EXHIBIT 24(a) Power of Attorney KNOW ALL MEN BY THESE PRESENTS, that the undersigned Principal Executive Officer, Principal Financial Officer, Principal Accounting Officer, officers and/or directors of UniSource Energy Corporation, an Arizona corporation, which corporation proposes to file with the Securities and Exchange Commission an Annual Report on Form 10-K for the year ended December 31, 1998, under the Securities Exchange Act of 1934, as amended, does each for himself and not for one another, hereby constitute and appoint Ira R. Adler, Dennis R. Nelson and Karen G. Kissinger and each of them, his true and lawful attorneys, in his name, place and stead, to sign his name to said proposed Annual Report on Form 10-K and any and all amendments thereto, and to cause the same to be filed with the Securities and Exchange Commission, it being intended to grant and hereby granting to said attorneys, and each of them, full power and authority to do and perform any act and thing necessary and proper to be done in the premises as fully and to all intents and purposes as the undersigned could do if personally present; and each of the undersigned for himself hereby ratifies and confirms all that said attorneys, or any one of them, shall lawfully do or cause to be done by virtue hereof. IN WITNESS WHEREOF, each of the undersigned has hereunto set their hand as of the 31st day of March, 1999. /s/ James S. Pignatelli /s/ Larry W. Bickle _____________________________ _____________________________ James S. Pignatelli Larry W. Bickle, Director Principal Executive Officer and Chairman of the Board of Directors /s/ Elizabeth T. Bilby _____________________________ Elizabeth T. Bilby, Director /s/ Ira R. Adler _____________________________ Ira R. Adler /s/ Harold W. Burlingame Principal Financial Officer _____________________________ and Director Harold W. Burlingame, Director /s/ Karen G. Kissinger /s/ Jose L. Canchola _____________________________ _____________________________ Karen G. Kissinger Jose L. Canchola, Director Principal Accounting Officer /s/ John L. Carter _____________________________ John L. Carter, Director /s/ Daniel W. Fessler _____________________________ Daniel W. Fessler, Director /s/ John A. Jeter _____________________________ John A. Jeter, Director /s/ R. B. O'Rielly _____________________________ R. B. O'Rielly, Director /s/ Martha R. Seger _____________________________ Martha R. Seger, Director /s/ H. Wilson Sundt _____________________________ H. Wilson Sundt, Director