Use of geothermal energy by means of geothermal probes

When using geothermal energy, a distinction is made between deep and surface geothermal energy. With deep geothermal energy, heat probes are used. For a well-insulated detached house with a low flow temperature, 1-2 boreholes 50-100 m deep can be assumed. With surface geothermal energy, heat collectors are used. For a well-insulated detached house with a low flow temperature, 1-2 times the area of the house can be used as a rough guide for dimensioning.

In simple terms, the principle of a heat pump can be compared to that of a refrigerator - only in reverse. A refrigerant is also required here, which first absorbs heat from the environment in a circuit under low pressure in the evaporator. In the compressor, the temperature is increased by adding mechanical energy and finally released to the heating system in the condenser. This cycle is therefore only completely climate-neutral if the electricity supplied in the compressor is also generated from renewable energies.

The annual coefficient of performance (ratio of electricity required to the amount of energy generated) of a heat pump should be better than 3. An additional solar system for hot water would be ideal.

The use of geothermal energy, together with the necessary boreholes, must be reported to and applied for from the Lower Water Authority at the Office for the Environment, Energy and Climate Protection.

The use of geothermal energy through heat probes or collectors leads to the use of the thermal energy in the ground and therefore requires a permit. In the case of geothermal probes, for example, the drilling activity or the use of flushing additives are likely to change the composition of the groundwater. During operation of the probe, the groundwater can also be damaged by the leakage of a heat transfer medium. Offenbach is largely located in an area that is unfavorable for the use of geothermal energy in terms of water management. Although this does not rule out approval, it is more difficult to assess than in other areas.

The Hessian State Agency for Nature Conservation, Environment and Geology (HLNUG) has compiled the most important information on the use of near-surface geothermal energy on this website

You can use the geothermal viewer and the site assessment map to see which areas in Offenbach are favorable. You can also find out how to carry out the relevant construction work and what the technical requirements are in the construction information sheet.