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1. OPERATING CONTEXT (Details) | 12 Months Ended
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Dec. 31, 2019
Madeira Energia S.A. ('Madeira') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of affiliated | Madeira Energia S.A. (‘Madeira’) |
Classification | Affiliated company |
Description | Corporation engaged in the construction and commercial operation of the Santo Antônio Hydroelectric Plant, through its subsidiary Santo Antônio Energia S.A., in the basin of the Madeira river, in the State of Rondônia. |
Ativas Datacenter S.A. ('Ativas') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of affiliated | Ativas Datacenter S.A. (‘Ativas’) |
Classification | Affiliated entity |
Description | Corporation engaged in the supply of IT and communication infrastructure services, including physical hosting and related services for medium-sized and large corporations. |
FIP Melbourne (Usina de Santo Antonio) [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of affiliated | FIP Melbourne (Usina de Santo Antônio) |
Classification | Affiliated entity |
Description | Investment fund managed by Banco Modal S.A., whose objective is to seek appreciation of capital invested through acquisition of shares, convertible debentures or warrants issued by listed or unlisted companies, and/or other assets. This fund held 83% of the share capital of SAAG Investimentos S.A. (‘SAAG’), the objects of which are to own equity in Madeira Energia S.A. (‘Mesa’). |
Light S.A. ('Light') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of affiliated | Light S.A. (‘Light’) |
Classification | Affiliated entity |
Description | Listed company engaged in the following activities: energy generation, transmission, trading, distribution, and related services; and holding direct or indirect interest in companies engaged in similar activities. |
Guanhaes Energia S.A. ('Guanhaes Energia') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of joint venture | Guanhães Energia S.A. (‘Guanhães Energia’) |
Classification | Jointly-controlled entity |
Description | Corporation engaged in the production and sale of energy through building and commercial operation of the following Small Hydro Plants: Dores de Guanhães, Senhora do Porto and Jacaré, in the county of Dores de Guanhães; and Fortuna II, in the county of Virginópolis, in Minas Gerais. |
LightGer S.A. ('LightGer') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of joint venture | LightGer S.A. (‘LightGer’) |
Classification | Jointly-controlled entity |
Description | Corporation classified as independent power producer, formed to build and operate the Paracambi Small Hydro Plant (or PCH), on the Ribeirão das Lages river in the county of Paracambi, Rio de Janeiro State. |
Usina Hidreletrica Itaocara S.A. ('UHE Itaocara') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of joint venture | Usina Hidrelétrica Itaocara S.A. (‘UHE Itaocara’) |
Classification | Jointly-controlled entity |
Description | Corporation, comprising the partners of the UHE Itaocara Consortium, formed by Cemig GT and Itaocara Energia (of the Light group), responsible for construction of the Itaocara I Hydroelectric Plant. |
Axxiom Solucoes Tecnologicas S.A. ('Axxiom') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of joint venture | Axxiom Soluções Tecnológicas S.A. (‘Axxiom’) |
Classification | Jointly-controlled entity |
Description | Unlisted corporation, providing technology and systems solutions for operational management of public service concession holders, including companies operating in energy, gas, water and sewerage, and other utilities. Jointly controlled by Light (51%) and Cemig (49%). |
Hidreletrica Cachoeirao S.A. ('Cachoeirao') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of joint venture | Hidrelétrica Cachoeirão S.A. (‘Cachoeirão’) |
Classification | Jointly-controlled entity |
Description | Production and sale of energy as an independent power producer, through the Cachoeirão hydroelectric power plant located at Pocrane, in the State of Minas Gerais. |
Hidreletrica Pipoca S.A. ('Pipoca') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of joint venture | Hidrelétrica Pipoca S.A. (‘Pipoca’) |
Classification | Jointly-controlled entity |
Description | Independent production of energy, through construction and commercial operation of the Pipoca Small Hydro Plant (SHP, or Pequena Central Hidrelétrica – PCH), on the Manhuaçu River, in the municipalities of Caratinga and Ipanema, in Minas Gerais State. |
