NOVA Sunnova Energy International Inc

As filed with the Securities and Exchange Commission on July 27, 2023

Registration Statement No. 333-            

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-3

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

Sunnova Energy International Inc.

(Exact name of registrant as specified in its charter)

20 East Greenway Plaza, Suite 540

Houston, Texas 77046

Tel: (281) 892-1588

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

David Searle

Executive Vice President, General Counsel

Sunnova Energy International Inc.

20 East Greenway Plaza, Suite 540

Houston, Texas 77046

Tel: (281) 892-1588

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Travis J. Wofford

Douglas V. Getten

Baker Botts L.L.P.

910 Louisiana Street

Houston, Texas 77002

Tel: (713) 229-1234

Approximate date of commencement of proposed sale to the public: From time to time after this registration statement becomes effective.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box:  ☐

If any of the securities being registered on this Form are being offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box:  ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box.  ☒

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box.  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of Securities Act.  ☐

PROSPECTUS

SUNNOVA ENERGY INTERNATIONAL INC.

Common Stock

Preferred Stock

Debt Securities

Rights

Warrants

Depositary Shares

Purchase Contracts

Purchase Units

Units

We may offer and sell from time to time, together or separately, in one or more offerings, any combination of the securities listed above (collectively, the “securities”). The securities we may offer may be convertible into or exercisable or exchangeable for other securities.

In addition, the selling securityholders named in any supplement to this prospectus (the “selling securityholders”) may offer and sell any combination of the securities.

We and/or the selling securityholders may offer and sell these securities to or through one or more underwriters, dealers and agents, or directly to one or more purchasers, on a continuous or delayed basis.

This prospectus provides you with a general description of these securities and the general manner in which we or the selling securityholders will offer and sell the securities. Each time we or the selling securityholders offer and sell securities under this prospectus, we or the selling securityholders will provide a prospectus supplement that will contain specific information about the terms of that offering and the securities being offered. A prospectus supplement also may add, update or change information contained in this prospectus. You should carefully read this prospectus and any accompanying prospectus supplement before you invest in any of our securities. You should also read the documents we have referred you to in the “Where You Can Find More Information” section of this prospectus for information about us, including our financial statements.

We will not receive any proceeds from the sales by the selling securityholders of our securities. For a more detailed discussion about the selling securityholders, please read “Selling Securityholders.”

Our common stock trades on the New York Stock Exchange (the “NYSE”) under the symbol “NOVA.”

Investing in our securities involves risks. You should carefully review the risks and uncertainties described under the heading “Risk Factors” contained on page 6 herein and in any applicable prospectus supplement and under similar headings in the other documents incorporated by reference into this prospectus.

NEITHER THE SECURITIES AND EXCHANGE COMMISSION (THE “SEC”) NOR ANY STATE SECURITIES COMMISSION HAS APPROVED OR DISAPPROVED OF THESE SECURITIES OR DETERMINED IF THIS PROSPECTUS IS TRUTHFUL OR COMPLETE. ANY REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.

The date of this prospectus is July 27, 2023

TABLE OF CONTENTS

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ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement on Form S-3 that we have filed with the SEC using a “shelf” registration process. Under this shelf registration process, we and/or the selling securityholders may offer and sell from time to time, together or separately, in one or more offerings, any combination of the securities described in this prospectus.

This prospectus provides you with a general description of us and the securities offered under this prospectus. Each time we or the selling securityholders offer to sell securities under this prospectus, we or the selling securityholders will provide a prospectus supplement that will contain specific information about the terms of that offering and the securities being offered. A prospectus supplement also may add, update or change information in this prospectus. If there is any inconsistency between the information in this prospectus and any prospectus supplement, you should rely on the information in that prospectus supplement. You should read carefully this prospectus, any prospectus supplement and the additional information described below under the heading “Where You Can Find More Information.”

This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by reference to the actual documents. For additional information about our business, operations and financial results, please read the documents incorporated by reference herein under the heading “Where You Can Find More Information.”

THIS PROSPECTUS MAY NOT BE USED TO SELL ANY SECURITIES UNLESS ACCOMPANIED BY A PROSPECTUS SUPPLEMENT.

We and the selling securityholders have not authorized anyone to provide any information or to make any representations other than those contained in this prospectus or incorporated by reference in this prospectus. We and the selling securityholders take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. We are not offering these securities in any state where the offer is not permitted. You should not assume that the information in this prospectus is accurate as of any date other than the date on the cover page of this prospectus or that any information we have incorporated by reference is accurate as of any date other than the date of the documents incorporated by reference. Our business, financial condition, results of operations and prospects may have changed since those dates.

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CAUTIONARY LANGUAGE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus (including any prospectus supplement and the information incorporated or deemed to be incorporated by reference in this prospectus) contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”) and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). Forward-looking statements generally relate to future events or Sunnova’s future financial or operating performance. Actual outcomes and results may differ materially from what is expressed or forecast in such forward-looking statements. In some cases, you can identify these statements because they contain words such as “anticipate,” “believe,” “contemplate,” “continue,” “could,” “estimate,” “expect,” “future,” “goal,” “intend,” “likely,” “may,” “plan,” “potential,” “predict,” “project,” “seek,” “should,” “target,” “will” or the negative of these words or other similar terms or expressions that concern our expectations, strategy, plans or intentions. Forward-looking statements contained in this prospectus (including any prospectus supplement and the information incorporated or deemed to be incorporated by reference in this prospectus) include, but are not limited to, statements about:

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Our actual results and timing of these events may differ materially from those anticipated in these forward-looking statements as a result of many factors, including but not limited to those discussed under “Risk Factors” in this prospectus, the “Risk Factors” section beginning on page 22 of our annual report on Form 10-K for the year ended December 31, 2022 and the “Risk Factors” section beginning on page 53 of our quarterly report on Form 10-Q for the quarter ended March 31, 2023, each of which is incorporated by reference into this prospectus. Moreover, we operate in a very competitive and rapidly changing environment and new risks emerge from time to time. It is not possible for our management to predict all risks, nor can we assess the impact of all factors on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements we may make. In light of these risks, uncertainties and assumptions, the forward-looking events and circumstances discussed in this prospectus may not occur and actual results could differ materially and adversely from those anticipated or implied in the forward-looking statements. We undertake no obligation to update any forward-looking statements for any reason after the date of this prospectus to conform these statements to actual results or to changes in our expectations, except as required by law.

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ABOUT SUNNOVA ENERGY INTERNATIONAL INC.

Unless the context otherwise requires, references to “Sunnova,” “Registrant,” “we,” “our,” “us” or like terms refer to Sunnova Energy International Inc. (“SEI”) and its consolidated subsidiaries.

Company Overview

We are a leading Energy as a Service provider, serving over 348,000 customers in more than 45 United States (“U.S.”) states and territories. Our goal is to be the source of clean, affordable and reliable energy with a simple mission: to power energy independence so home and business owners have the freedom to live life uninterrupted. We were founded to deliver customers a better energy service at a better price; and, through our energy service offerings, we are disrupting the traditional energy landscape and the way the 21st century customer generates and consumes electricity.

We have a differentiated dealer model in which we partner with local dealers who originate, design and install our customers’ solar energy systems, energy storage systems and related products and services on our behalf. Our focus on our dealer model enables us to leverage our dealers’ specialized knowledge, connections and experience in local markets to drive customer origination while providing our dealers with access to high quality products at competitive prices, as well as technical oversight and expertise. We believe this structure provides operational flexibility, reduces exposure to labor shortages and lowers fixed costs relative to our peers, furthering our competitive advantage.

We offer customers products to power their homes and businesses with affordable solar energy and related products and services. We are able to offer savings compared to utility-based retail rates with little to no up-front expense to the customer in conjunction with solar and solar plus energy storage, and, in the case of the latter, are able to also provide energy resiliency. Our solar service agreements typically take the form of a lease, power purchase agreement (“PPA”), loan or cash purchase; however, we also offer service plans for systems we did not originate. We make it possible in some states for a customer to obtain a new roof and/or other ancillary products. We also allow customers originated through our homebuilder channel the option of purchasing the system when the customer closes on the purchase of a new home. The initial term of our solar service agreements is typically between 10 and 25 years. Service is an integral part of our agreements and includes operations and maintenance, monitoring, repairs and replacements, equipment upgrades, on-site power optimization for the customer (for both supply and demand), the ability to efficiently switch power sources among the solar panel, grid and energy storage system, as appropriate, and diagnostics. During the life of the contract, we have the opportunity to integrate related and evolving servicing and monitoring technologies to upgrade the flexibility and reduce the cost of our customers’ energy supply.

In the case of leases and PPAs, we also currently receive tax benefits and other incentives from federal, state and local governments, a portion of which we finance through tax equity, non-recourse debt structures and hedging arrangements in order to fund our upfront costs, overhead and growth investments. We have an established track record of attracting capital from diverse sources. From our inception through June 30, 2023, we have raised more than $13.3 billion in total capital commitments from equity, debt and tax equity investors.

