**Tucson      Electric Power Company**

**Computation      of Ratio of Earnings to Fixed Charges**

|                                                                                    |   | 3                  Months                  Ended                       |   | 12                  Months                  Ended |  12                  Months                  Ended |                      |
|-----------------------------------------------------------------------------------------|--------|------------------------------------------------------------------------|--------|---------------------------------------------------|---------------------------------------------------------|---------------------------|
|                                                                                    |   | Mar.                  31,                                              |   | Mar.                  31,                         |                                                    | Dec.                  31, |   | Dec.                  31, |   | Dec.                  31, |   | Dec.                  31, |   | Dec.                  31, |   |
|                                                                                    |   | 2006                                                                   |   | 2006                                              |                                                    | 2005                      |   | 2004 |   | 2003 |   | 2002 |   | 2001 |   |
|                                                                                    |   |  -                  Thousands                  of Dollars -  |   |
| **Fixed                  Charges:**                                                     |   |                                                                   |   |                                              |                                                    |                      |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
|   Interest                  on Long-Term Debt                                 |   | $                                                                      | 12,649 |                                              | $                                                       | 51,912                    |   | $ | 56,243 |   | $ | 69,904 |   | $ | 76,585 |   | $ | 65,620 |   | $ | 68,678 |   |
|   Other                  Interest                  (1)                        |   |                                                                   | 969    |                                              |                                                    | 2,818                     |   |   | 2,597 |   |   | 1,263 |   |   | 1,820 |   |   | 273 |   |   | 441 |   |
|   Interest                  on Capital Lease                  Obligations     |   |                                                                   | 18,539 |                                              |                                                    | 77,866                    |   |   | 79,064 |   |   | 85,869 |   |   | 84,053 |   |   | 87,783 |   |   | 90,506 |   |
| **Total                  Fixed Charges**                                                |   |                                                                   | 32,157 |                                              |                                                    | 132,596                   |   |   | 137,904 |   |   | 157,036 |   |   | 162,458 |   |   | 153,676 |   |   | 159,625 |   |
|                                                                                    |   |                                                                   |   |                                              |                                                    |                      |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| **Net                  Income**                                                         |   |                                                                   | 16,587 |                                              |                                                    | 69,545                    |   |   | 48,267 |   |   | 46,127 |   |   | 128,913 |   |   | 55,390 |   |   | 77,778 |   |
|                                                                                    |   |                                                                   |   |                                              |                                                    |                      |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| **Less:**                                                                               |   |                                                                   |   |                                              |                                                    |                      |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
|   Cumulative                  Effect of                  Accounting Change -  |   |                                                                   |   |                                              |                                                    |                      |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
|     Net                  of                  Tax                    |   |                                                                   | -      |                                              |                                                    | (626                      | ) |   | (626 | ) |   | - |   |   | 67,471 |   |   | - |   |   | 470 |   |
| **Net                  Income from Continuing Operations**                              |   |                                                                   | 16,587 |                                              |                                                    | 70,171                    |   |   | 48,893 |   |   | 46,127 |   |   | 61,442 |   |   | 55,390 |   |   | 77,308 |   |
|                                                                                    |   |                                                                   |   |                                              |                                                    |                      |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| **Add                  (Deduct):**                                                      |   |                                                                   |   |                                              |                                                    |                      |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
|   (Income)                  Losses from Equity                  Investees (2) |   |                                                                   | (53    | )                                            |                                                    | (352                      | )  |   | (314 | )  |   | (131 | )  |   | (76 | )  |   | 17 |   |   | 700 |   |
|   Income                  Taxes                                               |   |                                                                   | 11,528 |                                              |                                                    | 47,596                    |   |   | 33,907 |   |   | 34,815 |   |   | 21,090 |   |   | 36,434 |   |   | 57,545 |   |
|   Total                  Fixed                  Charges                       |   |                                                                   | 32,157 |                                              |                                                    | 132,596                   |   |   | 137,904 |   |   | 157,036 |   |   | 162,458 |   |   | 153,676 |   |   | 159,625 |   |
|                                                                                    |   |                                                                   |   |                                              |                                                    |                      |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| **Total                  Earnings before Taxes**                                        |   |                                                                   |   |                                              |                                                    |                      |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| **and                  Fixed Charges**                                                  |   | $                                                                      | 60,219 |                                              | $                                                       | 250,011                   |   | $ | 220,390 |   | $ | 237,847 |   | $ | 244,914 |   | $ | 245,517 |    | $ | 295,178 |   |
|                                                                                    |   |                                                                   |   |                                              |                                                    |                      |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
|                                                                                    |   |                                                                   |   |                                              |                                                    |                      |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| **Ratio                  of Earnings to Fixed Charges**                                 |   |                                                                   | 1.873  |                                              |                                                    | 1.886                     |   |   | 1.598 |   |   | 1.515 |   |   | 1.508 |   |   | 1.598 |   |   | 1.849 |   |