Żarnowiec Pumped Storage Power Station

The Żarnowiec Pumped Storage Power Station is a pumped-storage power station located about 7 km (4.3 mi) 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.[4]

Żarnowiec Pumped Storage Power Station
Penstocks connecting the upper and lower reservoirs
Country	Poland
Location	Czymanowo
Coordinates	54°43′20.18″N 18°04′56.48″E
Status	Operational
Construction began	1973
Opening date	1983
Owner(s)	PGE Polska Grupa Energetyczna
Upper reservoir
Creates	Upper Żarnowiec
Total capacity	16,445,000 m3 (13,332 acre⋅ft)[1]
Lower reservoir
Creates	Lake Żarnowiec
Total capacity	124,000,000 m3 (101,000 acre⋅ft)[2]
Power Station
Hydraulic head	119.3 m (391 ft)
Turbines	4 x 170 MW reversible Francis turbines[3]
Installed capacity	680 MW

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.[5]