Mottec hydropower plant optimised for a sustainable energy future

First commissioned in 1958, the Mottec power plant in the Val d’Anniviers valley in central Valais is at the core of the hydroelectric complex belonging to the company Forces Motrices de la Gougra. It accounts for approximately 20% of the facility’s total production output and plays a key role as a link between the Moiry dam (its main reservoir) and the Tourtemagne dam in the adjacent valley. The shareholders of Forces Motrices de la Gougra SA – Alpiq with 54%, Rhonewerke with 27.5%, the municipalities of Anniviers (7.71%), Sierre (7.5%), Chippis (1.79%) and Chalais (0.5%), and Oiken with 1.0% – have invested around CHF 35 million to replace the three generating units at the plant. The Swiss Federal Office of Energy (SFOE) is also contributing up to CHF 5.4 million towards Forces Motrices de la Gougra’s financing for the project as part of the support measures for large hydropower plants envisaged in the Energy Strategy 2050.

Work to increase the plant’s generating capacity by 5 million kWh per year – equivalent to the energy consumption of more than 1,000 households – began in 2018 and was finished in 2025. This will push the facility’s overall capacity up from 69 MW to 87 MW, creating even more flexibility for responding to fluctuations in the power grid. “Thanks to this project, we have significantly improved the efficiency and reliability of our installations”, says Georges-Alain Zuber, Director of Forces Motrices de la Gougra SA, “This means we can optimise the use of water and will be better placed to play a part in regulating the power grid, which is essential for integrating the intermittent generation of solar and wind energy into the system”.

Commitment to the future

This project is part of a comprehensive optimisation scheme at Forces Motrices de la Gougra. The main installations, which were built in the late 1950s, are being renovated so that they can reliably produce renewable, local energy for decades to come. In addition to the work carried out at Mottec, the Navizence plant at the lower level of the facility was fully refurbished in 2013, and the Vissoie plant is currently being modernised too. In particular, an agreement reached in 2022 between Forces Motrices de la Gougra SA and the concessions granting authorities on the intrinsic value of the facilities at the end of the concession periods helped to make these investments possible. According to Michaël Plaschy, Chairman of Forces Motrices de la Gougra SA, “The opening of the upgraded Mottec power plant represents a major milestone in our long-term commitment to sustainable energy generation. Increased production and greater flexibility will put us in a better position to meet future energy needs ”.

Aside from this modernisation work, planning for raising the Moiry dam, which is one of the projects being run by the Swiss Confederation’s Hydropower Round Table, will continue throughout 2025. 
In addition, an application for authorisation to build a new water intake tunnel to replace the existing tunnel between Vissoie and Niouc was submitted in March 2025.

Mottec: the centrepiece of the fifth-largest hydropower facility in Valais

The Mottec power plant is part of the hydropower facility operated by Forces Motrices de la Gougra, located in the Val d’Anniviers valley. This power plant enables to first turbine the water stored in the Lac de Moiry reservoir, which is situated nearly 600 metres higher. It is also equipped with pumps which channel water from the Navizence and Tourtemagne rivers into Lac de Moiry. The Gougra complex is the fifth-largest hydropower facility in Valais in terms of production capacity. It generates 640 GWh of renewable electricity per year on average – the equivalent of the average annual consumption of more than 140,000 households.

Link: Flyer « Réhabilitation de la centrale de Mottec » (PDF – in French)

For more information about Forces Motrices de la Gougra SA, visit www.gougra.ch.