Hydroelectricity on the rise, and pumping!

Pumped storage hydroelectricity is a type of hydroelectric power generation used by some power plants for load balancing. The first use of pumped storage was in the 1890’s in Italy and Switzerland. In the 1930’s reversible hydroelectric turbines became available. These turbines could operate as both turbine generators and in reverse as electric motor driven pumps.

The method stores energy in the form of water, pumped from a lower elevation reservoir to a higher elevation. Low-cost off-peak electric power is used to runt he pumps involved during the process. During periods of high electrical demand, the stored water is released through turbines. Although the losses of the pumping process make the plant a net consumer of energy overall, the system increases its revenue by selling more electricity during periods of peak demand, when electricity prices are highest.
There is over 90 GW of pumped storage in operation world wide, which is about 3 % of global generation capacity. Pumped storage plants are characterized by long construction times and high capital expenditure. Pumped storage is the most widespread energy storage system in use on power networks. Its main applications are for energy management, frequency control and provision of reserve.