Exhibit 12 SEMCO ENERGY, Inc. Ratio of Earnings to Fixed Charges (Thousands of Dollars) Years ended December 31, ----------------------------------------------------- Description 2002 2001 2000 (b) 1999 (b) 1998 (b) - ----------------------------------------------- --------- --------- --------- --------- --------- Earning as defined (a) Income (loss) before income taxes, divid- ends on trust preferred securities, discon- tinued operations & extraordinary items. . . $ 27,679 $ 14,942 $ 33,156 $ 25,653 $ 15,015 Fixed charges as defined. . . . . . . . . . . . 44,500 45,019 42,604 20,732 14,915 --------- Less preferred securities dividend require- ments of consolidated subsidiaries . . . . . (13,232) (13,235) (7,699) (242) (274) Other items . . . . . . . . . . . . . . . . . . 0 0 0 158 178 --------- --------- --------- --------- --------- Earnings as defined . . . . . . . . . . . $ 58,947 $ 46,726 $ 68,061 $ 46,301 $ 29,834 ========= ========= ========= ========= ========= Fixed charges as defined (a) Interest expense. . . . . . . . . . . . . . . . $ 30,237 $ 30,945 $ 32,637 $ 19,193 $ 14,191 Amortization of debt expense. . . . . . . . . . 1,031 839 2,268 1,297 450 Preferred securities dividend requirements of consolidated subsidiaries . . . . . . . . 13,232 13,235 7,699 242 274 --------- --------- --------- --------- --------- Fixed charges as defined. . . . . . . . . $ 44,500 $ 45,019 $ 42,604 $ 20,732 $ 14,915 ========= ========= ========= ========= ========= Ratio of earnings to fixed charges. . . . . . . 1.32 1.04 1.60 2.23 2.00 ========= ========= ========= ========= ========= <FN> Notes: (a) Earnings and fixed charges as defined in instructions for Item 503 of Regulation S-K. (b) The ratio of earnings to fixed charges calculations for years prior to 2001 have been restated to account for the effect of discontinuing the Company's engineering business during the fourth quarter of 2001.