Country Bulgaria Status Operational Owner NEK EAD | Location Pazardzhik Province Upper reservoir Belmeken reservoir | |
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Commission date 1995 (units 1 and 2)
1999 (units 3 and 4) Units operational 4 x 216 MW reversible Francis turbine Similar Sestrimo Hydro Power Pl, Belmeken Dam, Kardzhali Hydroelectric Power St, Ivaylovgrad Dam, Vacha Reservoir | ||
The Chaira Pumped Storage Hydro Power Plant (Chaira PSHPP) was built in the Rila mountains, about 100 kilometres (62 mi) southeast of the capital city, Sofia. Chaira has generating capacity of 864 megawatts (1,159,000 hp) and a pumping capacity of 788 megawatts (1,057,000 hp), and is thus the largest pumped-storage plant in southeast Europe. The power plant is equipped with four reversible Francis pump-turbines, each rated at 216 megawatts (290,000 hp) in the generating mode, and 197 megawatts (264,000 hp) in pumping mode. Units 1 and 2 have been in operation since 1995, and that time Chaira was the highest head in the world for a single-stage pump turbine (690 metres (2,260 ft) generating and 701 metres (2,300 ft) pumping). Units 3 and 4 came online in 1999. The pump-turbines and motor-generators were supplied by Toshiba, and three of them were manufactured under Japanese supervision in Bulgaria. The upper compensating basin for Chaira is the Belmeken reservoir that is connected to the Chaira pumped storage hydro power plant by two headrace tunnels with a diameter of 4.2 metres (14 ft) and two penstocks with diameter 4.4 metres (14 ft), reducing to 4.2 metres (14 ft).