In addition to providing ongoing service as a standard component of our solar service agreements, we also offer ongoing energy services to customers who purchased their solar energy system through third parties. Under these arrangements, we agree to provide monitoring, maintenance and repair services to these customers for the life of the service contract they sign with us. In addition, we offer one-time repair services to customers who purchased their solar energy systems through third parties. We also offer complementary products as well as non-solar financing. Specifically, our offerings include a non-solar loan program enabling customers to finance the purchase of products independent of a solar energy system or energy storage system. We believe the quality and scope of our comprehensive energy service offerings, whether to customers that obtained their solar energy system through us or through another party, is a key differentiator between us and our competitors.

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In April 2021, we acquired SunStreet, Lennar’s residential solar platform that focuses primarily on solar energy systems and energy storage systems for homebuilders. In connection with that acquisition, we entered into an agreement pursuant to which we would be the exclusive solar and storage provider for Lennar’s new home communities with solar across the U.S. for a period of four years. We believe the acquisition provides a new strategic path to further scale our solar business, reduces customer acquisition costs, provides a multi-year supply of sites through the development of new solar communities and allows us to pursue the development of clean and resilient microgrids across the U.S.

We also enter into leases with third-party owners of pools of solar energy systems to receive such third party’s interest in those systems. In connection therewith, we assume the related customer PPA and lease obligations, entitling us to future customer cash flows as well as certain credits, rebates and incentives (including SRECs) under those agreements, in exchange for a lease payment, whether upfront or over time, to the third-party owner, which may be made in the form of cash or shares of our common stock. We believe such arrangements enhance our long-term contracted cash flows and are complementary to our overall business model.

We commenced operations in January 2013 and began providing solar energy services under our first solar energy system in April 2013. Since then, our brand, innovation and focused execution have driven significant, rapid growth in our market share and in the number of customers on our platform. We operate one of the largest residential fleets of solar energy systems in the U.S., comprising more than 1,919 megawatts of generation capacity and serving over 348,000 customers.

Corporate Information

Our principal executive office is located at 20 East Greenway Plaza, Suite 540, Houston, Texas 77046, our telephone number is (281) 892-1588 and our website address is www.sunnova.com. Information on our website or any other website is not incorporated by reference in this prospectus and does not constitute a part of this prospectus.

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RISK FACTORS

An investment in our securities involves a significant degree of risk. You should carefully consider the information included in this prospectus, any prospectus supplement, and the documents we have incorporated by reference in this prospectus and any prospectus supplement, including those in Item 1A “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2022, as updated by quarterly and other reports and documents we file with the SEC that are incorporated by reference herein or therein, in evaluating an investment in our securities. If any of these risks actually occur, they may materially and adversely affect our business, financial condition, cash flows and results of operations. In this event, the trading price of our common stock or value of our securities could decline, and you could lose all or part of your investment in us. We may experience additional risks and uncertainties not currently known to us; or, as a result of developments occurring in the future, conditions that we currently deem to be immaterial may also materially and adversely affect our business, financial condition, cash flows and results of operations. If we or any selling securityholder sell any securities pursuant to a prospectus supplement, we or such selling securityholder may include additional risk factors relevant to such securities in such prospectus supplement.

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USE OF PROCEEDS

Unless we inform you otherwise in a prospectus supplement, we anticipate using any net proceeds from the sale of our securities offered by this prospectus for general corporate purposes. These purposes may include, but are not limited to:

Pending any specific application, we may initially invest funds in short-term liquid investments or apply them to the reduction of short-term indebtedness, or indebtedness under our credit agreements.

We will not receive any proceeds from the sales by the selling securityholders of our securities.

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DESCRIPTION OF THE CAPITAL STOCK

General

The following description summarizes certain important terms of our capital stock and certain important provisions included in our second amended and restated certificate of incorporation, second amended and restated bylaws and stockholders agreement. This summary does not purport to be complete and is qualified in its entirety by the provisions of our second amended and restated certificate of incorporation, second amended and restated bylaws and stockholders agreement and to the applicable provisions of Delaware law. We have filed copies of those documents with the SEC, and they are incorporated by reference as exhibits to the registration statement of which this prospectus forms a part. See “Where You Can Find More Information.”

Our authorized capital stock consists of 1,010,000,000 shares of capital stock, $0.0001 par value per share, of which

Common Stock

Dividend Rights

Subject to preferences that may apply to any shares of preferred stock outstanding at the time, the holders of our common stock are entitled to receive dividends out of funds legally available if our board of directors, in its discretion, determines to issue dividends and then only at the times and in the amounts that our board of directors may determine.

Voting Rights

Holders of our common stock are entitled to one vote for each share held on all matters submitted to a vote of stockholders. Stockholders do not have the ability to cumulate votes for the election of directors.

No Preemptive or Similar Rights

Our common stock is not entitled to preemptive rights and is not subject to conversion, redemption or sinking fund provisions.

Right to Receive Liquidation Distributions

If we become subject to a liquidation, dissolution or winding-up, the assets legally available for distribution to our stockholders would be distributable ratably among the holders of our common stock and any participating preferred stock outstanding at that time, subject to prior satisfaction of all outstanding debt and liabilities and the preferential rights and payment of liquidation preferences, if any, on any outstanding shares of preferred stock.

Fully Paid and Non-Assessable

All of the shares of our common stock are fully paid and non-assessable.

Preferred Stock

No shares of our preferred stock are outstanding. Pursuant to our second amended and restated certificate of incorporation, our board of directors has the authority, without further vote or action by our stockholders, to issue

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from time to time shares of preferred stock in one or more series and to establish from time to time the number of shares to be included in each series. Our board of directors may designate the powers, rights, preferences, and privileges of the shares of each series of preferred stock and any of its qualifications, limitations or restrictions, including dividend rights, conversion rights, voting rights, redemption rights, liquidation preference, and sinking fund terms, in each case without further vote or action by our stockholders. Our board of directors may also increase or decrease the number of shares of any series of preferred stock, but not below the number of shares of that series then outstanding, without any further vote or action by our stockholders. The issuance of preferred stock, while providing flexibility in connection with possible acquisitions and other corporate purposes, could, among other things, have the effect of delaying, deterring, or preventing a change in control, restricting dividends on our common stock, diluting the voting power and other rights of our common stock and impairing the liquidation rights of our common stock. Such issuance could have the effect of decreasing the market price of our common stock. We currently have no plans to issue any shares of preferred stock.

Options

As of June 30, 2023, we have granted to management and certain of our employees options to purchase a total of 4,031,506 shares of our common stock, with a weighted-average exercise price of approximately $17.61 per share that remained outstanding under our equity compensation plans.

Registration Rights

On May 14, 2020, in connection with the issuance of our 9.75% convertible senior notes due 2025 (the “Notes”), we entered into a Registration Rights Agreement (the “2020 Registration Rights Agreement”) with the investors in the Notes. Pursuant to, and subject to the limitations set forth in, the 2020 Registration Rights Agreement, we agreed to use our commercially reasonable efforts to prepare and file a shelf registration statement registering the offer and sale of (a) the Notes and (b) the shares of common stock issued or issuable upon conversion of the Notes, and to cause such shelf registration statement to become effective on or prior to August 1, 2020 and to keep such shelf registration statement effective until all the Notes or shares of common stock issuable upon conversion of the outstanding Notes have been sold or disposed of. The filing of our shelf registration statement on Form S-3ASR, filed August 3, 2020 (the “2020 Shelf Registration Statement”), satisfies our obligation under the 2020 Registration Rights Agreement to file a registration statement to cover the resale of the Notes, and the filing of the 2020 Shelf Registration Statement and this shelf registration statement satisfies our obligation under the 2020 Registration Rights Agreement to file a registration statement to cover the resale of the shares of our common stock issuable upon conversion of the Notes.

On April 1, 2021, we entered into a Stockholders Agreement (the “2021 Stockholders Agreement”) with Lennar Corporation and LEN X, LLC (“LEN X”). Pursuant to the 2021 Stockholders Agreement, if LEN X owns at any time following the date that is two years after the closing date of the merger contemplated in the Agreement and Plan of Merger, dated as of February 17, 2021, by and among us, Lennar Corporation and LEN X (the “Merger Agreement”), any shares of our common stock issued pursuant to the terms of the Merger Agreement or the related earnout agreement, excluding any shares for which Rule 144 under the Securities Act is available for the sale or disposition of such shares, in excess of 5% of the total outstanding shares of our common stock and any other of our securities entitling the holder to vote generally for the election of directors on our board of directors, LEN X may send a written request to us to register any such shares of our common stock, and we will, as soon as reasonably practicable, prepare and file a shelf registration statement registering the offer and sale of such shares of common stock and will use commercially reasonable efforts to cause such shelf registration statement to become effective as soon as practicable after filing and to cause the shelf registration statement to remain continuously effective until all of such shares of common stock have been sold or disposed of. We may, upon written notice to LEN X, cease the preparation and filing of such a shelf registration statement or suspend LEN X’s use of any prospectus which is a part of such a shelf registration statement under certain circumstances, subject to certain restrictions.

