Significant Accounting Policies (Policies)	12 Months Ended
Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying annual audited consolidated financial statements ("consolidated financial statements") include our consolidated balance sheets, statements of operations, statements of redeemable noncontrolling interests and equity and statements of cash flows and have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") from records maintained by us. Our consolidated financial statements include our accounts and those of our subsidiaries in which we have a controlling financial interest. In accordance with the provisions of the Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") 810, Consolidation, we consolidate any VIE of which we are the primary beneficiary. We form VIEs with our investors in the ordinary course of business to facilitate the funding and monetization of certain attributes associated with our solar energy systems. The typical condition for a controlling financial interest is holding a majority of the voting interests of an entity. However, a controlling financial interest may also exist in entities, such as VIEs, through arrangements that do not involve holding a majority of the voting interests. 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.
Reclassifications	Reclassifications Certain prior period amounts have been reclassified to conform to the current period presentation. These reclassifications did not have a significant impact on our consolidated financial statements.
Use of Estimates	Use of Estimates The application of GAAP in the preparation of the consolidated financial statements requires us to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. We base our estimates on historical experience and on various other assumptions believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results could differ materially from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents We maintain cash and cash equivalents, which consists principally of demand deposits, with investment-grade financial institutions. We are exposed to credit risk to the extent cash and cash equivalents balances exceed amounts covered by the Federal Deposit Insurance Corporation ("FDIC"). As of December 31, 2022 and 2021, we had cash and cash equivalents deposits of $337.5 million and $225.7 million, respectively, in excess of the FDIC's current insured limit of $250,000. We have not experienced any losses on our deposits of cash and cash equivalents.
Restricted Cash	Restricted CashWe record cash that is restricted as to withdrawal or use under the terms of certain contractual agreements as restricted cash. Our restricted cash primarily represents cash held to service certain payments under the Sunnova EZ-Own Portfolio, LLC ("EZOP"), Sunnova TEP Holdings, LLC ("TEPH"), Helios II Issuer, LLC ("HELII"), Helios III Issuer, LLC ("HELIII"), Sunnova RAYS I Issuer, LLC ("RAYSI"), Sunnova Sol Issuer, LLC ("SOLI"), Sunnova Helios IV Issuer, LLC ("HELIV"), Sunnova TEP IV-G, LLC ("TEPIVG"), Sunnova Asset Portfolio 8, LLC ("AP8"), Sunnova Sol II Issuer, LLC ("SOLII"), Sunnova Helios V Issuer, LLC ("HELV"), Sunnova Helios VI Issuer, LLC ("HELVI"), Sunnova Helios VII Issuer, LLC ("HELVII"), Sunnova TEP V-A, LLC ("TEPVA"), Sunnova TEP V-B, LLC ("TEPVB"), Sunnova TEP V-C, LLC ("TEPVC"), Sunnova TEP 6-B, LLC ("TEP6B"), Sunnova Sol III Issuer, LLC ("SOLIII"), Sunnova Helios VIII Issuer, LLC ("HELVIII"), Sunnova Helios IX Issuer, LLC ("HELIX"), Sunnova Sol IV Issuer, LLC ("SOLIV"), Sunnova Helios X Issuer, LLC ("HELX"), Sunnova TEP 7-A, LLC ("TEP7A"), Sunnova TEP 7-B, LLC ("TEP7B"), Sunnova TEP 7-C, LLC ("TEP7C") and Sunnova TEP 7-D, LLC ("TEP7D") financing arrangements (see Note 9, Long-Term Debt and Note 13, Redeemable Noncontrolling Interests and Noncontrolling Interests) and balances collateralizing outstanding letters of credit related to a reinsurance agreement and one of our operating leases for office space (see Note 17, Commitments and Contingencies).
Accounts Receivable	Accounts ReceivableAccounts Receivable—Trade. Accounts receivable—trade primarily represents trade receivables from 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.Accounts Receivable—Other. Accounts receivable—other primarily represents receivables from our dealers or other parties related to the sale of inventory and the use of inventory procured by us.
Inventory	InventoryInventory is stated at the lower of cost and net realizable value using the first-in, first-out method. Inventory primarily represents (a) raw materials, such as energy storage systems, photovoltaic modules, inverters, meters and modems, (b) homebuilder construction in progress and (c) other associated equipment purchased. These materials are typically procured by us and used by our dealers, sold to our 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) recognize in accounts receivable—other when procured by us and used by our dealers, (c) expense to cost of revenue—inventory sales if sold directly to a dealer or other party, (d) capitalize to property and equipment when installed on an existing home or business or (e) capitalize to property and equipment when placed in service under the homebuilder program. 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 net realizable value.
Concentrations of Risk	Concentrations of Risk Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash, cash equivalents, restricted cash, accounts receivable and notes receivable. The concentrated risk associated with cash, cash equivalents and restricted cash is mitigated by our policy of banking with creditworthy institutions. Typically, amounts on deposit with certain banking institutions exceed FDIC insurance limits. We do not generally require collateral or other security to support accounts receivable. To reduce credit risk related to our relationship with our dealers, management performs periodic credit evaluations and ongoing assessments of our dealers' financial condition.
Dealer Commitments	Dealer Commitments We enter into exclusivity and other similar agreements with certain key dealers pursuant to which we agree to pay an incentive if such dealers install a certain minimum number of solar energy systems within specified periods. These incentives are recorded in other assets in the consolidated balance sheets and are amortized to general and administrative expense in the consolidated statements of operations generally over the term of the customer agreements, which is estimated at an average of 23 years. See Note 17, Commitments and Contingencies.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value is an exit price representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions market participants would use in pricing an asset or a liability. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. ASC 820 establishes a three-tier fair value hierarchy, which prioritizes inputs that may be used to measure fair value as follows: •Level 1—Observable inputs that reflect unadjusted quoted market prices in active markets for identical assets or liabilities that are accessible at the measurement date. •Level 2—Observable inputs other than Level 1 prices, such as quoted market prices for similar assets or liabilities in active markets, quoted market prices in markets that are not active or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. •Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the level in the fair value hierarchy must be determined based on the lowest level input that is significant to the fair value measurement. An assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and consideration of factors specific to the asset or liability. Our financial instruments include cash, cash equivalents, accounts receivable, customer notes receivable, investments in solar receivables, accounts payable, accrued expenses, long-term debt, interest rate swaps and caps and contingent consideration. 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 and based on quoted market prices in active markets for identical assets or liabilities that are accessible at the measurement date (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 investments in solar receivables based on a discounted cash flows model that utilizes market data related to solar irradiance, production factors by region and projected electric utility rates in order to build up revenue projections (Level 3). In addition, lease-related revenue and maintenance and service costs were supported through the use of available market studies and data. We estimate the fair value of our fixed-rate long-term debt based on an analysis of debt with similar book values, maturities and required market yields based on current interest rates (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 and counterparty credit risk as key inputs. The floating interest rate is based on observable rates consistent with the frequency of the interest cash flows (Level 2). For contingent consideration, we estimate the fair value of the installation earnout using the Monte Carlo model based on the forecasted placements for the installations and the microgrid earnout using a scenario-based methodology based on the probabilities of the microgrid earnout, both using Level 3 inputs. See Note 7, Customer Notes Receivable, Note 8, Investments in Solar Receivables, Note 9, Long-Term Debt, Note 10, Derivative Instruments and Note 12, Acquisitions.Changes in the fair value of our investments in solar receivables are included in other operating expense/income in the consolidated statements of operations. Changes in the fair value of our contingent consideration are included in other operating expense/income in the consolidated statements of operations.
