Expansion water volume

The expansion water volume or the expansion flow rate is the maximum amount of water that can be removed from a hydropower plant by its turbines and thus used to generate electricity . If the flow rate is greater, i.e. if not all of the available water can be passed through the turbine system, the excess water is discharged via a weir . The expansion water volume is usually given in cubic meters per second (m³ / s).

Together with the height of fall and the degree of efficiency of the power plant parts , the volume of water developed determines the bottleneck capacity and the normal working capacity of a hydropower plant.