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Piggyback Registration Rights

Pursuant and subject to the terms and conditions of the 2020 Registration Rights Agreement, if we propose to offer any of our shares of common stock under the Securities Act in connection with a public offering of such securities solely for cash, we shall, at such time, promptly give each stockholder who is a party to the 2020 Registration Rights Agreement notice of such offering. Upon the written request of such stockholder, we shall, subject to the terms and conditions of the applicable registration rights agreement, cause to be registered or included in the prospectus supplement, as applicable, all of the common stock owned or held by each such stockholder (including common stock issued or issuable upon conversion of such stockholder’s preferred stock) that each such stockholder has requested to be included in such registration.

Anti-Takeover Provisions

Certain provisions of Delaware law, our second amended and restated certificate of incorporation and our second amended and restated bylaws, which are summarized below, may have the effect of delaying, deferring or discouraging another person from acquiring control of us. They are also designed, in part, to encourage persons seeking to acquire control of us to negotiate first with our board of directors. We believe that the benefits of increased protection of our potential ability to negotiate with an unfriendly or unsolicited acquirer outweigh the disadvantages of discouraging a proposal to acquire us because negotiation of these proposals could result in an improvement of their terms.

Delaware Law

A corporation may elect not to be subject to Section 203 of the General Corporation Law of the State of Delaware (the “DGCL”). We have elected to not be subject to the provisions of Section 203 of the DGCL. However, our second amended and restated certificate of incorporation contains provisions that are similar to Section 203. In general, our second amended and restated certificate of incorporation prohibits us from engaging in a “business combination” while our common stock is registered under Section 12(b) or 12(g) under the Exchange Act, with an “interested stockholder” for a period of three years after the date of the transaction in which the person became an interested stockholder, unless:

Generally, a business combination includes a merger of us or any of our subsidiaries with the interested stockholder or any sale or disposition (except proportionately as our stockholder) of assets representing more than 10% of our consolidated assets or the aggregate market value of our capital stock. Subject to certain exceptions, an interested stockholder is a person who, together with affiliates and associates, owns 15% or more of our voting stock or is an affiliate of us and, within the previous three years, owned 15% or more of our voting stock. In our case, however, the ECP Stockholders (meaning, for purposes of our second amended and restated certificate of incorporation, Energy Capital Partners III, LP, Energy Capital Partners III-A, LP, Energy Capital

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Partners III-B, LP, Energy Capital Partners III-C, LP, Energy Capital Partners III-D, LP, Energy Capital Partners III (Sunnova Co-Invest), LP and each of their respective affiliates that owns any shares of our common stock or preferred stock) and their affiliates or associates and any of their direct transferees (excluding any person who acquires voting stock through a broker’s transaction on an exchange or pursuant to an underwritten public offering) will not be deemed to be interested stockholders regardless of the percentage of our voting stock owned by them, and accordingly will not be subject to such restrictions, subject to certain exceptions for the acquisition of additional shares of common stock. This provision could delay mergers or other takeover or change in control attempts with respect to us and, accordingly, may discourage attempts to acquire us.

Second Amended and Restated Certificate of Incorporation and Second Amended and Restated Bylaw Provisions

Our second amended and restated certificate of incorporation and our second amended and restated bylaws include a number of provisions that could delay or discourage an unsolicited takeover or a change in control or changes in our board of directors or management team, including the following:

Choice of Forum

Our second amended and restated certificate of incorporation provides that, unless we consent in writing to the selection of an alternative forum, the sole and exclusive forum for (1) any derivative action or proceeding

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brought on our or our stockholders’ behalf, (2) any action asserting a claim of breach of a fiduciary duty owed by any of our current or former directors, officers, employees, agents and stockholders to us or our stockholders, (3) any action asserting a claim arising pursuant to any provision of the DGCL, our second amended and restated certificate of incorporation or our second amended and restated bylaws, (4) any action as to which the DGCL confers jurisdiction to the Court of Chancery of the State of Delaware or (5) any other action asserting a claim that is governed by the internal affairs doctrine shall be the Court of Chancery of the State of Delaware. Our second amended and restated certificate of incorporation also provides that, to the fullest extent permitted by applicable law, the federal district courts of the U.S. is the exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act, subject to and contingent upon a final adjudication in the State of Delaware of the enforceability of such exclusive forum provision.

Notwithstanding the foregoing, the exclusive forum provision will not apply to suits brought to enforce any liability or duty created by the Exchange Act or any other claim for which the federal courts have exclusive jurisdiction. Any person or entity purchasing or otherwise acquiring an interest in any shares of our capital stock shall be deemed to have notice of and to have consented to the forum provisions in our second amended and restated certificate of incorporation. These choice-of-forum provisions may limit a stockholder’s ability to bring a claim in a judicial forum that he, she or it believes to be favorable for disputes with us or our directors, officers or other employees, which may discourage such lawsuits. Alternatively, if a court were to find these provisions of our second amended and restated certificate of incorporation inapplicable or unenforceable with respect to one or more of the specified types of actions or proceedings, we may incur additional costs associated with resolving such matters in other jurisdictions, which could materially adversely affect our business, financial condition and results of operations and result in a diversion of the time and resources of our management and board of directors.

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Computershare Trust Company, N.A. The transfer agent and registrar’s address is 150 Royall Street, Suite 101, Canton, Massachusetts 02021.

Limitations of Liability and Indemnification

Our second amended and restated certificate of incorporation and our second amended and restated bylaws contain provisions that limit the liability of our directors and officers for monetary damages to the fullest extent permitted by the DGCL. Consequently, our directors are not personally liable to us or our stockholders for monetary damages for breach of fiduciary duty as a director, except liability:

Any amendment to, or repeal of, these provisions will not eliminate or reduce the effect of these provisions in respect of any act, omission or claim that occurred or arose prior to that amendment or repeal. If the DGCL is amended to provide for further limitations on the personal liability of directors of corporations, then the personal liability of our directors will be further limited to the greatest extent permitted by the DGCL.

We have entered into and intend to continue to enter into separate indemnification agreements with each of our directors and officers that provide the maximum indemnity allowed to directors and executive officers by

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Section 145 of the DGCL and also to provide for certain additional procedural protections. We believe that these agreements and insurance policies are necessary to attract and retain qualified individuals to serve as directors and executive officers.

These indemnification provisions and the indemnification agreements entered into between us and our officers and directors may be sufficiently broad to permit indemnification of our officers and directors for liabilities (including reimbursement of expenses incurred) arising under the Securities Act.

We maintain liability insurance policies that indemnify our directors and officers against various liabilities, including certain liabilities arising under the Securities Act and the Exchange Act, which may be incurred by them in their capacity as such.

Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers or persons controlling our company pursuant to the foregoing provisions, we have been informed that, in the opinion of the SEC, such indemnification is against public policy as expressed in the Securities Act and is therefore unenforceable.

Listing

Our common stock is listed on the NYSE under the symbol “NOVA.”

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DESCRIPTION OF THE DEBT SECURITIES

Any debt securities that we may offer under this prospectus will be our general unsecured obligations. The debt securities will be either senior debt securities or subordinated debt securities (collectively, the “debt securities”). We will issue any senior debt securities under the senior indenture that we will enter into with the trustee named in the senior indenture. We will issue any subordinated debt securities under the subordinated indenture that we will enter into with the trustee named in the subordinated indenture. In this description, we sometimes call the senior indenture and the subordinated indenture the “indentures.” We have filed forms of these documents as exhibits to the registration statement, of which this prospectus is a part, and supplemental indentures and forms of debt securities containing the terms of the debt securities being offered will be filed as exhibits to the registration statement of which this prospectus is a part or will be incorporated by reference from reports that we file with the SEC. See “Where You Can Find More Information.”

The indentures will be qualified under the Trust Indenture Act of 1939, as amended, or the “Trust Indenture Act.” We use the term “trustee” to refer to either the trustee under the senior indenture or the trustee under the subordinated indenture, as applicable.

We have summarized the provisions of the indentures and the debt securities below. You should read the indentures for more details regarding the provisions described below and for other provisions that may be important to you.

General

The senior debt securities will constitute our senior debt and will rank equally with all of our unsecured and unsubordinated debt. The subordinated debt securities will be subordinated to, and thus have a position junior to, any senior debt securities and all our other senior debt. The indentures will not limit the amount of debt we may issue under the indentures, and, unless we inform you otherwise in a prospectus supplement, they will not limit the amount of other unsecured debt or securities we may incur or issue. We may issue debt securities under the indentures from time to time in one or more series, each in an amount we authorize prior to issuance.

We derive substantially all of our operating income from, and hold substantially all our assets through, our subsidiaries. As a result, we will depend on distributions of cash flow and earnings of our subsidiaries in order to meet our payment obligations under any debt securities we offer under this prospectus and our other obligations. These subsidiaries are separate and distinct legal entities and will have no obligation to pay any amounts due on our debt securities or to provide us with funds for our payment obligations, whether by dividends, distributions, loans or otherwise. In addition, provisions of applicable law, such as those limiting the legal sources of dividends, could limit our subsidiaries’ ability to make payments or other distributions to us and they could agree to contractual restrictions on their ability to make distributions. In addition, holders of the debt securities will have a junior position to the claims of creditors of our subsidiaries on their assets and earnings.

