| Abstract |
Despite the difficult economic situation for Germany in the beginning of the 21st century, a substantial number of medium to large geothermal heat pump plants has been realised, and the interest still is growing. The fact that modern office buildings usually require cooling, even in the moderate German climate, enhances the economic chances of shallow geothermal installations drastically. Ground coupling is usually done by either borehole heat exchangers (BHE, or "vertical loops" in US terms) or by groundwater wells, but also energy piles are present. The building types include schools, small and large offices, a specific "low energy office" combined with one of the largest BHE fields within Germany, commercial buildings like warehouses, a sports hall, etc. Some of the systems are designed in such a way that the underground temperature is influenced intentionally, and thus qualify as Underground Thermal Energy Storage. Proven design procedures, including in-situ measurements and simulation, are used to guarantee trouble-free long-term operation. In most cases of commercial GSHP, the possible cooling load is the key factor for layout and for the potential economic and ecological benefits. The paper explains the development of such systems and gives some general numbers, and then focuses on certain successful examples. |