DC 11: Energy recovery from underground quarries during filling by geothermal energy storage.

Numerous underground quarries have exploited the subsoil of Lille metropolitan area, mainly in the Chalk layer, at shallow depths, which threaten the stability of adjacent buildings and infrastructures. These cavities are generally filled by cement grout for stabilization depending on the urban needs. The aim is to study the feasibility of exploiting these cavities for seasonal thermal energy storage.

1. Assess the thermal capacity of a backfilled cavity, using prototyping, physical and numerical modelling.
2. Perform short- and long-term risk analysis (backfill stability, environmental impact, influence of/on the water table).
3. Design the energy storage system, in particular the ground heat exchanger.
4. Instrument and monitor an in-situ installation in a cavity in terms of thermal exchange process.