Reversable system for all seasons

• Installed annual capacity of 130 kW produces 70 MWh of renewable energy
• Total energy cost savings of around 10 %
• Reduced annual CO2 emission of 24 tonnes

Chemaudin is a village of some 1 500 inhabitants located west of Besançon in eastern France. The municipality is responsible for the physical operation of the Denise Arnoux school group, which includes a nursery and elementary school. As part of a new building project to house extracurricular activities, it carried out an energy audit in 2008, followed by a study in 2010 on low-energy alternatives for heating. The community decided to use geothermal energy, which can heat the school in winter and be reversed for cooling in hotter months.

Geothermal wells and vertical probes were drilled to a depth of 100 metres. These probes or synthetic tubes draw energy from the ground and transmit it to a heat pump mounted above-ground which produces water at a temperature of 45°C that manages the heating and cooling needs on the premises.

Key results

With an installed capacity of 130 kW, the system produces 70 MWh of renewable energy per year for heating. The heat pump produces six times more energy than it consumes. This high output ratio makes it possible to cover almost 85 % of the heating needs using renewable energy sources.

Electricity consumption in the new heating system increased marginally from 146 MWh to 150 MWh per annum. The municipality therefore saves around 10 % on adjusted energy costs, and it emits 24 tonnes less CO2 per year.