Geothermal energy for the Peninsula: guided tour of an innovative drainage network

Nestled at the confluence of the Drac and Isère rivers, the Grenoble Peninsula has become in just a few years a laboratory for experimentation and innovation. For the new buildings in the district, the City of Grenoble has chosen to use a geothermal system on groundwater with shared discharges into a drainage network in the Isère region.

The City-zen Days were an opportunity for the SEM InnoVia, prime contractor of this mine network, to showcase this ambitious project during two visits. The latter began with a presentation by Franck Izoard, InnoVia project manager, on the imposing model of the Presqu’île urban project located in Canopea, the prototype pavilion of the Presqu’île.

A network itinerary was then waiting for participants with several European partners. By following the network’s route, visitors were able to visit one of the boiler room rooms and rush underground to discover the counting and regulating chamber. This allows the system to remain constantly supplied with water, regardless of the water table level, and to control the temperature and volume of water discharged.

The SEM InnoVia organizes numerous visits all year round and some of them have been particularly inspiring… Proof of the success of the system, two geothermal groundwater projects are currently being deployed on the Esplanade site and on the university campus of Saint-Martin d’Hères. On the Esplanade, the buildings of Grenoble Habitat will benefit from a connection to the geothermal network from the end of 2018.

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Definition and operation of geothermal energy with drainage network

Geothermal energy refers to the energy from the heat contained in the earth’s crust and surface layers. In the case of the Presqu’île project, geothermal energy is exploited via a vertical catchment on groundwater that pumps water at a temperature of about 10 to 12°C. There are two other types of capture: horizontal ground capture and vertical ground capture. Each building then has a borehole to extract water from the groundwater table, located 4 to 5 metres from the ground surface. The term exhaure defines the operation of evacuating infiltration water by piping and pumping. It is the last phase of the process, namely the discharge of pumped water into the Isère.

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More info :

• Read Franck Izoard’s presentation during the Project Forum
• Watch the video of the project
• Franck Izoard talks to us about the project in video