The Brazilian Transmission System

In Brazil, in 1993, the National Electric Power Transmission System (Sintrel) was created to ensure free access to the national electric interconnected grid to independent producers and self producers on an at cost basis. Sintrel was made up largely of transmission systems owned by the companies controlled by Eletrobas, which was also the entity in charge of managing Sintrel. The Sintrel plan was not successful due to large state companies (such as CEMIG, CESP, and COPEL) failing to cooperate with the plan and forbidding the use of their transmission lines.

Until recently the country had two large transmission systems, one covering the South, Southeast and parts of the Central West, the other the Northeast and parts of the North. These two main systems were joined with a 1,277 km, 500 kV line, called the ‘North-South Interconnection’. The basic transmission network comprises all transmission lines of 230 kV or higher and substations with equipment for this voltage, operated by public energy supply concessionaires. Transmission lines used by only one generating plant or one major consumer are not part of the basic network.

The national transmission system still fails to reach many regions in the North and Northwest, notably the state capitals Manaus, Macapá, Boa Vista, Rio Branco and Porto Velho. These state capitals, as well as dozens of smaller cities, receive power from regional standalone systems, normally supplied by under-sized diesel generators. These isolated systems represent 3.4% of national consumption. Improvements are now in the planning stage. Boa Vista will soon be served by a cross-border link from the Guri hydropower complex in Venezuela, and Manaus and Porto Velho will receive substantial gas fired generating capacity.

The outstanding features of transmission in Brazil are the long distances between power plants and major consumer centres and connections between regions depending on the diversity of the hydrological basins. 87% of installed capacity is hydro-powered.