balance Sheet Captions - Other Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Restricted cash	$ 68,968	$ 95,014	$ 65,298
Construction in progress - customer notes receivable	102,242	85,604
Exclusivity and other bonus arrangements with dealers, net	62,600	55,709
Straight-line revenue adjustment, net	35,877	33,411
Derivative assets	14,291	0
Other	26,816	24,634
Total	$ 310,794	$ 294,372

Detail of Certain Balance She_5

Detail of Certain Balance Sheet Captions - Other Current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Interest payable	$ 10,318	$ 17,718
Deferred revenue	9,026	3,754
Current portion of performance guarantee obligations	2,349	3,308
Current portion of operating and finance lease liability	1,217	1,206
Other	22	27
Total	$ 22,932	$ 26,013

Asset Retirement Obligations _3

Asset Retirement Obligations ("ARO") (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
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	$ 41,788	$ 31,053
Additional obligations incurred	2,290	2,067
Accretion expense	652	489
Other	(16)	(15)
Balance at end of period	$ 44,714	$ 33,594

Customer Notes Receivable - Nar

Customer Notes Receivable - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan systems not yet placed in service	$ 102,200,000		$ 85,600,000
Interest income	7,180,000	$ 4,620,000
Customer notes receivable not accruing interest	0		0
Interest income for nonaccrual loans	0	0
Amortized cost	8,600,000		8,600,000
Customer notes receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Interest income	7,100,000	4,400,000
Accrued investment income receivable	1,800,000		$ 1,200,000
Accrued investment income receivable, written off	$ 0	$ 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	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Customer notes receivable	$ 672,897	$ 555,089
Allowance for credit losses	(20,919)	(17,668)	$ (12,136)	$ (1,091)
Current portion of customer notes receivable	29,077	24,035
Customer Notes Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current portion of customer notes receivable	29,100	24,000
Carrying Value
Accounts, Notes, Loans and Financing Receivable [Line Items]
Customer notes receivable	651,978	537,421
Estimated Fair Value
Accounts, Notes, Loans and Financing Receivable [Line Items]
Customer notes receivable	$ 664,534	$ 548,238

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	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Balance at beginning of period	$ 17,668	$ 1,091
Provision for current expected credit loss	3,251	1,811
Other, net	0	(1)
Balance at end of period	20,919	12,136
Provision for expected credit losses	$ 62	53
Impact of ASC 326 adoption
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Balance at beginning of period		$ 9,235

Customer Notes Receivable - S_3

Customer Notes Receivable - Schedule of Aged Receivables (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	$ 17,797	$ 17,092
Financing receivable, not past due	655,100	537,997
Total	672,897	555,089
1-90 days past due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	9,202	8,504
91-180 days past due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	1,815	1,733
Greater than 180 days past due
Financing Receivable, Past Due [Line Items]
Financing receivable, past due	$ 6,780	$ 6,855

Customer Notes Receivable - S_4

Customer Notes Receivable - Schedule of Amortized cost of Customer Notes Receivable (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
2021	$ 129,799
2020	261,450
2019	132,412
2018	86,868
2017	32,357
Prior	30,011
Total	672,897	$ 555,089
Performing
Financing Receivable, Credit Quality Indicator [Line Items]
2021	129,799
2020	261,183
2019	131,093
2018	84,994
2017	30,426
Prior	28,622
Total	666,117
Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
2021	0
2020	267
2019	1,319
2018	1,874
2017	1,931
Prior	1,389
Total	$ 6,780

