Drilling of the geothermal doublet at Gentilly: marking the rebirth of geothermal in France
The start of drilling, in 2013, marked a decisive step in building the Arcueil-Gentilly district heating network known as ARGÉO, a project led by ENGIE Réseaux.
This hi-tech and completely safe operation will continue until February this year. Two successive wells of 1,600-meter depth will recover naturally-heated water from the Dogger Aquifer. This geological feature runs beneath the Paris Region at a depth of between 1,500 and 2,000 meters, and contains water at between 55°C and 85°C.
60% of network energy needs covered
Since 2015, the geothermal plant meet 60% of the energy needed to power the district heating network, thereby avoiding the atmospheric emission of 14,600 metric tons of CO2 every year; a volume equivalent to the annual emissions of 8,000 vehicles.
With a total power rating of 48 MW, the ARGÉO network provide space heating and domestic hot water for 10,000 homes equivalent (public facilities, communal housing developments and company offices) via a 13-kilometer network.
This project represents a total investment of €32.2 million, 23% of which is being met by subsidies from ADEME (the French Environment and Energy Management Agency) and the Paris Region.
Controlling energy prices
At a time when heating accounts for the majority of household energy consumption (74%), according to ADEME, the ARGÉO heating network will offer a practical and effective solution to the problem of energy insecurity. And since renewables will then contribute more than 50% of the energy used by the network, consumers will benefit from the lower VAT rate of 5.5% on their bills.
As the first completely new geothermal facility and network project in the Paris Region for more than 30 years, this project forms part of a wider program of energy transition initiated by the two towns involved with the goal of achieving a series of environmental, economic and social targets.
An innovative geothermal project in the 19th arrondissement of Paris
In November 2012, Cofely Réseaux received the ‘Northeast Paris’ Innovation Award presented at the Journées de la Géothermie event in recognition of this project to create a geothermal facility capable of generating heating and cooling for a very densely populated urban community with a broad diversity of rented real estate. Located in the new eco-community for the 19th arrondissement of Paris, this facility stands out not only for its performance, but also for its complexity. The area includes housing, offices, business premises and public facilities and spaces, including the 2,400-seater Philharmonie concert hall. This 1,200 m² geothermal plant for ‘Northeast Paris’ is constructed underground on three levels.
Geothermal in the Paris Region
- The sedimentary rock of the Paris Basin makes it geologically suitable for geothermal energy projects. As a result, it is one of France’s two largest reservoirs, accounting for 80% of all geothermal energy currently generated in France.
- There are now 33 geothermal installations in operation across the Paris Region. Between them, they provide energy for 170,000 homes equivalent, saving more than 130,000 metric tons equivalent of oil (Tep) every year
- Geothermal accounts for 10% of all energy distributed by Paris Region district heating networks.
- In 2005, the ADEME department for the region, the BRGM (the French Geological and Mining Research Bureau) and the Regional Council introduced a joint plan to relaunch geothermal in the Paris Region in order to support the revival of existing operations and encourage the creation of new facilities with a view to eventually doubling the number of homes equivalent heated by this form of energy.