| Exhibit      12.3                                                                                                                 |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |
|-----------------------------------------------------------------------------------------------------------------------------------|--------|----------------------------|--------|--------|--------|--------|--------|--------|--------|--------|--------|--------|--------|--------|--------|
|                                                                                                                              |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |
| WISCONSIN      POWER AND LIGHT COMPANY                                                                                            |   |                       |   |   |   |   |   |   |   |   |   |   |   |
|                                                                                                                              |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |
| RATIO      OF EARNINGS TO FIXED CHARGES AND RATIO OF EARNINGS TO COMBINED                                                         |   |
| FIXED      CHARGES AND PREFERRED DIVIDEND REQUIREMENTS                                                                            |   |                       |   |   |   |   |   |   |   |   |
|                                                                                                                              |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |
|                                                                                                                              |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |
|                                                                                                                              |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |
|                                                                                                                              |   | Years Ended Dec.      31,  |   |
|                                                                                                                              |   | 2009                       |   |   | 2008   |   |   | 2007   |   |   | 2006   |   |   | 2005   |   |
|                                                                                                                              |   | (dollars in      millions) |   |
| EARNINGS:                                                                                                                         |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Net      income                                                                                                                   |   | $                          | 89.5   |   |   | $      | 118.4  |   |   | $      | 113.5  |   |   | $      | 105.3  |   |   | $ | 105.1 |   |
| Income taxes      (a)                                                                                                             |   |                       | 45.8   |   |   |   | 68.4   |   |   |   | 59.3   |   |   |   | 62.2   |   |   |   | 60.9 |   |
| Income before income      taxes                                                                                                   |   |                       | 135.3  |   |   |   | 186.8  |   |   |   | 172.8  |   |   |   | 167.5  |   |   |   | 166.0 |   |
|                                                                                                                              |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Fixed charges as      defined                                                                                                     |   |                       | 99.9   |   |   |   | 90.7   |   |   |   | 84.8   |   |   |   | 81.9   |   |   |   | 73.9 |   |
|                                                                                                                              |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Adjustment for      undistributed equity earnings                                                                                 |   |                       | (7.1   | )      |   |   | (6.1   | )      |   |   | (6.7   | )      |   |   | (3.8   | ) |   |   | (1.6 | ) |
|                                                                                                                              |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Total earnings as      defined                                                                                                    |   | $                          | 228.1  |   |   | $      | 271.4  |   |   | $      | 250.9  |   |   | $      | 245.6  |   |   | $ | 238.3 |   |
|                                                                                                                              |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| FIXED      CHARGES:                                                                                                               |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Interest      expense                                                                                                             |   | $                          | 74.8   |   |   | $      | 62.2   |   |   | $      | 49.6   |   |   | $      | 48.3   |   |   | $ | 40.4 |   |
| Estimated interest      component of rent expense                                                                                 |   |                       | 25.1   |   |   |   | 28.5   |   |   |   | 35.2   |   |   |   | 33.6   |   |   |   | 33.5 |   |
| Total fixed charges      as defined                                                                                               |   | $                          | 99.9   |   |   | $      | 90.7   |   |   | $      | 84.8   |   |   | $      | 81.9   |   |   | $ | 73.9 |   |
|                                                                                                                              |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Ratio of Earnings to      Fixed Charges                                                                                           |   |                       | 2.28   |   |   |   | 2.99   |   |   |   | 2.96   |   |   |   | 3.00   |   |   |   | 3.22 |   |
|                                                                                                                              |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Preferred dividend      requirements (pre-tax basis) (b)                                                                          |   | $                          | 5.0    |   |   | $      | 5.2    |   |   | $      | 5.0    |   |   | $      | 5.2    |   |   | $ | 5.2 |   |
|                                                                                                                              |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Fixed charges and      preferred dividend requirements                                                                            |   | $                          | 104.9  |   |   | $      | 95.9   |   |   | $      | 89.8   |   |   | $      | 87.1   |   |   | $ | 79.1 |   |
|                                                                                                                              |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| Ratio of Earnings to      Combined Fixed Charges and                                                                              |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
|    Preferred      Dividend Requirements                                                                            |   |                       | 2.17   |   |   |   | 2.83   |   |   |   | 2.79   |   |   |   | 2.82   |   |   |   | 3.01 |   |
|                                                                                                                              |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| (a)      Includes net interest related to unrecognized taxbenefits.                                                               |   |                       |   |   |   |   |   |   |   |   |   |   |   |
|                                                                                                                              |   |                       |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |
| (b)      Preferred dividend requirements (pre-tax basis) are computed by dividing      the preferred dividend requirements by one |   |
| hundred percent      minus the respective annual effective income tax rate.                                                       |   |                       |   |   |   |