Our right to receive any assets of any subsidiary, and therefore the right of the holders of our debt securities to participate in those assets, will be effectively subordinated to the claims of that subsidiary’s creditors, including trade creditors. In addition, even if we are a creditor of any subsidiary, our rights as a creditor would be subordinate to any security interest in the assets of that subsidiary and any indebtedness of that subsidiary senior to that held by us.

We may issue the debt securities of any series in definitive form or as a book-entry security in the form of a global security registered in the name of a depositary we designate.

We may issue the debt securities in one or more series with various maturities, and we may sell those debt securities at par, at a premium or with an original issue discount.

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Terms

A prospectus supplement relating to any series of debt securities being offered will specify whether the debt securities are senior debt securities or subordinated debt securities and will include specific terms relating to the offering. These terms will include some or all of the following:

If we sell any debt securities for any foreign currency or currency unit or if payments on the debt securities are payable in any foreign currency or currency unit, we will describe in a prospectus supplement the restrictions, elections, tax consequences, specific terms and other information relating to those debt securities and the foreign currency or currency unit.

Subordination

Under the subordinated indenture, payment of the principal, interest and any premium on the subordinated debt securities will generally be subordinated and junior in right of payment to the prior payment in full of all Senior Debt (as defined below). Unless we inform you otherwise in a prospectus supplement, we may not make any payment of principal, interest or any premium on the subordinated debt securities if:

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Unless we inform you otherwise in a prospectus supplement, a covenant default will prevent us from making payments on the subordinated debt securities only for up to 179 days after holders of the Senior Debt give the trustee for the subordinated debt securities notice of the covenant default.

The subordination provisions will not affect our obligation, which will be absolute and unconditional, to pay, when due, principal of, premium, if any, and interest on the subordinated debt securities. In addition, the subordination provisions will not prevent the occurrence of any default under the subordinated indenture.

Unless we inform you otherwise in a prospectus supplement, the subordinated indenture will not limit the amount of Senior Debt that we may incur. As a result of the subordination of the subordinated debt securities, if we become insolvent, holders of subordinated debt securities may receive less on a proportionate basis than our other creditors.

Unless we inform you otherwise in a prospectus supplement, “Senior Debt” will mean all notes or other indebtedness, including guarantees, of Sunnova for money borrowed and similar obligations, unless the indebtedness states that it is not senior to the subordinated debt securities or our other junior debt.

Consolidation, Merger and Sale of Assets

The indentures generally will permit a consolidation, amalgamation or merger between us and another entity. They also will permit the sale by us of substantially all of our assets as an entirety. The indentures will provide, however, that we may consolidate or amalgamate with another entity to form a new entity or merge into any other entity or transfer or dispose of substantially all of our assets as an entirety to any other entity only if:

On the assumption by the successor of the obligations under the indentures, the successor will be substituted for us, and we will be relieved of any further obligation under the indentures and the debt securities.

Events of Default

Unless we inform you otherwise in a prospectus supplement, the following will be events of default with respect to a series of debt securities:

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A default under one series of debt securities would not necessarily be a default under another series. The trustee may withhold notice to the holders of the debt securities of any default or event of default, except in any payment on the debt securities, if the trustee in good faith determines that withholding notice is in the interest of the holders of the debt securities.

If an event of default for any series of debt securities occurs and is continuing, the trustee or the holders of at least 25% in principal amount of the outstanding debt securities of the series affected by the default, or, in some cases, 25% in principal amount of all senior debt securities or subordinated debt securities affected, voting as one class, may declare the principal of and all accrued and all unpaid interest on those debt securities to be immediately due and payable. If an event of default relating to events of bankruptcy, insolvency or reorganization occurs, the principal of and all accrued and unpaid interest on all the debt securities will become immediately due and payable without any action on the part of the applicable trustee or any holder. The holders of a majority in principal amount of the outstanding debt securities of the series affected by the default, or of all senior debt securities or subordinated debt securities affected, voting as one class, may in some cases rescind this accelerated payment requirement. Depending on the terms of our other indebtedness, an event of default under either of the indentures may give rise to cross defaults on our other indebtedness.

A holder of a debt security of any series will be able to pursue any remedy under the applicable indenture only if:

This provision will not, however, affect the right of a holder of a debt security to sue for enforcement of any overdue payment.

In most cases, holders of a majority in principal amount of the outstanding debt securities of a series, or of all debt securities affected, voting as one class, will be able to direct the time, method and place of:

Each indenture will require us to file with the trustee each year a written statement as to our compliance with the covenants contained in that indenture.

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Modification and Waiver

We may amend or supplement either indenture if the holders of a majority in principal amount of the outstanding debt securities of all series issued under the applicable indenture and affected by the amendment or supplement, acting as one class, consent to it. Without the consent of the holder of each debt security affected, however, no amendment or supplement may:

We and the applicable trustee may agree to amend or supplement either indenture or waive any provision of either indenture without the consent of any holders of debt securities in some circumstances, including:

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The holders of a majority in principal amount of the outstanding debt securities of any series, or of all senior debt securities or subordinated debt securities affected, voting as one class, may waive any existing or past default or event of default with respect to those debt securities. Those holders may not, however, waive any default or event of default in any payment on any debt security or compliance with a provision that cannot be amended or supplemented without the consent of each holder affected.

Discharge and Defeasance

We will be discharged from all obligations under the applicable indenture with respect to any series of debt securities, except for surviving obligations relating to any conversion rights and to register the transfer or exchange of the debt securities, if:

To exercise our right to be discharged, we must deliver to the applicable trustee an opinion of counsel and an officers’ certificate stating that all conditions precedent to the satisfaction and discharge of the applicable indenture have been complied with.

In addition to our right of discharge described above, if we deposit with the applicable trustee funds or government securities sufficient to make payments on the debt securities of a series on the dates those payments are due and payable, then, at our option, either of the following will occur:

If we defease a series of debt securities, the holders of the debt securities of the series affected will not be entitled to the benefits of the applicable indenture, except for our obligations to:

Unless we inform you otherwise in a prospectus supplement, we will be required to deliver to the applicable trustee an opinion of counsel that the deposit and related defeasance would not cause the holders of the debt securities to recognize income, gain or loss for U.S. federal income tax purposes. If we elect legal defeasance, that opinion of counsel must be based on a ruling from the IRS or a change in law to that effect.

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Governing Law

New York law will govern the indentures and the debt securities.

Trustee

If an event of default occurs and is continuing, the trustee must exercise such of the rights and powers vested in it by the applicable indenture, and use the same degree of care and skill in their expertise, as a prudent person would exercise or use under the circumstances in the conduct of such person’s own affairs. The trustee will become obligated to exercise any of its powers under the indentures at the request of any of the holders of any debt securities only after those holders have offered the trustee indemnity and/or security satisfactory to the trustee.

Each indenture will limit the right of the trustee, if it becomes one of our creditors, to obtain payment of claims or to realize on certain property received for any such claim, as security or otherwise. The trustee may engage in other transactions with us. If the trustee acquires any conflicting interest, however, it must eliminate that conflict or resign.

Form, Exchange, Registration and Transfer

We will issue the debt securities in registered form, without interest coupons. We will not charge a service charge for any registration of transfer or exchange of the debt securities. We may, however, require the payment of any tax or other governmental charge payable for that registration.

Debt securities of any series will be exchangeable for other debt securities of the same series with the same total principal amount and the same terms but in different authorized denominations in accordance with the applicable indenture. Holders may present debt securities for registration of transfer at the office of the security registrar or any transfer agent we designate. The security registrar or transfer agent will effect the transfer or exchange when it is satisfied with the documents of title and identity of the person making the request.

Unless we inform you otherwise in a prospectus supplement, we will appoint the trustee under each indenture as security registrar for the debt securities we issue under that indenture. If a prospectus supplement refers to any transfer agent initially designated by us, we may at any time rescind that designation or approve a change in the location through which any transfer agent acts. We will be required to maintain an office or agency for transfers and exchanges in each place of payment. We may at any time designate additional transfer agents for any series of debt securities or rescind the designation of any transfer agent.

In the case of any redemption, neither the security registrar nor the transfer agent will be required to register the transfer or exchange of any debt security:

Payment and Paying Agent

Unless we inform you otherwise in a prospectus supplement, we will make payments on the debt securities in U.S. dollars at the office of the applicable trustee or any paying agent we designate. At our option, we may make payments by check mailed to the holder’s registered address or, with respect to global debt securities, by wire transfer. Unless we inform you otherwise in a prospectus supplement, we will make interest payments to the person in whose name the debt security is registered at the close of business on the record date for the interest payment.

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Unless we inform you otherwise in a prospectus supplement, we will designate the trustee under each indenture as our paying agent for payments on debt securities we issue under that indenture. We may at any time designate additional paying agents or rescind the designation of any paying agent or approve a change in the office through which any paying agent acts.

Subject to the requirements of any applicable abandoned property laws, the trustee and paying agent will repay to us upon written request any funds held by them for payments on the debt securities that remain unclaimed for two years after the date upon which that payment has become due. After repayment to us, holders entitled to those funds must look only to us for payment.

Book-Entry Debt Securities

We may issue the debt securities of a series in the form of one or more global debt securities that would be deposited with a depositary or its nominee identified in a prospectus supplement. We may issue global debt securities in either temporary or permanent form. We will describe in a prospectus supplement the terms of any depositary arrangement and the rights and limitations of owners of beneficial interests in any global debt security.

Conversion Rights

The terms and conditions of any series of debt securities being offered that are convertible into common stock of Sunnova will be set forth in a prospectus supplement. These terms will include the conversion price, the conversion period, provisions as to whether conversion will be at the option of the holder or Sunnova, the events requiring an adjustment of the conversion price and provisions affecting conversion if such series of debt securities are redeemed.

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DESCRIPTION OF THE RIGHTS

We may issue rights to our stockholders for the purchase of common stock. Each series of rights will be issued under rights agreements to be entered into between us and a bank or trust company, as rights agent. You should read the particular terms of the rights, which will be described in more detail in the applicable prospectus supplement. The particular terms of any rights offered by any prospectus supplement, and the extent to which the general provisions summarized below may apply to the offered securities, will be described in the prospectus supplement.

The applicable prospectus supplement will describe the terms of any series of rights we offer, the rights agreement relating to the rights and the rights certificates, including, to the extent applicable:

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DESCRIPTION OF THE WARRANTS

We may issue warrants to purchase any combination of common stock, preferred stock, debt securities, depositary shares and purchase contracts. Each warrant will entitle the holder to purchase for cash a number of securities at the exercise price as will in each case be described in, or can be determined from, the applicable prospectus supplement relating to the offered warrants.

Warrants may be issued independently or together with any securities and may be attached to or separate from the securities. The warrants will be issued under warrant agreements to be entered into between us and a bank or trust company, as warrant agent. You should read the particular terms of the warrants, which will be described in more detail in any applicable prospectus supplement. The particular terms of any warrants offered by any prospectus supplement, and the extent to which the general provisions summarized below may apply to the offered securities, will be described in a prospectus supplement.

Any applicable prospectus supplement will describe the terms of warrants we offer, the warrant agreement relating to the warrants and the certificates representing the warrants, including, to the extent applicable:

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DESCRIPTION OF THE DEPOSITARY SHARES

Shares of preferred stock may be offered either separately or represented by depositary shares. We may also, at our option, elect to offer fractional shares of preferred stock. If we exercise this option, we will issue receipts for depositary shares, each of which will represent a fraction of a share of a particular series of preferred stock, to be described in an applicable prospectus supplement.

The shares represented by depositary shares will be deposited under a deposit agreement between us and a bank or trust company selected by us and having its principal office in the U.S. and having a combined capital and surplus of at least $50,000,000. Subject to the terms of the deposit agreement, each owner of a depositary share will be entitled, in proportion to the applicable share or fraction thereof represented by the depositary share, to all of the rights and preferences, if any, of the share represented thereby, including any dividend, voting, redemption, conversion and liquidation rights. The depositary shares will be evidenced by depositary receipts issued pursuant to the deposit agreement.

The particular terms of the depositary shares offered by any prospectus supplement will be described in a prospectus supplement, which will also include a discussion of material U.S. federal income tax consequences.

We will include a copy of the form of deposit agreement, including the form of depositary receipt, and any other instrument establishing the terms of any depositary shares we offer as exhibits to a filing we will make with the SEC in connection with that offering. See “Where You Can Find More Information.”

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DESCRIPTION OF THE PURCHASE CONTRACTS AND PURCHASE UNITS

We may issue purchase contracts representing contracts obligating holders, subject to the terms of such purchase contracts, to purchase from us, and us to sell to the holders, a specified or varying number of our common stock, preferred stock or other securities described in this prospectus at a future date or dates. Alternatively, the purchase contracts may, subject to the terms of such purchase contracts, obligate us to purchase from holders, and obligate the holders to sell to us, a specified or varying number of common stock, preferred stock or other securities described in this prospectus. The price per unit of our common stock, preferred stock or other securities described in this prospectus and number of units may be fixed at the time the purchase contracts are entered into or may be determined by reference to a specific formula set forth in the purchase contracts. We may issue the purchase contracts separately or as part of units, which we refer to as “purchase units,” consisting of a purchase contract and other securities or obligations issued by us or third parties, including government securities, in each case, securing the holders’ obligations to purchase the relevant securities under the purchase contracts. The purchase contracts may require us to make periodic payments to the holders of the purchase contracts or purchase units or vice versa, and such payments may be unsecured or prefunded on some basis.

Any applicable prospectus supplement will describe the terms of any purchase contract or purchase units. The description in a prospectus supplement will not necessarily be complete and will be qualified in its entirety by reference to the purchase contracts, and, if applicable, collateral arrangements and depositary arrangements, relating to the purchase contracts or purchase units.

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DESCRIPTION OF THE UNITS

We may issue units of securities consisting of one or more of the following securities: common stock, preferred stock, debt securities, rights, warrants, depositary shares and purchase contracts. We may evidence each series of units issued by unit certificates that we will issue under a separate unit agreement. We may enter into unit agreements with a unit agent. Each unit agent will be a bank or trust company that we select. You should read the particular terms of these documents, which will be described in more detail in a prospectus supplement.

If we offer any units, certain terms of that series of units will be described in a prospectus supplement, including, without limitation, the following, as applicable:

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SELLING SECURITYHOLDERS

Selling securityholders may from time to time offer and sell our securities pursuant to this prospectus and any applicable prospectus supplement. Selling securityholders are persons or entities that, directly or indirectly, have acquired or from time to time acquire, our securities. Such selling securityholders may be parties to registration rights agreements with us, or we otherwise may have agreed or agree to register their securities for resale.

The applicable prospectus supplement will set forth the name of each of the selling securityholders and the number of securities beneficially owned by such selling securityholders that are covered by such prospectus supplement.

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PLAN OF DISTRIBUTION

We or the selling securityholders may sell the securities on a delayed or continuous basis in and outside the U.S. through the methods described below or through any other method permitted pursuant to applicable law, including through a combination of such methods.

A prospectus supplement, if required, will set forth any required information such as the terms of the offering and the method of distribution and will include the following information:

Sale Through Underwriters or Dealers

If we or the selling securityholders use underwriters in the sale of securities, the underwriters will acquire the securities for their own account. The underwriters may resell the securities from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. Underwriters may offer securities to the public either through underwriting syndicates represented by one or more managing underwriters or directly by one or more firms acting as underwriters. The obligations of the underwriters to purchase the securities may be subject to conditions, and the underwriters will be obligated to purchase all the offered securities if they purchase any of them. The underwriters may change from time to time any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers.

Underwriters may sell our common stock under this prospectus by any method permitted by law deemed to be an “at the market” offering as defined in Rule 415 under the Securities Act, which includes sales made directly on the New York Stock Exchange, on any other existing trading market for our common stock or to or through a market maker, or in privately negotiated transactions. Unless stated otherwise in any applicable prospectus supplement, the sales agent with respect to any such at the market offering will make all sales using commercially reasonable efforts consistent with its normal trading and sales practices, on mutually agreeable terms between the sales agent and us or the selling securityholders. Any applicable prospectus supplement will include the amount of any compensation to be received by the sales agent.

During and after an offering through underwriters, the underwriters may purchase and sell the securities in the open market. These transactions may include overallotment and stabilizing transactions and purchases to cover syndicate short positions created in connection with the offering. The underwriters also may impose a penalty bid, which means that selling concessions allowed to syndicate members or other broker-dealers for the offered securities sold for their account may be reclaimed by the syndicate if the offered securities are repurchased by the syndicate in stabilizing or covering transactions. These activities may stabilize, maintain or otherwise affect the market price of the offered securities, which may be higher than the price that might otherwise prevail in the open market. If commenced, the underwriters may discontinue these activities at any time.

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If we or the selling securityholders use dealers in the sale of securities, we or the selling securityholders will sell the securities to them as principals. They may then resell those securities to the public at varying prices determined by the dealers at the time of resale. We or the selling securityholders also may agree to sell, and the relevant underwriters or agents may agree to solicit offers to purchase, blocks of securities. The terms of each such agreement will be set forth in more detail in any applicable prospectus supplement and any related free writing prospectus. The dealers participating in any sale of the securities may be deemed to be underwriters within the meaning of the Securities Act with respect to any sale of those securities. If required, we or the selling securityholders will include in any applicable prospectus supplement the names of the dealers and the terms of the transaction.

Direct Sales and Sales Through Agents

We or the selling securityholders may sell the securities directly. In that event, no underwriters or agents would be involved. We also may sell the securities through agents we designate from time to time to solicit offers from purchasers to purchase the securities included in this prospectus or to sell such securities in ordinary brokerage transactions on our or the selling securityholders’ behalf. If required, a prospectus supplement will name any agent involved in the offer or sale of the offered securities and will describe any commissions payable by us or the selling securityholders to the agent. Unless stated otherwise in any applicable prospectus supplement, any agent will agree to use its reasonable best efforts to solicit purchases for the period of its appointment.

