Kraftwerke Mattmark AG
High-pressure storage power stations in the Saas Valley
Kraftwerke Mattmark AG, which is based in Saas Grund (VS), is co-owned by the following companies: Elektrizitäts-Gesellschaft Laufenburg AG (38.88%), Centralschweizerische Kraftwerke AG (27.78%), BKW FMB Beteiligungen AG (11.11%), Sitten Town Council (11.11%), ewl Kraftwerke AG (5.56 %) and Siders Town Council (5.56%).
The plants belonging to Kraftwerke Mattmark AG were built between 1958 and 1966, apart from the Zermeiggern pump station, which was built between 1983 and 1987 after some of the water catches under the Allalin Glacier were disturbed following advancement work on the glacier, making it impossible for the glacier's streams to flow into the Mattmark reservoir.
The first time the water level backed up fully in 1969 the Mattmark barrage was handed over for commercial power station operation. It has a capacity of 100m m3 of water and was created for the sole purpose of generating electrical energy. In 2001, the Mattmark barrage was converted into a multi-purpose storage facility in order to protect the underlying Saas Valley and the Rhone Valley, given the experiences of the floods in the 1990s. Since then, the canton of Valais has had a flood absorption capacity of 3.6m m3 at its disposal in Mattmark.
In addition to the natural catchment area of 37.1 km2, the streams of the Saaser Vispa on the left and right banks, with a catchment of 51.1 km2, are fed to the Mattmark reservoir. 45% of the catchment is glaciated.
The water which is stored in the Mattmark reservoir is used in the two power stations at Zermeiggern (Saas Almagell) and Stalden over a maximum fall head of 459 m for the Mattmark-Zermeiggern stage and 1029 m for the Zermeiggern-Stalden stage. The inflow from the intermediate catchment of 74.2 km2, which is stored in the Zermeiggern compensating basin can be turbined in the Stalden underground central power station or be pumped to the Mattmark reservoir via the Zermeiggern pumps. The Saas Fee power station with the Feevispa water catch is used exclusively to regulate the flow of the Saaser Vispa.
The mean annual production is 649m kWh, with 298m kWh generated in the cold half of the year and 351m kWh generated during the warm half of the year.
The managerial mandate is held by Axpo Hydro Energy.
| Facts & figures | |
|---|---|
| Mean annual production: | 649.0m kWh |
| Total installed turbine output: | 260.5 MW |
| Installed pump output: | 46 MW |
| Zermeiggern power station | |
|---|---|
| Mean annual production: | 133.5m kWh |
| Installed output: | 74 MW |
| Turbines: | 2 vertical-axis Francis turbines, each 37 |
| Water reservoir: | Mattmark reservoir with 100m m3 of usable storage capacity |
| Zermeiggern pump station | |
|---|---|
| Mean annual consumption: | 27.7m kWh |
| Installed output: | 46 MW |
| Pumps: | 2 vertical-axis pumps, single-flow, 4-stage, with 23 MW |