Country Japan Status Operational Upper reservoir Kamihikawa Reservoir Construction began 1991 | Location Kōshū Construction cost $2.2 billion USD Height 105 m | |
 | ||
Commission date Unit 1: 1999
Unit 2: 2000
Unit 3: 2024
Unit 4: 2014 Address 3064 Nanahomachi Seto, Otsuki, Yamanashi Prefecture 409-0626, Japan Owner Tokyo Electric Power Company Similar Fukashiro Dam, Kannagawa Hydropower Plant, Tamahara Dam, Shiobara Pumped Storage P, Imaichi Dam | ||
The Kazunogawa Dam (葛野川ダム) uses water from the Sagami River system to power a 1,200 MW pumped storage hydroelectric scheme. It is located 18 kilometres (11 mi) east of Kōshū in Yamanashi Prefecture, Japan. The station is designed to have an installed capacity of 1,600 megawatts (2,100,000 hp) and three of the four 400 megawatts (540,000 hp) generators are currently operational. Construction on the power station began in 1993 and the first generator was commissioned on 3 December 1999. The second was commissioned on 8 June 2000. The third on become operational on 9 June 2014, six year early due to post-power demand from the Great East Japan earthquake. The fourth and final generator is slate to be commissioned by 2024. It is owned by TEPCO and was constructed at a cost of $2.2 billion USD.
Design and operationEdit
The upper reservoir for the power station is created by the Kamihikawa Dam at 35°42′58″N 138°49′57″E which is a 87 metres (285 ft) tall and 494-metre (1,621 ft) long rock-fill embankment type. It has a fill volume of 4,110,000 cubic metres (5,380,000 cu yd). The upper reservoir's capacity is 11,470,000 cubic metres (9,300 acre·ft) of which 8,300,000 cubic metres (6,700 acre·ft) is active (or "useful) for power generation.
When energy demand is high, water from the upper reservoir is released down to the underground power station via a single 3.3 kilometres (2.1 mi) long headrace tunnel which splits into two 1.8 kilometres (1.1 mi) tunnels before each separate into two 620 metres (2,030 ft) long penstocks. Each penstock feeds a single reversible 400 MW Francis turbine-generator with water before it is released into a 3.3 kilometres (2.1 mi) long tailrace tunnel which discharges into the lower reservoir, created by the Kazunogawa Dam. When energy demand is low and therefore inexpensive, the turbines reverse into pumps and send water from the lower reservoir back to the upper reservoir. The process is repeated when necessary to help balance electricity loads. The difference in elevation between the upper and lower reservoirs affords an effective hydraulic head of 714 metres (2,343 ft) and maximum of 779 metres (2,556 ft).
The Kazunogawa Dam is 105.2 metres (345 ft) tall and 263.5 metres (865 ft) long roller-compacted concrete gravity dam. It has a structural volume of 622,000 cubic metres (814,000 cu yd). The lower reservoir's capacity is 11,500,000 cubic metres (9,300 acre·ft) of which 8,300,000 cubic metres (6,700 acre·ft) is active (or "useful) for pumping into the upper reservoir.