Kannagawa Hydropower Plant
Encyclopedia
The Kannagawa Hydropower Plant is an under construction pumped-storage hydroelectric power plant near Minamiaiki in Nagano Prefecture
and 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 MW pump-generators for a total installed capacity of 2,820 MW. Only Unit 1 has commenced commercial operation and did so in 2005. When completed, the plant will have the largest pumped-storage power capacity in the world.
connecting the two reservoirs is 3.8 mi (6.1 km) long. The power station also has an effective hydraulic head
of 653 m (2,142.4 ft) and maximum discharge of 510 m3/s. Unit 1 commenced commercial operation in 2005 and Unit 2 is expected for 2012. The other four units are expected to be operational by 2020 or later.
and is a 136 m (446.2 ft) high and 444 m (1,456.7 ft) long rock-fill dam. It is made of 7300000 m³ (9,548,039.5 cu yd) of material and withholds a 19170000 cubic metre reservoir. The Ueno Dam, in Gunma Prefecture
, is a 120 m (393.7 ft) high and 350 m (1,148.3 ft) long concrete-gravity dam. It is made of 720000 m³ (941,724.4 cu yd) of material and withholds a 18400000 cubic metre reservoir.
Nagano Prefecture
is a prefecture of Japan located in the Chūbu region of the island of Honshū. The capital is the city of Nagano.- History :Nagano was formerly known as the province of Shinano...
and Gunma Prefecture
Gunma Prefecture
is a prefecture of Japan located in the northwest corner of the Kantō region on Honshu island. Its capital is Maebashi.- History :The remains of a Paleolithic man were found at Iwajuku, Gunma Prefecture, in the early 20th century and there is a public museum there.Japan was without horses until...
, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
. The power plant utilizes the Minamiaiki River along with an upper and lower reservoir created by two dams, the upper Minamiaiki Dam
Minamiaiki Dam
The Minamiaiki Dam is a rock-fill embankment dam on the Minamiaiki River in Minamiaiki, Nagano Prefecture, Japan. Together with the Ueno Dam, it provides water for the Kannagawa Hydropower Plant owned by the Tokyo Electric Power Company. The Minamiaiki dam is the higher of the two dams...
and the lower Ueno Dam
Ueno Dam
Ueno Dam is a concrete gravity dam in the Gunma Prefecture of Japan. The dam serves as the lower reservoir of the Kannagawa Hydropower Plant.-References:...
. The power station in between the two dams will contain six 470 MW pump-generators for a total installed capacity of 2,820 MW. Only Unit 1 has commenced commercial operation and did so in 2005. When completed, the plant will have the largest 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 power station
The power station is 1600 ft (487.7 m) underground and measures 708 ft (215.8 m) long, 108 ft (32.9 m) wide, and 169 ft (51.5 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 tunnelTunnel
A tunnel is an underground passageway, completely enclosed except for openings for egress, commonly at each end.A tunnel may be for foot or vehicular road traffic, for rail traffic, or for a canal. Some tunnels are aqueducts to supply water for consumption or for hydroelectric stations or are sewers...
connecting the two reservoirs is 3.8 mi (6.1 km) long. The power station also has an effective hydraulic head
Hydraulic head
Hydraulic head or piezometric head is a specific measurement of water pressure above a geodetic datum. It is usually measured as a water surface elevation, expressed in units of length, at the entrance of a piezometer...
of 653 m (2,142.4 ft) and maximum discharge of 510 m3/s. Unit 1 commenced commercial operation in 2005 and Unit 2 is expected for 2012. The other four units are expected to be operational by 2020 or later.
The dams
The Minamiaiki Dam is located in Nagano PrefectureNagano Prefecture
is a prefecture of Japan located in the Chūbu region of the island of Honshū. The capital is the city of Nagano.- History :Nagano was formerly known as the province of Shinano...
and is a 136 m (446.2 ft) high and 444 m (1,456.7 ft) long rock-fill dam. It is made of 7300000 m³ (9,548,039.5 cu yd) of material and withholds a 19170000 cubic metre reservoir. The Ueno Dam, in Gunma Prefecture
Gunma Prefecture
is a prefecture of Japan located in the northwest corner of the Kantō region on Honshu island. Its capital is Maebashi.- History :The remains of a Paleolithic man were found at Iwajuku, Gunma Prefecture, in the early 20th century and there is a public museum there.Japan was without horses until...
, is a 120 m (393.7 ft) high and 350 m (1,148.3 ft) long concrete-gravity dam. It is made of 720000 m³ (941,724.4 cu yd) of material and withholds a 18400000 cubic metre reservoir.