Derivative Instruments	Derivative Instruments Our derivative instruments consist of interest rate swaps and caps that are not designated as cash flow hedges or fair value hedges. We use interest rate swaps and caps to manage our net exposure to interest rate changes. We record the derivatives in other assets, other current liabilities and other long-term liabilities, as appropriate, in the consolidated balance sheets and the changes in fair value are recorded in interest expense, net in the consolidated statements of operations. We include unrealized gains and losses on derivatives as a non-cash reconciling item in operating activities in the consolidated statements of cash flows. We include realized gains and losses on derivatives as a change in components of operating assets and liabilities in operating activities in the consolidated statements of cash flows. See Note 10, 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, net of cash incentives. 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 $3.3 billion as of December 31, 2022, 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. Certain customers may receive cash incentives. We defer recognition of the payment of these cash incentives and recognize them over the life of the contract as a reduction to revenue. The deferred payment is recorded in other assets for customers who receive the cash incentives under our lease and PPA agreements, and as a contra-liability in other long-term liabilities for customers who receive the cash incentives under our loan agreements. 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 20 or 25 years with an opportunity for customers to renew for up to an additional 10 years, via two five-year or one 10-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 20 or 25 years with an opportunity for customers to renew for up to an additional 10 years, via two five-year or one 10-year renewal options. In most cases, 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 related 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 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 as early as the first anniversary of the solar energy system's placed in service date and then every annual period thereafter. See Note 17, Commitments and Contingencies. Inventory Sales. Inventory sales revenue represents revenue from the direct sale of inventory to our dealers or other parties. We recognize the related revenue under ASC 606 upon shipment. Shipping and handling costs are included in cost of revenue—inventory sales in the consolidated statements of operations. Solar Renewable Energy Certificates. Each solar renewable energy certificate ("SREC") represents the environmental benefit of one megawatt hour (1,000 kWh) generated by a solar energy system. SRECs can be sold separate from the actual electricity generated by the renewable-based generation source. We account for the SRECs we generate from our solar energy systems as governmental incentives with no costs incurred to obtain them and do not consider those SRECs output of the underlying solar energy systems. We classify these SRECs as inventory held until sold and delivered to third parties. As we did not incur costs to obtain these governmental incentives, the inventory carrying value for the SRECs was $0 as of December 31, 2022 and 2021. We enter into economic hedges related to expected production of SRECs through forward contracts. While these fixed price forward contracts serve as an economic hedge against spot price fluctuations for the SRECs, the contracts do not qualify for hedge accounting and are not designated as cash flow hedges or fair value hedges. 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. Cash Sales. Cash sales revenue represents revenue from a customer's purchase of a solar energy system from us typically when purchasing a new home. We recognize the related revenue under ASC 606 upon verification of the home closing. 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 solar energy systems and energy storage systems to customers with financing provided by us and sales of service plans and repair services. 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 on a straight-line basis over the life of the contract, which is typically 10 years. We recognize revenue from repair services in the period in which the service was performed. 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 600 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. See Note 7, Customer Notes Receivable. Deferred Revenue Deferred revenue consists of amounts for which the criteria for revenue recognition have not yet been met and includes (a) payments for unfulfilled performance obligations which will be recognized on a straight-line basis over the remaining term of the respective solar service agreements, net of any cash incentives earned by the customers, (b) down payments and partial or full prepayments from customers and (c) differences due to the timing of energy production versus billing for certain types of PPAs.
Performance Guarantee Obligations	Performance Guarantee Obligations In most cases, we guarantee certain specified minimum solar energy production output under our leases and loan agreements, generally over a term between 10 and 25 years. The amounts are generally measured and credited to the customer's account as early as the first anniversary of the solar energy system's placed in service date and then every annual period thereafter. We monitor the solar energy systems to ensure these outputs are achieved. We evaluate if any amounts are due to our customers based upon not meeting the guaranteed solar energy production outputs at each reporting period end. For leases, these estimated amounts are recorded as a reduction to revenues from customers and a current or long-term liability, as applicable. For loans, these estimated amounts are recorded as an increase to cost of revenue—other and a current or long-term liability, as applicable. See Note 17, Commitments and Contingencies.
Property and Equipment	Property and Equipment Solar Energy Systems and Energy Storage Systems. Depreciation and amortization of solar energy systems and energy storage systems are calculated using the straight-line method over the estimated useful lives of the solar energy systems and energy storage systems and are recorded in cost of revenue—depreciation. While solar energy systems and energy storage systems are in the design, construction and installation stages prior to being placed in service, the development of the systems is accounted for through construction in progress. The components of the design, construction and installation of the solar energy systems and energy storage systems are as follows: •Dealer's costs (engineering, procurement and construction) •Direct costs (costs directly related to a solar energy system or energy storage system) •Indirect costs (costs incurred in the design, construction and installation of the solar energy system or energy storage system but not directly associated with a particular asset) Solar energy systems and energy storage systems are carried at the cost of acquisition or construction (including design and installation) less certain utility rebates and federal and state tax incentives (including federal investment tax credits, known as "Section 48(a) ITCs") and are depreciated over the useful lives of the assets. We account for the Section 48(a) ITCs in accordance with the deferral gross up method, thus reducing the cost basis of the qualifying solar energy systems and energy storage systems by the rate applicable to Section 48(a) ITCs. However, as discussed in Note 11, Income Taxes, we have a full valuation allowance, which is recorded against deferred income taxes and requires the gross up of the basis of the qualifying solar energy systems and energy storage systems back to the full value. Depreciation begins when a solar energy system or energy storage system is placed in service. Costs associated with repair and maintenance of a solar energy system or energy storage system are expensed as incurred. Costs associated with improvements to a solar energy system or energy storage system, which extend the life, increase the capacity or improve the efficiency of the systems, are capitalized and depreciated over the remaining life of the asset. Property and Equipment, Excluding Solar Energy Systems and Energy Storage Systems. Property and equipment, including information technology system projects, computers and equipment, leasehold improvements, furniture and fixtures, vehicles and other property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization are calculated using the straight-line method over the estimated useful lives of the respective assets and are recorded in general and administrative expense. