Heat pump analysis surprises: More buildings suitable than previously assumed

"The current discussions and changes around heating subsidies are unsettling many owners. This makes it all the more important not to make decisions dependent on political debate, but to check the structural facts of one's own property. Our analysis shows that the potential for heat pumps in many cities is much greater than expected – especially for detached and semi-detached houses. Nevertheless, every property remains individual and there are major regional differences nationwide. A careful examination therefore remains the most important step before making an investment decision. It helps to compare several specialist companies and get independent advice to find the right solution for your own building."says Swen Dreßen, expert for energy-efficient living at Aroundhome.

In particular, large cities in eastern Germany often offer better technical conditions for heat pumps than many cities in western Germany. In Dresden, for example, more than four out of five buildings (82.5 percent) are generally suitable for at least one heat pump technology. In Düsseldorf, on the other hand, this applies to only about two out of five buildings (40.9 percent). Dresden is followed by Bielefeld (78.2 percent), Berlin (74.9 percent), Hamburg (68.1 percent) and Bochum (66.1 percent). Leipzig (66.0 percent), Dortmund (65.0 percent) and Hanover (60.2 percent) also perform above average. Looking beyond the largest cities, Frankfurt/Oder (90.5 percent), Neumünster (85.5 percent) and Cottbus (83.0 percent) offer the highest potential nationwide.

At the lower end of the ranking, in addition to Düsseldorf (40.9 percent)¹, Frankfurt am Main (41.4 percent)¹, Cologne (44.4 percent) and Mannheim (45.1 percent) are at the lower end of the ranking. The average among the twenty largest cities is 58.9 percent overall.

¹ Düsseldorf and Frankfurt am Main are at the bottom of the ranking, among other things due to their dense building structure. Small distances between residential buildings and small plots of land limit the supply of environmental heat there. According to the data of the FfE, at least 40.9 and 41.4 percent of residential buildings in both cities can be technically supplied with a heat pump.

The type of building also has a considerable influence on the suitability of a heat pump. Among the building types considered by the FfE, detached detached and semi-detached houses offer the best technical conditions with an average of 91 percent. This is followed by small apartment buildings with three to six residential units (83.4 percent) and semi-detached houses (71.0 percent). The potential is significantly lower for terraced houses (40.0 percent) and large apartment buildings with seven or more residential units (32.7 percent).

Depending on the property, space available and geological conditions, different heat pump technologies are suitable. Air source heat pumps require comparatively little construction effort, as usually only a suitable installation location for the device is required. Geothermal probes and geothermal collectors, on the other hand, require suitable soil conditions and sufficient land area and are therefore less common, especially in densely built-up urban areas. Solar ice storage systems are particularly suitable for new buildings or major renovation projects.

Nationwide, the air-source heat pump offers the greatest technical potential with an average of 65 percent. This is followed by geothermal probe heat pumps (47 percent), solar ice storage (37 percent) and geothermal collectors (24 percent). Groundwater heat pumps were not examined as part of the analysis.

Dresden (75.9 percent), Berlin (67.7 percent) and Bielefeld (64.2 percent) offer particularly good conditions for air source heat pumps. For geothermal probes, Bielefeld (55.9 percent), Dresden (52.5 percent) and Bochum (49.2 percent) lead the ranking. Dresden (40.0 percent), Leipzig (37.4 percent) and Bielefeld (34.8 percent) have the greatest potential for solar ice storage. Dresden is also ahead for geothermal collectors with 27.2 percent, followed by Leipzig (26.8 percent) and Bielefeld (23.9 percent).

On average, the potential is lowest in the major cities in western Germany. For example, air-source heat pumps in Düsseldorf (29.4 percent), Mannheim (30.9 percent) and Frankfurt am Main (32.1 percent) achieve the lowest values. For geothermal probes, Cologne (13.8 percent), Frankfurt am Main (18.5 percent) and Düsseldorf (20.3 percent) are at the bottom of the ranking. For solar ice storage systems, Nuremberg (11.0 percent), Düsseldorf (13.1 percent) and Munich (14.4 percent) perform the weakest. Cologne (3.6 percent), Nuremberg (4.3 percent) and Düsseldorf (5.0 percent) have the lowest potential for geothermal collectors.

All results of the investigation can be found under the following link:
https://www.aroundhome.de/heizung/studien/waermepumpen-potenzial-grossstaedte/

For the evaluation, Aroundhome evaluated the data from the heat pump traffic light of the research project FfE (Forschungsstelle für Energiewirtschaft e. V.). The analysis is based on the publicly available datasets of the FfE OpenData portal and examines the technical potential of different heat pump technologies by federal states, cities and building types. Air source heat pumps, geothermal probes, geothermal collectors and solar ice storage systems as well as detached and semi-detached houses, semi-detached houses, terraced houses and small and large apartment buildings were taken into account.