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v3.24.3

Regulatory Matters (Tables) | 9 Months Ended
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Sep. 30, 2024
Regulatory Assets [Line Items] |
Regulatory Assets | Regulatory assets were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| September 30, 2024 |  | December 31, 2023 |  | September 30, 2024 |  | December 31, 2023 |  | September 30, 2024 |  | December 31, 2023
Tax-related | $1,000 |  | $934 |  | $885 |  | $831 |  | $115 |  | $103
AROs | 418 |  | 194 |  | 223 |  | 160 |  | 195 |  | 34
Pension and OPEB costs | 329 |  | 347 |  | 163 |  | 171 |  | 166 |  | 176
Assets retired early | 181 |  | 273 |  | 169 |  | 259 |  | 12 |  | 14
Derivatives | 80 |  | 102 |  | 24 |  | 34 |  | 56 |  | 68
Commodity cost recovery | 76 |  | 120 |  | 8 |  | 12 |  | 68 |  | 108
WPL’s Western Wisconsin gas distribution expansion investments | 42 |  | 44 |  | — |  | — |  | 42 |  | 44
IPL’s Duane Arnold Energy Center purchased power agreement amendment | 24 |  | 42 |  | 24 |  | 42 |  | — |  | —
Other | 200 |  | 205 |  | 72 |  | 68 |  | 128 |  | 137
| $2,350 |  | $2,261 |  | $1,568 |  | $1,577 |  | $782 |  | $684
Regulatory Liabilities | Regulatory liabilities were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| September 30, 2024 |  | December 31, 2023 |  | September 30, 2024 |  | December 31, 2023 |  | September 30, 2024 |  | December 31, 2023
Tax-related | $589 |  | $566 |  | $286 |  | $299 |  | $303 |  | $267
Cost of removal obligations | 359 |  | 366 |  | 215 |  | 242 |  | 144 |  | 124
Derivatives | 47 |  | 65 |  | 26 |  | 34 |  | 21 |  | 31
Commodity cost recovery | 45 |  | 48 |  | 8 |  | 13 |  | 37 |  | 35
Other | 32 |  | 85 |  | 18 |  | 56 |  | 14 |  | 29
| $1,072 |  | $1,130 |  | $553 |  | $644 |  | $519 |  | $486
IPL [Member] |
Regulatory Assets [Line Items] |
Regulatory Assets | Regulatory assets were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| September 30, 2024 |  | December 31, 2023 |  | September 30, 2024 |  | December 31, 2023 |  | September 30, 2024 |  | December 31, 2023
Tax-related | $1,000 |  | $934 |  | $885 |  | $831 |  | $115 |  | $103
AROs | 418 |  | 194 |  | 223 |  | 160 |  | 195 |  | 34
Pension and OPEB costs | 329 |  | 347 |  | 163 |  | 171 |  | 166 |  | 176
Assets retired early | 181 |  | 273 |  | 169 |  | 259 |  | 12 |  | 14
Derivatives | 80 |  | 102 |  | 24 |  | 34 |  | 56 |  | 68
Commodity cost recovery | 76 |  | 120 |  | 8 |  | 12 |  | 68 |  | 108
WPL’s Western Wisconsin gas distribution expansion investments | 42 |  | 44 |  | — |  | — |  | 42 |  | 44
IPL’s Duane Arnold Energy Center purchased power agreement amendment | 24 |  | 42 |  | 24 |  | 42 |  | — |  | —
Other | 200 |  | 205 |  | 72 |  | 68 |  | 128 |  | 137
| $2,350 |  | $2,261 |  | $1,568 |  | $1,577 |  | $782 |  | $684
Regulatory Liabilities | Regulatory liabilities were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| September 30, 2024 |  | December 31, 2023 |  | September 30, 2024 |  | December 31, 2023 |  | September 30, 2024 |  | December 31, 2023
Tax-related | $589 |  | $566 |  | $286 |  | $299 |  | $303 |  | $267
Cost of removal obligations | 359 |  | 366 |  | 215 |  | 242 |  | 144 |  | 124
Derivatives | 47 |  | 65 |  | 26 |  | 34 |  | 21 |  | 31
Commodity cost recovery | 45 |  | 48 |  | 8 |  | 13 |  | 37 |  | 35
Other | 32 |  | 85 |  | 18 |  | 56 |  | 14 |  | 29
| $1,072 |  | $1,130 |  | $553 |  | $644 |  | $519 |  | $486
WPL [Member] |
Regulatory Assets [Line Items] |
Regulatory Assets | Regulatory assets were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| September 30, 2024 |  | December 31, 2023 |  | September 30, 2024 |  | December 31, 2023 |  | September 30, 2024 |  | December 31, 2023
Tax-related | $1,000 |  | $934 |  | $885 |  | $831 |  | $115 |  | $103
AROs | 418 |  | 194 |  | 223 |  | 160 |  | 195 |  | 34
Pension and OPEB costs | 329 |  | 347 |  | 163 |  | 171 |  | 166 |  | 176
Assets retired early | 181 |  | 273 |  | 169 |  | 259 |  | 12 |  | 14
Derivatives | 80 |  | 102 |  | 24 |  | 34 |  | 56 |  | 68
Commodity cost recovery | 76 |  | 120 |  | 8 |  | 12 |  | 68 |  | 108
WPL’s Western Wisconsin gas distribution expansion investments | 42 |  | 44 |  | — |  | — |  | 42 |  | 44
IPL’s Duane Arnold Energy Center purchased power agreement amendment | 24 |  | 42 |  | 24 |  | 42 |  | — |  | —
Other | 200 |  | 205 |  | 72 |  | 68 |  | 128 |  | 137
| $2,350 |  | $2,261 |  | $1,568 |  | $1,577 |  | $782 |  | $684
Regulatory Liabilities | Regulatory liabilities were comprised of the following items (in millions):
| Alliant Energy |  | IPL |  | WPL
| September 30, 2024 |  | December 31, 2023 |  | September 30, 2024 |  | December 31, 2023 |  | September 30, 2024 |  | December 31, 2023
Tax-related | $589 |  | $566 |  | $286 |  | $299 |  | $303 |  | $267
Cost of removal obligations | 359 |  | 366 |  | 215 |  | 242 |  | 144 |  | 124
Derivatives | 47 |  | 65 |  | 26 |  | 34 |  | 21 |  | 31
Commodity cost recovery | 45 |  | 48 |  | 8 |  | 13 |  | 37 |  | 35
Other | 32 |  | 85 |  | 18 |  | 56 |  | 14 |  | 29
| $1,072 |  | $1,130 |  | $553 |  | $644 |  | $519 |  | $486

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