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful lives. Upon disposition, the cost and related accumulated depreciation of the assets are removed from property and equipment and the resulting gain or loss is reflected in the consolidated statements of operations. Repair and maintenance costs are expensed as incurred.
Acquisitions	Acquisitions Business combinations are accounted for using the acquisition method of accounting in accordance with ASC 805, Business Combinations, as amended by Accounting Standards Update ("ASU") No. 2017-01, Business Combinations: Clarifying the Definition of a Business. The purchase price of an acquisition is measured at the estimated fair value of the assets acquired, equity instruments issued and liabilities assumed at the acquisition date. Any noncontrolling interests acquired are also initially measured at fair value. Costs that are directly attributable to the acquisition are expensed as incurred to general and administrative expense. We recognize goodwill if the aggregate fair value of the total purchase consideration and the noncontrolling interests is in excess of the aggregate fair value of the assets acquired and liabilities assumed. We may engage third-party valuation firms to assist in determining the fair values. The operating results of an acquired business are included in our results of operations from the date of acquisition. We have up to one year from the acquisition date to complete the fair value purchase price allocation. See Note 12, Acquisitions. Asset acquisitions are measured based on the cost to us, including transaction costs. Asset acquisition costs, or the consideration transferred by us, are assumed to be equal to the fair value of the net assets acquired. If the consideration transferred is cash, measurement is based on the amount of cash we paid to the seller, as well as transaction costs incurred. Consideration given in the form of non-monetary assets, liabilities incurred or equity instruments issued is measured based on either the cost to us or the fair value of the assets or net assets acquired, whichever is more clearly evident. The cost of an asset acquisition is allocated to the assets acquired based on their estimated fair values. Goodwill is not recognized in an asset acquisition.
Intangibles	IntangiblesOur purchased intangible assets are stated at cost less accumulated amortization. Our intangible assets acquired from a business combination or asset acquisition are stated at the estimated fair value on the date of the acquisition less accumulated amortization (see Note 12, Acquisitions). We amortize intangible assets to general and administrative expense using the straight-line method.
Goodwill	Goodwill Goodwill represents the excess of the purchase price over the fair value of assets acquired and liabilities assumed. The purchase price is allocated using the information currently available, and may be adjusted, up to one year from the acquisition date, after obtaining more information regarding, among other things, asset valuations, liabilities assumed and revisions to preliminary estimates. Goodwill is reviewed for impairment at least annually or whenever events or changes in circumstances indicate the carrying amount may be impaired. When assessing goodwill for impairment, we use qualitative and if necessary, quantitative methods in accordance with GAAP. In 2022, we utilized a qualitative assessment and concluded it was more likely than not the fair value was greater than the carrying amount. As such, no further testing is required.
Deferred Financing Costs	Deferred Financing Costs Deferred financing costs are capitalized and amortized to interest expense, net over the term of the related debt using the effective interest method for term loans or the straight-line method for revolving credit facilities. The unamortized balance of deferred financing costs is recorded in current portion of long-term debt, current portion of long-term debt—affiliates, long-term debt, net and long-term debt, net—affiliates (see Note 9, Long-Term Debt) for term loans or in other current assets and other assets for revolving credit facilities and debt and equity transactions not yet completed, in the consolidated balance sheets.
Asset Retirement Obligation ("ARO")	Asset Retirement Obligation ("ARO") We have AROs arising from contractual requirements to perform certain asset retirement activities at the time the solar energy systems are disposed. We recognize an ARO at the point an obligating event takes place, typically when the solar energy system is placed in service. An asset is considered retired when it is permanently taken out of service, such as through a sale or disposal. The liability is initially measured at fair value (as a Level 3 measurement) based on the present value of estimated removal and restoration costs and subsequently adjusted for changes in the underlying assumptions and for accretion expense. The accretion expense is recognized in general and administrative expense in the consolidated statements of operations. The corresponding asset retirement costs are capitalized as part of the carrying amount of the solar energy system and depreciated over the solar energy system's remaining useful life. See Note 6, AROs.
Warranty Obligations	Warranty Obligations In connection with our solar service agreements, we warrant the solar energy systems against defects in workmanship, against component or materials breakdowns and against any damages to rooftops during the installation process. The dealers' warranties on the workmanship, including work during the installation process, and the manufacturers' warranties over component parts have a range of warranty periods which are generally 10 to 25 years. As of December 31, 2022 and 2021, a warranty reserve of $3.0 million and $815,000, respectively, is recorded in other long-term liabilities in the consolidated balance sheets.
Advertising Costs	Advertising CostsWe expense advertising costs as they are incurred to general and administrative expense in the consolidated statements of operations
Defined Contribution Plan	Defined Contribution Plan In April 2015, we established the Sunnova Energy Corporation 401(k) Profit Sharing Plan ("401(k) plan") available to employees who meet the 401(k) plan's eligibility requirements. The 401(k) plan allows participants to contribute a percentage of their compensation to the 401(k) plan up to the limits set forth in the Internal Revenue Code. We may make additional discretionary contributions to the 401(k) plan as a percentage of total participant contributions, subject to established limits. Participants are fully vested in their contributions and any safe harbor matching contributions we make. We made safe harbor matching contributions of $1.8 million, $1.3 million and $820,000 during the years ended December 31, 2022, 2021 and 2020, respectively, which are recorded in general and administrative expense in the consolidated statements of operations.
