Story: 10.09.2008
Nant-de-Drance - Power station to meet peak capacity
Alpiq and the Swiss Federal Railways (SBB) are constructing the Nant de Drance pumped storage station in the lower Valais region. On 25 August 2008 the Swiss Federal Department of Environment, Transport, Energy and Communications (DETEC) issued the Concession and Construction License. Atel and the SBB are together investing CHF 999 million in the production of flexibly available energy.
With the issuing of the Concession and the Construction Licence for the 600 MW Nant de Drance (NdD) project, a further important milestone has been achieved on the path to a secure future energy supply for Switzerland and the public transport. It is now foreseen that the construction work will start in September and that the construction and operating company, "Bau- und Betriebsgesellschaft NdD SA", will be founded with Alpiq holding 60% and the SBB a 40% share.
The Nant de Drance project involves constructing a pumped storage power station in an underground cavern between the existing Emosson and Vieux Emosson reservoirs, a pair of lakes situated in the community of Finhaut. The power station is designed to generate electricity at times of peak consumption. Water from Vieux Emosson will be channelled through turbine generators to the Emosson reservoir 300 meters below. At night and at weekends, when demand for electricity is lower, the water will be pumped back from the lower to the upper reservoir. Equipped with 600-megawatt turbines, the Nant de Drance power station is expected to generate around 1500 million kWh of peak energy a year. The pumps will require some 1800 million kWh of energy.
Environment remains intact
Building work will be non-invasive with a minimal impact on the countryside. The cavern housing the power station lies deep under rock and will be accessed by a five-kilometre long gallery, the entrance to which is adjacent to Le Châtelard power station operated by the Swiss Federal Railways. The electricity generated will feed into the 380 kV grid at Martigny via existing electricity masts and pylons.