Exhibit 23 ---------- Consent of Independent Accountants We hereby consent to the incorporation by reference in the Registration Statements on Form S-8 (No. 333-53333 and No. 333-53309) of UniSource Energy Corporation of our report dated June 21, 2002 relating to the financial statements of the Tucson Electric Power Company 401(k) Plan, which appears in this Form 11-K. PricewaterhouseCoopers LLP Los Angeles, California June 25, 2002