UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 10-Q/A

Amendment No.1

QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE

SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended March 31, 2013

Commission file number: 0-19771

ACORN ENERGY, INC.

(Exact name of registrant as specified in charter)

302-656-1707

(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 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. (Check one):

Large accelerated filer ¨  Accelerated filer x  Non-accelerated filer ¨  Smaller reporting company ¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).

Yes ¨  No x

Indicate the number of shares outstanding of each of the issuer's classes of common stock, as of the latest practicable date.

Explanatory Note

The purpose of this Amendment No. 1 to the Quarterly Report on Form 10-Q of Acorn Energy, Inc. for the quarterly period ended March 31, 2013, filed with the Securities and Exchange Commission on May 9, 2013 (the “Form 10-Q”), is solely to file certifications of the Chief Executive Officer and Chief Financial Officer as Exhibits 31.1, 31.2, 32.1 and 32.2 to the Form 10-Q which were inadvertently omitted in the initial filing of the Form 10-Q.

No other changes have been made to the Form 10-Q. This Amendment No. 1 to the Form 10-Q speaks as of the original filing date of the Form 10-Q, does not reflect events that may have occurred subsequent to the original filing date, and does not modify or update in any way disclosures made in the original Form 10-Q.

PART II

ITEM 6. EXHIBITS.

* This exhibit includes a management contract, compensatory plan or arrangement in which one or more directors or executive officers of the Registrant participate.

# This exhibit is filed or furnished herewith.

## This exhibit has been previously filed or furnished.

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 its principal financial officer thereunto duly authorized.