Geothermal energy in the bank Crédit Agricole
Overview
Crédit Agricole has set a new benchmark in sustainable architecture by opting for geothermal energy to heat and power its new 19,000 square meter building in the La Rochelle urban area.
This building is remarkable not just for its design but also for its energy generation and consumption. It achieves net zero energy emissions, thanks to an extensive geothermal system comprising 35 probes that delve 250 meters underground, linked by 9 kilometers of heat exchange networks. This makes it one of the largest geothermal installations in France.
By leveraging geothermal energy, Crédit Agricole anticipates and adheres to stringent French regulations concerning the carbon footprint of buildings. This approach has also enabled the bank to secure prestigious certifications such as the HQE (High Environmental Quality) and BEPOS (Positive Energy Building) labels, signifying high energy performance and minimal energy consumption.
Technical details
The drilling project, carried out by Geoforage, a subsidiary of the German Weishaupt Group, took place between March and June 2016. The installation features 35 vertical geothermal probes (VGS), each extending 250 meters below the surface—significantly deeper than the typical French boreholes, which rarely exceed 150 meters. The pipes used in this project were manufactured to meet specific demands, featuring a "double U" structure to accommodate two independent loops of high-density polyethylene pipes in each borehole. These were then filled with a cement-based mixture, and a heat transfer fluid circulates through the pipework, supplying heat pumps.
The geothermal system at Crédit Agricole's headquarters has yielded outstanding results. The probes have generated over 1001 MW of energy, split between 488 MW for cooling and 513 MW for heating. In 2018, the building produced 985 MW of electricity, of which 365 MW was consumed by the offices, and 620 MW was fed back into the grid. This impressive balance demonstrates the building’s potential for self-sufficiency, barring the need to re-inject energy into the grid.
In an innovative move, RFID (Radio Frequency Identification) markers from the company Eliot were integrated with the probes. This allows for precise underground positioning using a radio transceiver, facilitating future maintenance and work.
The renovation of Crédit Agricole's headquarters was a substantial investment, totalling €50 million. Of this, the geothermal project accounted for €990,000, with €200,000 subsidized by the heat fund.
Summary
Depth of drilling: 250m of drilling
Annual geothermal needs: 1,621 MWh (heating), 1,030 MWh (cooling), 100% annual geothermal thermal cover (excluding GMI).
Temperature of the water drawn: 93-4 degrees
Units covered: 19 000 m²
Public contribution: €200 000 Fonds chaleur
CO2 emissions avoided: 34,699 tons per year of CO2 saving
Savings in customers’ bills: 7 teq CO2