The Kannagawa Hydropower Plant (神流川発電所) is an under construction

pumped-storage Pumped-storage hydroelectricity (PSH), or pumped hydroelectric energy storage (PHES), is a type of hydroelectric energy storage used by electric power systems for load balancing. The method stores energy in the form of gravitational potential ...

hydroelectric Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined and ...

power plant A power station, also referred to as a power plant and sometimes generating station or generating plant, is an industrial facility for the generation of electric power. Power stations are generally connected to an electrical grid. Many pow ...

near Minamiaiki in

Nagano Prefecture is a landlocked prefecture of Japan located in the Chūbu region of Honshū. Nagano Prefecture has a population of 2,052,493 () and has a geographic area of . Nagano Prefecture borders Niigata Prefecture to the north, Gunma Prefecture to the ...

and

Ueno is a district in Tokyo's Taitō Ward, best known as the home of Ueno Park. Ueno is also home to some of Tokyo's finest cultural sites, including the Tokyo National Museum, the National Museum of Western Art, and the National Museum of Na ...

Gunma Prefecture is a prefecture of Japan located in the Kantō region of Honshu. Gunma Prefecture has a population of 1,937,626 (1 October 2019) and has a geographic area of 6,362 km2 (2,456 sq mi). Gunma Prefecture borders Niigata Prefecture and Fukushima ...

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

. The power plant utilizes the Minamiaiki River along with an upper and lower reservoir created by two dams, the upper Minamiaiki Dam and the lower Ueno Dam. The power station in between the two dams will contain six pump-generators for a total installed capacity of . Unit 1 commenced commercial operation in 2005 and Unit 2 in 2012.HydroWorld: Unit 2 online at Japan's Kannagawa pumped-storage plant
/ref> When completed, the plant will have the second-largest (after

Bath County Pumped Storage Station The Bath County Pumped Storage Station is a pumped storage hydroelectric power plant, which is described as the "largest battery in the world", with a maximum generation capacity of 3,003 MW, an average of 2,772 MW, and a total storage capacity ...

) pumped-storage power capacity in the world.

Construction

In July 1993, the Kannagawa Hydropower Field Survey Office was initiated and in July 1995, the power plant was approved by the Electric Power Development Coordination Council. In May 1997, construction on the project began and by October 2003, the area behind the Ueno Dam was being inundated with water and the next year, the Minamiaiki Dam's reservoir began to fill as well. Both dams were completed and the upper reservoir was filled by 2004. The first generator was commissioned on 22 December 2005 and the second on 7 June 2012. The remaining units 3-6 are scheduled for commissioning by 2032.

Power station

The power station is underground and measures long, wide, and high. It will contain 6 x 470 MW pump generators for a total capacity of 2,820 MW. Water from the upper Minamiaiki Reservoir is transferred through the power house and after producing electricity, it is brought to the lower Ueno Reservoir. The pump-generators can then pump water from the lower reservoir back up to the upper reservoir for re-use in hydroelectric power production. The water

tunnel A tunnel is an underground passageway, dug through surrounding soil, earth or rock, and enclosed except for the entrance and exit, commonly at each end. A pipeline is not a tunnel, though some recent tunnels have used immersed tube cons ...

connecting the two reservoirs is long. The power station also has an effective

hydraulic head Hydraulic head or piezometric head is a specific measurement of liquid pressure above a vertical datum., 410 pages. See pp. 43–44., 650 pages. See p. 22. It is usually measured as a liquid surface elevation, expressed in units of length, ...

of and maximum discharge of .

Dams

The Minamiaiki Dam is located in

and is a high and long rock-fill dam. It is made of of material and withholds a reservoir. The Ueno Dam, in

, is a high and long concrete-gravity dam. It is made of of material and withholds a reservoir.

References

{{reflist Energy infrastructure completed in 2005 Energy infrastructure completed in 2012 Pumped-storage hydroelectric power stations in Japan Tokyo Electric Power Company

Construction

Power station

Dams

See also

References