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17. PROPERTY, PLANT AND EQUIPMENT (Details) - BRL (R$) R$ in Millions | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | --- | --- | ---
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | R$ 2,407 | R$ 2,450 | [1] | R$ 2,662 |  | R$ 2,762
Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | 2,230 | 2,317 |  | 2,542 |  | 2,656
Investment property under construction or sevelopment [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | 177 | 133 |  | 120 |  | 106
Land [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | 224 | 229 | [2],[3] | 215 | [2] | 211
Reservoirs, dams and watercourses [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | 1,020 | 1,080 |  | 1,150 |  | 1,234
Buildings works and improvements [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | 264 | 274 |  | 314 |  | 331
Machinery and equipment [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | 717 | 729 |  | 854 |  | 874
Vehicles [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | 2 | 2 |  | 5 |  | 3
Furniture and utensils [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | 3 | 3 |  | R$ 4 |  | R$ 3
Historical cost [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | 7,506 | 7,385 |  |  |  |
Historical cost [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | 7,329 | 7,252 |  |  |  |
Historical cost [member] | Investment property under construction or sevelopment [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | 177 | 133 |  |  |  |
Historical cost [member] | Land [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | 247 | 248 |  |  |  |
Historical cost [member] | Reservoirs, dams and watercourses [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | 3,300 | 3,280 |  |  |  |
Historical cost [member] | Buildings works and improvements [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | 1,100 | 1,092 |  |  |  |
Historical cost [member] | Machinery and equipment [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | 2,647 | 2,598 |  |  |  |
Historical cost [member] | Vehicles [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | 21 | 20 |  |  |  |
Historical cost [member] | Furniture and utensils [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | 14 | 14 |  |  |  |
Accumulated depreciation and amortisation [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | (5,099) | (4,935) |  |  |  |
Accumulated depreciation and amortisation [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | (5,099) | (4,935) |  |  |  |
Accumulated depreciation and amortisation [member] | Land [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | (23) | (19) |  |  |  |
Accumulated depreciation and amortisation [member] | Reservoirs, dams and watercourses [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | (2,280) | (2,200) |  |  |  |
Accumulated depreciation and amortisation [member] | Buildings works and improvements [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | (836) | (818) |  |  |  |
Accumulated depreciation and amortisation [member] | Machinery and equipment [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | (1,930) | (1,869) |  |  |  |
Accumulated depreciation and amortisation [member] | Vehicles [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | (19) | (18) |  |  |  |
Accumulated depreciation and amortisation [member] | Furniture and utensils [member] | Investment property completed [member] |  |  |  |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |  |  |  |
Net PP&E | R$ (11) | R$ (11) |  |  |  |
[1] | See note 2.8.
[2] | Balances of R$4 were transferred between Intangible assets, concession contract assets and PP&E.
[3] | Certain land sites linked to concession contracts and without provision for reimbursement are amortized in accordance with the period of the concession.

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