The Forces Motrices Hongrin-Léman SA (FMHL) plant in the municipality of Veytaux was inaugurated on Thursday, six years after construction began to install two new 120 MW turbines at the existing 240 MW plant.
Of the upgraded plant’s 480 MW capacity, 420 MW will be used in operation and 60 MW will be held in reserve, developer Alpiq said.
The original plant came online in 1970 and generates power with water from a storage reservoir at peak demand times. Water is pumped to the reservoir from Lake Geneva at a rate of 24 cubic metres per second at times of low demand.
The two new turbines were built inside a 100x25x56-metre underground cavern and are controlled remotely by Alpiq’s Centre d’Exploitation et de Gestion de la Production in Lausanne.
Alpiq said the plant is now the second most powerful pumped storage facility in Switzerland, behind the 1480 MW Linth-Limmern plant in the canton of Glarus. It is expected to generate around 1 GWh of peak power per year.
Investors in the CHF331m ($328m) project include partners Romande Energie (which holds a 41 per cent stake), Alpiq (39 per cent), Groupe E (13 per cent) and the City of Lausanne (6.4 per cent).