As filed with the Securities and Exchange Commission on April 22, 2013

Registration No. 333-            

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-8

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

HANNON ARMSTRONG SUSTAINABLE INFRASTRUCTURE CAPITAL, INC.

(Exact name of registrant as specified in its charter)

2013 Hannon Armstrong Sustainable Infrastructure Capital, Inc. Equity Incentive Plan

(Full title of the plan)

Steven Chuslo, Esq.

Executive Vice President and General Counsel

Hannon Armstrong Sustainable Infrastructure Capital, Inc.

1906 Towne Centre Blvd, Suite 370

Annapolis, MD 21401

(410) 571-6161

(Name and address, including zip code, and telephone number, including

area code, of agent for service)

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

CALCULATION OF REGISTRATION FEE

CONTENTS

PART I

INFORMATION REQUIRED IN THE SECTION 10(A) PROSPECTUS

Item 1. Plan Information.^*

Item 2. Registrant Information and Employee Plan Annual Information.^*

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PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference.

The following documents previously filed by Hannon Armstrong Sustainable Infrastructure Capital, Inc. (the “Company”) with the SEC are incorporated by reference in this registration statement:

(a) The Company’s prospectus, dated April 17, 2013, filed pursuant to Rule 424(b) under the Securities Act (the “Prospectus”); and

(b) The description of the Company’s Common Stock, contained in the Company’s Registration Statement on Form 8-A filed with the SEC on April 15, 2013 to register the Common Stock under the Exchange Act of 1934, as amended (the “Exchange Act”), including any amendment or report filed for the purpose of updating such description.

All documents subsequently filed by the Company pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act, prior to the filing of a post-effective amendment to this registration statement which indicates that all securities offered have been sold or which deregisters all securities then remaining unsold, shall be deemed to be incorporated by reference in this registration statement and to be part hereof from the date of filing of such documents.

Any statement contained in a document incorporated or deemed to be incorporated by reference in this registration statement shall be deemed to be modified or superseded for purposes of this registration statement to the extent that a statement contained in this registration statement, or in any other subsequently filed document that also is or is deemed to be incorporated by reference in this registration statement, modifies or supersedes such prior statement. Any statement contained in this registration statement shall be deemed to be modified or superseded to the extent that a statement contained in a subsequently filed document that is or is deemed to be incorporated by reference in this registration statement modifies or supersedes such prior statement. Any statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this registration statement.

Item 4. Description of Securities.

Not applicable.

Item 5. Interests of Named Experts and Counsel.

Not applicable.

Item 6. Indemnification of Directors and Officers.

Maryland law permits a Maryland corporation to include in its charter a provision eliminating the liability of its directors and officers to the corporation and its stockholders for money damages except for liability resulting from (1) actual receipt of an improper benefit or profit in money, property or services or (2) active and deliberate dishonesty that is established by a final judgment and is material to the cause of action. Our charter contains such a provision which eliminates the liability of our directors and officers to the maximum extent permitted by Maryland law.

Our charter authorizes us to obligate ourselves, and our bylaws obligate us, to the maximum extent permitted by Maryland law, to indemnify and, without requiring a preliminary determination of the ultimate entitlement to indemnification, pay or reimburse reasonable expenses in advance of final disposition of a proceeding to (1) any of our present or former director or officer, (2) any individual who, while serving as our director or officer and at our request, serves or has served another corporation, real estate investment trust (“REIT”), limited liability company, partnership, joint venture, trust, employee benefit plan or any other enterprise as a director, officer, partner, trustee, managing member or manager of such corporation, REIT, limited liability company, partnership, joint venture, trust, employee benefit plan or other enterprise, or (3) any individual who served any predecessor of the ours, including Hannon Armstrong Capital, LLC, in a similar capacity, and who is made or threatened to be

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made a party to or witness in the proceeding by reason of his or her service in such capacity or capacities. Our charter and bylaws also permit us to indemnify and advance expenses to any employee or agent of ours or of any predecessor.

The Maryland General Corporation Law (“MGCL”) requires a Maryland corporation (unless its charter provides otherwise, which our charter does not) to indemnify a director or officer who has been successful, on the merits or otherwise, in the defense of any proceeding to which he or she is made or threatened to be made a party by reason of his or her service in that capacity. The MGCL permits a Maryland corporation to indemnify its present and former directors and officers, among others, against judgments, penalties, fines, settlements and reasonable expenses actually incurred by them in connection with any proceeding to which they may be made or threatened to be made a party by reason of their service in those or other capacities unless it is established that (1) the act or omission of the director or officer was material to the matter giving rise to the proceeding and (A) was committed in bad faith or (B) was the result of active and deliberate dishonesty, (2) the director or officer actually received an improper personal benefit in money, property or services or (3) in the case of any criminal proceeding, the director or officer had reasonable cause to believe that the act or omission was unlawful. Under the MGCL, a Maryland corporation may not indemnify a director or officer in a suit by or in the right of the corporation in which the director or officer was adjudged to be liable to the corporation or in a proceeding in which the director or officer was adjudged to be liable on the basis that personal benefit was improperly received, unless in either case a court orders indemnification and then only for expenses. In addition, the MGCL permits a corporation to advance reasonable expenses to a director or officer upon the corporation’s receipt of (1) a written affirmation by the director or officer of his or her good faith belief that he or she has met the standard of conduct necessary for indemnification by the corporation and (2) a written undertaking by him or her or on his or her behalf to repay the amount paid or reimbursed by the corporation if it is ultimately determined that the standard of conduct was not met.

In addition, we have entered into indemnification agreements with each of our directors and executive officers that provide for indemnification to the maximum extent permitted by Maryland law.

Item 7. Exemption from Registration Claimed.

Not applicable.

Item 8. Exhibits.

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Item 9. Undertakings.

(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 prospectus filed with the Commission 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;

(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) and (a)(1)(ii) of this section 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 Commission by the registrant pursuant to section 13 or section 15(d) of the Exchange Act that are incorporated by reference in 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.

(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 section 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 registrant has been advised that in the opinion of the Securities and Exchange Commission such indemnification is against public policy as expressed in the 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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SIGNATURES

Pursuant to the requirements of the Securities Act, the registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S–8 and has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of New York, State of New York, on April 22, 2013.

Pursuant to the requirements of the Securities Act, this registration statement has been signed by the following persons in the capacities and on the date indicated.

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