France inaugurated an ambitious pilot project last month to produce electricity at a commercial scale using geothermal energy in Soultz-sous-Forets in Alsace.
The project – a Franco-German joint venture – is the world’s most advanced project of its type for the mass production of geothermal energy. If successful, it will be followed by an industrial prototype of 20 megawatts with the capacity to supply electricity to a town of 20,000 residents.
At the official inauguration on June 13, Prime Minister Francois Fillon injected the first geothermal kilowatt into the Strasbourg electricity grid.
How does it work? The basic principle is to convert the high temperatures deep below the earth’s surface – 200 C at a depth of five kilometres – into electricity. By fracturing granite bedrock at that depth and pumping its saline water, engineers are able to extract the rock’s thermal energy and use it to produce electricity. Some local residents have filed lawsuits claiming property damage from the shaking resulting from the underground blasts.
The Soultz project was initiatied in 1987 and funded by the European Commission. Since 2001, it has been managed by a consortium of European energy companies, including France’s EDF. Technical details available here.