This is a helpful comment given the confusion above. The concept seems more related to Thermal Mass than geothermal energy. https://en.wikipedia.org/wiki/Therm

This is a helpful comment given the confusion above. The concept seems more related to Thermal Mass than geothermal energy. https://en.wikipedia.org/wiki/Thermal_mass https://en.wikipedia.org/wiki/Thermal_mass I’m fascinated by Eathships which rely on this along with convection to regulate air temperature. https://en.wikipedia.org/wiki/Earthship https://en.wikipedia.org/wiki/Earthship