Reservoir levels

Funil hydroelectric reservoir (FURNAS file)

Brazilian hydroelectric power plants are part of the National Grid (NG) whose operation is planned and programmed by the National Electrical System Operator (NSO).

The NSO, which is responsible for operating all energy generation and transmission installations in Brazil, defines each power station's reservoir levels and power output in order to ensure power supply safety and continuity t the lowest possible cost.

All energy produced by Brazilian generators is sent to the SIN and subsequently distributed in real-time by NSO according to demand.
 

Usable volume
 

The usable volume is the difference between a reservoir’s maximum level and its dead volume, i.e., the usable volume is the part of a reservoir’s water level that can be effectively used to generate power.

The NSO releases daily reports logging the level of each reservoir, their usable volume and water inflow and outflow.

Be aware

Hydroelectric power plants generate energy when the water passes through a turbine. Increasing output also increases the amount of reservoir water outflow that drives the turbines and flows downstream to meet the demands of other cities, operating the wind turbines of other power plants and generating further power.

That is why it is important to be aware of any sudden increases in the flow of rivers close to the power plant dam. When the NSO orders a sudden increase in a plant’s power generation, this can lead to a sharp increase in a river’s water flow and potentially flood the river banks.

Maintaining reservoirs

Erosion, irregular occupation of river banks and deforestation around water sources can all reduce the lifespan of the source and affect water quality.

Droughts and unregulated dykes are the main reasons that hydro plant reservoir levels fall.