UniSource Energy Corporation 
Computation of Ratio of Earnings to Fixed Charges
 3 Months Ended
    
    
    12 Months Ended
    
    
    12 Months EndedMarch 31,
    
    
    March 31,
    
    
    Dec. 31,
    
    
    Dec. 31,
    
    
    Dec. 31,
    
    
    Dec. 31,
    
    
    Dec. 31,2010
    
    
    2010
    
    
    2009
    
    
    2008
    
    
    2007
    
    
    2006
    
    
    2005-Thousands of Dollars-Fixed Charges:Interest on Long-Term Debt
    
    $
    15,240
    
    
    $
    58,731
    
    
    $
    58,134
    
    
    $
    70,227
    
    
    $
    73,095
    
    
    $
    75,039
    
    
    $
    76,762Other Interest (1)
    
    
    886
    
    
    
    3,884
    
    
    
    3,468
    
    
    
    1,837
    
    
    
    5,480
    
    
    
    7,922
    
    
    
    3,153Interest on Capital Lease Obligations
    
    
    13,602
    
    
    
    50,650
    
    
    
    53,682
    
    
    
    57,272
    
    
    
    64,499
    
    
    
    72,586
    
    
    
    79,098Estimated Interest Portion of Rental Expense
    
    
    63
    
    
    
    322
    
    
    
    345
    
    
    
    188
    
    
    
    258
    
    
    
    326
    
    
    
    391Total Fixed Charges
    
    $
    29,791
    
    
    $
    113,587
    
    
    $
    115,629
    
    
    $
    129,524
    
    
    $
    143,332
    
    
    $
    155,873
    
    
    $
    159,404Net Income
    
    $
    19,972
    
    
    $
    119,311
    
    
    $
    104,258
    
    
    $
    14,021
    
    
    $
    58,373
    
    
    $
    67,447
    
    
    $
    46,144Add:Discontinued Operations Loss  Net of Tax
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    1,796
    
    
    
    5,483Cumulative Effect of Accounting Change Loss  Net of Tax
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    626Net Income from Continuing Operations
    
    
    19,972
    
    
    
    119,311
    
    
    
    104,258
    
    
    
    14,021
    
    
    
    58,373
    
    
    
    69,243
    
    
    
    52,253Add (Deduct):(Income) Losses from Equity Investees
    
    
    (76
    )
    
    
    1,731
    
    
    
    1,834
    
    
    
    713
    
    
    
    340
    
    
    
    (210
    )
    
    
    (2,113
    )Income Taxes
    
    
    12,435
    
    
    
    73,526
    
    
    
    64,348
    
    
    
    16,976
    
    
    
    39,079
    
    
    
    43,936
    
    
    
    37,623Total Fixed Charges
    
    
    29,791
    
    
    
    113,587
    
    
    
    115,629
    
    
    
    129,524
    
    
    
    143,332
    
    
    
    155,873
    
    
    
    159,404Total Earnings before Taxes and Fixed Charges
    
    $
    62,122
    
    
    $
    308,155
    
    
    $
    286,069
    
    
    $
    161,234
    
    
    $
    241,124
    
    
    $
    268,842
    
    
    $
    247,167Ratio of Earnings to Fixed Charges
    
    
    2.085
    
    
    
    2.713
    
    
    
    2.474
    
    
    
    1.245
    
    
    
    1.682
    
    
    
    1.725
    
    
    
    1.551
 (1)
    
    Excludes recognition of Allowance for Borrowed Funds Used During Construction.