Building permit granted for the new Navizence power plant at Chippis

On 10 March 2010, Forces Motrices de la Gougra (FMG) obtained the building permit for the new Navizence power plant at Chippis. The plant joined the electricity grid in 1908. FMG is now refurbishing it completely, at the same time making it more energy efficient. The new facility will have a total capacity of 70 megawatts and will be gradually commissioned between now and the end of 2013.

The Navizence power plant at Chippis came into service in 1908 During its modernisation in the 1950s, FMG extended the scheme by adding the Moiry dam, the Tourtemagne reservoir and the Vissoie and Mottec powerhouses. With an annual production of around 650 million kilowatt hours, the FMG facilities are in fifth place among the hydropower schemes in Valais Canton. The shareholders are Alpiq (with a 54% stake through Alpiq Ltd., the former Atel Ltd.), Rhonewerke (27.5%), the municipalities responsible for granting the Navizence concession (10%), Sierre municipality (7.5%) and Sierre Energie (1%).

The seven generating sets of the Navizence power plant, with their total capacity of 50 megawatts, turbine the water from Val d'Anniviers and the Tourtemagne Valley for a third time, generating on average about 290 million kilowatt hours every year. After more than 100 years of operation, FMG have decided to completely renovate the Chippis facilities.

Work over three years to improve energy efficiency

In February 2009, the Canton of Valais granted FMG approval for the lower Navizence concession, formerly owned by Alusuisse / Rhonewerke. Based on the favourable preliminary opinions expressed by the Federal Office for the Environment, the municipalities concerned and the relevant departments of the Cantonal administration, the Canton of Valais Department for Economy, Energy and Spatial Development issued the building permit for the new Navizence power plant on 10 March 2010.

The project comprises the modernisation of the internal facilities without major changes to the collecting works or the external features of the scheme. Groupement d'Ingénieurs pour la Centrale de Navizence (GICN), comprising the engineering consultancies of Lombardi SA, Groupe E and SD Ingénierie, has been commissioned to realise the project. The first stage will involve the refurbishment of the power plant and the existing tailrace. Three new 23.7 megawatt generating sets will be built by Andritz. The new plant will thus have a capacity of 70 megawatts. 20 megawatts of the total will be kept as a reserve for the optimisation of generation throughout the year, especially during scheduled maintenance work. With this refurbishment, the plant will meet current operating requirements. The final stage of the work concerns the building of a new 65 kilovolt switching station in the existing buildings.

Re-commissioning scheduled for the end of 2013

The renovation work will start at the end of March and continue through to the end of 2013. The connection of the 3 new generating sets will take place in two stages, the first in autumn 2011 and the second in spring 2013. Plant outages will thus be limited to a few months throughout the period of the work. The total budget of the project is about 75 million swiss francs. The investment is being financed by the Gougra AG power stations.