Exhibit (12)(B) to the Sierra Pacific Resources 1999 Form 10-K NEVADA POWER COMPANY CALCULATION OF PRE-TAX INTEREST COVERAGES (dollars in thousands) 1999 1998 1997 --------- --------- --------- Total Income Before Interest Charges $ 131,930 $ 151,619 $ 140,215 Less: Equity in Earnings of Sierra Pacific Resources (13,058) - - Add: Income Taxes: Included in operating expense 19,943 42,949 43,478 Included in other income - net 1,272 2,522 1,747 Allowance for Borrowed Funds Used During Construction 8,356 6,080 2,579 --------- --------- --------- Total Numerator $ 148,443 $ 203,170 $ 188,019 ========= ========= ========= Interest Charges: Long-Term Debt $ 64,454 $ 56,995 $ 50,791 Other 8,815 6,018 1,531 --------- --------- --------- Total Denominator $ 73,269 $ 63,013 $ 52,322 ========= ========= ========= Pre-Tax Interest Coverage 2.03 3.22 3.59 ========= ========= =========