Renewable heat
Heat pumps
Heat pumps can be used to harness environmental heat. They play a major role in many future scenarios, especially for space heating. The German government did not mention a target for the expansion of heat pumps in its coalition agreement - the term "heat pump" does not appear a single time in the entire document. However, the Eröffnungsbilanz Klimaschutz of the Federal Ministry for Economic Affairs and Climate Action (BMWK) mentions a corridor of "4.1 to 6 million heat pumps" in 2030. This figure is likely to refer to the provision of space heating in individual buildings (excluding large-scale heat pumps in heating networks and high-temperature heat pumps). In the context of the 2nd Heat Pump Summit in November 2022, the BMWK then stated a target of around six million heat pumps in 2030 and an addition of at least 500,000 heat pumps per year each from 2024. There is no monthly updated public data on the number of heating heat pumps in Germany. We use AGEE-Stat as a data source up to the end of 2022 and figures from the BDH for the current year. The expansion of heat pumps is currently lagging far behind the target path (data for the current year * incomplete).
For comparison, scenarios of the Ariadne project can also be added to the figure. The lead model for heat pumps (REMod) identifies a stock of 5.3 million heat pumps in 2030 (in individual buildings) in the Technology mix scenario, which is below the government target. By 2045, this heat pump inventory grows to about 15 million. In addition, the heat pump expansion paths of four other studies can be compared, which together with the Ariadne scenarios have been dubbed the "Big 5" scenarios, namely "Climate Neutral Germany 2045" by Agora Energiewende, "Climate Paths 2.0" (scenario Zielpfad) by BDI, "Towards climate neutrality" (Leitstudie Aufbruch Klimaneutralität, scenario KN100) by Dena, and "Long-term scenarios 3" (scenario TN-Strom) by BMWK. Up to 2045, heat pump additions are particularly high in the BMWK long-term scenarios, and lowest in the Dena lead study.
Shares in the heating sector
The coalition aims for a "very high" share of renewables in the heating sector. Yet, a quantitative target is only provided for "climate neutral" heat in the coalition agreement, which should reach 50 percent of the total heat supply by 2030. As other options, such as imported climate-neutral hydrogen or carbon capture and storage appear to be implausible in the German heating sector by 2030, we interpret the quantiative target in fact as a renewable energy target, slightly deviating from the exact wording of the coalition agreement.
In 2021, the share of renewable energies in final energy consumption for heating and cooling (including district heating consumption) amounted to 15.7% according to AGEE-Stat data. By 2030, this share must therefore increase by almost four percentage points per year and thus much more than in previous years in order to achieve the target. However, development is currently well below this target path.
... in various climate neutrality studies
For a further look into the future beyond 2030, climate neutrality studies can be used to examine the feasibility of climate neutrality for Germany in 2045. The chart below shows the studies by Agora, Ariadne, BDI and McKinsey for the heating and building sector.
The Ariadne study shows the share of renewable energies in the heating sector over time, increasing from approximately 13 percent in 2020 to approximately 55 percent in 2030 and to approximately 100 percent in 2045. The scenarios from Agora, BDI, and McKinsey refer to the building sector and further differentiate by heat generator. In these scenarios, the share of heat pumps is the largest, rising to 20 percent and 25 percent, respectively, in 2030 and becoming the dominant technology at around 50 percent in 2045.
Emissions
Using emissions data for the building sector and assumptions regarding land use development, the intensity of greenhouse gas emissions (GHG emissions) per square meter can also be derived, which can serve as a useful reference point on the path to climate neutrality. The graph below shows sectoral GHG emissions in kilograms (kg) per square meter (m2) according to the climate neutrality scenarios of Agora, Ariadne, BDI, and dena. The average of the Ariadne and Agora scenarios was used for land use development. In the scenarios for private households and the trade, commerce, and services (T&C) sector, the GHG intensity decreases from an average of 22 kg/m2 in the period 2018-20 to 13 kg/m2 in 2030 and to approximately 0.45 kg/m2 in 2045.
A historical comparison can also be made for the GHG intensity for private households. The graph below shows the historical greenhouse gas emissions per square meter for the historical development since 1990 based on data from the Federal Environment Agency, as well as the development according to the scenarios for climate neutrality in 2045 from Agora and Ariadne. As can be seen from the graph, the GHG intensity remained unchanged at approximately 23 kg/m² between 2015 and 2020. However, according to the scenarios for CN 2045, it will already decrease to approximately 18 kg/m² in 2025 and to below 1 kg/m² in 2040. Ariadne data was used for the emissions data exclusively for private households for climate neutrality in 2045. Agora data was used for the area development for private households for climate neutrality in 2045.