Brazilian utility Furnas Centrais Elétricas reports that it is spilling water from five dams that impound water for hydroelectric plants for the first time since March 2011.
The five plants, in the Rio Grande river basin, are Furnas, Mascarenhas de Moraes, Luiz Carlos Barreto de Carvalho, Marimbondo and Porto Colombia. The levels of the reservoirs and the energy dispatched are programmed by the National Electric System Operator (ONS), responsible for operating the set of Brazilian reservoirs in an integrated manner, with the objective of guaranteeing energy security.
As a result of heavy rains that are occurring in the basin, ONS defined the opening of the spillways of the Mascarenhas de Moraes, Luiz Carlos Barreto de Carvalho and Marimbondo hydroelectric plants on Jan. 13. The spillway for the Porto Colombia plant has been open since Jan. 9. Furnas said the spillways of these plants have not been opened in cascade for flood control since March 2011.
Below are specifics on the five facilities:
The spillway of 1,216 MW Furnas was opened at 500 m³/s. Currently, the spilled flow is at 1,000 m³/s. The Furnas plant is operating as ordered by ONS, with an average generation of 875 MW, around 72% of its installed capacity.
The spillway of 478 MW Mascarenhas de Moraes was opened at 120 m³/s. Currently, the spilled flow is at 1,500 m³/s. The Mascarenhas plant is operating as ordered by ONS, with an average generation of 326 MW, around 68% of its installed capacity.
The spillway of 1,050 MW Luiz Carlos Barreto de Carvalho was opened at 1,000 m³/s. Currently, the average discharge is 1,300 m³/s. The Luiz Carlos Barreto plant is operating as ordered by ONS, with an average generation of 737 MW, about 70% of its installed capacity.
The spillway of 320 MW Porto Colombia is currently spilling at 2,600 m³/s. The Porto Colombia plant is operating as ordered by ONS, with an average generation of 198 MW, around 62% of its installed capacity.
The spillway of 1,440 MW Marimbondo was opened at 500 m³/s. Currently, the spilled flow is 2,900 m³/s. The Marimbondo plant is operating as ordered by ONS, with an average generation of 1,125 MW, which corresponds to 78% of its installed capacity.
Furnas is a privately held federally-owned mixed-capital corporation controlled by Centrais Elétricas Brasileiras S.A. – Eletrobras.
In December 2022, Hydro Review reported that the level of water in the reservoirs of Brazil’s southeast/center-west hydroelectric system ended 2022 at about 50% of capacity, double what they were a year ago. The recovery of the hydro reservoirs is a result of higher rainfall in 2022 compared with 2021, when Brazil faced its worst drought in 91 years. Hydroelectricity accounts for around 60% of Brazil’s total installed power capacity of 191 GW.
