SUEZ and geothermal sources
The earth contains an intense heat which is produced mainly by the rocks in its crust. This heat is currently used depending on the temperature level of the geothermal water: - Very low energy geothermal sources (water from 10° to 30°C) for heating greenhouses, - Low energy geothermal sources (water from 45° to 75°C) for heating buildings, - Very high energy geothermal sources (water from 100° to 150°C) for electricity production. The SUEZ group has, for more than 30 years, promoted the use of this geothermal energy which generates neither waste nor greenhouse gases, and which is economically stable. Therefore, thanks to geothermal energy, over 400,000 tons less CO2 is released into the atmosphere each year in France.
SUEZ group know-how
Specialising in geothermal energy, Elyo, a subsidiary of the SUEZ group, has in particular developed this energy source in the Parisian basin, location of the world's highest density of active geothermal operations. There, Elyo provides 25% of heat from geothermal sources, thus covering the requirements of the equivalent of 23,000 homes. Elyo has thus created in Ile-de-France an agency devoted to geothermal activity, grouping together the technical, legal and financial skills required to provide a response adapted to all potential clients. This expertise allows it to optimise and increase energy production, to develop the network (new operations, extensions, connections) and to ensure the overall management of contracts with local authorities.
SOGESUB: geothermal sources in Sucy-en-Brie (Ile-de-France)
Since 1983, the Société de Géothermie de Sucy-en-Brie (SOGESUB), a subsidiary of Elyo, has financed, produced and operated a deep geothermal operation. First of all, two boreholes were made to a depth of 2000 metres. One is used to draw geothermal water to a geological layer known as "Dogger", the other to reinject it into the same aquifer at a distance of around one kilometre. Secondly, an underground plant was constructed and a heat distribution network of 2 km was installed in the ground, providing geothermal energy to 2350 connected homes and school buildings. Since 2007, to accompany the extension of the distribution network and to increase the production capacity, a new production well is planned, while the two previous wells will be converted into reinjection wells. This new stage will allow the implementation of the first geothermal "triplet" in the Ile de France region.
Key figures
Geothermal operations in the Ile-de-France region Opérations Homes or equivalent Geo-produced energy Champigny-sur-Marne 7000 57.000 MWh Fresnes 5200 35.000 MWh Sucy-en-Brie 2350 25.000 MWh Thiais 4000 35.000 MWh Tremblay-en-France 4000 40.000 MWh