Exhibit 23.1
CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
We have issued our reports dated June 14, 2010, with respect to the consolidated financial statements, schedule and internal control over financial reporting included in the Annual Report on Form 10-K for the year ended March 31, 2010 of Orion Energy Systems, Inc., which are incorporated by reference in this Registration Statement. We consent to the incorporation by reference in the Registration Statement of the aforementioned reports.
/s/ Grant Thornton LLP
Milwaukee, Wisconsin
September 27, 2010
September 27, 2010