- Hydroelectric Technology
- List of Hydroelectric Power
Posted by Energetic
The Grande Dixence Dam is a concrete gravity dam on the Dixence River at the head of the Val d'Hérens in the canton of Valais in Switzerland. At 285 m (935 ft) high, it is the tallest gravity dam in the world and is part of the Cleuson-Dixence Complex. With the primary purpose of hydroelectric power generation, the dam fuels four power stations, totaling the installed capacity to 2,069 MW, generating approximately 2,000 GWh annually, enough to power 400,000 Swiss households.
The dam withholds Lac des Dix (Lake Dix), its pumped-storage reservoir. The reservoir receives its water from four different pumping stations; the Z’Mutt, Stafel, Ferpècle and Arolla. At peak capacity, it contains approximately 400,000,000 m3 (1.4×1010 cu ft) of water, with depths reaching up to 284 m (932 ft). Construction on the dam began in 1950 and was completed in 1964, before officially commissioning in 1965.
The Chandoline Hydroelectric Power Station was the power station for the original Dixence Dam. The Grande Dixence Dam submerged the original dam but the power station still operates with water received from the reservoir of the Grande Dixence Dam, Lac des Dix. The power station is the smallest of the four, producing 120 MW from five pelton turbines with a gross head of 1,748 m (5,735 ft).
The Fionnay Hydroelectric Power Station receives water from the Grande Dixence Dam by a 9 km (6 mi) long tunnel with an average gradient of 10%. Once the tunnel reaches a surge chamber at Louvie in Bagnes, it turns into a penstock which descends at a gradient of 73% for 800 m (2,625 ft) until it reaches the power station. The water, now flowing at a maximum rate of 45 m3/s (1,589 cu ft/s) spins six pelton turbines, generating a combined maximum capacity of 290 MW.
After arriving at the Fionnay Power Station from the Grande Dixence Dam, water then travels through a 16 km (10 mi) pressure tunnel which eventually leads into the Péroua surge chamber, 1,000 m (3,281 ft) above the Nendaz Power Station. The water, which remains at a maximum rate of 45 m3/s (1,589 cu ft/s) spins six pelton turbines, generating a combined maximum capacity of 390 MW.
The Nendaz power station is located within mountains between Aproz and Riddes and is the second-largest hydroelectric power station in Switzerland after the Bieudron Power Station.
The water travels down a long penstock from the Grande Dixence Dam before reaching the Bieudron Hydroelectric Power Station 1,883 m (6,178 ft) down. The water spins three pelton turbines, generating a combined capacity of 1,269 MW. The power station was constructed after the Nendaz and Fionnay power stations. The power station was built by both Grande Dixence SA and Energie Ouest Suisse between 1993 and 1998 at a cost of US$1.2 billion.
The Bieudron Power Station alone holds three world records, for the height of its head (1,883 m (6,178 ft)), the output of each Pelton turbine (3 × 423 MW) and the output per pole of the generators (35.7 MVA). It was taken out of service in December 2000 after the rupture of a penstock. The power station became partially operational in December 2009 and should be fully operational in 2010.
|Grande Dixence Dam|
|Dam and spillways|
|Type of dam||Gravity dam|
|Height||285 m (935 ft)|
|Length||700 m (2,297 ft)|
|Base width||200 m (656 ft)|
|Volume||6,000,000 m3 (210,000,000 cu ft)|
|Creates||Lac des Dix|
|Capacity||400,000,000 m3 (1.4×1010 cu ft)|
|Catchment area||46 km2 (18 sq mi)|
|Surface area||4 km2 (2 sq mi)|
|Max. water depth||284 m (932 ft)|
|Installed capacity||2,069 MW|
|Annual generation||2,000 GWh|