Amazonia Energia Participacoes S.A. ('Amazonia Energia') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of joint venture | Amazônia Energia Participações S.A (‘Amazônia Energia’) |
Classification | Jointly-controlled entity |
Description | Special-purpose company created by Cemig GT (74.50% ownership) and Light (25.50%), for acquisition of an equity interest of 9.77% in Norte Energia S.A. (‘Nesa’), the company holding the concession for the Belo Monte Hydroelectric Plant, on the Xingu River, in the Northern Brazilian State of Pará. |
Retiro Baixo Energetica S.A. ('RBE') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of joint venture | Retiro Baixo Energética S.A. (‘RBE’) |
Classification | Jointly-controlled entity |
Description | Corporation that holds the concession to operate the Retiro Baixo Hydroelectric Plant, on the Paraopeba River, in the São Francisco river basin, in the municipalities of Curvelo and Pompeu, in Minas Gerais. |
Alianca Norte Energia Participacoes S.A. ('Alianca Norte') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of joint venture | Aliança Norte Energia Participações S.A. (‘Aliança Norte’) |
Classification | Jointly-controlled entity |
Description | Special-purpose company created by Cemig GT (49% ownership) and Vale S.A. 51%), for acquisition of an equity interest of 9% in Norte Energia S.A. (‘Nesa’), the company holds the concession for the Belo Monte Hydroelectric Plant, on the Xingu River, in the Northern Brazilian State of Pará. |
Baguari Energia S.A. ('Baguari Energia') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of joint venture | Baguari Energia S.A. (‘Baguari Energia’) |
Classification | Jointly-controlled entity |
Description | Corporation engaged in the construction, operation, maintenance and commercial operation of the Baguari Hydroelectric Plant, through participation in the UHE Baguari Consortium (Baguari Energia 49%, Neoenergia 51%), on the Doce river in Governador Valadares, Minas Gerais. |
Renova Energia S.A. ('Renova Energia') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of joint venture | Renova Energia S.A. (‘Renova Energia’) |
Classification | Jointly-controlled entity |
Description | Listed company engaged in the development, construction and operation of plants generating power from renewable sources – wind power, small hydro plants (SHPs), and solar energy; trading of energy; and related activities. |
Alianca Geracao de Energia S.A. ('Alianca') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of joint venture | Aliança Geração de Energia S.A. (‘Aliança’) |
Classification | Jointly-controlled entity |
Description | Unlisted company created by Cemig GT and Vale S.A. as a platform for consolidation of generation assets held by the two parties in generation consortia, and investments in future generation projects. For their shares, the two parties subscribed the following generation plant assets: Porto Estrela, Igarapava, Funil, Capim Branco I, Capim Branco II, Aimorés, and Candonga. With these assets Aliança has total installed generation capacity, in operation, of 1,257 MW (physical offtake guarantee 668 MW average). It also has other generation projects. Vale and Cemig GT respectively hold 55% and 45% of the total capital. |
Transmissora Alianca de Energia Eletrica S.A. ('TAESA') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of joint venture | Transmissora Aliança de Energia Elétrica S.A. (‘TAESA’) |
Classification | Jointly-controlled entity |
Description | Corporation engaged in the construction, operation and maintenance of energy transmission facilities in 18 states of Brazil through direct and indirect equity interests in investees |
Companhia de Transmissao Centroeste de Minas ('Centroeste') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of joint venture | Companhia de Transmissão Centroeste de Minas (‘Centroeste’) | [1]
Classification | Jointly-controlled entity | [1]
Description | Corporation engaged in the construction, operation and maintenance of the Furnas-Pimenta transmission line – part of the national grid. | [1]
Cemig Geracao e Transmissao S.A. ('Cemig GT' or 'Cemig Geracao e Transmissao') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Cemig Geração e Transmissão S.A. (‘Cemig GT’ or ‘Cemig Geração e Transmissão’) |
Classification | Subsidiary |
Description | Wholly-owned subsidiary engaged in the energy generation and transmission services. Its shares are listed in Brazil, but are not actively traded. Cemig GT has interests in 83 power plants (76 of which are hydroelectric, 6 are wind power, 1 is a thermal plant and 1 is solar), of which 45 are controlled by Cemig GT, and associated transmission lines, most of which are part of the Brazilian national generation and transmission grid system, with total installed generation capacity of 3,235 MW (information not reviewed by the external auditors). |
