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ACQUISITIONS AND DISPOSITIONS - Schedule of Construction Projects (Details) - Southern Power - MW | 12 Months Ended
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Dec. 31, 2024 | Dec. 31, 2022 | Dec. 31, 2021
Garland Solar Storage |  |  |
Business Acquisition [Line Items] |  |  |
Approximate Nameplate Capacity (MW) |  | 88 | 88
PPA Contract Period |  | 20 years |
Nameplate capacity placed in service (in MWs) |  | 15 | 73
Tranquility Solar Storage |  |  |
Business Acquisition [Line Items] |  |  |
Approximate Nameplate Capacity (MW) |  | 72 | 72
PPA Contract Period |  | 20 years |
Nameplate capacity placed in service (in MWs) |  |  | 32
Tranquillity Solar Storage |  |  |
Business Acquisition [Line Items] |  |  |
Nameplate capacity placed in service (in MWs) |  | 40 |
Millers Branch Solar Development Phase 1 |  |  |
Business Acquisition [Line Items] |  |  |
Approximate Nameplate Capacity (MW) | 200 |  |
PPA Contract Period | 20 years |  |
Millers Branch Solar Development Phase 2 |  |  |
Business Acquisition [Line Items] |  |  |
Approximate Nameplate Capacity (MW) | 180 |  |
PPA Contract Period | 15 years |  |
Millers Branch Solar Development Phase 3 |  |  |
Business Acquisition [Line Items] |  |  |
Approximate Nameplate Capacity (MW) | 132 |  |
PPA Contract Period | 15 years |  |
South Cheyenne Solar Facility |  |  |
Business Acquisition [Line Items] |  |  |
Approximate Nameplate Capacity (MW) | 150 |  |
PPA Contract Period | 20 years |  |

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