EES (Energie Electrique du Simplon) invested CHF 20 million in the complete restoration of the Tannuwald hydroelectric power plant in the Swiss canton of Valais.

The original seven machine groups commenced operation in 1981 and are being replaced by new two high-power groups. The first group, consisting of a Pelton turbine, a generator and a ball valve, was installed at the start of November. Similarly, the transformers and electrical conduits are also due for replacement. The 2.8 km high-pressure pipeline from the storage basin to the power plant had already been completely renewed by the summer of 2019 and the recommissioning of the plant is scheduled for June 2020. The new infrastructure will enable the plant to achieve a significant increase in potential power output from 5.8 MW to 6.8 MW. In future, annual production will be around 22 GWh – an increase of 4 GWh/a