| Abstract |
The ubiquitous shallow geothermal resources can feasibly be utilized by geothermal heat pumps. They represent the fastest growing segment on the geothermal market. The present status worldwide and in Europe is summarized, with special emphasis on Switzerland, the lead country in the dissemination of GHP technology. Further, the sustainability of GHP systems is addressed, mainly the basic questions of long-term operation. The sustainability of production is demonstrated for a single borehole heat exchanger (BHE) by a combined experimental and theoretical (=numerical modelling) approach. It turns out that BHE/HP systems operate, if properly designed, fully reliable on the long term, i.e. sustainable production can be guaranteed. |