ABSTRACT
Pumped storage hydro is a form of hydroelectric power generation for electric utilities that incorporates an energy storage feature. The fuel, water, moves between two reservoirs—an upper and a lower—with a significant vertical distance between them. Water is stored in the upper reservoir until such time as the utility determines that it is economic to use the water to produce electricity for the system, usually to keep coal-fired and nuclear power plants operating at economic levels during low load periods, such as at night and on weekends. Pumped storage is the most widespread energy storage system in use on power networks and is used for energy management, frequency control, and provision of reserves. Efficiency of any specific pumped storage facility, which is primarily dependent on the height between the upper and lower reservoirs, ranges from 70 to 85%.
