Seen from the outside, nothing suggests the gigantic installation hidden in the cliff. The Bois cable car in Chamonix leads to miles of galleries carved into the rock.
– Coline Mollard
Since 1973, EDF has been recovering meltwater from the sea ice to produce energy. The plant operates from April to December, and produces the equivalent of annual electricity consumption of 50,000 people.
– Coline Mollard
“There we have the sea ice above us, and we are heading towards the catchment, which is an opening on the underside of the glacier“, describes Loïc Trehiou, responsible for the hydraulic development of Les Bois. Under ten meters of ice, the water is captured, then filtered before reaching the power station.
The melting of the glacier threatens the installation
Outside, the glacier is melting visibly. “The sea ice is retreating inescapably. Since 1995, it has retreated 800 meters in this area“, observes Guillaume Marchal, in charge of studies and works. Within three to four years, the collection point will therefore be in the open airwith the risk of falling rocks that could block the opening.
“The glacier would no longer protect us. This kind of cover that it is currently creating will disappear.” – Guillaume Marchal, EDF works manager
“The difficulty is to know how the rock faces will behave at the level of this catchment, currently held by the glacier.“, explains Loïc Trehiou.
– Coline Mollard
It is now necessary to adapt quickly. “We are moving towards operation with the current main catchment, at 1,560 meters above sea level, which we are going to reinforce, and a second emergency catchment which we are going to rehabilitate, at 1,520 meters above sea level. Eventually, it is possible that only the second capture remains“, on which a grid will be put in place to prevent the rocks from passing.
The work starts next yearfor commissioning in 2024.