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 energy of water, pumped from a lower elevation reservoir to a higher elevation. Low-cost surplus off-peak electric power is typically used to run the pumps. During periods of high electrical demand, the stored water is released through turbines to produce electric power. Although the losses of the pumping process make the plant a net consumer of energy overall, the system increases revenue by selling more electricity during periods of peak demand, when electricity prices are highest. If the upper lake collects significant rainfall or is fed by a river then the plant may be a net energy producer in the manner of a traditional hydroelectric plant.
Mica Dam, a hydroelectric dam spanning the Columbia River 135 kilometres north of Revelstoke, British Columbia, Canada, was built as one of three Canadian projects under the terms of the 1964 Columbia River Treaty and is operated by BC Hydro. Completed in 1973 under the terms of the treaty, the Mica powerhouse had an original generating capacity of 1,805 megawatts (MW). Mica Dam, named after the nearby settlement of Mica Creek and its associated stream, in turn named after the abundance of mica minerals in the area, is one of the largest earthfill dams in the world. The reservoir for the dam is Kinbasket Lake, which was created when the dam was built. Water from the dam flows south directly into Revelstoke Lake, the reservoir for the Revelstoke Dam. Mica Dam is the tallest dam in Canada and second tallest in North America after the Chicoasén Dam in Mexico and it is the farthest upstream dam on the Columbia River. The dam's underground powerhouse was the second largest in the world at the time of its construction, and was the first 500 kV installation of sulphur hexafluoride (SF6) insulated switchgear in the world.
Lake Chelan Dam officially known as the Lake Chelan Hydroelectric Project is located approximately 32 miles (51 km) north of the city of Wenatchee in Chelan County, near the geographic center of Washington state. The dam is located at the lower or southeasterly end of 50.4 miles long Lake Chelan, and is within the limits of the city of Chelan. The powerhouse is located near the community of Chelan Falls. The reservoir has 677,400 acre feet (835,600,000 m3) of usable water storage. The 10-year average generation for the Project is 365,000 megawatt hours.
The Robert Moses Niagara Hydroelectric Power Station is a hydroelectric power station in Lewiston, New York, near Niagara Falls. Owned and operated by the New York Power Authority (NYPA), the plant diverts water from the Niagara River above Niagara Falls and returns the water into the lower portion of the river near Lake Ontario. It uses 13 generators at an installed capacity of 2,675 MW (3,587,000 hp).
The Tokuyama Dam is an embankment dam near Ibigawa, Ibi District, Gifu Prefecture in Japan. The dam was completed in 2008 and will support a 153 MW hydroelectric power station that is expected to be fully operational in 2015. Currently, Unit 1 at 23 MW was commissioned in May 2014. The dam was originally intended to withhold the upper reservoir of a 400 MW pumped-storage power station until a design change in 2004. The dam is also intended for flood control and water supply. It is the largest dam by structural volume in Japan and withholds the country's largest reservoir by volume as well.
The Ingula Pumped Storage Scheme is a pumped-storage power station in the escarpment of the Little Drakensberg range straddling the border of the KwaZulu-Natal and Free State provinces, South Africa. It is about 22 km (14 mi) North-East of Van Reenen.
Caliraya Dam is an embankment dam located in the town of Lumban province of Laguna, in the Sierra Madre Mountain Range of the Philippines. The reservoir created by the dam, Lake Caliraya, initially supplied one of the oldest hydroelectric plants in the Philippines, and later became a popular recreational area for numerous water sports and fishing. The dam's construction was started in 1939 under the supervision of the architecture firm of Pedro Siochi and Company and a small hydroelectric plant was operated in 1942.
Richard B. Russell Dam is a concrete-gravity and embankment dam located on the Savannah River at the border of South Carolina and Georgia, creating Richard B. Russell Lake. The dam was built by the U.S. Army Corps of Engineers between 1974 and 1985 for the purposes of flood control, hydroelectricity, recreation, additional stream flow regulation, water supply, and fish and wildlife management. The concrete structure of the dam spans 1,904 feet (580 m) and rises 210 feet (64 m) above the riverbed, housing a hydro-power plant with an installed 600 megawatts (800,000 hp) capacity. The Richard B. Russell Dam is the final large dam completed by the U.S. Army Corps in the Savannah River Basin and lies 30 miles downstream from the Hartwell Dam (1962) and 37 miles (60 km) upstream from the J. Strom Thurmond Dam (1954).
The Koyna Hydroelectric Project is the largest completed hydroelectric power plant in India. It is a complex project with four dams including the largest dam on the Koyna River, Maharashtra hence the name Koyna Hydroelectric Project. The project site is in Satara district near Patan.
