Work starts on GeoBrie geothermal heating network in Paris-Vallée de la Marne region, France
Ceremonial laying of the first pipe of the GeoBrie geothermal heating network in Pontault-Combault, France (source: Groupe Coriance)
Carlo Cariaga
17 Jun 2026
Work has started on the GeoBrie geothermal heating network that will supply heat to four neighboring communes in the eastern Île-de-France region in France.
Work has officially been launched for the GeoBrie geothermal heating network at the region covered by the Paris-Vallée de la Marne Agglomeration Community in the eastern of the Île-de-France region in France. The network will eventually cover 42 kilometers of distribution across the communes of Emerainville, Roissy-en-Brie, Pontault-Combault, and Plessis-Trevise. The construction and operation of the heating network has been entrusted to GeoBrie, a wholly owned subsidiary of Groupe Coriance, under a Public Service Concession contract.
The ceremonial deployment of the first pipe of the network was held in Pontault-Combault, with representatives from all communes in attendance. About 4 kilometers of the network is scheduled for installation this year in both Pontault-Combault and Roissy-en-Brie. Next year, this network will be expanded by an additional 13.8 kilometers. Work in Plessis-Trevisse will start in 2029, and Emerainville will follow by 2030. The whole network is expected to be completed by 2034.
The central heating plant will be located in Nautil, between the municipalities of Pontault-Combault and Roissy-en-Brie. It will harness thermal waters from the Dogger aquifer at 1700 meters depth in combination with heat pumps. The plant will also incorporate a 28-MW gas boiler in standby mode as backup energy source. However, the GeoBrie heating network is expected to be supplied by 94% geothermal energy. The network will eventually distribute about 116 GWh of heat per year, equivalent to the consumption of 12,000 homes.
The project represents an investment of EUR 107 million which will go towards the creation of the 42-kilometer distribution network, the construction of the geothermal heating plant and production facilities, the installation of 200 substations, and the implementation of connections to individual houses along the network.
The GeoBrie project benefits from the extensive knowledge on the Dogger aquifer in the eastern part of the Île-de-France region. Recently, an extensive two-year study had been concluded that helps characterize the potential for geothermal heating in the west and south of Île-de-France. This will help expand geothermal deployment in what is already the largest and densest geothermal heating development regions in Europe.
Source: Emerainville, Pontault-Combault, and Groupe Coriance