Long-Term Debt - Schedule of Lo

Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Long-term debt, non-current	$ 1,994,734	$ 1,924,653
Long-term debt, current	$ 116,205	$ 110,883
SEI | Convertible senior notes | 9.75% convertible senior notes
Debt Instrument [Line Items]
Stated interest rate	9.75%
Weighted average effective interest rates	21.70%	14.53%
Long-term debt, gross, non-current	$ 0	$ 95,648
Debt discount, net, non-current	0	(37,394)
Deferred financing costs, net, non-current	0	(239)
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]
Weighted average effective interest rates	8.39%	7.14%
Long-term debt, gross, non-current	$ 0	$ 0
Long-term debt, gross, current	0	2,254
HELI
Debt Instrument [Line Items]
Debt discount, net, non-current	(2,020)	(2,241)
Deferred financing costs, net, non-current	(3,607)	(4,004)
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	6.65%	6.55%
Long-term debt, gross, non-current	$ 201,759	$ 205,395
Long-term debt, gross, current	6,538	6,329
EZOP | Revolving credit facility
Debt Instrument [Line Items]
Debt discount, net, non-current	(1,266)	(1,431)
Debt discount, net, current	$ 0	$ 0
EZOP | Line of Credit | Revolving credit facility
Debt Instrument [Line Items]
Weighted average effective interest rates	3.65%	4.39%
Long-term debt, gross, non-current	$ 109,400	$ 171,600
Long-term debt, gross, current	0	0
HELII
Debt Instrument [Line Items]
Debt discount, net, non-current	(40)	(42)
Deferred financing costs, net, non-current	(4,896)	(5,085)
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	5.80%	5.71%
Long-term debt, gross, non-current	$ 221,668	$ 227,574
Long-term debt, gross, current	10,606	11,707
RAYSI
Debt Instrument [Line Items]
Debt discount, net, non-current	(1,334)	(1,376)
Deferred financing costs, net, non-current	(4,229)	(4,334)
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	5.57%	5.49%
Long-term debt, gross, non-current	$ 119,281	$ 120,391
Long-term debt, gross, current	5,744	5,836
HELIII
Debt Instrument [Line Items]
Debt discount, net, non-current	(2,395)	(2,423)
Deferred financing costs, net, non-current	(2,298)	(2,326)
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	4.06%	4.01%
Long-term debt, gross, non-current	$ 119,044	$ 122,047
Long-term debt, gross, current	12,295	13,065
TEPH
Debt Instrument [Line Items]
Debt discount, net, non-current	(3,332)	(3,815)
Debt discount, net, current	$ 0	$ 0
TEPH | Line of Credit | Revolving credit facility
Debt Instrument [Line Items]
Weighted average effective interest rates	5.73%	5.81%
Long-term debt, gross, non-current	$ 304,570	$ 239,570
Long-term debt, gross, current	0	0
TEPINV
Debt Instrument [Line Items]
Debt discount, net, non-current	(997)	(1,322)
Deferred financing costs, net, non-current	(1,442)	(1,758)
Debt discount, net, current	0	0
Deferred financing costs, net, current	$ 0	$ 0
TEPINV | Line of Credit | Revolving credit facility
Debt Instrument [Line Items]
Weighted average effective interest rates	12.19%	10.80%
Long-term debt, gross, non-current	$ 27,434	$ 25,240
Long-term debt, gross, current	22,302	29,464
SOLI
Debt Instrument [Line Items]
Debt discount, net, non-current	(110)	(113)
Deferred financing costs, net, non-current	(8,660)	(8,915)
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	3.94%	3.91%
Long-term debt, gross, non-current	$ 379,771	$ 384,258
Long-term debt, gross, current	15,383	15,416
HELIV
Debt Instrument [Line Items]
Debt discount, net, non-current	(849)	(885)
Deferred financing costs, net, non-current	(3,754)	(3,905)
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	4.10%	3.97%
Long-term debt, gross, non-current	$ 125,659	$ 129,648
Long-term debt, gross, current	$ 16,127	$ 16,515
AP8 | Line of Credit | Revolving credit facility
Debt Instrument [Line Items]
Weighted average effective interest rates	5.56%	5.31%
Long-term debt, gross, non-current	$ 21,205	$ 42,047
Long-term debt, gross, current	4,395	4,386
SOLII
Debt Instrument [Line Items]
Debt discount, net, non-current	(79)	(80)
Deferred financing costs, net, non-current	(5,825)	(5,866)
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	3.28%	3.18%
Long-term debt, gross, non-current	$ 246,872	$ 248,789
Long-term debt, gross, current	5,853	5,911
HELV
Debt Instrument [Line Items]
Debt discount, net, non-current	(949)	0
Deferred financing costs, net, non-current	(3,607)	0
Debt discount, net, current	0	0
Deferred financing costs, net, current	$ 0	$ 0
HELV | Solar loan-backed notes
Debt Instrument [Line Items]
Weighted average effective interest rates	2.31%
Long-term debt, gross, non-current	$ 169,760	$ 0
Long-term debt, gross, current	$ 16,962	$ 0

