The history of the power plant
Construction of the Nant de Drance pumped storage power plant took 14 years.
It was a high-altitude, large-scale project, with 18 km of tunnels, 1.7 million m3 of excavated rock, up to 650 workers on site, and an investment of more than CHF 2 billion. The site went into operation in mid-2022.
Best of 2013 to 2022
The construction story
Feasibility study and blueprint
2003
2007
Atel and the Swiss Federal Railways submit a concession and construction permit application to the Swiss Federal Office of Energy.
Start of work
The Federal Department of the Environment, Transport, Energy and Communications grants the concession and construction permit.
2008
2011
Decision to increase the capacity from 600 to 900 MW
Completion of work to raise the height of the Vieux Emosson.
Dam Completion of power house cavern drilling.
2014
2020
Synchronisation of the first turbine to the extra-high-voltage power grid
Commissioning of the plant
2022
Nant de Drance book
The 14 years of construction of the Nant de Drance power plant.
