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17. PROPERTY, PLANT AND EQUIPMENT (Details 3) | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Average annual depreciation rate | 3.14% | 3.13% | 3.72%
Hydroelectric generation [member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Average annual depreciation rate | 2.96% |  |
Wind power generation [member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Average annual depreciation rate | 4.94% |  |
Administration [member] |  |  |
Disclosure of detailed information about property, plant and equipment [line items] |  |  |
Average annual depreciation rate | 6.19% |  |

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- Definition Average annual depreciation rate property, plant and equipment. + References No definition available. + Details
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- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table. + References No definition available. + Details
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- Details
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- Details
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- Details
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