Managed by Lietuvos Energijos Gamyba the Kruonis Pumped Storage Hydroelectric Plant (KPSHP) is situated north of the town of Kruonis in the district of Kaisiadorys, and appears to be the only power plant of its type in the Baltic region. It is one of the new-generation energy units.
The KPSHP is intended to balance electricity supply and demand. It helps to prevent energy system accidents and liquidates its aftermath. Currently the KPSHP is capable of ensuring 94% of the total necessary energy reserves for Lithuania in case of emergency.
During periods of low demand (usually at night), the KPSHP is operated in pump mode and uses cheap surplus energy. It raises water from the lower Kaunas Reservoir to the upper 303 ha reservoir that is 100 m over the level of Kaunas Reservoir waters. During peak periods (day time), with normal energy demands, it operates as a traditional hydroelectric plant. In order to prevent and liquidate system accidents, it is important for units to ensure a rapid reserved capacity – in less than 2 minutes, if necessary, it can be switched on at full power. The KPSHP units can be started automatically by the anti-accidental system and can thus cover any deficit in power. Other equally important functions of KPSHP are to level the system load balance, to regulate voltage and frequency, and to start the system after a total system blackout.
The KPSHP generated 0,661 TWh of electricity in 2014.
The decision to build a powerful thermal power plant was made on 18 April 1960. When planning the construction of a nuclear power energy plant for the future, it became obvious, that a pumped storage plant, regulating the operation of the energy system and leveling load balance (i.e. improving the quality of electric energy supply, and compensating energy deficiency in case of an accident) was essential. After considering 6 sites for construction of the mentioned plant, Kruonis appeared to be the most suitable location for the prospective power plant with a potential for generating 1600 MW of energy. The main advantage of Kruonis PSHP was the opportunity to use the 63.5-km² Kaunas Reservoir for the lower pool.
Four years were spent on detailed designing. The technical project was accepted in 1978, and the cornerstone of the KPSHP premises was completed in 1984. Eight units of 200 MW were planned for the initially designed electrical capacity of 1600 MW, but later this amount was reduced to four units, but with increased capacity of 225 MW. The first unit began operating in 1992 while the fourth one - in 1998.
This year in order to promote production of energy from renewable resources, the KPSHP began using the largest (in terms of Lithuania) system for solar energy extraction. This system of using alternative energy resources is not only environmentally friendly, but also saves money. Starting in June, a battery of solar collectors began operating, and it is predicted that water heated in this way will be sufficient to cover the hot water demand for the plant‘s internal consumption.