Dniester Pumped Storage Power Station

Not to be confused with Dniester Hydroelectric Station.

Dniester Pumped Storage Power Station
Location of Dniester Pumped Storage Power Station in Ukraine
Country	Ukraine
Location	Sokyriany
Coordinates
Status	Partially operational
Construction began	1983
Commission date	2009-2017
Owner(s)	Ukrhydroenergo
Pumped-storage power station
Upper reservoir	Dniester Upper
Upper res. capacity	38,800,000 m3 (31,456 acre·ft)
Lower reservoir	Dniester HPP-I Dam
Lower res. capacity	70,000,000 m3 (56,750 acre·ft)
Hydraulic head	38.7 m (127 ft)
Generating units	7 x 324 MW reversible Francis turbines
Power generation
Nameplate capacity	972 MW

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, 3 of 7 324 megawatts (434,000 hp) generators are operational and when complete in 2017, the power station will have an installed capacity of 2,268 megawatts (3,041,000 hp).

Background

As part of the Dniester Hydro Power Complex, the pumped storage power station (PSP) was planned in the 1970s along with two dams (Dniester I & II) and a nuclear power plant. In 1983, Dniester II, a dam which creates the PSP's lower reservoir, was completed. The PSP was approved by 1988 and construction began that same year. Three years later in 1991 though, construction was suspended due to a funding fallout from the dissolution of the Soviet Union. The project was re-approved in 1993 and construction commenced again in 2001. Project costs increased due to the poor state of the existing facilities which were not maintained while the project was suspended. On December 22, 2009, the PSP's first generator was commissioned. The second generator was commissioned in December 2013. The third generator was comissioned on 21 December 2015.

Ukraine's problems funding the project have been compounded by controversy surrounding the project's transparency and impacts on the environment and water flow to Moldova downstream. Ukraine had sought funding from the World Bank who, in 2007, only funded US$29.6 million towards the PSP's electrical transmission system. Industry experts believe Ukraine will be able to complete the project independently. The power station is expected to be fully operational in 2017.

Design and operation

The power station begins operation by using reversible turbines to pump water, during low energy demand periods, from the lower reservoir which is created by the Dniester HPP-II Dam, located 7.5 kilometres (5 mi) to the southeast near the border with Moldova at . The lower reservoir has a storage capacity of 70,000,000 m³ (56,750 acre·ft). Water pumped from this reservoir is placed in the upper reservoir which is formed by a 360° "liver"-shaped embankment dam. The upper reservoir has a 38,800,000 m³ (31,456 acre·ft) storage capacity. During periods of high energy demand, water is released from the upper reservoir back to the power station for generation. This process is routinely repeated and helps balance loads. The difference in the two reservoirs affords a hydraulic head of 38.7 m (127 ft).

While only 3 are currently operational, the power station will contain 7 324 MW reversible Francis turbine generators. Its installed capacity will be 2,268 MW when generating and during pumping, the power station will consume a maximum of 2,947 MW. Regulating flows into the lower reservoir is the Dniester HPP-I Dam which is located upstream, 9 kilometres (5.6 mi) north of the power plant at . HPP-I has its own power plant with an installed capacity of 702 MW and a storage capacity of 3,000,000,000 m³ (2,432,140 acre·ft). HPP-II has an installed capacity of 40.8 MW.

See also

• List of power stations in Ukraine
• List of pumped-storage power stations