The Forces Motrices Hongrin-Léman (FMHL) company was founded in 1963 with the purpose of constructing a pumped storage hydroelectric facility. The main features of the project are the Hongrin dam and the two underground pumped storage power plants on Lake Geneva, near Chillon Castle.
Characterised by the two elegant curved arches of its dam, the Hongrin reservoir represents a real stock of energy. Located near Col des Mosses, it has a capacity of 52 million m3 of water, which corresponds to around 100 GWh, or 10 days of electricity consumption of the whole canton of Vaud.
The reservoir is fed by the rain eight water catchments, and by water that is pumped up from Lake Geneva. All the facilities are located in the canton of Vaud. Because FMHL’s catchment area lies in the two cantons of Vaud and Fribourg, its operation is based on an inter-cantonal concession. The plant operator is HYDRO Exploitation SA.
Type: Double arch dam
Height: 123 m / 95 m
Crest: 600 m
Reservoir capacity: 52 million m3
Area: 160 ha
Naturel catchment area: 46 km2
Total catchment area: 90.8 km2
The Veytaux I station, which entered service in 1971, comprises four hydroelectric turbines, each with a capacity of 60 MW. The station can process water at a rate of up to 32 m3/s. In the reverse direction, the pumps can pump up to 24 m3/s of Lake Geneva water up to Lake Hongrin, 880 metres higher.
Units: 4 x 2 Pelton turbines and 4 pumps
Capacity: 240 MW
In order to respond to the increasing demand for peak energy and balancing energy, FMHL doubled the capacity of the original facility by constructing a second power station, which was commissioned in 2017. Adjacent to the Veytaux I station, the Veytaux II station consists of two 120 MW generators.
Units: 2 Pelton turbines and 2 pumps
Capacity: 240 MW
Storage power plant
|Number of turbines:|
Veytaux I: 4 x 2 Pelton turbines / Veytaux II: 2 Pelton turbines
480 MW, with 60 MW in reserve
Commissioning: Veytaux I:
1971 / Veytaux II: 2017
Average annual production: