New surge tank commissioning at the Hongrin-Léman pumped-storage plant by real time simulation monitoring

FMHL (Forces Motrices Hongrin-Léman SA) is the owner’s company that belongs to the shareholders Romande Energie SA, Alpiq Suisse SA, Groupe E SA and City of Lausanne. Alpiq, as owners’ representative, is in charge of the supervision of the study and the implementation of the extension project and the operator is Hydro Exploitation SA. The FMHL power plant is a 240 MW pumped-storage power plant in Canton Vaud, Switzerland, which installed capacity is under extension to 480 MW with maximal output power set to 420 MW including 60 MW as reserve. This project, named FMHL+ consists in developing a new powerhouse to be operated in parallel to the existing powerhouse and connected to the same waterways. Increasing the output and input power of an existing hydroelectric scheme from 240 to 420 MW using existing head race tunnel and pressure shaft with maximum gross head of 878 mWC is a challenging task as far as the hydraulic transients are concerned.