The is an

arch dam An arch dam is a concrete dam that is curved upstream in plan. The arch dam is designed so that the force of the water against it, known as hydrostatic pressure, presses against the arch, causing the arch to straighten slightly and strengthen ...

on the Uji River just upstream from

Uji is a city on the southern outskirts of the city of Kyoto, in Kyoto Prefecture, Japan. Founded on March 1, 1951, Uji is between the two ancient capitals of Nara and Kyoto. The city sits on the Uji River, which has its source in Lake Biwa. ...

, Kyoto Prefecture,

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 main purpose of the dam is flood control but it supports a

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 station and creates the lower reservoir for the Kisenyama Pumped Storage Plant. The dam itself serves a 92 MW power station while the

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 ...

power station upstream has a 466 MW capacity. Construction on the dam began in 1955 and it was complete in 1964. The pumped-storage power station became operational in 1970. Both plants are owned by Kansai Electric Power Company.

Design

The dam is a tall, long variable-radius arch type with structural volume of . The dam withholds a reservoir called of of which is active or "useful" storage. It has a surface area of . The dam's spillway consists of four x floodgates on its crest with a maximum discharge capacity of . In the middle of the dam body, there are three x gate-controlled orifice openings with a maximum discharge of . The dam's power station has a 92 MW installed capacity and a discharge capacity of .

Kisenyama Pumped Storage Plant

Using Lake Hōō as the lower reservoir, water is pumped up to the upper reservoir via two pump-generators. The upper reservoir is created by a rock-fill dam that is high, long and has a crest width of . The dam also has structural volume of and withholds a reservoir of of which is active storage. From the upper reservoir, water can be released back down to the power station where the two 233 MW reversible

Francis turbine The Francis turbine is a type of water turbine. It is an inward-flow reaction turbine that combines radial and axial flow concepts. Francis turbines are the most common water turbine in use today, and can achieve over 95% efficiency. The proces ...

pump-generators use it for power production. This process can be repeated and generation usually occurs during peak usage periods. The high water level at the upper reservoir is above sea level while it is ASL in the lower reservoir. This affords the power station 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 . Its discharge capacity is . The first generator of the

power station was operational in January 1970, and the second in July of that year. It has a maximum output of 466 MW.

References

External links

{{Dams in Kyoto prefecture Dams completed in 1964 Dams in Kyoto Prefecture Arch dams Pumped-storage hydroelectric power stations in Japan

Design

Kisenyama Pumped Storage Plant

See also

References

External links