Long-Term Debt - Narrative (Det

Long-Term Debt - Narrative (Details) - USD ($)	1 Months Ended	3 Months Ended
	Feb. 28, 2021	Mar. 31, 2021	Mar. 31, 2020	Mar. 30, 2021
Debt Instrument [Line Items]
Borrowing capacity		$ 281,100,000
Debt conversion		95,648,000	$ 0
EZOP | Line of Credit | Revolving credit facility
Debt Instrument [Line Items]
Borrowing capacity		90,600,000
Repayments of debt	$ 107,300,000
Maximum borrowing capacity		350,000,000		$ 200,000,000
TEPH | Line of Credit | Revolving credit facility
Debt Instrument [Line Items]
Borrowing capacity		156,100,000
AP8 | Line of Credit | Revolving credit facility
Debt Instrument [Line Items]
Borrowing capacity		$ 34,400,000
Repayments of debt	$ 29,500,000
SEI | Convertible senior notes | 9.75% convertible senior notes
Debt Instrument [Line Items]
Stated interest rate		9.75%
Debt conversion		$ 97,100,000
HELV | Solar loan-backed notes | HELV Series 2021-A Class A
Debt Instrument [Line Items]
Stated interest rate	1.80%
Principal amount of debt issued	$ 150,100,000
Discount percent	0.001%
HELV | Solar loan-backed notes | HELV Series 2021-A Class B
Debt Instrument [Line Items]
Stated interest rate	3.15%
Principal amount of debt issued	$ 38,600,000
Discount percent	2.487%

Long-Term Debt - Schedule of Fa

Long-Term Debt - Schedule of Fair Value of Long-term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Net deferred financing costs and debt discounts	$ 51,700	$ 87,600
Carrying Value
Debt Instrument [Line Items]
Long-term debt	2,162,628	2,123,090
Estimated Fair Value
Debt Instrument [Line Items]
Long-term debt	$ 2,214,286	2,246,176
SEI | Convertible senior notes | 9.75% convertible senior notes
Debt Instrument [Line Items]
Stated interest rate	9.75%
SEI | Carrying Value | Convertible senior notes | 9.75% convertible senior notes
Debt Instrument [Line Items]
Long-term debt	$ 0	95,648
SEI | Estimated Fair Value | Convertible senior notes | 9.75% convertible senior notes
Debt Instrument [Line Items]
Long-term debt	0	100,482
Sunnova Energy Corporation | Carrying Value | Notes payable
Debt Instrument [Line Items]
Long-term debt	0	2,254
Sunnova Energy Corporation | Estimated Fair Value | Notes payable
Debt Instrument [Line Items]
Long-term debt	0	2,254
HELI | Carrying Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	208,297	211,724
HELI | Estimated Fair Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	216,578	220,941
HELII | Carrying Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	232,274	239,281
HELII | Estimated Fair Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	266,817	286,579
RAYSI | Carrying Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	125,025	126,227
RAYSI | Estimated Fair Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	138,191	146,506
HELIII | Carrying Value | Solar loan-backed notes
Debt Instrument [Line Items]
Long-term debt	131,339	135,112
HELIII | Estimated Fair Value | Solar loan-backed notes
Debt Instrument [Line Items]
Long-term debt	139,181	149,489
SOLI | Carrying Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	395,154	399,674
SOLI | Estimated Fair Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	404,116	427,511
HELIV | Carrying Value | Solar loan-backed notes
Debt Instrument [Line Items]
Long-term debt	141,786	146,163
HELIV | Estimated Fair Value | Solar loan-backed notes
Debt Instrument [Line Items]
Long-term debt	136,672	145,433
SOLII | Carrying Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	252,725	254,700
SOLII | Estimated Fair Value | Solar asset-backed notes
Debt Instrument [Line Items]
Long-term debt	241,066	254,674
HELV | Carrying Value | Solar loan-backed notes
Debt Instrument [Line Items]
Long-term debt	186,722	0
HELV | Estimated Fair Value | Solar loan-backed notes
Debt Instrument [Line Items]
Long-term debt	182,359	0
Revolving credit facility | EZOP | Carrying Value | Line of Credit
Debt Instrument [Line Items]
Long-term debt	109,400	171,600
Revolving credit facility | EZOP | Estimated Fair Value | Line of Credit
Debt Instrument [Line Items]
Long-term debt	109,400	171,600
Revolving credit facility | TEPH | Carrying Value | Line of Credit
Debt Instrument [Line Items]
Long-term debt	304,570	239,570
Revolving credit facility | TEPH | Estimated Fair Value | Line of Credit
Debt Instrument [Line Items]
Long-term debt	304,570	239,570
Revolving credit facility | TEPINV | Carrying Value | Line of Credit
Debt Instrument [Line Items]
Long-term debt	49,736	54,704
Revolving credit facility | TEPINV | Estimated Fair Value | Line of Credit
Debt Instrument [Line Items]
Long-term debt	49,736	54,704
Revolving credit facility | AP8 | Carrying Value | Line of Credit
Debt Instrument [Line Items]
Long-term debt	25,600	46,433
Revolving credit facility | AP8 | Estimated Fair Value | Line of Credit
Debt Instrument [Line Items]
Long-term debt	$ 25,600	$ 46,433

