The Champs-sur-Marne geothermal project, led by the Paris - Marne Valley Urban Agglomeration (CAPVM) and GéoMarne (a local subsidiary of ENGIE Solutions), has commenced. The two foreshafts were sunk in July 2019, before deeper drilling began in mid-November 2019, a symbolic step in the construction of the facility. For the first time, Ile-de-France residents will be able to take part in this local project and thus contribute to the zero-carbon transition through a new crowdfunding solution provided by Lumo.


The GéoMarne project in practice 

The new geothermal power plant will be installed at the Cité Descartes in Champs-sur-Marne, and will provide heat for the equivalent of 10,000 housing units in the towns of Champs-sur-Marne and Noisiel, via a 19 km heating network. This project will make a real contribution to renewable energy development goals and to fighting climate change: geothermal heat, a natural, local, renewable resource, will provide 82% of the energy for the heating network. This will enable heat to be supplied to residents of the CAPVM region with low environmental impact. 
This project, led by the local subsidiary GéoMarne, represents a total investment of €40 million. The facility is scheduled to be commissioned at the end of 2021. 

A crowdfunding operation enables local citizens to participate in this project and thus contribute to the zero-carbon transition

ENGIE Group’s key ambition is to assist towns and local authorities in their transition towards carbon-free energy. In this particular case, this is an inaugural operation for both ENGIE Solutions and Lumo. For Engie Solutions, the leader in geothermal energy in the Ile-de-France region with 40 years of expertise in this field, this is the first time that crowdfunding has been used to raise funds for this type of project. Lumo is also the first crowdfunding platform to give citizens the opportunity to contribute to a geothermal energy project.

In line with its community involvement approach, ENGIE Solutions has chosen to open up the project to local residents via a crowdfunding solution. This shows the company’s strong commitment to firmly anchoring the project within the region by making local residents part of its future success.

Lumo, an expert crowdfunding platform that serves the energy transition, will be responsible for the fundraising operation’s success, with support from its user community and distribution network. 

First CAPVM residents, then residents of the wider Ile-de-France region, will be able to invest their savings in this innovative facility from the month of November 2019 onwards. 

As of November 4th, 2019, internet users will be invited to discover the project and its investment procedure on the Lumo website and to “like” the page to receive regular updates.


A public meeting on the GéoMarne project, hosted by ENGIE Solutions and CAPVM, and by Lumo for the launch of the project’s crowdfunding operation, will be held on November 4th at 19h00 in the multipurpose hall at the Jean-Jaurès gymnasium, in Champs-sur-Marne (115 av. Jean Jaurès).

What does geothermal energy entail? 

A geothermal plant captures heat from below the Earth’s surface or from groundwater - where the water temperature is between 50 and 95°C - then turns it into energy. The captured heat is transferred to the district network to provide heating or domestic hot water for the buildings within a neighbourhood. The water is then reinjected back into the groundwater.

To enable this process, the so-called “doublet” technique is used: an extraction well allows calories to be captured from geothermal water and a reinjection well enables the total quantity of extracted water to be returned underground.  

View of the building site (10 September 2019): preparation of the platform.


Computer-generated image of the future geothermal power plant.


GéoMarne: key figures

  • Deep geothermal well, drilled to 1,900 m
  • Heat supply for the equivalent of 10,000 housing units in Champs-sur-Marne and Noisiel
  • 40 million euros of investment
  • 19 km of network
  • 82% renewable energy
  • Environmental impact (emissions saved): the equivalent of 17,000 vehicles per year