FernWP – District and process heat supply by heat pumps as a replacement for coal combustion

The planned phase-out of coal by 2038 not only makes an important contribution to reducing CO2 emissions, it also has a direct impact on the heat supply. Power plants that still provide district and process heat today will no longer be available in the foreseeable future and will have to be replaced by climate-neutral technologies.

Large-scale heat pumps (LSHP) and high-temperature heat pumps (HTHP) could take over this task in the future. As a basic technology that lays the foundation for the integration of renewable energies, they play a central role in the energy transition.

Numerous obstacles still hamper the dissemination of the technology and prevent penetration of the technology market. LSGPs have comparatively long payback periods, making them only conditionally competitive from an economic perspective. In addition, there is a lack of well-founded knowledge and experience regarding the economic application potentials.

From a technical point of view, providing heat at the required high temperature levels while maintaining high performance and efficiency is still a challenge. In order to meet the growing demands, it is necessary to consider the further development of the technology and the refrigerants to be used.


The project "District and process heat supply by heat pumps as a replacement for coal combustion" addresses the technical and economic barriers that currently still impede the widespread use of large-scale heat pumps. In this context, it provides answers to important questions that arise when integrating GWP into district and process heat supply:

  • Which renewable heat sources are suitable for use by LSHP and high temperature heat pumps?
  • What are the requirements of district heating networks for LSHP?
  • In which direction do the construction elements of LSHP need to be further developed in terms of design?
  • Which refrigerants are suitable for use in LSHP?
  • How can the economic efficiency of heat LSHP be improved by means of suitable operating strategies?
  • What needs to be considered from a techno-economic perspective in the system integration of heat LSHP?
  • What framework conditions stand in the way of higher market penetration of LSHP and can these be changed?
  • What potential do high-temperature heat pumps have for providing process heat and how do they need to be technologically developed?