Kannagawa Hydropower Plant

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Kannagawa Hydropower Plant
Minamiaiki Dam.jpg
The upper Minamiaiki Dam
Kannagawa Hydropower Plant is located in Japan
Kannagawa Hydropower Plant
Location of Kannagawa Hydropower Plant
Country Japan
Location Nagano Prefecture and Gunma Prefecture
Coordinates 36°00′18″N 138°39′09″E / 36.00500°N 138.65250°E / 36.00500; 138.65250Coordinates: 36°00′18″N 138°39′09″E / 36.00500°N 138.65250°E / 36.00500; 138.65250
Status In partial operation
Commission date Unit 1: 2005
Unit 2: 2012
Units 3-6: 2020
Owner(s) Tokyo Electric Power Company
Pumped-storage power station
Upper reservoir Minamiaiki Reservoir
Upper res. capacity 19,170,000 m3 (15,540 acre⋅ft)
Lower reservoir Ueno Reservoir
Lower res. capacity 18,400,000 m3 (14,900 acre⋅ft)
Hydraulic head 653 m (2,142 ft)
Thermal power station
Type Pumped-storage
Power generation
Units operational 2 x 470 MW (630,000 hp)
Units under const. 4 x 470 MW (630,000 hp)
Nameplate capacity 2,820 MW (3,780,000 hp)

The Kannagawa Hydropower Plant (神流川発電所) is an under construction pumped-storage hydroelectric power plant near Minamiaiki in Nagano Prefecture and Ueno in Gunma Prefecture, Japan. 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 470 megawatts (630,000 hp) pump-generators for a total installed capacity of 2,820 megawatts (3,780,000 hp). Unit 1 commenced commercial operation in 2005 and Unit 2 in 2012.[1] When completed, the plant will have the second-largest (after Bath County Pumped Storage Station) pumped-storage power capacity in the world.[2][3]


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.[2] Both dams were completed and the upper reservoir was filled by 2004.[3] The first generator was commissioned on 22 December 2005 and the second on 7 June 2012. The remaining units are scheduled for commissioning by 2020.[4][5]

Power station[edit]

The power station is 1,600 feet (490 m) underground and measures 708 ft (216 m) long, 108 feet (33 m) wide, and 169 feet (52 m) 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 connecting the two reservoirs is 3.8 miles (6.1 km) long.[3] The power station also has an effective hydraulic head of 653 metres (2,142 ft) and maximum discharge of 510 cubic metres per second (18,000 cu ft/s).[6]


The Minamiaiki Dam is located in Nagano Prefecture and is a 136 metres (446 ft) high and 444 metres (1,457 ft) long rock-fill dam. It is made of 7,300,000 cubic metres (9,500,000 cu yd) of material and withholds a 19,170,000 m3 (677,000,000 cu ft) reservoir. The Ueno Dam, in Gunma Prefecture, is a 120 metres (390 ft) high and 350 metres (1,150 ft) long concrete-gravity dam. It is made of 720,000 cubic metres (940,000 cu yd) of material and withholds a 18,400,000 m3 (650,000,000 cu ft) reservoir.[6]

See also[edit]


  1. ^ HydroWorld: Unit 2 online at Japan's Kannagawa pumped-storage plant
  2. ^ a b "Press Release: Commencement of Commercial Operation of Unit 1 of Kannagawa Hydropower Plant-- Pumped-Storage Power Plant with World's Largest Capacity". TEPCO. Dec 22, 2005. Retrieved 31 August 2010. 
  3. ^ a b c Peltier, Robert (August 15, 2006). "Kannagawa Hydropower Plant, Japan". Power Magazine. Retrieved 31 August 2010. 
  4. ^ "Operational Commencement of Unit 2, Kannagawa Hydroelectric Power Station". TEPCO. 7 June 2012. Retrieved 14 July 2014. 
  5. ^ "Kannagawa Hydroelectric Power Station" (PDF). TEPCO. 7 June 2012. Retrieved 14 July 2014. 
  6. ^ a b "Specifications of Kannagawa Pumped Storage Power Plant". IEAHydro. Archived from the original on 27 July 2010. Retrieved 31 August 2010.