Kraftwerke Mauvoisin AG
High-pressure storage power stations in the Val de Bagnes and in the Rhone Valley
Kraftwerke Mauvoisin AG, which is located in Sion (VS),is a power station which is co-owned by Elektrizitäts-Gesellschaft Laufenburg AG (29.25%), BKW FMB Beteiligungs-Gesellschaft AG (19.5%), Centralschweizerische Kraftwerke AG (19.5%), Axpo AG (19.5%), Electricité de France SA (9.75%) and Bagnes Town Council (2.5%).
The Mauvoisin barrage and the Mauvoisin-Fionnay and Fionnay-Riddes power station stages were built between 1950 and 1958, and the Chanrion power station was built from 1959 to 1964. The Champsec power station, which was built in 1930, was integrated into Kraftwerke Mauvoisin AG in the course of reversion.
Standing at a height of 250 m, the Mauvoisin arch dam is an imposing structure. It forms the Mauvoisin reservoir with a top water level of 1975 m above sea level and a storage capacity of 204m m3. It is fed not only by the natural inflow with a catchment of 114 km2, water is also fed to it from the streams on the left and right banks in the middle Val de Bagnes with a catchment of 53 km2. 43% of the catchment is glaciated.
The inflow from the streams on the right bank above the Mauvoisin reservoir with a catchment of 60.9 km2 are processed in the Chanrion run-of-river power station. The works water is then fed to the Mauvoisin reservoir.
The water which is stored in the Mauvoisin reservoir is used in the two power stations at Fionnay and Riddes over a maximum fall head of 482 m for the Mauvoisin-Fionnay stage and over 1,014 m for the Fionnay-Riddes stage. The inflow is collected from the 21 km2 of intermediate catchment in Fionnay and stored in the compensating basin in Fionnay; it is also turbined in Riddes.
The inflows from the streams on the right bank of the Dranse de Bagnes are turbined in the Champsec power station. They are collected below the Fionnay compensating basin. If the water regime is low, water can also be fed to the power station from the Fionnay compensating basin.
The mean annual production is 1027m kWh, with 605m kWh generated in the cold half of the year and 422m kWh generated during the warm half of the year.
The managerial mandate is held by Axpo Hydro Energy.
| Chanrion power station | |
|---|---|
| Mean annual production: | 74m kWh |
| Installed output: | 30 MW |
| Turbines: | 1 twin-nozzle, horizontal-axis, double Pelton turbine, 30 MW |
| Water reservoir: | Breney compensating chamber with 4,610 m3 of usable capacity |
| Fionnay power station | |
|---|---|
| Mean annual production: | 278m kWh |
| Installed output: | 138 MW |
| Turbines: | 3 vertical-axis Francis turbines, each 46 MW |
| Water reservoir: | Mauvoisin reservoir with 204m m3 of usable storage capacity |