We or the selling securityholders may sell the securities directly to institutional investors or others who may be deemed to be underwriters within the meaning of the Securities Act with respect to any sale of those securities. We will describe the terms of any such sales in a prospectus supplement.

Delayed Delivery Contracts

We or the selling securityholders may authorize agents, underwriters or dealers to solicit offers from certain types of institutions to purchase securities from us or the selling securityholders at the public offering price under delayed delivery contracts. These contracts would provide for payment and delivery on a specified date in the future. The contracts would be subject only to those conditions described in a prospectus supplement. Such prospectus supplement will describe the commission payable for solicitation of those contracts.

Remarketing

We or the selling securityholders may offer and sell any of the securities in connection with a remarketing upon their purchase, in accordance with a redemption or repayment by their terms or otherwise, by one or more remarketing firms acting as principals for their own accounts or as our or the selling securityholders’ agents. The name of any remarketing firm, the terms of any remarketing agreement and the compensation to be paid to the remarketing firm will be included in a prospectus supplement, as required. Remarketing firms may be deemed to be underwriters within the meaning of the Securities Act.

Derivative Transactions

We or the selling securityholders may enter into derivative transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. If any applicable prospectus supplement indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement, including in short sale transactions then the third parties may use securities pledged by us or the selling securityholders or borrowed from us, the selling securityholders or others to settle those sales or to close out any related open borrowings of securities, and may use securities received from us or the selling securityholders in settlement of those derivatives to close out any related open borrowings of securities. The third parties in these sale transactions will be underwriters and will be identified in such applicable prospectus supplement or in a post-effective amendment to the registration statement of which this prospectus forms a part.

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General Information

In connection with the sale of the securities, underwriters, dealers or agents may be deemed to have received compensation from us or the selling securityholders in the form of underwriting discounts or commissions and also may receive commissions from securities purchasers for whom they may act as agent. Underwriters may sell the securities to or through dealers, and the dealers may receive compensation in the form of discounts, concessions or commissions from the underwriters or commissions from the purchasers for whom they may act as agent. We will provide in a prospectus supplement any required information regarding any underwriting discounts or other compensation that we or the selling securityholders pay to underwriters or agents in connection with the securities offering, and any discounts, concessions or commissions that underwriters allow to dealers.

The selling securityholders and any underwriters, dealers or agents participating in a distribution of the securities may be deemed to be underwriters within the meaning of the Securities Act, and any discounts and commissions received by them and any profit realized by them on resale of the securities may be deemed to be underwriting discounts and commissions under the Securities Act. We or the selling securityholders may agree to indemnify underwriters, dealers and agents who participate in the distribution of securities against certain liabilities to which they may become subject in connection with the sale of the securities, including liabilities arising under the Securities Act, or to contribute with respect to payments that the agents, dealers or underwriters may be required to make because of those liabilities. Agents, dealers and underwriters, or their affiliates or associates, may be customers of, engage in transactions with or perform services for us or the selling securityholders in the ordinary course of their businesses.

Other than our common stock, which is listed on the New York Stock Exchange and trades under the ticker symbol “NOVA”, each series of offered securities will have no established trading market. We may elect to list any series of offered securities on an exchange, but we are not obligated to do so. It is possible that one or more underwriters may make a market in a series of offered securities. However, they will not be obligated to do so and may discontinue market making at any time without notice. We cannot assure you as to the liquidity of, or the trading market for, any of our offered securities.

To the extent required, this prospectus may be amended or supplemented from time to time to describe a specific plan of distribution. The place and time of delivery for the securities in respect of which this prospectus is delivered may be set forth in a prospectus supplement, if required.

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LEGAL MATTERS

The validity of the securities offered by this prospectus and certain other legal matters will be passed upon for us by Baker Botts L.L.P., Houston, Texas. If certain legal matters in connection with an offering of the securities made by this prospectus are passed on by counsel for the underwriters or the selling securityholders of such offering, that counsel will be named in a prospectus supplement related to that offering.

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EXPERTS

The financial statements and management’s assessment of the effectiveness of internal control over financial reporting (which is included in Management’s Report on Internal Control over Financial Reporting) incorporated in this prospectus by reference to the Annual Report on Form 10-K for the year ended December 31, 2022 have been so incorporated in reliance on the report of PricewaterhouseCoopers LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

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WHERE YOU CAN FIND MORE INFORMATION

We file annual, quarterly and current reports, proxy statements and other information with the SEC. Our SEC filings are available to the public over the internet at the SEC’s website at www.sec.gov. You can also obtain information about us at the offices of the New York Stock Exchange, 20 Broad Street, New York, New York 10005. You may find additional information about us on our website at www.sunnova.com, where we post our SEC filings. The information contained on, or that can be accessed through, our website (other than the specified SEC filings incorporated by reference in this prospectus) is not a part of this prospectus and is not incorporated by reference in this prospectus. You should not consider such information contained on our website or that can be accessed through our website to be part of this prospectus.

We incorporate by reference information into this prospectus, which means that we disclose important information to you by referring you to another document filed separately with the SEC. The information incorporated by reference is deemed to be part of this prospectus, and information that we file later with the SEC will automatically update and supersede this information. Any statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus. Unless this prospectus or the information incorporated by reference herein indicates that another date applies, you should not assume that the information in this prospectus is current as of any date other than the date of this prospectus or that any information we have incorporated by reference herein is accurate as of any date other than the date of the document incorporated by reference.

We incorporate by reference the documents listed below and any future filings made with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (excluding information furnished and not filed in accordance with SEC rules) on or after the date of this prospectus. These reports contain important information about us, our financial condition and our results of operations:

You may request a copy of our filings, at no cost, by writing or telephoning us at the following address or phone number:

Sunnova Energy International Inc.

Attention: Investor Relations

20 East Greenway Plaza, Suite 540

Houston, Texas 77046

(281) 892-1588

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PART II

INFORMATION NOT REQUIRED IN THE PROSPECTUS

The following table sets forth all expenses payable by us in connection with the issuance and distribution of the securities being registered. We have agreed to pay all offering expenses, other than underwriting discounts and commissions, for the selling securityholders incurred in connection with the sale by the selling securityholders.

The DGCL provides that a corporation may indemnify any person who was or is a party, or is threatened to be made a party, to any threatened, pending or completed action, suit or proceeding, whether civil, criminal, administrative or investigative (other than an action by or in the right of the corporation by reason of the fact that he is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise), against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by him in connection with such action, suit or proceeding if he acted in good faith and in a manner he reasonably believed to be in or not opposed to the best interests of the corporation and, with respect to any criminal action or proceeding, had no reasonable cause to believe his conduct was unlawful. A similar standard is applicable in the case of derivative actions (i.e., actions by or in the right of the corporation), except that indemnification extends only to expenses, including attorneys’ fees, incurred in connection with the defense or settlement of such action and the statute requires court approval before there can be any indemnification where the person seeking indemnification has been found liable to the corporation.

Our second amended and restated certificate of incorporation and our second amended and restated bylaws contain provisions that limit the liability of our directors and officers for monetary damages to the fullest extent permitted by the DGCL. Consequently, our directors are not personally liable to us or our stockholders for monetary damages for breach of fiduciary duty as a director, except liability:

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Any amendment to, or repeal of, these provisions will not eliminate or reduce the effect of these provisions in respect of any act, omission or claim that occurred or arose prior to that amendment or repeal. If the DGCL is amended to provide for further limitations on the personal liability of directors of corporations, then the personal liability of our directors will be further limited to the greatest extent permitted by the DGCL.

We have entered into and intend to continue to enter into separate indemnification agreements with each of our directors and officers that provide the maximum indemnity allowed to directors and executive officers by Section 145 of the DGCL and also to provide for certain additional procedural protections. We believe that these agreements and insurance policies are necessary to attract and retain qualified individuals to serve as directors and executive officers.

These indemnification provisions and the indemnification agreements entered into between the registrant and its officers and directors may be sufficiently broad to permit indemnification of the registrant’s officers and directors for liabilities (including reimbursement of expenses incurred) arising under the Securities Act.

We maintain liability insurance policies that indemnify our directors and officers against various liabilities, including certain liabilities arising under the Securities Act and the Exchange Act, which may be incurred by them in their capacity as such.

Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers or persons controlling our company pursuant to the foregoing provisions, we have been informed that, in the opinion of the SEC, such indemnification is against public policy as expressed in the Securities Act and is therefore unenforceable.

See the Exhibit Index on the page immediately preceding the signature page for a list of exhibits filed as part of this registration statement on Form S-3, which Exhibit Index is incorporated herein by reference.

(a) The undersigned registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this registration statement:

(i) To include any prospectus required by Section 10(a)(3) of the Securities Act;

(ii) To reflect in the prospectus any facts or events arising after the effective date of the registration statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represent a fundamental change in the information set forth in the registration statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of a prospectus filed with the SEC pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20% change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective registration statement; and

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(iii) To include any material information with respect to the plan of distribution not previously disclosed in the registration statement or any material change to such information in the registration statement;

provided, however, that paragraphs (a)(1)(i), (a)(1)(ii) and (a)(1)(iii) do not apply if the information required to be included in a post-effective amendment by those paragraphs is contained in periodic reports filed with or furnished to the SEC by the registrant pursuant to Section 13 or Section 15(d) of the Exchange Act that are incorporated by reference in the registration statement, or is contained in a form of prospectus filed pursuant to Rule 424(b) that is part of the registration statement.

