The largest hydroelectric construction project in Valais enters a new, major phase

Almost two years after arriving in Châtelard (Valais), tunnel workers prepare to cut through the last metres of the access tunnel to the future pumped storage power plant of Nant de Drance. This stage, which is on the verge of being completed, is all-important for Alpiq, the CFF and the Forces Motrices Valaisannes (FMV) – the three partners that actively support the project.

The excavation of the access tunnel, which began end 2010 in Châtelard, is almost completed. Only about 400 metres remain before the tunnel workers reach their goal: a cavern currently being excavated through rock 600 metres below the surface between the Emosson and Vieux Emosson reservoirs. This 5.6 km access tunnel will enable underground traffic between Châtelard and the upper part of the site at Emosson. Traffic on the road leading to the reservoir will thus be significantly reduced and the upper part of the construction site will henceforth be accessible year-round, even in the middle of winter. At Vieux-Emosson, work to raise the retaining wall began in June. This year, part of the crest of the retaining wall will be demolished by blasting in order to be heightened by over 20 metres in 2013.

A real asset both for Valais and for Switzerland Three years after the beginning of construction, the partners of Nant de Drance SA, Alpiq (54 %), the CFF (36 %) and the FMV (10 %), are well pleased with the project’s progress. Mr. Michael Wider, Chairman of the Board, points out that the “three partners are working together with construction management and the companies involved in the site to successfully complete this project. The future Nant de Drance power plant represents a real asset for Valais and for Switzerland, as it will ensure a secure supply of electricity for Switzerland’s power grid, as well as for the CFF railway network."

 Within the framework of the Federal Council’s new energy policy, the Nant de Drance pump and turbine plant is to be one of the essential resources in responding to the increasing need for balancing energy, i.e. the power needed at all times for a steady balance on the electricity grid between generation and consumption. Since pumped storage hydroelectric power stations represent a real stock of renewable energy that can be injected into the grid at any time, the Nant de Drance will ideally complement the uneven generation of new renewable energy. In order to allow the energy that will be generated at Nant de Drance to be transported and to secure the country’s electricity supply, the Swiss high-voltage grid and particularly the Valais grid will have to be upgraded. The Federal Council has in fact described the extension of the grid as being “imperative for Switzerland’s future generation infrastructure”.