Income Taxes	Income Taxes We account for income taxes under an asset and liability approach. Deferred income taxes reflect the impact of temporary differences between assets and liabilities recognized for financial reporting purposes and the amounts recognized for income tax reporting purposes, net operating loss, carryforwards, and other tax credits measured by applying currently enacted tax laws. A valuation allowance is provided when necessary to reduce deferred tax assets to an amount that is more likely than not to be realized. We determine whether a tax position taken in a filed tax return, planned to be taken in a future tax return or claim, or otherwise subject to interpretation, is more likely than not to be sustained upon examination, including resolution of any related appeals or litigation processes, based on the technical merits of the position, or prospectively approved when such approval may be sought in advance. We use a two-step approach to recognize and measure uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the available evidence indicates it is more likely than not the position will be sustained upon tax authority examination, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit or obligation as the largest amount that is more than 50% likely of being realized upon ultimate settlement. See Note 11, Income Taxes.
Comprehensive Income (Loss)	Comprehensive Income (Loss) We are required to report comprehensive income (loss), which includes net income (loss) as well as other comprehensive income (loss). There were no differences between comprehensive loss and net loss as reported in the consolidated statements of operations for the periods presented.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets Long-lived assets, such as property and equipment, are reviewed for impairment whenever events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset be tested for possible impairment, we first compare undiscounted cash flows expected to be generated by that asset or asset group to its carrying value. If the carrying value of the long-lived asset or asset group is not recoverable on an undiscounted cash flow basis, impairment is recognized to the extent the carrying value exceeds its fair value. Fair value is determined through various valuation techniques including discounted cash flow models, quoted market values and third-party independent appraisals as considered necessary. Impairment charges are recorded in operations and maintenance expense for solar energy systems that relate to revenue from contracts with customers and general and administrative expense for all other property and equipment and other long-lived assets.
Segment Information	Segment Information Operating segments are defined as components of a company about which separate financial information is available that is evaluated regularly by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. Our chief operating decision maker is the chief executive officer. Based on the financial information presented to and reviewed by our chief operating decision maker in deciding how to allocate resources and in assessing performance, we have determined we have a single reportable segment: solar energy products and services. Our principal operations, revenue and decision-making functions are located in the U.S.
Basic and Diluted Net Income (Loss) Per Share	Basic and Diluted Net Income (Loss) Per Share Our basic net income (loss) per share attributable to stockholders is calculated by dividing the net income (loss) attributable to stockholders by the weighted-average number of shares of common stock outstanding for the period. Our diluted net income (loss) per share attributable to stockholders is calculated by giving effect to all potential common stock equivalents outstanding for the period determined using the treasury stock method or the if-converted method, as applicable. During periods in which we incur a net loss attributable to stockholders, stock options and restricted stock units are considered to be common stock equivalents but are excluded from the calculation of diluted net loss per share attributable to stockholders as the effect is antidilutive. See Note 16, Basic and Diluted Net Loss Per Share.
Equity-Based Compensation	Equity-Based Compensation We account for equity-based compensation, which requires the measurement and recognition of compensation expense related to the fair value of equity-based compensation awards. Equity-based compensation expense includes the compensation cost for all share-based awards granted to employees, consultants and members of our board of directors (our "Board") based on the grant date fair value estimate. This also applies to awards modified, repurchased or canceled during the periods reported. We use the Black-Scholes option-pricing model to measure the fair value of stock options at the measurement date. We use the closing price of our common stock on the grant date to measure the fair value of restricted stock units at the measurement date. We account for forfeitures as they occur. Equity-based compensation expense is recorded in general and administrative expense in the consolidated statements of operations. See Note 15, Equity-Based Compensation.
Redeemable Noncontrolling Interests and Noncontrolling Interests	Redeemable Noncontrolling Interests and Noncontrolling Interests Noncontrolling interests represent third-party interests in the net assets of certain consolidated subsidiaries (the "tax equity entities"). For these tax equity entities, we have determined the appropriate methodology for calculating the noncontrolling interest balances that reflects the substantive economic arrangements in the operating agreements is a balance sheet approach using the hypothetical liquidation at book value ("HLBV") method. Under the HLBV method, the amounts reported as noncontrolling interests in the consolidated balance sheets represent the amounts third-party investors would hypothetically receive at each balance sheet date under the liquidation provisions of the operating agreements, assuming the net assets of the subsidiaries were liquidated at amounts determined in accordance with GAAP and distributed to the investors. The noncontrolling interest balances in these subsidiaries are reported as a component of equity in the consolidated balance sheets. The amount of income or loss allocated to noncontrolling interests in the results of operations for the subsidiaries using HLBV are determined as the difference in the noncontrolling interest balances in the consolidated balance sheets at the start and end of each reporting period, after taking into account any capital transactions between the subsidiaries and the third-party investors. Factors used in the HLBV calculation include GAAP income (loss), taxable income (loss), capital contributions, investment tax credits, distributions and the stipulated targeted investor return specified in the subsidiaries' operating agreements. Changes in these factors could have a significant impact on the amounts that investors would receive upon a hypothetical liquidation. The use of the HLBV method to allocate income (loss) to the noncontrolling interest holders may create volatility in the consolidated statements of operations as the application of HLBV can drive changes in net income or loss attributable to noncontrolling interests from period to period. We classify certain noncontrolling interests with redemption features that are not solely within our control outside of permanent equity in the consolidated balance sheets. Redeemable noncontrolling interests are reported using the greater of the carrying value at each reporting date as determined by the HLBV method or the estimated redemption value at the end of each reporting period. Estimating the redemption value of the redeemable noncontrolling interests requires the use of significant assumptions and estimates, such as projected future cash flows at the time the redemption feature can be exercised. The redeemable noncontrolling interests and noncontrolling interests are recorded net of related issuance costs and net of the basis difference in the solar energy systems transferred to the tax equity entities in the consolidated balance sheets. This basis difference is reflected as equity in subsidiaries attributable to parent in the consolidated statements of redeemable noncontrolling interests and equity.
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 March 2022, the FASB issued Accounting Standards Update ("ASU") No. 2022-02, Financial Instruments—Credit Losses: Troubled Debt Restructurings and Vintage Disclosures, to eliminate the accounting guidance for troubled debt restructurings while enhancing disclosure requirements for certain loan refinancings and restructurings by creditors when a borrower is experiencing financial difficulty. This ASU is effective for annual and interim reporting periods beginning in January 2023. We adopted this ASU in January 2023 and determined it did not have a significant impact on our consolidated financial statements and related disclosures.

Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2022

The accompanying annual audited consolidated financial statements ("consolidated financial statements") include our consolidated balance sheets, statements of operations, statements of redeemable noncontrolling interests and equity and statements of cash flows and have been prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") from records maintained by us. Our consolidated financial statements include our accounts and those of our subsidiaries in which we have a controlling financial interest. In accordance with the provisions of the Financial Accounting Standards Board ("FASB") Accounting Standards Codification ("ASC") 810, Consolidation, we consolidate any VIE of which we are the primary beneficiary. We form VIEs with our investors in the ordinary course of business to facilitate the funding and monetization of certain attributes associated with our solar energy systems. The typical condition for a controlling financial interest is holding a majority of the voting interests of an entity. However, a controlling financial interest may also exist in entities, such as VIEs, through arrangements that do not involve holding a majority of the voting interests. 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.

Reclassifications

Certain prior period amounts have been reclassified to conform to the current period presentation. These reclassifications did not have a significant impact on our consolidated financial statements.

Use of Estimates

The application of GAAP in the preparation of the consolidated financial statements requires us to make estimates and assumptions that affect the amounts reported in the consolidated financial statements and accompanying notes. We base our estimates on historical experience and on various other assumptions believed to be reasonable, the results of which form the basis for making judgments about the carrying values of assets and liabilities. Actual results could differ materially from those estimates.

Cash and Cash Equivalents

We maintain cash and cash equivalents, which consists principally of demand deposits, with investment-grade financial institutions. We are exposed to credit risk to the extent cash and cash equivalents balances exceed amounts covered by the Federal Deposit Insurance Corporation ("FDIC"). As of December 31, 2022 and 2021, we had cash and cash equivalents deposits of $337.5 million and $225.7 million, respectively, in excess of the FDIC's current insured limit of $250,000. We have not experienced any losses on our deposits of cash and cash equivalents.

Restricted Cash

Restricted CashWe record cash that is restricted as to withdrawal or use under the terms of certain contractual agreements as restricted cash. Our restricted cash primarily represents cash held to service certain payments under the Sunnova EZ-Own Portfolio, LLC ("EZOP"), Sunnova TEP Holdings, LLC ("TEPH"), Helios II Issuer, LLC ("HELII"), Helios III Issuer, LLC ("HELIII"), Sunnova RAYS I Issuer, LLC ("RAYSI"), Sunnova Sol Issuer, LLC ("SOLI"), Sunnova Helios IV Issuer, LLC ("HELIV"), Sunnova TEP IV-G, LLC ("TEPIVG"), Sunnova Asset Portfolio 8, LLC ("AP8"), Sunnova Sol II Issuer, LLC ("SOLII"), Sunnova Helios V Issuer, LLC ("HELV"), Sunnova Helios VI Issuer, LLC ("HELVI"), Sunnova Helios VII Issuer, LLC ("HELVII"), Sunnova TEP V-A, LLC ("TEPVA"), Sunnova TEP V-B, LLC ("TEPVB"), Sunnova TEP V-C, LLC ("TEPVC"), Sunnova TEP 6-B, LLC ("TEP6B"), Sunnova Sol III Issuer, LLC ("SOLIII"), Sunnova Helios VIII Issuer, LLC ("HELVIII"), Sunnova Helios IX Issuer, LLC ("HELIX"), Sunnova Sol IV Issuer, LLC ("SOLIV"), Sunnova Helios X Issuer, LLC ("HELX"), Sunnova TEP 7-A, LLC ("TEP7A"), Sunnova TEP 7-B, LLC ("TEP7B"), Sunnova TEP 7-C, LLC ("TEP7C") and Sunnova TEP 7-D, LLC ("TEP7D") financing arrangements (see Note 9, Long-Term Debt and Note 13, Redeemable Noncontrolling Interests and Noncontrolling Interests) and balances collateralizing outstanding letters of credit related to a reinsurance agreement and one of our operating leases for office space (see Note 17, Commitments and Contingencies).

Accounts Receivable

Accounts ReceivableAccounts Receivable—Trade. Accounts receivable—trade primarily represents trade receivables from 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.Accounts Receivable—Other. Accounts receivable—other primarily represents receivables from our dealers or other parties related to the sale of inventory and the use of inventory procured by us.

Inventory

InventoryInventory is stated at the lower of cost and net realizable value using the first-in, first-out method. Inventory primarily represents (a) raw materials, such as energy storage systems, photovoltaic modules, inverters, meters and modems, (b) homebuilder construction in progress and (c) other associated equipment purchased. These materials are typically procured by us and used by our dealers, sold to our 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) recognize in accounts receivable—other when procured by us and used by our dealers, (c) expense to cost of revenue—inventory sales if sold directly to a dealer or other party, (d) capitalize to property and equipment when installed on an existing home or business or (e) capitalize to property and equipment when placed in service under the homebuilder program. 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 net realizable value.

Concentrations of Risk

Financial instruments that potentially subject us to concentrations of credit risk consist primarily of cash, cash equivalents, restricted cash, accounts receivable and notes receivable. The concentrated risk associated with cash, cash equivalents and restricted cash is mitigated by our policy of banking with creditworthy institutions. Typically, amounts on deposit with certain banking institutions exceed FDIC insurance limits. We do not generally require collateral or other security

to support accounts receivable. To reduce credit risk related to our relationship with our dealers, management performs periodic credit evaluations and ongoing assessments of our dealers' financial condition.

Dealer Commitments

We enter into exclusivity and other similar agreements with certain key dealers pursuant to which we agree to pay an incentive if such dealers install a certain minimum number of solar energy systems within specified periods. These incentives are recorded in other assets in the consolidated balance sheets and are amortized to general and administrative expense in the consolidated statements of operations generally over the term of the customer agreements, which is estimated at an average of 23 years. See Note 17, Commitments and Contingencies.

Fair Value of Financial Instruments

Fair value is an exit price representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. As such, fair value is a market-based measurement that should be determined based on assumptions market participants would use in pricing an asset or a liability. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. ASC 820 establishes a three-tier fair value hierarchy, which prioritizes inputs that may be used to measure fair value as follows:

•Level 1—Observable inputs that reflect unadjusted quoted market prices in active markets for identical assets or liabilities that are accessible at the measurement date.

