The Chaira Pumped Storage Hydro Power Plant (Chaira PSHPP) was built in the

Rila Rila (, ) is the highest mountain range of Bulgaria, the Balkans, Balkan Peninsula, and Southeast Europe. It is situated in southwestern Bulgaria and forms part of the Rila–Rhodope Mountains, Rhodope Massif. The highest summit is Musala at an e ...

mountain range, about southeast of

Bulgaria Bulgaria, officially the Republic of Bulgaria, is a country in Southeast Europe. It is situated on the eastern portion of the Balkans directly south of the Danube river and west of the Black Sea. Bulgaria is bordered by Greece and Turkey t ...

's capital city,

Sofia Sofia is the Capital city, capital and List of cities and towns in Bulgaria, largest city of Bulgaria. It is situated in the Sofia Valley at the foot of the Vitosha mountain, in the western part of the country. The city is built west of the Is ...

. Part of the major

Belmeken–Sestrimo–Chaira Hydropower Cascade The Belmeken–Sestrimo–Chaira Hydroelectric Cascade () is situated in the Pazardzhik Province, southern Bulgaria and is the largest and most complex hydroelectric complex in the country. Located in the eastern part of the Rila, Rila mountain ra ...

, Chaira has generating capacity of and a pumping capacity of . The power plant is equipped with four reversible Francis pump-turbines, each rated at in the generating mode, and in pumping mode. Units 1 and 2 have been in operation since 1995, and at that time Chaira was the largest pumped-storage plant in southeast Europe with the highest head in the world for a single-stage pump turbine ( generating and pumping). Units 3 and 4 came online in 1999. The pump-turbines and motor-generators were supplied by

Toshiba is a Japanese multinational electronics company headquartered in Minato, Tokyo. Its diversified products and services include power, industrial and social infrastructure systems, elevators and escalators, electronic components, semiconductors ...

, and three of them were manufactured under Japanese supervision in

. The upper basin for Chaira is formed by the

Belmeken Dam Belmeken Reservoir () is located in the eastern part of the Rila mountain range of southwestern Bulgaria. It is named after the summit of Belmeken (2,626 m), rising about a kilometer northwest of the lake. Location Belmeken Reservoir l ...

which connects to the pumped storage plant by two headrace tunnels with a diameter of and two

penstocks A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydro turbines and sewerage systems. The term is of Scots origin, and was inherited from the earlier technology of mill ponds ...

with diameter , reducing to .Chaira PSP
Outflow from the Belmeken reservoir supplies the

Sestrimo Hydro Power Plant The Sestrimo Hydro Power Plant is an active hydro power project in the eastern Rila mountains near Sestrimo village, Bulgaria. Water is supplied by the Belmeken Dam to three turbines with a nominal output of around 80 MW which will deliver up t ...

References

Energy infrastructure completed in 1995 1995 establishments in Bulgaria Hydroelectric power stations in Bulgaria Buildings and structures in Pazardzhik Province Pumped-storage hydroelectric power stations in Bulgaria {{hydroelectric-power-plant-stub