Żarnowiec Pumped Storage Power Station

The Żarnowiec Pumped Storage Power Station is a pumped-storage power station located about 7 km south of Żarnowiec, in Puck County, northern Poland. It was constructed between 1973 and 1983 and underwent a modernisation between 2007 and 2011, with the upper reservoir reconstructed in 2006.

With a capacity of 680 MW, it is the largest hydroelectric power station in Poland. It uses four 170 MW Francis pump-turbines to send water from its lower reservoir, Lake Żarnowiec, up to an upper reservoir for storage. During periods of high power demand, the water is released back down to the turbines to produce power. Water is pumped back up during periods of low power demand, such as night time. The power station was originally intended to be a load balancer for Żarnowiec Nuclear Power Plant which was supposed to be constructed on the opposite side of Lake Żarnowiec.