PUMPED STORAGE HYDRO POWER (PSH)

Why in news: The Mines Secretary recently stressed on the role of leading organisations under the mines ministry, including the GSI, to build pumped storage hydropower projects and highways.

• PSH is a type of hydroelectric energy storage.
• It is a configuration of two water reservoirs at different elevations that can generate power as water moves down from one to the other (discharge), passing through a turbine.

• The water is pumped to the higher reservoir at times of low demand and low electricity prices. At times of high demand and higher prices, the water is then released to drive turbine in a powerhouse and supply electricity to the grid.
• The system also requires power as it pumps water back into the upper reservoir (recharge).
• PSH plants operate much like conventional hydropower plants, except PSH has the ability to use the same water over and over again. 
• The technology absorbs surplus energy at times of low demand and releases it when demand is high.
• Open-loop versus Closed-loop:
  • Open-loop PSHhas an ongoing hydrologic connection to a natural body of water.
  • With closed-loop PSH, reservoirs are not connected to an outside body of water.