Derivative Instruments - Narrat

Derivative Instruments - Narrative (Details) - EZOP - Interest Rate Swap - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Derivative [Line Items]
Aggregate notional amount of unwound derivative	$ 131,700	$ 0
Realized loss	$ 68	$ 59

Derivative Instruments - Outsta

Derivative Instruments - Outstanding Derivative Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Interest rate swap
Derivative [Line Items]
Aggregate Notional Amount	$ 490,483	$ 383,670
EZOP | Interest Rate Swap One
Derivative [Line Items]
Fixed Interest Rate	1.00%
Aggregate Notional Amount	$ 180,181	$ 130,373
EZOP | Interest Rate Swap One | Minimum
Derivative [Line Items]
Fixed Interest Rate		0.483%
EZOP | Interest Rate Swap One | Maximum
Derivative [Line Items]
Fixed Interest Rate		2.62%
TEPH | Interest Rate Swap Two
Derivative [Line Items]
Aggregate Notional Amount	$ 270,170	$ 202,272
TEPH | Interest Rate Swap Two | Minimum
Derivative [Line Items]
Fixed Interest Rate	0.121%	0.528%
TEPH | Interest Rate Swap Two | Maximum
Derivative [Line Items]
Fixed Interest Rate	2.534%	2.114%
TEPINV | Interest Rate Swap Three
Derivative [Line Items]
Fixed Interest Rate	2.50%	2.50%
Aggregate Notional Amount	$ 40,132	$ 51,025

Derivative Instruments - Balanc

Derivative Instruments - Balance Sheet (Details) - Not designated as hedging instrument - Interest rate swap - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Total, net	$ 14,291	$ (13,407)
Other assets
Derivatives, Fair Value [Line Items]
Derivative asset, fair value	14,291	0
Other long-term liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, fair value	$ 0	$ (13,407)

Derivative Instruments - Intere

Derivative Instruments - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Derivative Instruments, Gain (Loss) [Line Items]
Unrealized (gain) loss	$ (18,705)	$ 7,596
Interest Rate Swap | Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Realized loss	591	31,898
Unrealized (gain) loss	(18,705)	7,596
Total	$ (18,114)	$ 39,494

Income Taxes (Details)

Income Taxes (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Effective income tax rate	0.00%	0.00%
Income tax penalties and interest accrued	$ 0		$ 0

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Repayments of Debt [Line Items]
Non-cash conversion of convertible senior notes for common stock	$ 95,648	$ 0
9.75% convertible senior notes | Convertible senior notes | SEI
Repayments of Debt [Line Items]
Stated interest rate	9.75%
Non-cash conversion of convertible senior notes for common stock	$ 97,100
Debt conversion, shares issued (in shares)	7,196,035

