EXHIBIT 12 AVISTA CORPORATION Computation of Ratio of Earnings to Fixed Charges and Preferred Dividend Requirements Consolidated (Thousands of Dollars) 12 months ended Years Ended December 31 June 30, ----------------------------------------- 2004 2003 2002 2001 2000 --------- -------- -------- -------- -------- Fixed charges, as defined: Interest expense $ 85,435 $ 85,013 $ 96,005 $100,180 $ 64,765 Amortization of debt expense and premium - net 8,046 7,972 8,861 5,639 3,409 Interest portion of rentals 4,329 4,452 6,140 5,140 4,324 --------- -------- -------- -------- -------- Total fixed charges $ 97,810 $ 97,437 $111,006 $110,959 $ 72,498 ========= ======== ======== ======== ======== Earnings, as defined: Income from continuing operations $ 42,304 $ 50,643 $ 42,174 $ 68,241 $109,065 Add (deduct): Income tax expense 26,632 35,340 34,849 40,585 81,143 Total fixed charges above 97,810 97,437 111,006 110,959 72,498 --------- -------- -------- -------- -------- Total earnings $ 166,746 $183,420 $188,029 $219,785 $262,706 ========= ======== ======== ======== ======== Ratio of earnings to fixed charges 1.70 1.88 1.69 1.98 3.62 Fixed charges and preferred dividend requirements: Fixed charges above $ 97,810 $ 97,437 $111,006 $110,959 $ 72,498 Preferred dividend requirements (1) -- 1,910 4,387 3,878 41,394 --------- -------- -------- -------- -------- Total $ 97,810 $ 99,347 $115,393 $114,837 $113,892 ========= ======== ======== ======== ======== Ratio of earnings to fixed charges and preferred dividend requirements 1.70 1.85 1.63 1.91 2.31 (1) Preferred dividend requirements have been grossed up to their pre-tax level. Effective July 1, 2003, preferred dividends are included in interest expense with the adoption of SFAS No. 150.