Stave Falls Dam is a dual-dam power complex on the Stave River in Stave Falls, British Columbia, Canada. The dam was completed in 1912 for the primary purpose of hydroelectric power production. To increase the capacity of Stave Lake, the dam was raised in 1925 and the Blind Slough Dam constructed in an adjacent watercourse 500 m (1,600 ft) to the north, which was the site of the eponymous Stave Falls. In 2000, the dam's powerhouse was replaced after a four-year upgrade. The powerhouse was once British Columbia's largest hydroelectric power source and is a National Historic Site of Canada.
Castaic Power Plant, also known as the Castaic Pumped-Storage Plant, is a seven unit pumped-storage hydroelectric plant, operated by the Los Angeles Department of Water and Power, which provides peak load power from the falling water on the West Branch of the California State Aqueduct. It is a cooperative venture between the LADWP and the Department of Water Resources of the State of California. An agreement between the two organizations was signed on September 2, 1966, for construction of the project.
The Okutadami Dam (奥只見ダム) is a concrete gravity dam on the Tadami River, 26 km (16 mi) east of Uonuma on the border of Niigata and Fukushima Prefectures, Japan. The primary purpose of the dam is hydroelectric power generation and it supports a 560 MW power station which is the largest conventional hydroelectric power station in Japan. The dam also forms the second largest reservoir in Japan, next to that of the Tokuyama Dam.
The Vianden Pumped Storage Plant is located just north of Vianden in Diekirch District, Luxembourg. The power plant uses the pumped-storage hydroelectric method to generate electricity and serves as a peaking power plant. Its lower reservoir is located on the Our River, bordering Germany, and the upper is elevated above on the nearby Saint Nicholas Mountain. Construction on the plant began in 1959 and the first pump-generators were commissioned in 1962. A tenth pump-generator was installed in 1976 bringing the plant's installed generating capacity to 1,096 megawatts (1,470,000 hp). The plant generates an average of 1,650 gigawatt-hours (5,900 TJ) annually but of course consumes even more. Generally the efficiency of this energy storage method is around 70-80%. The plant is owned by Société électrique de l'Our and RWE. Construction on an eleventh pump-generator began in 2010 and it is expected to be commissioned in 2013, which will bring the plant's installed capacity to 1,296 megawatts (1,738,000 hp).
The Upper North Fork Feather River Project is a hydroelectric scheme in the Sierra Nevada of California, within Lassen and Plumas Counties. The project consists of three dams, five power plants, and multiple conduits and tunnels in the headwaters of the North Fork Feather River, a major tributary of the Feather—Sacramento River systems. The total installed capacity is 362.3 megawatts (MW), producing an annual average of 1,171.9 gigawatt hours (GWh). The project is also contracted for the delivery of irrigation water between March 31 and October 31 of each year. The project is owned and operated by Pacific Gas and Electric Company.
Northfield Mountain is a pumped-storage hydroelectric plant and reservoir located on and under the similarly named Northfield Mountain in Erving and Northfield, Massachusetts. It is currently owned by FirstLight Power Resources, which purchased the facility from Northeast Utilities in 2006.
The Bissorte Dam is a gravity dam in the Maurienne Valley, in Savoie, France, about 7 km (4.3 mi) east of Valmeinier. It was built from 1930 to 1935 to supply a hydroelectric plant capable of generating 75 megawatts (MW) of power.
The Snoqualmie Falls Hydroelectric Plant is located just north of Snoqualmie in King County, Washington state, US. It is situated about 22 mi (35 km) east of Seattle. Located just below the Snoqualmie Falls, the power plant consists of two power houses, Plant 1 and Plant 2. Plant 1 was completed in 1899 and is located underground. It is the first completely underground hydroelectric power plant ever built in the world. Plant 2 was built in 1910 and is located along the right bank of the Snoqualmie River. Both plants receive water from a small reservoir created by a weir atop the falls. Plant 1 has an installed capacity of 13.7 MW and Plant 2 a capacity of 40.2 MW for a total installed capacity of 53.9 MW, enough to power 40,000 homes.
Alto Lindoso Dam is a concrete double curvature arch dam on the Lima River. It is located in the municipality Ponte da Barca, in Viana do Castelo District, Portugal. The dam lies in Peneda-Gerês National Park close to the border with Spain.
Salamonde Dam is a concrete arch dam on the Cávado River, where the river forms the border line between the districts of Braga and Vila Real. It is located in the municipality Vieira do Minho, in Braga District, Portugal.
Wreck Cove is the largest hydroelectric system in Nova Scotia with a generating capacity of 215.8 MW. Constructed from 1975 to 1978, south of the Cape Breton Highlands National Park, Wreck Cove collects drainage water from 216 square kilometres (83 sq mi) of the Cape Breton Highlands plateau to generate renewable electricity. It consists of two generating stations: the Gisborne Generating Station, with an installed capacity of 3.5 MW, and the Wreck Cove Generating Station, with an installed capacity of 212 MW, producing on average 318 million kWh annually - enough energy to power about 30,000 homes.
