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 Acorn Energy, Inc. of our report dated March 30, 2009 relating to the financial statements, which appears in Acorn Energy Inc.’s Annual Report on Form 10-K for the year ended December 31, 2008. We also consent to the incorporation by reference of our report dated March 30, 2009 relating to the financial statement schedules, which appears in such Annual Report on Form 10-K. We also consent to the reference to us under the heading “Experts” in such Registration Statement.

/s/ Kesselman & Kesselman

September 10, 2009

Tel Aviv, Israel