Exhibit 12 TUCSON ELECTRIC POWER COMPANY COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES (IN THOUSANDS) 12 Months Ending September 30, December 31, December 31, December 31, December 31, December 31, 1998 1997 1996 1995 1994 1993 --------------- ------------ ------------ ----------- ------------ ---------- Fixed Charges: Interest on Long-Term Debt 74,068 63,573 59,647 69,174 69,353 68,053 Other Interest* 11,707 9,640 11,721 9,113 7,591 9,175 Interest on Capital Lease Obligations** 83,192 83,019 84,383 83,986 82,511 81,932 ------- ------- ------- ------- ------- ------- Total Fixed Charges 168,967 156,232 155,751 162,273 159,455 159,160 Net Income 34,603 83,572 120,852 54,905 20,740 (25,816) Add (Deduct): Income Taxes - Operating Expense 17,625 19,297 9,795 8,920 (91) (91) Income Taxes - Other (713) (41,401) (91,950) (29,356) (4,820) (5,186) Total Fixed Charges 168,967 156,232 155,751 162,273 159,455 159,160 Total Earnings before Taxes and Fixed -------- -------- -------- -------- -------- -------- Charges 220,482 217,700 194,448 196,742 175,284 128,067 Ratio of Earnings to Fixed Charges 1.305 1.393 1.248 1.212 1.099 0.805 <FN> * Excludes recognition of Allowance for Borrowed Funds Used During Construction. ** Capital Lease Interest Paid from Statement of Cash Flows.