Impact of grout thermal conductivity on the long-term efficiency of the ground-source heat pump system

shown that in thermogeological environment with mediocre thermal conductivity, distinction in COP was modest for each of the four analysed grouting material during 30 years. Comparing investment costs with savings in electricity for each grout mix case, conclusion is that there is no real benefit of implementing enhanced grout in mediocre thermal conductivity environment such as marly-clays.