Exhibit (12)(A) to the Sierra Pacific Resources 1999 Form 10-K SIERRA PACIFIC RESOURCES CALCULATION OF PRE-TAX INTEREST COVERAGES (dollars in thousands) 1999 1998 1997 -------- -------- -------- Total Income Before Interest Charges $171,016 $151,619 $140,215 Add: Income Taxes: Included in operating expense 26,086 42,949 43,478 Included in other income - net 1,272 2,522 1,747 Allowance for Borrowed Funds Used During Construction 8,127 6,080 2,579 -------- -------- -------- Total Numerator $206,501 $203,170 $188,019 ======== ======== ======== Interest Charges: Long-Term Debt $ 81,731 $ 56,995 $ 50,791 Other 26,356 6,018 1,531 -------- -------- -------- Total Denominator $108,087 $ 63,013 $ 52,322 ======== ======== ======== Pre-Tax Interest Coverage 1.91 3.22 3.59 ======== ======== ========