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

Rila Rila ( bg, Рила, ) 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 Mus ...

mountains, about southeast of

Bulgaria Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedon ...

's capital city,

Sofia Sofia ( ; bg, София, Sofiya, ) is the capital and largest city of Bulgaria. It is situated in the Sofia Valley at the foot of the Vitosha mountain in the western parts of the country. The city is built west of the Iskar river, and ha ...

. 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 , commonly known as Toshiba and stylized as TOSHIBA, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. Its diversified products and services include power, industrial and social infrastructure system ...

, and three of them were manufactured under Japanese supervision in

. The upper basin for Chaira is formed by the

Belmeken Dam The dam of Belmeken ( bg, Белмекен ) is situated in the Rila Mountains in Bulgaria and is the highest reservoir on the Balkan peninsula. There is a pumped-storage plant the Chaira Hydro Power Plant built between the lake and a lower bas ...

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 inherited from the earlier technology of mill ponds and watermills. Hyd ...

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 Watt#Megawatt, MW which will ...

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