•Level 2—Observable inputs other than Level 1 prices, such as quoted market prices for similar assets or liabilities in active markets, quoted market prices in markets that are not active or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

•Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

In certain cases, the inputs used to measure fair value may fall into different levels of the fair value hierarchy. In such cases, the level in the fair value hierarchy must be determined based on the lowest level input that is significant to the fair value measurement. An assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and consideration of factors specific to the asset or liability. Our financial instruments include cash, cash equivalents, accounts receivable, customer notes receivable, investments in solar receivables, accounts payable, accrued expenses, long-term debt, interest rate swaps and caps and contingent consideration. 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 and based on quoted market prices in active markets for identical assets or liabilities that are accessible at the measurement date (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 investments in solar receivables based on a discounted cash flows model that utilizes market data related to solar irradiance, production factors by region and projected electric utility rates in order to build up revenue projections (Level 3). In addition, lease-related revenue and maintenance and service costs were supported through the use of available market studies and data. We estimate the fair value of our fixed-rate long-term debt based on an analysis of debt with similar book values, maturities and required market yields based on current interest rates (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 and counterparty credit risk as key inputs. The floating interest rate is based on observable rates consistent with the frequency of the interest cash flows (Level 2). For contingent consideration, we estimate the fair value of the installation earnout using the Monte Carlo model based on the forecasted placements for the installations and the

microgrid earnout using a scenario-based methodology based on the probabilities of the microgrid earnout, both using Level 3 inputs. See Note 7, Customer Notes Receivable, Note 8, Investments in Solar Receivables, Note 9, Long-Term Debt, Note 10, Derivative Instruments and Note 12, Acquisitions.Changes in the fair value of our investments in solar receivables are included in other operating expense/income in the consolidated statements of operations. Changes in the fair value of our contingent consideration are included in other operating expense/income in the consolidated statements of operations.

Derivative Instruments

Our derivative instruments consist of interest rate swaps and caps that are not designated as cash flow hedges or fair value hedges. We use interest rate swaps and caps to manage our net exposure to interest rate changes. We record the derivatives in other assets, other current liabilities and other long-term liabilities, as appropriate, in the consolidated balance sheets and the changes in fair value are recorded in interest expense, net in the consolidated statements of operations. We include unrealized gains and losses on derivatives as a non-cash reconciling item in operating activities in the consolidated statements of cash flows. We include realized gains and losses on derivatives as a change in components of operating assets and liabilities in operating activities in the consolidated statements of cash flows. See Note 10, 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, net of cash incentives. 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 $3.3 billion as of December 31, 2022, 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.

Certain customers may receive cash incentives. We defer recognition of the payment of these cash incentives and recognize them over the life of the contract as a reduction to revenue. The deferred payment is recorded in other assets for customers who receive the cash incentives under our lease and PPA agreements, and as a contra-liability in other long-term liabilities for customers who receive the cash incentives under our loan agreements.

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 20 or 25 years with an opportunity for customers to renew for up to an additional 10 years, via two five-year or one 10-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 20 or 25 years with an opportunity for customers to renew for up to an additional 10 years, via two five-year or one 10-year renewal options.

In most cases, 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 related 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 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 as early as the first anniversary of the solar energy system's placed in service date and then every annual period thereafter. See Note 17, Commitments and Contingencies.

Inventory Sales. Inventory sales revenue represents revenue from the direct sale of inventory to our dealers or other parties. We recognize the related revenue under ASC 606 upon shipment. Shipping and handling costs are included in cost of revenue—inventory sales in the consolidated statements of operations.

Solar Renewable Energy Certificates. Each solar renewable energy certificate ("SREC") represents the environmental benefit of one megawatt hour (1,000 kWh) generated by a solar energy system. SRECs can be sold separate from the actual electricity generated by the renewable-based generation source. We account for the SRECs we generate from our solar energy systems as governmental incentives with no costs incurred to obtain them and do not consider those SRECs output of the underlying solar energy systems. We classify these SRECs as inventory held until sold and delivered to third parties. As we did not incur costs to obtain these governmental incentives, the inventory carrying value for the SRECs was $0 as of December 31, 2022 and 2021. We enter into economic hedges related to expected production of SRECs through forward contracts. While these fixed price forward contracts serve as an economic hedge against spot price fluctuations for the SRECs, the contracts do not qualify for hedge accounting and are not designated as cash flow hedges or fair value hedges. 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.

Cash Sales. Cash sales revenue represents revenue from a customer's purchase of a solar energy system from us typically when purchasing a new home. We recognize the related revenue under ASC 606 upon verification of the home closing.

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 solar energy systems and energy storage systems to customers with financing provided by us and sales of service plans and repair services. 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 on a straight-line basis over the life of the contract, which is typically 10 years. We recognize revenue from repair services in the period in which the service was performed.

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 600 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. See Note 7, Customer Notes Receivable.

Deferred Revenue

Deferred revenue consists of amounts for which the criteria for revenue recognition have not yet been met and includes (a) payments for unfulfilled performance obligations which will be recognized on a straight-line basis over the remaining term of the respective solar service agreements, net of any cash incentives earned by the customers, (b) down payments and partial or full prepayments from customers and (c) differences due to the timing of energy production versus billing for certain types of PPAs.

Performance Guarantee Obligations

In most cases, we guarantee certain specified minimum solar energy production output under our leases and loan agreements, generally over a term between 10 and 25 years. The amounts are generally measured and credited to the customer's account as early as the first anniversary of the solar energy system's placed in service date and then every annual period thereafter. We monitor the solar energy systems to ensure these outputs are achieved. We evaluate if any amounts are due to our customers based upon not meeting the guaranteed solar energy production outputs at each reporting period end. For leases,

these estimated amounts are recorded as a reduction to revenues from customers and a current or long-term liability, as applicable. For loans, these estimated amounts are recorded as an increase to cost of revenue—other and a current or long-term liability, as applicable. See Note 17, Commitments and Contingencies.

Property and Equipment

Solar Energy Systems and Energy Storage Systems. Depreciation and amortization of solar energy systems and energy storage systems are calculated using the straight-line method over the estimated useful lives of the solar energy systems and energy storage systems and are recorded in cost of revenue—depreciation. While solar energy systems and energy storage systems are in the design, construction and installation stages prior to being placed in service, the development of the systems is accounted for through construction in progress. The components of the design, construction and installation of the solar energy systems and energy storage systems are as follows:

•Dealer's costs (engineering, procurement and construction)

•Direct costs (costs directly related to a solar energy system or energy storage system)

•Indirect costs (costs incurred in the design, construction and installation of the solar energy system or energy storage system but not directly associated with a particular asset)

Solar energy systems and energy storage systems are carried at the cost of acquisition or construction (including design and installation) less certain utility rebates and federal and state tax incentives (including federal investment tax credits, known as "Section 48(a) ITCs") and are depreciated over the useful lives of the assets. We account for the Section 48(a) ITCs in accordance with the deferral gross up method, thus reducing the cost basis of the qualifying solar energy systems and energy storage systems by the rate applicable to Section 48(a) ITCs. However, as discussed in Note 11, Income Taxes, we have a full valuation allowance, which is recorded against deferred income taxes and requires the gross up of the basis of the qualifying solar energy systems and energy storage systems back to the full value. Depreciation begins when a solar energy system or energy storage system is placed in service. Costs associated with repair and maintenance of a solar energy system or energy storage system are expensed as incurred. Costs associated with improvements to a solar energy system or energy storage system, which extend the life, increase the capacity or improve the efficiency of the systems, are capitalized and depreciated over the remaining life of the asset.

