Pump storage power plants
Large pump storage hydroelectric plants, usually at high altitudes, store surplus energy by pumping water (potential energy) from a catchment basin into a barrier lake over 1,000 m (approx. 3,000 ft) higher. To generate power, water is discharged through turbines into the basin below. For the operator, it is important to keep the time for switching from pumping to generating electricity as short as possible. This process is monitored using hundreds of measuring points, and results are recorded and stored in a database.