Exhibit 23

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We hereby consent to the incorporation by reference in the Registration Statements on Form S-8 (No. 333-53333 and No. 333-53309) of UNS Energy Corporation of our report dated June 27, 2014 relating to the financial statements of Tucson Electric Power Company 401 (k) Plan, which appears in this Form 11-K.

/s/ PricewaterhouseCoopers LLP

Phoenix, AZ

June 27, 2014