Alstom has been awarded a €125 million contract to equip the new628 MW Nant de Drance hydropower station, near Finhaut in the southwestern Canton Valais of Switzerland, with its first variable speed pump storage power plant. This partner project, between Swiss energy provider Alpiq, Forces Motrices Valaisannes (FMV) and Swiss federal railways SBB, demonstrates the first ever use of this type of technology in Switzerland.
Alstom will supply four 157 MW vertical Francis reversible turbines, four 170 MVA vertical asynchronous motor/generator units and further key equipment to the new plant, as well as handling complete site delivery, erection, supervision and commissioning.
The new installation integrates two state-of-the-art technologies: a conventional pump turbine and a variable speed pump turbine. The former pumps the water into a reservoir located in the higher lake during periods of low energy demand and releases it to produce energy during peak times, while the latter regulates the level of energy it consumes, thus contributing to better grid regulation.
Alstom Hydro’s facilities in Grenoble, France and Birr, Switzerland will be in charge of the engineering and manufacturing of the equipment, to be delivered in stages up to 2017. Civil works on this project began in 2008.
Switzerland produces about 66 000 GWh of energy per year, with hydroelectricity making up more than 50%. Due to increasing demand and an ageing fleet, some 25 000 to 35 000 GWh per year will need to be replaced or renewed by 2035, representing about 50% of today’s installed capacity. About a fifth of the mountains of the Alps are located in Switzerland, rendering the country’s geography particularly adapted to the use of pump storage power plants.
