UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q/A

Amendment No. 1

(Mark One)

For the quarterly period ended September 30, 2015

or

For the transition period from                      to                     

Commission File Number 1-12014

POWERSECURE INTERNATIONAL, INC.

(Exact name of registrant as specified in its charter)

(919) 556-3056

(Registrant’s telephone number, including area code)

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (Section 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  x    No  ¨

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.

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).    Yes  ¨    No  x

As of October 30, 2015, 22,483,912 shares of the issuer’s Common Stock were outstanding.

EXPLANATORY NOTE

This Form 10-Q/A, Amendment No. 1 (this “Amendment”) of PowerSecure International, Inc., a Delaware corporation (“PowerSecure”), amends PowerSecure’s quarterly report on Form 10-Q for the fiscal quarter ended September 30, 2015 as filed with the Securities and Exchange Commission (the “SEC”) on November 4, 2015 (the “Original Form 10-Q”). This Amendment is being filed for the sole purpose of refiling the Engineering Procurement and Construction Agreement (the “Agreement”), which was filed as Exhibit 10.1 to the Original Form 10-Q, in response to a comment received from the staff of the SEC in connection with PowerSecure’s request for confidential treatment of certain portions of the Agreement.

As disclosed in the Original Form 10-Q, PowerSecure has been notified by its utility counterparty in the Agreement that the size and scope of the solar project underlying the Agreement may be reduced or terminated, and thus that the Agreement may be amended or terminated, due to a change in the utility customer’s requirements. Accordingly, PowerSecure and the utility are evaluating the impact of potential and evolving modifications to the size and scope of this solar project. This evaluation may result in either a mutually acceptable reduction in the size and scope of the solar project or the mutual termination of the entire solar project. As of the date of this Amendment, the project and the Agreement have not been amended, restated or terminated. PowerSecure cannot provide any assurance about the amount of revenues, if any, it will receive from any modification of this project or that the Agreement will not be terminated in its entirety resulting in no revenues or profits to PowerSecure.

Except as discussed above, this Amendment does not reflect events occurring after the filing of the Original Form 10-Q, and does not modify, revise, change or update in any way PowerSecure’s financial statements or notes thereto or any other disclosure or information contained in the Original Form 10-Q.

In addition, as required by Rule 12b-25 under the Securities Exchange Act of 1934, as amended, new certifications by PowerSecure’s principal executive officer and principal financial officer are filed herewith as exhibits to this Amendment.

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PART II

OTHER INFORMATION

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

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