Regionalization of building heat – supplementary study for the Net-work Development Plan 2025
Objective and methodology of the study
As part of the study, a methodology was developed and applied to project and regionalize the demand for building heat and the corresponding distribution of heating technologies within Germany. The focus was on technologies that are linked to the electricity infrastructure and on the private households (pHH) and the services (GHD) sectors. In the course of the study, the effects of legal framework conditions were taken into account, three different scenarios were designed and relevant parameters were shown in technological, spatial and annual resolution. The spatial resolution at municipal level was achieved with the help of extensive regionalization logic. In addition to the demand for heating in buildings, the regional development of air conditioning requirements was also estimated.
The three scenarios, which provide possible framework conditions for German-wide projections of building heat demand up to the year 2045, were calculated using the FfE building sector models PriHM (private households) and TerM (tertiary sector). These modelling results were then regionalized by means of small-scale regionalization at municipal and district level. The model for small-scale regionalization is based on the FfE geodatabase FREM. FfE’s building-specific data models for heat demand (HOUSE), heat pump potential (heat pump traffic light) and heating network potential ( HeatGrid) play a special role here. In particular, this results in the final energy consumption by region, technology and scenario as well as the number of heat pumps by region and scenario.
Characteristics of the transformation pathways
The three scenarios A, B and C were developed in consultation with the transmission system operators. Scenario A is aimed at a relatively diversified heat supply. This involves an ambitious expansion of local/district heating, the use of direct hydrogen heating and the utilization of biomass potential in the building sector based on [1]. The ramp-up of heat pumps is slower and the pace of building envelope renovation is also moderate. In contrast, scenario C ascribes a more important role to electricity as an energy carries. Here, a rapid ramp-up of heat pumps is accompanied by renovation activities. The expansion of local/district heating is less ambitious than in scenario A. Biomass boilers are substituted in order to shift part of the sustainably available potential to the industrial sector, and direct hydrogen heating systems are not used. Scenario B lies between the two scenarios described above. Compared to scenario C, renovation and the ramp-up of heat pumps is delayed with an identical expansion of local/district heating. In addition to roughly constant number of biomass boilers, a small number of direct hydrogen heating systems are also used.
Results
Figure 1 shows the modelling results of the transformation pathways for space and water heating, together named as building heat applications, cumulated for each scenario for pHH and GHD. The total demand for heating in buildings decreases in all three scenarios by 2045. In scenario A, the demand for building heat is reduced from 794 TWh in 2019 to 646 TWh in the target year 2045, or by 18,6 %, as a result of the transformation measures. In scenario B, the corresponding reduction is 21.5% and in scenario C 25.9%. Heat pumps, which are utilized to a significant extent in all scenarios, play a particularly important role in scenario C. Here, the demand for electricity from heat pumps is 54 TWh in 2030 and 117 TWh in 2045. In scenario B, the corresponding values are 39 TWh and 105 TWh respectively, which reflects the assumed delayed ramp-up in the 2020s. In scenario A, the demand for electricity from heat pumps in the target year 2045 is significantly lower than the values from scenarios B and C at 72 TWh.
Figure 2 shows the number of heat pumps per sector, year and scenario. Overall, the total number of heat pumps across both sectors will vary between 10.9 and 18.8 million heat pumps in 2045.
The regional distribution of the number of heat pumps in the target year 2045 for each scenario is shown in Figure 3. In all scenarios, the regions with high final energy consumption are the most prominent. In scenario A, due to the expansion of biomass heating systems and more hydrogen district heating systems, fewer heat pumps are located where the potential for heat pumps and heating networks is low and where there is proximity to the hydrogen core network or hydrogen industrial sites.
In addition to the final energy consumption of building heat, in particular the electricity demand of heat pumps and their number, the regional electricity demand, which is used to provide local/district heating, was analyzed as part of the study. Specially, this demand is attributable to large scale heat pumps and electrode boilers. An excursus also analyzed the possible development of electricity demand due to the expected increase in electrically supplied air conditioning cooling.
The report also contains a description of the legal framework and subsidies in the context of building heat, as well as technology profiles of heating options that will be permitted in the future.
More Information
Literature
[1] Projektionsbericht 2021 für Deutschland. Berlin: Bundesministerium für Umwelt, Naturschutz und nukleare Sicherheit (BMU), 2021.
