Mignot Hospital, Le Chesnay-Rocquencourt, Yvelines, France (source: Département des Yvelines / flilckr, Creative Commons)

A geothermal heating project in the commune of Le Chesnay-Rocquencourt is expected to supply stable and renewable heat to Yvelines, France by 2025. This project is being developed by GeomY3, a joint company of Engie Solutions, the Yvelines departmental council, the municipality, and the current operator of the locale’s boiling room and district heating network. A capital of EUR 5.3 million has been used to set up the company.

From October 2025, this project will supply heat to the 7500 households, the Parly 2 shopping center, the Mignot hospital, the town hall, the swimming pool, and the Nouvelle France condominium.

Work on the first borehole is expected to start at the end of 2023. The borehole will be drilled to a depth of 1500 meters to target geothermal water at a temperature of 61 degrees Celsius. The Yvelines council has also made available the land located at the crossroads of the D186 and D307 for construction of the future geothermal heating plant.

There are also plans of drilling two additional wells that will supply geothermal heat to the neighboring towns of La Celle Saint Cloud, Bailly, Noisy-le-Roi, and Bougival. An additional 8000 households are expected to benefit from this planned expansion.

“It’s a great Christmas present for everyone,” commented Le Chesnay-Rocquencourt Mayor Richard Delepierre. “Ther was a risk that the initial project was going to be postponed, but I defended the position with the elected officials concerned that the train was rolling and that I would not stop it.”

“Geothermal energy is security in terms of supply and the assurance of stable prices for thirty years. The lifespan of a borehole is in fact thirty years and the Earth’s energy is infinite underground. The device will also make it possible to limit the nuisances linked to the comings and goings of the trucks which usually supply the networks with energy,” added a Celle Saint Cloud Mayor Olivier Delaporte.

In late 2021, the commune of Vélizy-Villacoubla (also in Yvelines) inaugurated a new geothermal heating plant with the involvement of Engie Solutions, ADEME, and the regional council.