(2) That, for the purpose of determining any liability under the Securities Act, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

(4) That, for the purpose of determining liability under the Securities Act to any purchaser:

(i) Each prospectus filed by the registrant pursuant to Rule 424(b)(3) shall be deemed to be part of the registration statement as of the date the filed prospectus was deemed part of and included in the registration statement; and

(ii) Each prospectus required to be filed pursuant to Rule 424(b)(2), (b)(5) or (b)(7) as part of a registration statement in reliance on Rule 430B relating to an offering made pursuant to Rule 415(a)(1)(i), (vii) or (x) for the purpose of providing the information required by Section 10(a) of the Securities Act shall be deemed to be part of and included in the registration statement as of the earlier of the date such form of prospectus is first used after effectiveness or the date of the first contract of sale of securities in the offering described in the prospectus. As provided in Rule 430B, for liability purposes of the issuer and any person that is at that date an underwriter, such date shall be deemed to be a new effective date of the registration statement relating to the securities in the registration statement to which such prospectus relates, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof. Provided, however, that no statement made in a registration statement or prospectus that is part of the registration statement or made in a document incorporated or deemed incorporated by reference into the registration statement or prospectus that is part of the registration statement will, as to a purchaser with a time of contract of sale prior to such effective date, supersede or modify any statement that was made in the registration statement or prospectus that was part of the registration statement or made in any such document immediately prior to such effective date.

(5) That, for purposes of determining liability of the registrant under the Securities Act to any purchaser in the initial distribution of the securities, the undersigned registrant undertakes that in a primary offering of securities of the undersigned registrant pursuant to the registration statement, regardless of the underwriting method used to sell the securities to the purchaser, if the securities are offered or sold to such purchaser by means of any of the following communications, the undersigned registrant will be a seller to the purchaser and will be considered to offer or sell such securities to such purchaser:

(i) Any preliminary prospectus or prospectus of the undersigned registrant relating to the offering required to be filed pursuant to Rule 424;

(ii) Any free writing prospectus relating to the offering prepared by or on behalf of the undersigned registrant or used or referred to by the undersigned registrant;

(iii) That portion of any other free writing prospectus relating to the offering containing material information about the undersigned registrant or its securities provided by or on behalf of the undersigned registrant; and

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(iv) Any other communication that is an offer in the offering made by the undersigned registrant to the purchaser.

(b) The undersigned registrant hereby undertakes that, for purposes of determining any liability under the Securities Act, each filing of the registrant’s annual report pursuant to Section 13(a) or 15(d) of the Exchange Act (and, where applicable, each filing of an employee benefit plan’s annual report pursuant to Section 15(d) of the Exchange Act) that is incorporated by reference in the registration statement shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(c) Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the undersigned registrant has been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

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EXHIBIT INDEX†

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SIGNATURES

Pursuant to the requirements of the Securities Act of 1933, as amended, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in Houston, Texas, on July 27, 2023.

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POWER OF ATTORNEY

Each person whose signature appears below appoints William J. Berger, David Searle and Robert L. Lane, and each of them, any of whom may act without the joinder of the other, as his or her true and lawful attorneys-in-fact and agents, with full power of substitution and re-substitution, for him or her and in his or her name, place and stead, in any and all capacities, to sign any and all amendments (including post-effective amendments) to this registration statement and any registration statement (including any amendment thereto) and to file the same, with all exhibits thereto, and all other documents in connection therewith, with the Securities and Exchange Commission, granting unto said attorneys-in-fact and agents full power and authority to do and perform each and every act and thing requisite and necessary to be done, as fully to all intents and purposes as he might or would do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents, or any of them of their or his or her substitute and substitutes, may lawfully do or cause to be done by virtue hereof.

Pursuant to the requirements of the Securities Act of 1933, as amended, this registration statement has been signed below by the following persons in the capacities and on the dates indicated.

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Exhibit 5.1

July 27, 2023

Sunnova Energy International Inc.

20 East Greenway Plaza, Suite 540

Houston, Texas 77046

Ladies and Gentlemen:

We have acted as counsel to Sunnova Energy International Inc., a Delaware corporation (the “Company”), with respect to certain legal matters in connection with the registration statement on Form S–3 (the “Registration Statement”) to be filed by the Company with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Securities Act”). The Registration Statement includes a prospectus (the “Base Prospectus”) that provides it will be supplemented in the future, if required, by one or more prospectus supplements (each, a “Prospectus Supplement”). The Registration Statement, including the Base Prospectus (as supplemented from time to time, if required, by one or more Prospectus Supplements), relates to:

(a) the Company’s proposed offer and sale, from time to time, pursuant to Rule 415 of the Securities Act, of an indeterminate amount of (i) shares of common stock, par value $0.0001 per share, of the Company (“Common Stock”), (ii) shares of preferred stock, par value $0.0001 per share, of the Company (“Preferred Stock”) in one or more series, (iii) unsecured debt securities of the Company (“Debt Securities”), which may be issued in one or more series, consisting of notes, debentures or other evidences of indebtedness, (iv) depositary shares of the Company representing Preferred Stock (the “Depositary Shares”), (v) warrants for the purchase of Common Stock, Preferred Stock, Debt Securities, Depositary Shares, Purchase Contracts (as defined below) or any combination thereof (the “Warrants”), (vi) rights to purchase Common Stock (the “Rights”), (vii) purchase contracts to purchase from or sell to the Company shares of Common Stock, Preferred Stock or other securities of the Company (the “Purchase Contracts”), (viii) units consisting of a Purchase Contract and other securities or obligations issued by the Company or third parties, including government securities, in each case, securing the holder’s obligations to purchase the relevant securities under such Purchase Contract (such units, “Purchase Units”) and (ix) units consisting of any combination of Common Stock, Preferred Stock, Debt Securities, Depositary Shares, Warrants, Rights or Purchase Contracts (the “Units” and, together with the Common Stock, the Preferred Stock, the Debt Securities, the Depositary Shares, the Warrants, the Rights, the Purchase Contracts and the Purchase Units, the “Securities”); and

(b) the proposed resale by selling securityholders of the Company (the “Selling Securityholders”) of an indeterminate amount of shares of outstanding Common Stock (the “Secondary Common Stock”). The Selling Securityholders will be identified (i) in the applicable Prospectus Supplement; (ii) in a post-effective amendment to the Registration Statement; or (iii) in filings the Company may make with the Commission under the Securities Exchange Act of 1934, as amended, that are incorporated by reference into the Registration Statement.

Each series of senior Debt Securities will be issued pursuant to an indenture, in the form filed as Exhibit 4.25 with the Registration Statement, to be entered into between the Company and the trustee thereunder (as may be amended or supplemented from time to time, the “Senior Base Indenture”). Each series of subordinated Debt Securities will be issued pursuant to an indenture, in the form filed as Exhibit 4.26 to the Registration Statement, to be entered into between the Company and the trustee thereunder (as may be amended or supplemented from time to time, the “Subordinated Base Indenture” and, together with the Senior Base Indenture, the “Indentures”). The applicable Indenture will be supplemented, in connection with the issuance of each such series of Debt Securities, by a supplemental indenture, officers’ certificate or other writing (each, a “Supplemental Indenture Document”) thereunder establishing the form and terms of such series of Debt Securities.

This opinion is being furnished to you for filing as Exhibit 5.1 to the Registration Statement.

In our capacity as your counsel in the connection referred to above and as a basis for the opinions herein after expressed, we have examined (a) the Second Amended and Restated Certificate of Incorporation of the Company, as amended to date (the “Certificate of Incorporation”), (b) the Second Amended and Restated By-laws of the Company, as amended to date (the “By-laws” and together with the Certificate of Incorporation, the “Charter Documents”), (c) the Registration Rights Agreement between the Company and the persons named therein, dated as of May 14, 2020, (d) the Stockholders Agreement, by and among the Company, Lennar Corporation and LEN X, LLC, dated as of April 1, 2021, (e) the Indentures, (f) originals, or copies certified or otherwise identified, of the corporate records of the Company, including minute books of the Company as furnished to us by the Company, certificates of public officials and of representatives of the Company, statutes and other instruments and documents and (g) the Registration Statement and the Base Prospectus. In giving such opinions below, we have relied, to the extent we deemed proper, without independent investigation, upon certificates, statements and other representations of officers and other representatives of the Company and of governmental and public officials with respect to the accuracy and completeness of the material factual matters contained therein or covered thereby.

In making our examination, we have assumed, without independent investigation, that each document submitted to us for review is accurate and complete, each such document that is an original is authentic, each such document that is a copy conforms to an authentic original and all signatures on each such document are genuine.

