Grande Dixence Dam
Encyclopedia
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 , generating approximately annually, enough to power 400,000 Swiss households.
The dam withholds Lac des Dix (Lake Dix), its reservoir
. The reservoir receives its water from four different pumping stations; the Z’Mutt, Stafel, Ferpècle and Arolla. At peak capacity, it contains approximately 400000000 cubic metre 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.
canton which contains 56% of Switzerland
's glaciers and stores the largest amount of water in Europe. In 1927, EOS acquired the license for the upper Dixence basin. In 1929, 1,200 workers constructed the first Dixence dam which would be complete in 1935. The first dam would supply water to the Chandoline Power Station which has a capacity of 120 MW.
After the Second World War, growing industries needed electricity and construction on the Cleuson Dam began in 1947 and was completed in 1951. Plans for the Super Dixence Dam were now being finalized by the recently founded company, Grande Dixence SA. Construction on the Super Dixence Dam soon began later in 1950. By 1964, 3,000 workers had finished pouring 6000000 cubic metre of concrete, completing the dam. The original Dixence dam was submerged by the filling of Lac des Dix beginning in 1957, it can still be seen when the reservoir level is low.
In the 1980s, Grande Dixence SA and EOS began the Cleuson-Dixence project which improved the quality of electricity produced by building new tunnels along with the Bieudron Power Station. By the time the Cleuson-Dixence Complex was complete, the power generated had more than doubled.
surrounds the dam, reaching a depth of 200 m (656 ft) and extending 100 m (328 ft) on each side of the valley.
Although the dam is situated on the relatively small Dixence River, water supplied from other rivers and streams is pumped by the Z’Mutt, Stafel, Ferpècle and Arolla pumping stations. The pumping stations transport the water through 100 km (62 mi) of tunnels into its reservoir, Lac des Dix. Water from the 87 m (285 ft) high Cleuson Dam, located 7 km (4 mi) to the northwest, is also transported from its reservoir, the Lac de Cleuson
. Three penstock
s transport water from Lac des Dix to the Chandoline, Fionnay, Nendaz and Bieudron power stations, before being discharged into the Rhône River
below. All the pumping stations, power stations and dams form the Cleuson-Dixence Complex. Although the complex operates with water being pumped from one reservoir to another, it does not technically qualify as a pumped-storage scheme.
Most of the water comes from glacier
s when they melt during the summer. The lake is usually at full capacity by late September, and empties during the winter, eventually reaching its lowest point around April.
with a gross head of 1748 m (5,735 ft).
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 spins six pelton
turbines, generating a combined maximum capacity of .
turbines, generating a combined maximum capacity of .
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.
from the Grande Dixence Dam before reaching the Bieudron Power Station 1883 m (6,178 ft) down. The water spins three pelton turbines, generating a combined capacity of . 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 (1883 m (6,178 ft)), the output of each Pelton turbine and the output per pole of the generators . 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.
Val d'Hérens
Val d'Hérens is an alpine valley in the Valais canton of Switzerland. It was formed by the Hérens glacier, which retreated at the end of the last ice age....
in the canton of Valais
Valais
The Valais is one of the 26 cantons of Switzerland in the southwestern part of the country, around the valley of the Rhône from its headwaters to Lake Geneva, separating the Pennine Alps from the Bernese Alps. The canton is one of the drier parts of Switzerland in its central Rhône valley...
in Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
. 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 , generating approximately annually, enough to power 400,000 Swiss households.
The dam withholds Lac des Dix (Lake Dix), its reservoir
Reservoir
A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...
. The reservoir receives its water from four different pumping stations; the Z’Mutt, Stafel, Ferpècle and Arolla. At peak capacity, it contains approximately 400000000 cubic metre 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.
History
In 1922, Energie Ouest Suisse (EOS) became established with a few small power stations. To generate substantial amount of electricity, EOS looked to the ValaisValais
The Valais is one of the 26 cantons of Switzerland in the southwestern part of the country, around the valley of the Rhône from its headwaters to Lake Geneva, separating the Pennine Alps from the Bernese Alps. The canton is one of the drier parts of Switzerland in its central Rhône valley...
canton which contains 56% of Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
's glaciers and stores the largest amount of water in Europe. In 1927, EOS acquired the license for the upper Dixence basin. In 1929, 1,200 workers constructed the first Dixence dam which would be complete in 1935. The first dam would supply water to the Chandoline Power Station which has a capacity of 120 MW.
After the Second World War, growing industries needed electricity and construction on the Cleuson Dam began in 1947 and was completed in 1951. Plans for the Super Dixence Dam were now being finalized by the recently founded company, Grande Dixence SA. Construction on the Super Dixence Dam soon began later in 1950. By 1964, 3,000 workers had finished pouring 6000000 cubic metre of concrete, completing the dam. The original Dixence dam was submerged by the filling of Lac des Dix beginning in 1957, it can still be seen when the reservoir level is low.
