Hydropower project on the Grimsel enters the implementation phase
Kraftwerke Oberhasli AG (KWO) will begin construction of the new Grimsel 4 pumped-storage plant in June. The underground facility is designed to enable the flexible use of the water stored in Lake Räterichsboden and Lake Grimsel. KWO is investing 300 million Swiss francs in the project.
According to a press release, the Board of Directors of Kraftwerke Oberhasli AG (KWO), based in Innertkirchen, has approved an investment of 300 million Swiss francs in the construction of the new Grimsel 4 pumped-storage power station. The plant will enable the water from the two reservoirs, Räterichsboden and Grimsel, to be used to ensure grid stability. The concession and planning permission have already been granted.
Grimsel 4 consists of an underground power station between the two lakes. Two reversible pump-turbines, each with a discharge capacity of 35 cubic metres per second and an installed capacity of 84 megawatts, pump water up into Lake Grimsel as required or use it to drive the turbines as it flows into Lake Räterichsboden. The water tunnel between the two lakes is around 1,200 metres long and has a diameter of 6 metres. The access tunnel to the power station is around 1,800 metres long.
Construction will begin in June and is scheduled for completion in February 2032. Excavation work for the power station will commence in early 2028.
KWO was founded in 1925. It currently operates 13 hydroelectric power stations and eight reservoirs. BKW holds a 50 per cent stake in the company. The municipal utilities of Basel (IWB), Bern (ewb) and Zurich (ewz) share the remaining half equally.