POWER OF ATTORNEY

                  FOR SEC FILINGS ON FORMS ID, 3, 4, 5 AND 144
                          IN RESPECT OF SECURITIES OF
           HANNON ARMSTRONG SUSTAINABLE INFRASTRUCTURE CAPITAL, INC.

The undersigned hereby constitutes and appoints each of Steven Chuslo,
Katherine Dent, Jay Bernstein, Andrew Epstein, Michael Kessler, Matthew Worden
and Tae Ho Cho or any one of them acting alone, as her true and lawful
attorney-in-fact and agent, with full power of substitution and resubstitution
for her in her name and stead in any and all capacities, to sign and file for
and on her behalf, in respect of any acquisition, disposition or other change
in beneficial ownership of any shares of common stock, par value $0.01 per
share, of Hannon Armstrong Sustainable Infrastructure Capital, Inc. (the
"Company"), the following:

    (i)   any Form ID to be filed with the Securities and Exchange Commission
          (the "SEC");

    (ii)  any Initial Statement of Beneficial Ownership of Securities on Form
3 to be filed with the SEC;

    (iii) any Statement of Changes of Beneficial Ownership of Securities on
          Form 4 to be filed with the SEC;

    (iv)  any Annual Statement of Beneficial Ownership of Securities on Form 5
to be filed with the SEC;

    (v)   any Notice of Proposed Sale of Securities on Form 144 to be filed
with the SEC; and

    (vi)  any and all agreements, certificates, receipts, or other documents
in connection therewith.

The undersigned hereby gives full power and authority to the attorney-in-fact
to seek and obtain as the undersigned's representative and on the
undersigned's behalf, information on transactions in the Company's securities
from any third party, including brokers, employee benefit plan administrators
and trustees, and the undersigned hereby authorizes any such person to release
such information to the undersigned and approves and ratifies any such release
of information.

The undersigned hereby grants unto such attorney-in-fact and agent full power
and authority to do and perform each and every act and thing requisite and
necessary in connection with such matters and hereby ratifies and confirms all
that any such attorney-in-fact and agent or substitute may do or cause to be
done by virtue hereof.

The undersigned acknowledges that:

(i) neither the Company nor such attorney-in-fact assumes (i) any
liability for the undersigned's responsibility to comply with the
requirement of the Securities Exchange Act of 1934, as amended (the
"Exchange Act"), (ii) any liability of the undersigned for any failure to
comply with such requirements or (iii) any obligation or liability
of the undersigned for profit disgorgement under Section 16(b) of the
Exchange Act; and

(i) this Power of Attorney does not relieve the undersigned from
responsibility for compliance with the undersigned's obligations under the
Exchange Act, including without limitation the reporting
requirements under Section 16 of the Exchange Act


This Power of Attorney shall remain in full force and effect until revoked by
the undersigned in a signed writing delivered to such attorney-in-fact.


IN WITNESS WHEREOF, the undersigned has executed this Power of Attorney.


Date: March 3, 2017             /s/ Rebecca Blalock
                               ------------------------------------
                                Rebecca Blalock