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.
Grid energy storage is a collection of methods used for energy storage on a large scale within an electrical power grid. Electrical energy is stored during times when electricity is plentiful and inexpensive or when demand is low, and later returned to the grid when demand is high, and electricity prices tend to be higher.
Kruonis Pumped Storage Plant is located near Kruonis, Lithuania, 34 km (21 mi) east of Kaunas. Its main purpose is to provide grid energy storage. It operates in conjunction with the Kaunas Hydroelectric Power Plant. During periods of low demand, usually at night, Kruonis PSHP raises water from the lower Kaunas reservoir to the upper one using cheap surplus energy. The station is designed to have an installed capacity of 1,600 MW but only four 225 MW generators are currently operational. With a fully filled upper reservoir the plant can generate 900 MW for about 12 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 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.
The Goldisthal Pumped Storage Station is a pumped-storage power station in the Thüringer Mountains at the upper run of the river Schwarza in Goldisthal, Germany. It was constructed between 1997 and 2004. It has an installed capacity of 1,060 megawatts (1,420,000 hp), the largest hydroelectric power plant in Germany and one of largest in Europe.
The Siah Bisheh Pumped Storage Power Plant, also spelled Siyāhbisheh and Siah Bishe, is located in the Alborz Mountain range near the village of Siah Bisheh and 48 km (30 mi) south of Chalus in Mazandaran Province, Iran. The power plant uses the pumped-storage hydroelectric method to generate electricity during periods of high energy demand, making it a peaking power plant, intended to fulfill peak electricity demand in Tehran 60 km (37 mi) to the south. When complete it will have an installed generating capacity of 1,040 megawatts (1,390,000 hp) and a pumping capacity of 940 megawatts (1,260,000 hp). Planning for the project began in the 1970s and construction began in 1985. It was delayed from 1992 until 2001 and the first generator went online in May 2013. The remaining generators were commissioned by 1 September 2015. The power plant is the first pumped-storage type in Iran and will also use the country's first concrete-face rock-fill dam – two of them.
The Kölnbrein Dam is an arch dam in the Hohe Tauern range within Carinthia, Austria. It was constructed between 1971 and 1979 and at 200 metres (660 ft) high, it is the tallest dam in Austria. The dam's reservoir serves as the primary storage in a three-stage pumped-storage power system that consists of nine dams, four hydroelectric power plants and a series of pipeline and penstocks. The complex is owned by Verbund power company and is referred to as the Malta-Reisseck Power Plant Group. The installed capacity of the group is 1,028.5 MW and its annual generation is 1,216 gigawatt-hours (4,380 TJ).
The Lam Takhong Dam is an embankment dam on the Lam Takhong River between Pak Chong District and Sikhio District in Nakhon Ratchasima Province, Thailand. The dam was originally constructed in 1974 for the purposes of irrigation and water supply but after 2002, its water storage also serves as the lower reservoir for the Lam Takhong pumped storage power plant, Thailand's first power plant of that type.
The Dniester Pumped Storage Power Station is a pumped storage hydroelectric scheme that uses the Dniester River 8 kilometres (5.0 mi) northeast of Sokyriany in Chernivtsi Oblast, Ukraine. Currently, three of seven 324-megawatt (434,000 hp) generators are operational and when complete in 2028, the power station will have an installed capacity of 2,268 megawatts (3,041,000 hp).
The Coo-Trois-Ponts Hydroelectric Power Station is a pumped-storage hydroelectric power station located in Trois-Ponts, Province of Liege, Belgium. Located next to the Amblève River, the power station uses its water to support a power scheme where water is pumped from a lower reservoir to one of two upper reservoirs known as Coo I and Coo II. When energy demand is high, water can be released from these reservoirs for power generation. The water then returns to the lower reservoir and the process repeats as needed. The same machines that pump the water to the upper reservoirs at a higher elevation are also used as generators. The plant was commissioned in two stages, Coo I (1969) and Coo II (1978). It is owned by Electrabel and has an installed capacity of 1,164 MW.
The Helms Pumped Storage Plant is located 50 mi (80 km) east of Fresno, California in the Sierra Nevada Mountain Range's Sierra National Forest. It is a power station that uses Helms Creek canyon on the North Fork of the Kings River for off-river water storage and the pumped-storage hydroelectric method to generate electricity. After being planned in the early 1970s, construction on the plant began in June 1977 and commercial operations began on 30 June 1984. It has an installed capacity of 1,212 MW and is owned by Pacific Gas and Electric Company.
The Linth–Limmern Power Stations are a system of hydroelectric power stations located south of Linthal in the canton of Glarus, Switzerland. The system uses five reservoirs and four power stations at steep variations in altitude.
The Edolo Pumped Storage Plant is located along the Oglio River just downstream of Edolo, Brescia Province in the Lombardy region of Italy. Using the pumped-storage hydroelectric method, it has an installed capacity of 1,000 megawatts (1,300,000 hp). Its generators were commissioned between April 1984 and November 1985. Lake Avio was previously completed in 1929 and Lake Benedetto completed in 1940.
The Upper Cisokan Pumped Storage Plant is a proposed pumped-storage hydropower facility in Indonesia, due for completion by 2025.
The Rocky Mountain Hydroelectric Plant is a pumped-storage power plant located 10 miles (16 km) northwest of Rome in the U.S. state of Georgia. It is named after Rock Mountain on top of which the plant's upper reservoir is located. Construction on the plant began in 1977 and it was commissioned in 1995. After upgrades were completed in 2011, the plant has an installed capacity of 1,095 megawatts (1,468,000 hp). It is owned by both Oglethorpe Power and Georgia Power which have 75 percent and 25 percent stakes, respectively.
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).
Power sector of Andhra Pradesh is divided into 4 categories namely Regulation, Generation, Transmission and Distribution. Andhra Pradesh Electricity Regulatory Commission (APERC) is the regulatory body. APGENCO deals with the electricity production and also maintenance, proposes new projects and upgrades existing ones as well. The APGENCO also set up a Special Purpose Vehicle (SPV), named as Andhra Pradesh Power Development Company Limited (APPDCL), a joint venture company of APGENCO and IL&FS to set up Krishnapatanam thermal power project.
The Hongping Pumped Storage Power Station is a 1,200 MW pumped-storage hydroelectric power station currently under construction about 11 km (6.8 mi) northwest of Hongping in Jing'an County of Jiangxi Province, China. Construction on the project began in June 2010. The first generator was commissioned in June 2014 and a second 1,200 MW phase is planned for completion in 2017. When fully operational, the power station will have an installed capacity of 2,400 MW. The power station operates by shifting water between an upper and lower reservoir to generate electricity. The lower reservoir is located on Hebei River and the upper reservoir is located in a valley above the north side of the lower reservoir. During periods of low energy demand, such as at night, water is pumped from Hongping Lower Reservoir up to the upper reservoir. When energy demand is high, the water is released back down to the lower reservoir but the pump turbines that pumped the water up now reverse mode and serve as generators to produce electricity. The process is repeated as necessary and the plant serves as a peaking power plant. It is operated by Jiangxi Hongping Pumped Storage Ltd.
The Revin Pumped Storage Power Plant is located in northern France, near Revin in the department of Ardennes and the Belgian border. The pumped storage power plant, commissioned in 1976, is owned by Électricité de France (EDF) and has a nameplate capacity of 800 megawatts (MW). Measured by capacity, it is the third largest pumped storage power plant in France.