In the 1980s, Grande Dixence SA and EOS began the Cleuson-Dixence project which improved the quality of electricity produced by building new tunnels along with the Bieudron Power Station. By the time the Cleuson-Dixence Complex was complete, the power generated had more than doubled.
Characteristics
The Grande Dixence Dam is a 285 m (935 ft) high, 700 m (2,297 ft) long concrete gravity dam. The dam is 200 m (656 ft) wide at its base and 15 m (49 ft) wide at its crest. The dam's crest reaches an altitude of 2365 m (7,759 ft). The dam structure contains approximately 6000000 cubic metre of concrete. To secure the dam to the surrounding foundation, a grout curtainGrout curtain
Grout curtains are barriers that protect a dam from seepage and can be used in initial construction or repair. Additionally, they can be used to strengthen foundations and contain spills.-Characteristics:...
surrounds the dam, reaching a depth of 200 m (656 ft) and extending 100 m (328 ft) on each side of the valley.
Although the dam is situated on the relatively small Dixence River, water supplied from other rivers and streams is pumped by the Z’Mutt, Stafel, Ferpècle and Arolla pumping stations. The pumping stations transport the water through 100 km (62 mi) of tunnels into its reservoir, Lac des Dix. Water from the 87 m (285 ft) high Cleuson Dam, located 7 km (4 mi) to the northwest, is also transported from its reservoir, the Lac de Cleuson
Lac de Cleuson
Lac de Cleuson is a reservoir in the municipality of Nendaz, Valais, Switzerland. Its surface area is 0.51 km². Water from the reservoir is often pumped into the Grande Dixence Dam's reservoir, Lac des Dix, for use in hydroelectricity production....
. Three penstock
Penstock
A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydraulic turbines and sewerage systems. It is a term that has been inherited from the technology of wooden watermills....
s transport water from Lac des Dix to the Chandoline, Fionnay, Nendaz and Bieudron power stations, before being discharged into the Rhône River
Rhône River
The Rhone is one of the major rivers of Europe, rising in Switzerland and running from there through southeastern France. At Arles, near its mouth on the Mediterranean Sea, the river divides into two branches, known as the Great Rhone and the Little Rhone...
below. All the pumping stations, power stations and dams form the Cleuson-Dixence Complex. Although the complex operates with water being pumped from one reservoir to another, it does not technically qualify as a pumped-storage scheme.
Most of the water comes from glacier
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...
s when they melt during the summer. The lake is usually at full capacity by late September, and empties during the winter, eventually reaching its lowest point around April.
Chandoline Power Station
The Chandoline 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 from five pelton turbinesPelton wheel
The Pelton wheel is an impulse turbine which is among the most efficient types of water turbines. It was invented by Lester Allan Pelton in the 1870s. The Pelton wheel extracts energy from the impulse of moving water, as opposed to its weight like traditional overshot water wheel...
with a gross head of 1748 m (5,735 ft).
Fionnay Power Station
The Fionnay 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 LouvieLac de Louvie
Lac de Louvie is a lake above Fionnay in the canton of Valais, Switzerland....
in Bagnes
Bagnes
Bagnes is a municipality in the district of Entremont in the canton of Valais in Switzerland.With an area of , Bagnes used to be the largest municipality of Switzerland until the formation of Glarus Süd in 2011.-History:...
, it turns into a penstock
Penstock
A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydraulic turbines and sewerage systems. It is a term that has been inherited from the technology of wooden watermills....
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 spins six pelton
Pelton wheel
The Pelton wheel is an impulse turbine which is among the most efficient types of water turbines. It was invented by Lester Allan Pelton in the 1870s. The Pelton wheel extracts energy from the impulse of moving water, as opposed to its weight like traditional overshot water wheel...
turbines, generating a combined maximum capacity of .
Nendaz Power Station
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, 1000 m (3,281 ft) above the Nendaz Power Station. The water, which remains at a maximum rate of 45 m3/s spins six peltonPelton wheel
The Pelton wheel is an impulse turbine which is among the most efficient types of water turbines. It was invented by Lester Allan Pelton in the 1870s. The Pelton wheel extracts energy from the impulse of moving water, as opposed to its weight like traditional overshot water wheel...
turbines, generating a combined maximum capacity of .
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.
Bieudron Power Station
The water travels down a long penstockPenstock
A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydraulic turbines and sewerage systems. It is a term that has been inherited from the technology of wooden watermills....
from the Grande Dixence Dam before reaching the Bieudron Power Station 1883 m (6,178 ft) down. The water spins three pelton turbines, generating a combined capacity of . 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$
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....
1.2 billion.
The Bieudron Power Station alone holds three world records, for the height of its head (1883 m (6,178 ft)), the output of each Pelton turbine and the output per pole of the generators . 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.