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v3.23.2

Regulatory Matters (Tables) | 6 Months Ended
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Jun. 30, 2023
Regulatory Assets [Line Items] |
Regulatory Assets | Regulatory assets were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| June 30, 2023 |  | December 31, 2022 |  | June 30, 2023 |  | December 31, 2022 |  | June 30, 2023 |  | December 31, 2022
Tax-related | $957 |  | $929 |  | $868 |  | $848 |  | $89 |  | $81
Pension and OPEB costs | 378 |  | 392 |  | 190 |  | 197 |  | 188 |  | 195
Assets retired early | 290 |  | 70 |  | 274 |  | 53 |  | 16 |  | 17
Asset retirement obligations | 197 |  | 151 |  | 156 |  | 110 |  | 41 |  | 41
Commodity cost recovery | 145 |  | 160 |  | 6 |  | 1 |  | 139 |  | 159
Derivatives | 102 |  | 84 |  | 41 |  | 48 |  | 61 |  | 36
IPL’s Duane Arnold Energy Center PPA amendment | 54 |  | 66 |  | 54 |  | 66 |  | — |  | —
WPL’s Western Wisconsin gas distribution expansion investments | 47 |  | 48 |  | — |  | — |  | 47 |  | 48
Other | 174 |  | 146 |  | 59 |  | 63 |  | 115 |  | 83
| $2,344 |  | $2,046 |  | $1,648 |  | $1,386 |  | $696 |  | $660
Regulatory Liabilities | Regulatory liabilities were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| June 30, 2023 |  | December 31, 2022 |  | June 30, 2023 |  | December 31, 2022 |  | June 30, 2023 |  | December 31, 2022
Tax-related | $572 |  | $579 |  | $301 |  | $303 |  | $271 |  | $276
Cost of removal obligations | 405 |  | 398 |  | 260 |  | 259 |  | 145 |  | 139
Derivatives | 90 |  | 210 |  | 48 |  | 115 |  | 42 |  | 95
Commodity cost recovery | 39 |  | 40 |  | 15 |  | 38 |  | 24 |  | 2
Electric transmission cost recovery | 19 |  | 20 |  | 14 |  | 10 |  | 5 |  | 10
WPL’s West Riverside liquidated damages | 17 |  | 32 |  | — |  | — |  | 17 |  | 32
Other | 66 |  | 45 |  | 38 |  | 29 |  | 28 |  | 16
| $1,208 |  | $1,324 |  | $676 |  | $754 |  | $532 |  | $570
IPL [Member] |
Regulatory Assets [Line Items] |
Regulatory Assets | Regulatory assets were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| June 30, 2023 |  | December 31, 2022 |  | June 30, 2023 |  | December 31, 2022 |  | June 30, 2023 |  | December 31, 2022
Tax-related | $957 |  | $929 |  | $868 |  | $848 |  | $89 |  | $81
Pension and OPEB costs | 378 |  | 392 |  | 190 |  | 197 |  | 188 |  | 195
Assets retired early | 290 |  | 70 |  | 274 |  | 53 |  | 16 |  | 17
Asset retirement obligations | 197 |  | 151 |  | 156 |  | 110 |  | 41 |  | 41
Commodity cost recovery | 145 |  | 160 |  | 6 |  | 1 |  | 139 |  | 159
Derivatives | 102 |  | 84 |  | 41 |  | 48 |  | 61 |  | 36
IPL’s Duane Arnold Energy Center PPA amendment | 54 |  | 66 |  | 54 |  | 66 |  | — |  | —
WPL’s Western Wisconsin gas distribution expansion investments | 47 |  | 48 |  | — |  | — |  | 47 |  | 48
Other | 174 |  | 146 |  | 59 |  | 63 |  | 115 |  | 83
| $2,344 |  | $2,046 |  | $1,648 |  | $1,386 |  | $696 |  | $660
Regulatory Liabilities | Regulatory liabilities were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| June 30, 2023 |  | December 31, 2022 |  | June 30, 2023 |  | December 31, 2022 |  | June 30, 2023 |  | December 31, 2022
Tax-related | $572 |  | $579 |  | $301 |  | $303 |  | $271 |  | $276
Cost of removal obligations | 405 |  | 398 |  | 260 |  | 259 |  | 145 |  | 139
Derivatives | 90 |  | 210 |  | 48 |  | 115 |  | 42 |  | 95
Commodity cost recovery | 39 |  | 40 |  | 15 |  | 38 |  | 24 |  | 2
Electric transmission cost recovery | 19 |  | 20 |  | 14 |  | 10 |  | 5 |  | 10
WPL’s West Riverside liquidated damages | 17 |  | 32 |  | — |  | — |  | 17 |  | 32
Other | 66 |  | 45 |  | 38 |  | 29 |  | 28 |  | 16
| $1,208 |  | $1,324 |  | $676 |  | $754 |  | $532 |  | $570
WPL [Member] |
Regulatory Assets [Line Items] |
Regulatory Assets | Regulatory assets were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| June 30, 2023 |  | December 31, 2022 |  | June 30, 2023 |  | December 31, 2022 |  | June 30, 2023 |  | December 31, 2022
Tax-related | $957 |  | $929 |  | $868 |  | $848 |  | $89 |  | $81
Pension and OPEB costs | 378 |  | 392 |  | 190 |  | 197 |  | 188 |  | 195
Assets retired early | 290 |  | 70 |  | 274 |  | 53 |  | 16 |  | 17
Asset retirement obligations | 197 |  | 151 |  | 156 |  | 110 |  | 41 |  | 41
Commodity cost recovery | 145 |  | 160 |  | 6 |  | 1 |  | 139 |  | 159
Derivatives | 102 |  | 84 |  | 41 |  | 48 |  | 61 |  | 36
IPL’s Duane Arnold Energy Center PPA amendment | 54 |  | 66 |  | 54 |  | 66 |  | — |  | —
WPL’s Western Wisconsin gas distribution expansion investments | 47 |  | 48 |  | — |  | — |  | 47 |  | 48
Other | 174 |  | 146 |  | 59 |  | 63 |  | 115 |  | 83
| $2,344 |  | $2,046 |  | $1,648 |  | $1,386 |  | $696 |  | $660
Regulatory Liabilities | Regulatory liabilities were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| June 30, 2023 |  | December 31, 2022 |  | June 30, 2023 |  | December 31, 2022 |  | June 30, 2023 |  | December 31, 2022
Tax-related | $572 |  | $579 |  | $301 |  | $303 |  | $271 |  | $276
Cost of removal obligations | 405 |  | 398 |  | 260 |  | 259 |  | 145 |  | 139
Derivatives | 90 |  | 210 |  | 48 |  | 115 |  | 42 |  | 95
Commodity cost recovery | 39 |  | 40 |  | 15 |  | 38 |  | 24 |  | 2
Electric transmission cost recovery | 19 |  | 20 |  | 14 |  | 10 |  | 5 |  | 10
WPL’s West Riverside liquidated damages | 17 |  | 32 |  | — |  | — |  | 17 |  | 32
Other | 66 |  | 45 |  | 38 |  | 29 |  | 28 |  | 16
| $1,208 |  | $1,324 |  | $676 |  | $754 |  | $532 |  | $570

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