Kazunogawa Pumped Storage Power Station
The Kazunogawa Pumped Storage Power Station is a pumped-storage hydroelectric power station near Kōshū in Yamanashi Prefecture, Japan. The station is designed to have an installed capacity of  and three of the four  generators are currently operational, for a total operational capacity of 1200 MW. 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 one became 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 slated to be commissioned by 2024. It is owned by TEPCO and was constructed at a cost of US$2.2 billion. Design and operation

The upper reservoir for the power station is created by the Kamihikawa Dam at  which is a  tall and  long rock-fill embankment type. It has a fill volume of . The upper reservoir's capacity is  of which  is active (or "useful) for power generation. The lower reservoir is formed by the Kazunogawa Dam  (葛野川ダム), which uses water from the Sagami River system. The Kazunogawa Dam is  tall and  long roller-compacted concrete gravity dam. It has a structural volume of . The lower reservoir's capacity is  of which  is active (or "useful) for pumping into the upper reservoir. When energy demand is high, water from the upper reservoir is released down to the underground power station via a single  long headrace tunnel which splits into two  tunnels before each separate into two  long penstocks. Each penstock feeds a single reversible 400 MW Francis turbine-generator with water before it is released into a  long tailrace tunnel which discharges into the lower reservoir. 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  and maximum of . See also

Fukashiro Dam – located downstream of Kazunogawa Dam
List of pumped-storage hydroelectric power stations

References

Dams completed in 1999
Energy infrastructure completed in 1999
Energy infrastructure completed in 2000
Energy infrastructure completed in 2014
Buildings and structures in Yamanashi Prefecture
Pumped-storage hydroelectric power stations in Japan
Underground power stations
1999 establishments in Japan