Cemig Baguari [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Cemig Baguari |
Classification | Subsidiary |
Description | Corporation engaged in the production and sale of energy as an independent power producer and in interests in investees or joint operations that are engaged in the production and sale of energy in future projects. |
Cemig Geracao Tres Marias Sa [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Cemig GeraçãoTrês Marias S.A. |
Classification | Subsidiary |
Description | Corporation engaged in the production and sale of energy as public service concession holder, by commercial operation of the Três Marias Hydroelectric Plant, and sale and trading of energy in the Free Market. This subsidiary has installed capacity of 396 MW, and guaranteed offtake level of 239 MW average. |
Cemig Geracao Salto Grande S.A. [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Cemig Geração Salto Grande S.A. |
Classification | Subsidiary |
Description | Corporation engaged in the production and sale of energy as public service concession holder, by commercial operation of the Salto Grande Hydroelectric Plant, and sale and trading of energy in the Free Market. This subsidiary has installed capacity of 102 MW, and guaranteed offtake level of 75 MW average. |
Cemig Geracao Itutinga S.A. [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Cemig Geração Itutinga S.A. |
Classification | Subsidiary |
Description | Corporation engaged in the production and sale of energy as public service concession holder, by commercial operation of the Itutinga Hydroelectric Plant, and sale and trading of energy in the Free Market. This subsidiary has installed capacity of 52 MW, and guaranteed offtake level of 28 MW average. |
Cemig Geracao Camargos S.A. [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Cemig Geração Camargos S.A. |
Classification | Subsidiary |
Description | Corporation engaged in the production and sale of energy as public service concession holder, by commercial operation of the Camargos Hydroelectric Plant, and sale and trading of energy in the Free Market. This subsidiary has installed capacity of 46 MW, and guaranteed offtake level of 21 MW average. |
Cemig Geracao Sul S.A. [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Cemig Geração Sul S.A. |
Classification | Subsidiary |
Description | Corporation engaged in the production and sale of energy as public concession holder, by commercial operation of the Coronel Domiciano, Marmelos, Joasal, Paciência and Piau Small Hydroelectric Plants, and trading in energy in the Free Market. Aggregate installed generation capacity is 39.53 MW; guaranteed offtake level of 27.42 MW average. |
Cemig Geracao Leste S.A. [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Cemig Geração Leste S.A. |
Classification | Subsidiary |
Description | Corporation engaged in the production and sale of energy as public concession holder, by operation of the Dona Rita, Sinceridade, Neblina, Ervália, Tronqueiras and Peti Small Hydroelectric Plants, and trading in energy in the Free Market. Aggregate installed generation capacity of these plants is 35.16 MW; guaranteed offtake level of 18.64 MW average. |
Cemig Geracao Oeste S.A. [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Cemig Geração Oeste S.A. |
Classification | Subsidiary |
Description | Corporation engaged in the production and sale of energy as public service concession holder, by commercial operation of the Gafanhoto, Cajuru and Martins Small Hydroelectric Plants, and sale and trading of energy in the Free Market. It has aggregate installed capacity of 28.90 MW, and guaranteed offtake level of 11.21 MW average. |
Rosal Energia S.A. [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Rosal Energia S.A. (‘Rosal’) |
Classification | Subsidiary |
Description | Corporation that holds the concession to generate and sell energy, operating the Rosal Hydroelectric Plant, on the border between the states of Rio de Janeiro and Espírito Santo. |
Sa Carvalho S.A. [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Sá Carvalho S.A. (‘Sá Carvalho’) |
Classification | Subsidiary |
Description | Corporation that holds the concession to generate and sell energy, operating the Sá Carvalho Hydroelectric Plant. |
Horizontes Energia S.A [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Horizontes Energia S.A. (‘Horizontes’) |
