Press / Newsroom

Heat pumps provide efficient and climate-friendly heating also in existing buildings. This is the conclusion of a research project by the Fraunhofer Institute for Solar Energy Systems ISE. Over four years, researchers conducted detailed measurements on 77 heat pumps in single-family to three-family homes. The result: the heat pumps achieved seasonal performance factors ranging from 2.6 to 5.4. The CO2 emissions of the heat pumps, calculated for the first time considering time-variable factors, were 64 percent lower in 2024 compared to those of natural gas heating systems. The research team also conducted long-term sound measurements and investigated how photovoltaic systems can be integrated into heat pump operation. In addition to Fraunhofer ISE, two energy suppliers and nine heat pump manufacturers participated in the project.

The head of the "Hydrogen Technologies" division additionally assumes the representation for institute director Prof. Dr. Andreas Bett as of October 1, 2025.

Deutsche Bahn is the largest electricity consumer in Germany, operating its own power grid of nearly 8,000 kilometers in length. The project "PV4Rail" examined how this grid can be utilized for the feed-in of solar power. The consortium lead by Fraunhofer ISE developed and tested an inverter for the direct feed-in of photovoltaic power, analyzed the photovoltaic potential along the tracks, and conducted techno-economic studies of railway power PV systems. These could become an important component of the energy transition if regulatory and market disadvantages were addressed.

The Fraunhofer Institute for Solar Energy Systems ISE has been awarded the German Sustainability Award (“Deutscher Nachhaltigkeitspreis”) for companies in the "Research and Development" sector. This was announced today by the Foundation for the German Sustainability Award e.V. The award is given to Fraunhofer ISE for its research and development achievements towards sustainability as well as for its commitment to integrating sustainability into operational processes.

Prof. Hans-Martin Henning was honored yesterday with a scientific symposium to mark his retirement. The director of the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg also shaped the Fraunhofer Society's energy research for many years. As chairman of the Expert Council for Climate Issues, he advised the German government on the implementation of the Climate Protection Act from 2020 to 2025 and, in this role, was a vocal advocate for consistent measures.