Three machine groups at the Mottec power station in the Swiss canton of Valais are to be refurbished, Forces Motrices de la Gougra has announced.

With an investment of CHF 31.2 million, the refurbishment will boost the capacity of the hydropower plant by 18MW from 69MW to 87MW and increase its annual output by 5 million kWh. In addition, the modernisation will extend the control range of the power plant, which will enhance its ability to provide grid services (ancillary services).

As part of the modernization, two of the three machine groups will be completely refurbished. This will involve the replacement of the main components: the gate valves, turbines, generators and transformers. The new components will increase the output of each of the two groups by 9MW from 23MW to 32MW. The third machine group will be overhauled. The measures will be carried out between 2020 and 2022.

In February 2019, the Swiss Federal Office of Energy (SFOE) granted Forces Motrices de la Gougra a gross investment contribution of CHF 4.9 million towards the increase of the two machine groups’ capacity. This investment contribution falls within the framework of the incentive measures for large-scale hydropower plants provided for by the Energy Strategy 2050. It was the SFOE’s first contribution in 2019.

The Mottec power station was constructed in 1958 and is a part of the Forces Motrices de la Gougra hydropower complex in Val d’Anniviers.  In terms of generation capacity, the Gougra complex is the fifth largest hydropower plant in the Swiss canton of Valais.

Thanks to meticulous planning, the Gougra hydropower complex will be able to continue operating during the construction period without any major impact on its output, Forces Motrices de la Gougra said.