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Operating Costs, Expenses and Other Revenue - Schedule of Other revenue (Details) - BRL (R$) R$ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2024 | Dec. 31, 2023 | Dec. 31, 2022
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Gains arising from the sale of PP&E (note 33a) | R$ 43 |  |  |
Gain on financial instruments – Swap | 147 |  |  |
Bargain purchase |  |  |  | 5
Adjustment to fair value of the previous shareholding interest |  | [1] | 9 |
Periodic Tariff Review, net | 1,521 | [2] |  |
Total | 3,195 |  | 327 | 57
C E M I G Sim [Member] |  |  |  |
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Bargain purchase | 14 | [3] |  | 5
Alianca Geracao [Member] |  |  |  |
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Gain on financial instruments – Swap | 1,617 |  |  |
Baguari Energia [Member] |  |  |  |
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Gain on financial instruments – Swap |  |  | 261 |
Retiro Baixo [Member] |  |  |  |
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Gain on financial instruments – Swap |  |  | 27 |
M E S A [Member] |  |  |  |
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Gain on financial instruments – Swap |  |  | 30 |
Renova Energia S A [Member] |  |  |  |
Disclosure of disaggregation of revenue from contracts with customers [line items] |  |  |  |
Gain on financial instruments – Swap |  |  |  | R$ 52
[1] | This refers to the gain on adjustment to fair value of the previous shareholding interest recognized in the process of acquisition by Cemig SIM, in the 2023 fiscal year, of the remaining 51% of UFV Campo Lindo 1, UFV Campo Lindo 2 and UFV Olaria 1.
[2] | This amount is net of PIS/Pasep and Cofins taxes. The total added to Contractual Assets was R$1,676. For more details see Note 13.
[3] | This amount is made up of advantageous purchases arising from acquisitions made by Cemig SIM, of which R$10 refers to the acquisition of UFV Jequitibá II and R$4 refers to the acquisition of Jequitibá I. For more details see Note 14.

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- Definition The amount of any gain recognised in a business combination in which the net of the identifiable assets acquired and the liabilities assumed exceeds the aggregate of the consideration transferred, non-controlling interest in the acquiree and fair value of the acquirer's previously held equity interest in the acquiree. [Refer: Total for all business combinations [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IFRS -Number 3 -IssueDate 2024-01-01 -Paragraph B64 -Subparagraph n -Clause i -URI https://taxonomy.ifrs.org/xifrs-link?type=IFRS&num=3&code=ifrs-tx-2024-en-r&anchor=para_B64_n_i&doctype=Appendix&subtype=B -URIDate 2024-03-27 + Details
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