Hydroelectricity, the energy produced in Haute Maurienne
Visible from the Canopée des Cimes, at the top of the Val Cenis ski area, the Mont Cenis dam allows EDF to produce electricity from hydraulic sources, 100% renewable energy and without greenhouse gas emissions.
The electricity produced in this way is used primarily in local areas, including Val Cenis. The electricity consumed to power the ski lifts, the snow guns and the premises is therefore renewable and carbon-free.
With the Mont-Cenis dam, but also those of Aussois and Bissorte, the Haute Maurienne Vanoise is home to enormous water reservoirs. These facilities supply the hydroelectric power stations of Aussois, Avrieux, Villarodin and Bissorte. These facilities produce, on average, each year the equivalent of twice the residential consumption of the Savoie department.
With its 320 million m3, the Mont-Cenis is the largest rockfill dam in France.
Since the beginning of the 20th century, the Mont-Cenis plateau, whose waters flow naturally towards Italy, had been developed for hydroelectric production. After the Second World War, following the Peace Treaty of 1947, the border that passed through the Mont-Cenis pass was moved in favor of France, which thus recovered the entire plateau, an ideal position for building a large-scale dam. The new dam, built by EDF between 1962 and 1969, created a reservoir with a capacity of 320 hm3, shared between the two countries at the rate of about 1/5 for Italy and 4/5 for France.
With its 120 m high and its length of 1,4 km, the Mont-Cenis dam is the main element of the hydraulic development of Haute Maurienne Vanoise. It is a "gravity dam", which means that it opposes its enormous mass of rock to the pressure of the water. To fill it, water has been collected from Bonneval sur Arc, for example. The reservoir is even connected to the Plan d'Aval dam, in Aussois on the other side of the valley! A set of galleries and penstocks allow, by a complex game of turbining and pumping, to transfer water from one reservoir to another to supply, according to the needs, the power plants of Villarodin, Avrieux and Aussois.
The Mont-Cenis site has been the subject of a program of work aimed at improving the landscape and preserving an international heritage, including the rehabilitation of the Grand-Croix mountain pasture, the undergrounding of power lines and the creation of a Franco-Italian network of hiking trails. The water from this development is also used in part for the production of artificial snow in several ski resorts in Haute Maurienne Vanoise.
In summer, learn more about hydroelectricity and the Mont-Cenis dam with the game trail "A dam in my landscape".
The Mont-Cenis dam is the last one in France to be guarded because of its location on the border between France and Italy. The barragists always work in duo with a French and an Italian technician. They spend several days on the site, surveying the kilometers of galleries that crisscross the mountain, taking readings and checking the quality of the installations.