Orion Energy Systems (OESX) 8-K/A The report accompanying these financial statements was issued by

Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

Orion Energy Systems, Inc.

Manitowoc, Wisconsin

We hereby consent to the incorporation by reference in the Registration Statement Forms S-8 (No. 333-169611 and 333-148401) of Orion Energy Systems, Inc. of our report dated September 13, 2013 relating to the combined financial statements of Harris Manufacturing, Inc. and Harris LED, LLC which appears in this Form 8-K.

/s/ BDO USA, LLP

Milwaukee, Wisconsin

September 13, 2013