This website uses cookies to improve your browsing experience and the continued use of the webpage indicates your consent to ÅF’s use of these cookies. Find out more about how ÅF uses cookies and how you can manage them here: Read more


Another Milestone Reached at Nant de Drance PSPP in Switzerland

On 3 March 2017, another important milestone in the construction of the 900 MW Pumped Storage Hydropower Plant Nant de Drance in Switzerland has been reached: at 11:15 after a successfully completed commissioning phase, the two 6 m diameter butterfly valves in the upstream gate chamber have officially been closed.

Thanks to this important step, impounding of the hydropower scheme’s upper reservoir, whose capacity was doubled to hold a live storage of 22 million m3, can now begin.

Construction of the underground gate chamber housing the two butterfly valves began in spring 2014 with the excavation of about 40’000 m3 of rock. The installation of the hydraulic steel structures was started in March 2014 on power waterway number 1 and has ended, as foreseen, today with the closing of both valves, just in time to store the large quantities of melting water arriving in the upstream reservoir at this time of the year.

We express our special thanks to our site management staff for their tremendous efforts to supervise and coordinate the contractors and for ensuring that this milestone could be reached on time.