Classification | Subsidiary |
Description | Corporation that is classified as an independent power producer operating the Machado Mineiro and Salto do Paraopeba Hydroelectric Plants in Minas Gerais; and the Salto do Voltão and Salto do Passo Velho Hydroelectric Plants, in the state of Santa Catarina. |
Cemig PCH S.A. [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Cemig PCH S.A. (‘PCH’) |
Classification | Subsidiary |
Description | Corporation that is classified as an independent power producer operating the Pai Joaquim hydroelectric power plant. |
Cemig Comercializadora De Energia Incentivada S.A. [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Cemig Comercializadora de Energia Incentivada S.A. |
Classification | Subsidiary |
Description | Corporation engaged in the production and sale as ndependent thermal generation power producer, in future projects. |
Cemig Trading S.A. [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Cemig Trading S.A. (‘Cemig Trading’) |
Classification | Subsidiary |
Description | Corporation engaged in trading and intermediation of energy. |
Empresa de Servicos e Comercializacao de Energia Eletrica S.A. [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Empresa de Serviços e Comercialização de Energia Elétrica S.A. |
Classification | Subsidiary |
Description | Corporation engaged in the production and sale of energy as an independent power producer, in future projects. |
Cemig Geracao Poco Fundo [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Cemig Geração Poço Fundo |
Classification | Subsidiary |
Description | Corporation engaged in the production and sale of energy, as an independent producer, through construction and operation of the hydroelectric power plant Poço Fundo, located in Machado river, in the State of Minas Gerais. |
Central Eolica Praias de Parajuru S.A. ('Central Eolica Praias de Parajuru') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Central Eólica Praias de Parajuru S.A. (‘Central Eólica Praias de Parajuru’) |
Classification | Subsidiary |
Description | Corporation engaged in the production and sale of energy at the wind power plant of the same name in the northeastern Brazilian state of Ceará. |
Central Eolica Volta do Rio S.A. ('Central Eolica Volta do Rio') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Central Eólica Volta do Rio S.A. (‘Central Eólica Volta do Rio’) |
Classification | Subsidiary |
Description | Corporation engaged in the production and sale of energy at the wind power plant of the same name in Acaraú, northeastern Brazilian state of Ceará. |
Cemig Distribuicao SA [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Cemig Distribuição S.A. (‘Cemig D’ or ‘Cemig Distribuição’) |
Classification | Subsidiary |
Description | Wholly-owned subsidiary, whose shares are listed in Brazil but are not actively traded; engaged in the distribution of energy through networks and distribution lines throughout almost the whole of Minas Gerais State. |
Companhia de Gas de Minas Gerais ('Gasmig') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Companhia de Gás de Minas Gerais (‘Gasmig’) |
Classification | Subsidiary |
Description | Corporation engaged in the acquisition, transportation and distribution of combustible gas or sub-products and derivatives, through a concession for the distribution of gas in the State of Minas Gerais. |
Cemig Geracao Distribuida [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Cemig Geração Distribuída |
Classification | Subsidiary |
Description | Wholly owned subsidiary engaged in: building and maintaining projects and equipment associated with energy efficiency and micro- and mini- distributed generation; providing consultancy and studies for distributed generation projects and equipment, for subscription to systems for customers to supply to the grid as generators, and technical, regulatory and economic feasibility analyses for these purposes. |
Efficientia S.A. ('Efficientia') [Member] |  |
Disclosure of subsidiaries [line items] |  |
Name of subsidiary | Efficientia S.A. (‘Efficientia’) |
Classification | Subsidiary |
Description | Corporation that provides energy efficiency and optimization services and energy solutions through studies and execution of projects; and services of operation and maintenance of energy supply facilities. |
[1] | On January 13, 2020, the Company completed the acquisition of the Eletrobras's equity interest in Centroeste, corresponding to 51%, becoming the owner of the investee's entire share capital. For further information, see note 18 - Investments.

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