Rains raise reservoir levels in three of the four Brazilian subsystems

The December rains caused three of the country’s four water subsystems to exceed the volumes forecast by the operator for December 31st. Only the southern reservoirs have a volume below that projected by the National Electric System Operator (ONS).

According to ONS data, compiled until Sunday (3), the reservoirs of the Southeast/Midwest subsystem have 26.7% of their capacity. The level already exceeds the 25% projected by the ONS for December 31 of last year.

In the Northeast subsystem, the current volume is 54.43%. That is, 2.83 percentage points higher than expected for that same date. In the reservoirs of the North subsystem, the increase was even greater. The current level is 60.7%: 8.1 percentage points above projection.

The numbers corroborate ONS expectations for the closing of January this year. With the forecast of more rain, the operator estimates even better numbers for the end of the first month of 2022. However, in relation to what exceeds the forecast for the end of the year, the agency claimed that the movement was already expected, in view of the high volume of rain in the period.

The exception to this rise in reservoir levels is the South subsystem. The volume is at 42.61%. The forecast was to be at 43% of capacity. According to ONS projections until January 31 of this year, this volume will continue to fall and should close the month at an even lower level.

The forecast until the 31st of January for the other subsystems is that the water levels will continue to rise. While the reservoirs of plants in the North should reach 85.7% of their maximum capacity by the end of the month, the Northeast may register a volume of 72.5%. In the Southeast/Midwest, the predicted level is 37% and, in the South, 34%.

The average considered ideal for the level of the reservoirs is at least 60% of the filled capacity. Even with the predicted increase, the volume should remain below the main reservoirs in the country. The Southeast/Midwest subsystem, for example, concentrates 70% of Brazil’s energy load.

Experts heard by CNN warn that, despite the forecast of improvements in relation to the scenario observed in 2021, the hydroelectric plants at the beginning of this year will still be fragile, with reservoirs below the ideal level. In addition, thermoelectric plants will continue to be used and, therefore, there will be little room for reductions in the energy bill.

With information from João Pedro Malar, from CNN