Property and Equipment, Excluding Solar Energy Systems and Energy Storage Systems. Property and equipment, including information technology system projects, computers and equipment, leasehold improvements, furniture and fixtures, vehicles and other property and equipment are stated at cost, less accumulated depreciation and amortization. Depreciation and amortization are calculated using the straight-line method over the estimated useful lives of the respective assets and are recorded in general and administrative expense. Leasehold improvements are amortized over the shorter of the lease term or the estimated useful lives. Upon disposition, the cost and related accumulated depreciation of the assets are removed from property and equipment and the resulting gain or loss is reflected in the consolidated statements of operations. Repair and maintenance costs are expensed as incurred.

Acquisitions

Business combinations are accounted for using the acquisition method of accounting in accordance with ASC 805, Business Combinations, as amended by Accounting Standards Update ("ASU") No. 2017-01, Business Combinations: Clarifying the Definition of a Business. The purchase price of an acquisition is measured at the estimated fair value of the assets acquired, equity instruments issued and liabilities assumed at the acquisition date. Any noncontrolling interests acquired are also initially measured at fair value. Costs that are directly attributable to the acquisition are expensed as incurred to general and administrative expense. We recognize goodwill if the aggregate fair value of the total purchase consideration and the noncontrolling interests is in excess of the aggregate fair value of the assets acquired and liabilities assumed. We may engage third-party valuation firms to assist in determining the fair values. The operating results of an acquired business are included in our results of operations from the date of acquisition. We have up to one year from the acquisition date to complete the fair value purchase price allocation. See Note 12, Acquisitions.

Asset acquisitions are measured based on the cost to us, including transaction costs. Asset acquisition costs, or the consideration transferred by us, are assumed to be equal to the fair value of the net assets acquired. If the consideration transferred is cash, measurement is based on the amount of cash we paid to the seller, as well as transaction costs incurred. Consideration given in the form of non-monetary assets, liabilities incurred or equity instruments issued is measured based on either the cost to us or the fair value of the assets or net assets acquired, whichever is more clearly evident. The cost of an asset acquisition is allocated to the assets acquired based on their estimated fair values. Goodwill is not recognized in an asset acquisition.

Intangibles

IntangiblesOur purchased intangible assets are stated at cost less accumulated amortization. Our intangible assets acquired from a business combination or asset acquisition are stated at the estimated fair value on the date of the acquisition less accumulated amortization (see Note 12, Acquisitions). We amortize intangible assets to general and administrative expense using the straight-line method.

Goodwill

Goodwill represents the excess of the purchase price over the fair value of assets acquired and liabilities assumed. The purchase price is allocated using the information currently available, and may be adjusted, up to one year from the acquisition date, after obtaining more information regarding, among other things, asset valuations, liabilities assumed and revisions to preliminary estimates. Goodwill is reviewed for impairment at least annually or whenever events or changes in circumstances indicate the carrying amount may be impaired. When assessing goodwill for impairment, we use qualitative and if necessary, quantitative methods in accordance with GAAP. In 2022, we utilized a qualitative assessment and concluded it was more likely than not the fair value was greater than the carrying amount. As such, no further testing is required.

Deferred Financing Costs

Deferred financing costs are capitalized and amortized to interest expense, net over the term of the related debt using the effective interest method for term loans or the straight-line method for revolving credit facilities. The unamortized balance of deferred financing costs is recorded in current portion of long-term debt, current portion of long-term debt—affiliates, long-term debt, net and long-term debt, net—affiliates (see Note 9, Long-Term Debt) for term loans or in other current assets and

other assets for revolving credit facilities and debt and equity transactions not yet completed, in the consolidated balance sheets.

Asset Retirement Obligation ("ARO")

We have AROs arising from contractual requirements to perform certain asset retirement activities at the time the solar energy systems are disposed. We recognize an ARO at the point an obligating event takes place, typically when the solar energy system is placed in service. An asset is considered retired when it is permanently taken out of service, such as through a sale or disposal.

The liability is initially measured at fair value (as a Level 3 measurement) based on the present value of estimated removal and restoration costs and subsequently adjusted for changes in the underlying assumptions and for accretion expense. The accretion expense is recognized in general and administrative expense in the consolidated statements of operations. The corresponding asset retirement costs are capitalized as part of the carrying amount of the solar energy system and depreciated over the solar energy system's remaining useful life. See Note 6, AROs.

Warranty Obligations

In connection with our solar service agreements, we warrant the solar energy systems against defects in workmanship, against component or materials breakdowns and against any damages to rooftops during the installation process. The dealers' warranties on the workmanship, including work during the installation process, and the manufacturers' warranties over component parts have a range of warranty periods which are generally 10 to 25 years. As of December 31, 2022 and 2021, a warranty reserve of $3.0 million and $815,000, respectively, is recorded in other long-term liabilities in the consolidated balance sheets.

Advertising Costs

Advertising CostsWe expense advertising costs as they are incurred to general and administrative expense in the consolidated statements of operations

Defined Contribution Plan

In April 2015, we established the Sunnova Energy Corporation 401(k) Profit Sharing Plan ("401(k) plan") available to employees who meet the 401(k) plan's eligibility requirements. The 401(k) plan allows participants to contribute a percentage of their compensation to the 401(k) plan up to the limits set forth in the Internal Revenue Code. We may make additional discretionary contributions to the 401(k) plan as a percentage of total participant contributions, subject to established limits. Participants are fully vested in their contributions and any safe harbor matching contributions we make. We made safe harbor matching contributions of $1.8 million, $1.3 million and $820,000 during the years ended December 31, 2022, 2021 and 2020, respectively, which are recorded in general and administrative expense in the consolidated statements of operations.

