Energie et eaux souterraines

Geothermal energy systems, closed or open, are increasingly considered for heating and/or cooling buildings. The efficiency of such systems depends on the thermal properties of the subsurface. Therefore, feasibility and impact studies performed prior to their installation should include a field characterization of thermal properties and a heat transfer model using parameter values measured in situ.

O

ur team develops in situ experiments and methodology for performing such field characterizations, especially for open systems. The experiments can then be simulated using numerical models and the best estimation of heat transfer and solute transport parameters is obtained by calibrating the model using inversion tools.

The developed concepts and tests may lead to real projects of various extents that can be optimized by the use of a rigorous and efficient methodology at the field scale.

Ongoing Project

Past projects

Characterization of fractured porous rock aquifers using a combined solute heat tracer test approach (2013-2015), post-doctoral research of Maria Klepikova.

See on ORBi the related publications and conferences abstracts.

Pumped-storage hydroelectricity using old underground works     

In conjunction with solar and wind renewable energy sources, the development of “pumped-storage hydroelectricity” allows to “store” (by pumping water in an upper reservoir) the electricity produced by solar and wind sources during low demand periods. Then, hydroelectricity is produced during peak demand periods with water flowing through turbines into a lower reservoir.

It is proposed to use abandoned mines (underground or open-mines) as a lower reservoir for such pumped-storage hydroelectricity production. Of course, an upper reservoir must also exist or be constructed above at the surface. Wallonia (South of Belgium) could be an excellent place for developing underground pumped-storage hydroelectricity (UPSHE) because there are many old/abandoned mines and open-pits which could be potentially used.

But, first of all, the pros and cons of this method should be evaluated. Given the subsurface conditions of the underground lower reservoirs, it is necessary to assess interactions between an UPSHE project and the aquifers. Possible leakage into the lower reservoir will reduce its capacity and thus the efficiency rate of the electricity production. On the other hand, an UPSHE project could affect the quantity and quality of groundwater.

Defining a rigorous methodology for studying these interactions between the underground or open-pit lower reservoir and its geological/ hydrogeological environment is a key point for (a) designing any UPSHE project and defining its future efficiency rate; (b) assessing impacts of the UPSHE system on the environment.

Past Projects

Hydrogeological modelling associated to pumped-storage hydro-electricity using old underground works (2014-2016) (Post-doctoral research of Estanislao Pujades)