In connection with this opinion, we have also assumed that:

(a) the Registration Statement and any amendments thereto (including post-effective amendments) will have become effective under the Securities Act;

(b) a Prospectus Supplement will have been prepared and filed with the Commission describing the Securities offered thereby;

(c) all Securities and Secondary Common Stock will be offered, issued and sold in compliance with applicable federal and state securities laws and in the manner stated in the Registration Statement (including post-effective amendments) and the appropriate Prospectus Supplement;

(d) the Board of Directors of the Company or, to the extent permitted by the Charter Documents, a duly constituted and acting committee thereof (such Board of Directors or committee being hereinafter referred to as the “Board”) will have taken all necessary corporate action to authorize the creation and issuance of the Securities and Secondary Common Stock and any other Securities issuable on the conversion, exchange, redemption or exercise thereof, and to authorize the terms of the offering and the issuance and sale of such Securities and related matters;

(e) a definitive purchase agreement, underwriting agreement, warrant agreement, unit agreement or similar agreement (each, a “Purchase Agreement”) with respect to any Securities or Secondary Common Stock offered will have been duly authorized and validly executed and delivered by the Company and the other parties thereto;

(f) any securities issuable upon conversion, redemption, exchange or exercise of any Securities being offered will be duly authorized, created and, if appropriate, reserved for issuance upon such conversion, redemption, exchange or exercise;

(g) all Securities and Secondary Common Stock, and any certificates in respect thereof, will be delivered either (i) in accordance with the provisions of the applicable Purchase Agreement approved by the Board upon payment of the consideration therefor provided for therein or (ii) upon conversion, exchange, redemption or exercise of any other Security, in accordance with the terms of such Security or the instrument governing such Security providing for such conversion, exchange, redemption or exercise as approved by the Board, for the consideration approved by the Board;

(h) in the case of shares of Common Stock or Preferred Stock, (i) certificates representing such shares will have been duly executed and will have been duly countersigned by a transfer agent and duly registered by a registrar of such stock, or, if uncertificated, valid book-entry notations will have been made in the share register of the Company in accordance with the provisions of the Charter Documents, (ii) there will be sufficient shares of Common Stock or

Preferred Stock, as applicable, authorized under the Company’s Charter Documents and not otherwise issued or reserved for issuance and (iii) the purchase price therefor payable to the Company, or if such shares are issuable on the conversion, exchange, redemption or exercise of another Security, the consideration payable to the Company for such conversion, exchange, redemption or exercise, will not be less than the par value of such shares;

(i) in the case of shares of Preferred Stock of any series, the Board will have taken all necessary corporate action to designate and establish the terms of such series and will have caused a certificate of designations respecting such series to be prepared and filed with the Secretary of State of the State of Delaware;

(j) in the case of Depositary Shares, (i) the Board will have taken all necessary corporate action to establish the terms of the Depositary Shares, including any action with respect to the Preferred Stock underlying such Depositary Shares, (ii) the applicable deposit agreement (the “Deposit Agreement”) will be duly authorized, executed and delivered by the Company and the depositary thereunder appointed by the Company, (iii) the terms of such Depositary Shares and of their issuance and sale will be duly established in conformity with the Deposit Agreement, (iv) such Depositary Shares will be authorized, offered and sold in accordance with the Deposit Agreement, (v) at the time of execution, countersignature, issuance and delivery of depositary receipts evidencing the Depositary Shares (“Receipts”), the related Deposit Agreement will be the valid and legally binding obligation of the depositary agent thereunder, enforceable against such party in accordance with its terms, (vi) the Securities underlying such Depositary Shares will be duly issued and deposited with the depositary, (vii) the Receipts will be duly issued against the deposit of such Securities in accordance with the Deposit Agreement, (viii) the Deposit Agreement and such Receipts will be governed by New York law and will not include any provision that is unenforceable and (ix) the Receipts will be duly executed, countersigned and registered in accordance with the provisions of the applicable Deposit Agreement and duly delivered to the purchasers thereof upon payment of the agreed-upon consideration therefor;

(k) in the case of Warrants, (i) the Board will have taken all necessary corporate action to authorize the terms of such Warrants and the warrant agreement relating thereto, (ii) such warrant agreement will have been duly executed and delivered by the Company and the warrant agent thereunder appointed by the Company, (iii) at the time of execution, countersignature, issuance and delivery of any Warrants, the related warrant agreement will be the valid and legally binding obligation of the warrant agent, enforceable against such party in accordance with its terms, (iv) such Warrants and such warrant agreement will be governed by New York law and will not include any provision that is unenforceable and (v) such Warrants or certificates representing such Warrants will be duly executed, countersigned, registered and delivered in accordance with the provisions of such warrant agreement;

(l) in the case of Rights, (i) the Board will have taken all necessary corporate action to authorize the terms of such Rights, (ii) the applicable rights agreement will be duly authorized by the Company and duly executed and delivered by the Company and the rights agent thereunder appointed by the Company, (iii) at the time of execution, countersignature,

issuance and delivery of any Rights, the related rights agreement will be the valid and legally binding obligation of the rights agent, enforceable against such party in accordance with its terms, (iv) such Rights or certificates representing such Rights, if any, will have been duly executed, countersigned, registered and delivered in accordance with the provisions of such rights agreement and the applicable Purchase Agreement and (v) such Rights and such rights agreement will be governed by New York law and will not include any provision that is unenforceable;

(m) in the case of Purchase Contracts, (i) the Board will have taken all necessary corporate action to establish the terms of such Purchase Contracts and approve the purchase contract agreement relating thereto, (ii) such Purchase Contracts will have been duly executed and delivered by the Company and the other parties thereto, (iii) at the time of execution, countersignature, issuance and delivery of any Purchase Contracts, the related purchase contract agreement will be the valid and legally binding obligation of the counterparty, enforceable against such party in accordance with its terms and (iii) such Purchase Contracts will be governed by New York law and will not include any provision that is unenforceable;

(n) in the case of Purchase Units, (i) the Board will have taken all necessary corporate action to establish the terms of such Purchase Units and the terms of the Securities included in such Purchase Units, if any, (ii) the action with respect to the Purchase Contracts included in such Purchase Units referred to in paragraph (m) above will have been taken, (iii) if such Purchase Units include securities other than Securities, such other securities will have been duly and validly executed, issued and delivered by the issuer thereof and will be legal, valid and binding obligations of such issuer, enforceable against such issuer in accordance with their respective terms and (iv) no agreement or other instrument establishing such Purchase Units or defining the rights of the holders of such Purchase Units will contain any provision that is unenforceable;

(o) in the case of Units, (i) the Board will have taken all necessary corporate action to establish the terms of such Units and the terms of the Securities included in such Units, (ii) the terms of the Units and the related Securities and their issuance and sale will have been duly established in conformity with the applicable contracts, agreements or indentures that are a component of the offered Units (including authorization of the issuance of any Securities to be issued pursuant to such Units) and (iii) any agreement or other instrument establishing such Unit or defining the rights of holders of such Unit will be governed by New York law and will not contain any provision that is unenforceable;

(p) in the case of Debt Securities of any series, (i) the Board will have taken all necessary corporate action to designate and establish the terms of such series of Debt Securities, in accordance with the terms of the applicable Indenture, including, if applicable, the execution and delivery of a Supplemental Indenture Document, and such Debt Securities will not include any provision that is unenforceable, (ii) a Supplemental Indenture Document will have been duly executed and delivered by the Company and, as applicable, the trustee thereunder, (iii) at the time of execution, authentication, issuance and delivery of the Debt Securities, the applicable Indenture will be the valid and legally binding obligation of the trustee thereunder, enforceable

against such party in accordance with its terms, (iv) the applicable Indenture will have become qualified under the Trust Indenture Act of 1939, as amended, and (v) forms of Debt Securities complying with the terms of the applicable Indenture and evidencing such Debt Securities will have been duly executed, authenticated, issued and delivered in accordance with the provisions of the applicable Indenture.

Based on the foregoing, and subject to the assumptions, qualifications, limitations, and exceptions set forth herein, we are of the opinion that:

The opinions set forth above are limited in all respects to matters of the contract law of the State of New York, the General Corporation Law of the State of Delaware and applicable federal law of the United States of America, in each case, as in effect on the date hereof.

We hereby consent to the filing of this opinion of counsel as Exhibit 5.1 to the Registration Statement. We also consent to the reference to our Firm under the heading “Legal Matters” in the Base Prospectus forming a part of the Registration Statement. In giving this consent, we do not hereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act or the rules and regulations of the Commission thereunder.

Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in this Registration Statement on Form S-3 of Sunnova Energy International Inc. of our report dated February 23, 2023 relating to the financial statements, financial statement schedule and the effectiveness of internal control over financial reporting, which appears in Sunnova Energy International Inc.’s Annual Report on Form 10-K for the year ended December 31, 2022. We also consent to the reference to us under the heading “Experts” in such Registration Statement.

/s/ PricewaterhouseCoopers LLP

Houston, Texas

July 27, 2023

Exhibit 107

Calculation of Filing Fee Tables

Form S-3

(Form Type)

Sunnova Energy International Inc.

(Exact Name of Registrant as Specified in its Charter)

Table 1: Newly Registered and Carry Forward Securities