Income Taxes

We account for income taxes under an asset and liability approach. Deferred income taxes reflect the impact of temporary differences between assets and liabilities recognized for financial reporting purposes and the amounts recognized for income tax reporting purposes, net operating loss, carryforwards, and other tax credits measured by applying currently enacted tax laws. A valuation allowance is provided when necessary to reduce deferred tax assets to an amount that is more likely than not to be realized.

We determine whether a tax position taken in a filed tax return, planned to be taken in a future tax return or claim, or otherwise subject to interpretation, is more likely than not to be sustained upon examination, including resolution of any related appeals or litigation processes, based on the technical merits of the position, or prospectively approved when such approval may be sought in advance. We use a two-step approach to recognize and measure uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the available evidence indicates it is more likely than not the position will be sustained upon tax authority examination, including resolution of related appeals or litigation processes, if any. The second step is to measure the tax benefit or obligation as the largest amount that is more than 50% likely of being realized upon ultimate settlement. See Note 11, Income Taxes.

Comprehensive Income (Loss)

We are required to report comprehensive income (loss), which includes net income (loss) as well as other comprehensive income (loss). There were no differences between comprehensive loss and net loss as reported in the consolidated statements of operations for the periods presented.

Impairment of Long-Lived Assets

Long-lived assets, such as property and equipment, are reviewed for impairment whenever events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. If circumstances require a long-lived asset be tested for possible impairment, we first compare undiscounted cash flows expected to be generated by that asset or asset group to its carrying value. If the carrying value of the long-lived asset or asset group is not recoverable on an undiscounted cash flow basis, impairment is recognized to the extent the carrying value exceeds its fair value. Fair value is determined through various valuation techniques including discounted cash flow models, quoted market values and third-party independent appraisals as considered necessary. Impairment charges are recorded in operations and maintenance expense for solar energy systems that relate to revenue from contracts with customers and general and administrative expense for all other property and equipment and other long-lived assets.

Segment Information

Operating segments are defined as components of a company about which separate financial information is available that is evaluated regularly by the chief operating decision maker, or decision-making group, in deciding how to allocate resources and in assessing performance. Our chief operating decision maker is the chief executive officer. Based on the financial information presented to and reviewed by our chief operating decision maker in deciding how to allocate resources and in assessing performance, we have determined we have a single reportable segment: solar energy products and services. Our principal operations, revenue and decision-making functions are located in the U.S.

Basic and Diluted Net Income (Loss) Per Share

Our basic net income (loss) per share attributable to stockholders is calculated by dividing the net income (loss) attributable to stockholders by the weighted-average number of shares of common stock outstanding for the period. Our diluted net income (loss) per share attributable to stockholders is calculated by giving effect to all potential common stock equivalents outstanding for the period determined using the treasury stock method or the if-converted method, as applicable. During periods in which we incur a net loss attributable to stockholders, stock options and restricted stock units are considered to be common stock equivalents but are excluded from the calculation of diluted net loss per share attributable to stockholders as the effect is antidilutive. See Note 16, Basic and Diluted Net Loss Per Share.

Equity-Based Compensation

We account for equity-based compensation, which requires the measurement and recognition of compensation expense related to the fair value of equity-based compensation awards. Equity-based compensation expense includes the compensation cost for all share-based awards granted to employees, consultants and members of our board of directors (our "Board") based on the grant date fair value estimate. This also applies to awards modified, repurchased or canceled during the periods reported. We use the Black-Scholes option-pricing model to measure the fair value of stock options at the measurement date. We use the closing price of our common stock on the grant date to measure the fair value of restricted stock units at the measurement date. We account for forfeitures as they occur. Equity-based compensation expense is recorded in general and administrative expense in the consolidated statements of operations. See Note 15, Equity-Based Compensation.

Redeemable Noncontrolling Interests and Noncontrolling Interests

Noncontrolling interests represent third-party interests in the net assets of certain consolidated subsidiaries (the "tax equity entities"). For these tax equity entities, we have determined the appropriate methodology for calculating the noncontrolling interest balances that reflects the substantive economic arrangements in the operating agreements is a balance sheet approach using the hypothetical liquidation at book value ("HLBV") method. Under the HLBV method, the amounts reported as noncontrolling interests in the consolidated balance sheets represent the amounts third-party investors would hypothetically receive at each balance sheet date under the liquidation provisions of the operating agreements, assuming the net assets of the subsidiaries were liquidated at amounts determined in accordance with GAAP and distributed to the investors. The noncontrolling interest balances in these subsidiaries are reported as a component of equity in the consolidated balance sheets. The amount of income or loss allocated to noncontrolling interests in the results of operations for the subsidiaries using HLBV are determined as the difference in the noncontrolling interest balances in the consolidated balance sheets at the start and end of each reporting period, after taking into account any capital transactions between the subsidiaries and the third-party investors. Factors used in the HLBV calculation include GAAP income (loss), taxable income (loss), capital contributions, investment tax credits, distributions and the stipulated targeted investor return specified in the subsidiaries' operating agreements. Changes in these factors could have a significant impact on the amounts that investors would receive upon a hypothetical liquidation. The use of the HLBV method to allocate income (loss) to the noncontrolling interest holders may create volatility in the consolidated statements of operations as the application of HLBV can drive changes in net income or loss attributable to noncontrolling interests from period to period. We classify certain noncontrolling interests with redemption features that are not solely within our control outside of permanent equity in the consolidated balance sheets. Redeemable noncontrolling interests are reported using the greater of the carrying value at each reporting date as determined by the HLBV method or the estimated redemption value at the end of each reporting period. Estimating the redemption value of the redeemable noncontrolling interests requires the use of significant assumptions and estimates, such as projected future cash flows at the time the redemption feature can be exercised. The redeemable noncontrolling interests and noncontrolling interests are recorded net of related issuance costs and net of the basis difference in the solar energy systems transferred to the tax equity entities in the consolidated balance sheets. This basis difference is reflected as equity in subsidiaries attributable to parent in the consolidated statements of redeemable noncontrolling interests and equity.

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 March 2022, the FASB issued Accounting Standards Update ("ASU") No. 2022-02, Financial Instruments—Credit Losses: Troubled Debt Restructurings and Vintage Disclosures, to eliminate the accounting guidance for troubled debt restructurings while enhancing disclosure requirements for certain loan refinancings and restructurings by creditors when a borrower is experiencing financial difficulty. This ASU is effective for annual and interim reporting periods beginning in January 2023. We adopted this ASU in January 2023 and determined it did not have a significant impact on our consolidated financial statements and related disclosures.