Equity-Based Compensation - Sto

Equity-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Number of Stock Options
Outstanding, beginning balance (in shares)	3,266,348
Granted (in shares)	75,031
Exercised (in shares)	(491,125)
Outstanding, ending balance (in shares)	2,850,254
Number of options, exercisable (in shares)	2,775,223
Number of options, vested and expected to vest (in shares)	2,850,254
Number of options, non-vested (in shares)	75,031
Weighted Average Exercise Price
Outstanding, beginning balance (in USD per share)	$ 16.06
Granted (in USD per share)	40.50
Exercised (in USD per share)	16.30
Outstanding, ending balance (in USD per share)	16.66
Weighted average exercise price, exercisable (in USD per share)	16.01
Weighted average exercise price, vested and expected to vest (in USD per share)	$ 16.66
Weighted Average Remaining Contractual Term (Years)
Outstanding	5 years 8 months 8 days	5 years 9 months 25 days
Granted	9 years 11 months 19 days
Exercisable	5 years 6 months 25 days
Vested and expected to vest	5 years 8 months 8 days
Weighted Average Grant Date Fair Value
Granted (in USD per share)	$ 18.35
Non-vested (in USD per share)	$ 18.35
Aggregate Intrinsic Value
Outstanding, beginning balance	$ 94,962
Exercised	15,549
Outstanding, ending balance	68,865
Exercisable	68,841
Vested and expected to vest	$ 68,865

Equity-Based Compensation - Nar

Equity-Based Compensation - Narrative (Details) - USD ($)	1 Months Ended	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options vested (in shares)		0	265,207
Stock options vested		$ 0	$ 791,000
Total unrecognized compensation expense	$ 1,400,000	$ 1,400,000
Long-Term Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized during period (in shares)	2,214,561
Shares authorized (in shares)	5,020,602	5,020,602
Number of shares available for grant	5.00%	5.00%
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period		2 years 2 months 23 days
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period		1 year 11 months 26 days
Stock units vested (in shares)		657,484	27,083
Restricted stock units, vested		$ 12,200,000	$ 325,000
Unrecognized compensation expense	$ 26,400,000	$ 26,400,000

Equity-Based Compensation - Res

Equity-Based Compensation - Restricted Stock Activity (Details) - $ / shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Number of Restricted Stock Units
Forfeited (in shares)	(11,294)
Weighted Average Grant Date Fair Value
Forfeited (in USD per share)	$ 16.22
Restricted Stock Units
Number of Restricted Stock Units
Outstanding, beginning balance (in shares)	2,059,184
Granted (in shares)	426,243
Vested (in shares)	(657,484)	(27,083)
Outstanding, ending balance (in shares)	1,816,649
Weighted Average Grant Date Fair Value
Outstanding (in USD per share)	$ 15.89		$ 11.95
Granted (in USD per share)	38.95
Vested (in USD per share)	$ 18.50

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
	Mar. 31, 2021	Mar. 31, 2020
Earnings Per Share [Abstract]
Net loss attributable to common stockholders—basic	$ (32,983)	$ (71,075)
Net loss attributable to common stockholders - diluted	$ (32,983)	$ (71,075)
Net loss per share attributable to common stockholders—basic and diluted (in USD per share)	$ (0.31)	$ (0.85)
Weighted average common shares outstanding—basic and diluted (in shares)	106,359,220	84,001,151

Basic and Diluted Net Loss Pe_4

Basic and Diluted Net Loss Per Share - Anti-Dilutive Weighted Average Shares (Details) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
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)	4,902,790	5,872,563
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)	1,682,132	4,230,768

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended
	Dec. 31, 2020	Aug. 31, 2019	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2019
Loss Contingencies [Line Items]
Current portion of performance guarantee obligations	$ 3,308		$ 2,349
Letter of credit outstanding			375
Other commitment	$ 55,700		62,600
Payments for dealer commitments			3,700	$ 5,300
Purchase term	1 year	5 years
Performance Guarantee Obligations
Loss Contingencies [Line Items]
Performance guarantee obligations	$ 5,718		2,905	$ 3,307	$ 6,468
Current portion of performance guarantee obligations	3,300		2,300
Long-term portion of performance guarantee obligations	$ 2,400		$ 556

Commitments and Contingencies_2

Commitments and Contingencies - Performance Guarantee Obligations (Details) - Performance Guarantee Obligations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Performance Guarantee Obligations [Roll Forward]
Balance at beginning of period	$ 5,718	$ 6,468
Accruals for obligations issued	433	683
Settlements made in cash	(3,246)	(3,844)
Balance at end of period	$ 2,905	$ 3,307

