Groundwater heat pumps take their energy from the groundwater near the surface. The groundwater, which is fed into the heat pump through a production well, provides constant energy by cooling it slightly through the cooling process. It is then returned to the original groundwater flow via a swallowing well or a seepage shaft. The temperature of the groundwater is constant throughout the year and is around 10-12°C. This makes the groundwater heat pump the most effective heat pump technology and achieves COP numbers of over 5. In summer, a passive cooling effect can also be carried into the building from the relatively cooler groundwater by the heat pump.
However, the following conditions must be met with regard to groundwater:
Certain layers of earth may not be penetrated for the construction of the well systems, which is why groundwater wells are always subject to approval. The well head is usually designed as a shaft made of concrete rings including a cover, so that the borehole remains accessible.
As a first step, an approved expert with hydrogeological and hydrochemical knowledge should be commissioned to examine and demonstrate the possibilities and obtain the permit, taking into account the very different applications and notification procedures from country to country. The water management offices usually keep lists of approved experts in the corresponding area. The permits are often also obtained from the executing companies if the operator commissions this.
Approval procedure for groundwater heat pumps:
Approval for the use of groundwater: The use of groundwater for thermal use, e.g. by heat pumps, is an offence requiring a permit in Germany pursuant to Section 9 (1) No. 5 WHG (Act on the Regulation of the Water Balance). As a rule, the operator must obtain a permit under water law from the responsible district office. The type and scope of the application documents are regulated on a country-by-country basis. In Bavaria, for example, the submission of the report of a private expert in water management (PSW) is mandatory.
Notification of boreholes: Drilling for groundwater wells is generally subject to notification in accordance with Section 49 (1) of the Water Resources Act. The so-called "drill notification" must be made at least one month before the start of the drilling work at the responsible state office or district office.
1: Heat pump
2: Buffer tank
3: Pressure pipe to the injection well
4: Suction pipe to the suction well
5: Shaft head
6: Well
7: Groundwater
Source: bauwion
