Green District Heating for Germany – Potential, Costs, Implementation

There is consensus at the scientific and political level that the expansion and consolidation of district heating networks are essential factors in achieving cost-effective reductions in energy-related GHG emissions in the building sector. While investment decisions in district heating are made for at least 20 years, a long-term reliable investment framework for “green district heating supply” is currently still lacking.

In this study, in addition to evaluating potentials as well as technical barriers and opportunities for heat from renewable energies, suitable (new) framework conditions for the accelerated transformation and decarbonization of district heating were elaborated and existing ones readjusted. In order to identify a suitable basis for this, the expected energy-economic significance of the district heating supply was analyzed, and relevant success factors for a sustainable conversion to “green district heating” were identified with their most essential characteristics.

The FfE processed the following work packages:

In the work package on the energy-economic framework, a meta-study has been carried out to frame the range of possible developments for the district heating sector via the scenarios of the five most relevant energy and climate policy studies. As part of this comparison, the development of space heating and domestic hot water demand, the share of district heating supply in total heating demand, and the share of climate-neutral heat sources in district heating were examined and prepared in the form of funnel diagrams. The development of the share of climate-neutral heat sources is shown in the figure below.

Figure 1: Example showing the range of possible developments from selected studies, here the share of climate-neutral heat sources in district heating

Furthermore, the FfE was responsible for the technical aspects of decarbonization and transformation of district heating. The meta-study of the technical elements focuses on three areas:

  • Decarbonization through the integration of climate-neutral heat sources
  • Necessary transformation measures in district heating networks for the integration of climate-neutral heat sources (e.g., temperature reduction)
  • Procedure for the development of an optimal transformation path to achieve a climate-neutral district heating supply

As part of developing an optimal transformation path, the study developed a general procedure for creating a transformation strategy. This procedure is summarized in the following figure.

Figure 2: Methodology for the creation of a transformation strategy

The overriding conclusion is that district heating transformation must always be seen in the context of heat transformation. Furthermore, due to the long-term nature of the considered time periods in the heat transformation, the developed strategy must be flexible in order to be able to adapt to changing framework conditions. Therefore, strategy development is an iterative and continuous process and must always be considered in the context of specific local requirements.