PDF - 9Mo - Grande Dixence SA

GD. P.54Nendazpower plantThe biggest hydropower plantin Switzerland after BieudronThe waters of Grande Dixence, having been turbineda first time at the Fionnay plant in the Bagnes valley,dive back deep inside the rock. They cross the mountainagain in the direction of the neighbouring Nendazvalley.The precious water - the “white gold” - is again channelledinto a pressure tunnel that ends in the Pérouasurge tank, 1000 metres above the Nendaz generatingstation. This second power plant is just as discreteand invisible as the one at Fionnay, because it too ishidden inside the mountain. It lies between Aproz andRiddes, on the banks of the Rhône, 478 m. above sealevel.The tunnel linking Fionnay and Nendaz is 16 kilometreslong and ends in another steel-lined penstock.On the way, water from the Fara, originating in theIsérables Valley, is added to the flow heading towardsNendaz.The Nendaz generating station is the biggest hydropowerplant in Switzerland after Bieudron. It workson the cascade principle with the Fionnay station, i.e.its capacity and discharge rate are modulated in tandemwith Fionnay. Together, the two stations generatearound 2 billion kWh per year.The plant has 6 generating units each equipped with2 Pelton turbines, giving a total capacity of 430 MW.14542314914157111414N13812345678910111213141516Nendaz steel-lined shaft. ø 2.9 mValve chamberMachine hallTransformersGallery and gangway of the 220 kV cables of the first 3 sets220 kV cables of the last 3 setsTailrace canalTailrace canal partial bulkheadPower plant access tunnelRhône bridgeService building, workshop and entrance to power plantChamoson switchyard control buildingWorkshop and central depôtProtective fillFionnay-Chamoson 220 kV lineChamoson 220 kV switchyard5610 101216