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28. OPERATING COSTS AND EXPENSES (Details 2) - BRL (R$) R$ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Disclosure Of Operating Costs And Expenses [line items] |  |  |  |
Energy purchased for resale | R$ 12,111 | R$ 11,286 | [1] | R$ 11,084
Supply from itaipu binacional [member] |  |  |  |
Disclosure Of Operating Costs And Expenses [line items] |  |  |  |
Energy purchased for resale | 1,990 | 1,429 |  | 1,351
Physical guarantee quota contracts [member] |  |  |  |
Disclosure Of Operating Costs And Expenses [line items] |  |  |  |
Energy purchased for resale | 780 | 715 |  | 679
Quotas for Angra I and II nuclear plants [member] |  |  |  |
Disclosure Of Operating Costs And Expenses [line items] |  |  |  |
Energy purchased for resale | 303 | 269 |  | 267
Spot market [member] |  |  |  |
Disclosure Of Operating Costs And Expenses [line items] |  |  |  |
Energy purchased for resale | 1,497 | 1,886 |  | 1,818
Proinfa program [member] |  |  |  |
Disclosure Of Operating Costs And Expenses [line items] |  |  |  |
Energy purchased for resale | 318 | 376 |  | 324
Bilateral contracts [member] |  |  |  |
Disclosure Of Operating Costs And Expenses [line items] |  |  |  |
Energy purchased for resale | 333 | 311 |  | 484
Energy acquired in regulated market auctions [member] |  |  |  |
Disclosure Of Operating Costs And Expenses [line items] |  |  |  |
Energy purchased for resale | 3,334 | 3,021 |  | 3,346
Energy acquired in the free market [member] |  |  |  |
Disclosure Of Operating Costs And Expenses [line items] |  |  |  |
Energy purchased for resale | 3,977 | 4,098 |  | 3,871
Distributed generation ('geracao distribuida') [member] |  |  |  |
Disclosure Of Operating Costs And Expenses [line items] |  |  |  |
Energy purchased for resale | 678 | 207 |  |
PIS/pasep and cofins credits [member] |  |  |  |
Disclosure Of Operating Costs And Expenses [line items] |  |  |  |
Energy purchased for resale | R$ (1,099) | R$ (1,026) |  | R$ (1,056)
[1] | See note 2.8.

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