At September 30, 2012, minimum future commitments related to these operating expense purchase obligations were as follows (in millions): | | | | | | | | | | | | | | Alliant Energy | | IPL | | WPL | Purchased power (a): | | | | | | Duane Arnold Energy Center (DAEC) (IPL) |
| $271 |
| |
| $271 |
| |
| $— |
| Kewaunee Nuclear Power Plant (Kewaunee) (WPL) | 95 |
| | — |
| | 95 |
| Other | 63 |
| | 4 |
| | 59 |
| | 429 |
| | 275 |
| | 154 |
| Natural gas | 344 |
| | 208 |
| | 136 |
| Coal (b) | 302 |
| | 79 |
| | 52 |
| SO2 emission allowances | 34 |
| | 34 |
| | — |
| Other (c) | 22 |
| | 9 |
| | 13 |
| |
| $1,131 |
| |
| $605 |
| |
| $355 |
|
| | (a) | Includes payments required by PPAs for capacity rights and minimum quantities of MWhs required to be purchased. Excludes contracts that are considered operating leases. |
| | (b) | Corporate Services entered into system-wide coal contracts on behalf of IPL and WPL that include minimum future commitments of $171 million that have not been directly assigned to IPL and WPL since the specific needs of each utility were not yet known as of September 30, 2012. |
| | (c) | Includes individual commitments incurred during the normal course of business that exceeded $1 million at September 30, 2012. |
|