Commitments and Contingencies_3

Commitments and Contingencies - Lease Expenses and Other Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Operating lease expense	$ 336	$ 336
Finance lease expense:
Finance lease amortization expense	25	2
Interest on lease liabilities	3	0
Short-term lease expense	10	16
Variable lease expense	261	7
Total	$ 635	$ 361

Commitments and Contingencies_4

Commitments and Contingencies - Lease Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Right-of-use assets:
Operating leases	$ 8,558	$ 8,779
Finance leases	367	391
Total right-of-use assets	8,925	9,170
Current lease liabilities:
Operating leases	1,108	1,094
Finance leases	110	112
Long-term leases liabilities:
Operating leases	9,885	9,742
Long-term portion of lease liability	178	203
Total lease liabilities	$ 11,281	$ 11,151
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other assets	Other assets
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other current liabilities	Other current liabilities
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	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash paid (received) for amounts included in the measurement of lease liabilities:
Operating cash flow from operating leases	$ (42)	$ 11
Operating cash flows from finance leases	3	0
Financing cash flows from finance leases	28	1
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	0	0
Finance leases	0	$ 0
Leasehold improvements reimbursements	$ 423
Weighted average remaining lease term (years):
Operating leases	8 years 2 months 23 days	8 years 5 months 19 days
Finance leases	3 years 8 months 26 days	3 years 11 months 26 days
Weighted average discount rate:
Operating leases	3.93%	3.93%
Finance leases	3.38%	3.39%

Commitments and Contingencies_6

Commitments and Contingencies - Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Operating Leases
Remaining 2021	$ 1,155
2022	1,559
2023	1,594
2024	1,616
2025	1,633
2026 and thereafter	5,984
Total	13,541
Amount representing interest	(2,021)
Amount representing leasehold incentives	(527)
Present value of future payments	10,993
Current portion of lease liability	(1,108)	$ (1,094)
Long-term portion of lease liability	9,885	9,742
Finance Leases
Remaining 2021	91
2022	88
2023	69
2024	55
2025	0
2026 and thereafter	0
Total	303
Amount representing interest	(15)
Amount representing leasehold incentives	0
Present value of future payments	288
Current portion of lease liability	(110)	(112)
Long-term portion of lease liability	$ 178	$ 203

Commitments and Contingencies_7

Commitments and Contingencies - Dealer Commitments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Other Commitments [Line Items]
Total	$ 62,600	$ 55,700
Long-Term Dealer Commitments
Other Commitments [Line Items]
Remaining 2021	31,530
2022	40,118
2023	18,110
2024	7,970
2025	938
2026 and thereafter	0
Total	$ 98,666

Commitments and Contingencies_8

Commitments and Contingencies - Purchase Commitments (Details) $ in Thousands	Mar. 31, 2021USD ($)
Commitments and Contingencies Disclosure [Abstract]
Remaining 2021	$ 15,642
2022	26,810
2023	26,605
2024	19,807
2025	0
2026 and thereafter	0
Total	$ 88,864

Commitments and Contingencies_9

Commitments and Contingencies - Future Commitments (Details) $ in Thousands	Mar. 31, 2021USD ($)
Commitments and Contingencies Disclosure [Abstract]
Remaining 2021	$ 8,026
2022	2,216
2023	26
2024	26
2025	7
2026 and thereafter	0
Total	$ 10,301

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended
	Apr. 29, 2021	Feb. 28, 2021	Mar. 31, 2020
Subsequent Event [Line Items]
Contributions from redeemable noncontrolling interests and noncontrolling interests			$ 3,170
Class A members | Sunnova TEP V-D | Subsequent Event
Subsequent Event [Line Items]
Contributions from redeemable noncontrolling interests and noncontrolling interests	$ 50,000
SunStreet Energy Group, LLC
Subsequent Event [Line Items]
Business acquisition, shares issued in exchange (in shares)		6,984,225
Business acquisition, shares issued at closing (in shares)		3,095,329
Business acquisition, shares issuable as earnout (in shares)		3,888,896