• Geothermal boreholes (or ground heat exchangers) are the interface between a heat pump and the ground. The ground can be used either as a heat source (when it captures the thermal energy of the earth core) or as a heat storage (when the ground between two adjacent boreholes stores heat in the summer to release during winter)
  • The drilling process consists of introducing polyethylene pipes in the boreholes. The pipes are filled with water or glycol, which are used as heat carrier fluid in a closed loop
  • Usually, after introducing the pipes in the borehole, the latter are filled with concrete to improve heat transfer and to protect the aquifers
  • The relatively high cost of a geothermal drilling system requires a very strict sizing (optimization). This is done by:
  1. Accurately understanding the thermal properties of all geological layers crossed by the borehole (Thermal Response Test – TRT)
  2. Using a software to optimize and simulate the heat exchanger functioning (EED Design)
  3. Using drilling techniques that are adapted to local geological conditions, with the lowest costs (Execution)