Viessmann Deutschland GmbH builds another solar thermal energy system on the island of Föhr

Allendorf (Eder)/ Föhr, Germany, July 2, 2025 – The construction of another large-scale solar thermal energy plant on the North Sea island of Föhr began in early February 2025. The Energiegenossenschaft Föhr eG is continuing its efforts to make the popular vacation island even more sustainable. The Viessmann Deutschland GmbH is responsible for the implementation and construction of the turnkey system. The company is part of Viessmann Climate Solutions, which belongs to Carrier Global Corporation (NYSE: CARR), global leader in intelligent climate and energy solutions.

Large-scale project for more renewable energies

Föhr, known for its beautiful landscape and as a popular tourist destination in Schleswig-Holstein, Germany, is increasingly focusing on sustainable energy sources. In addition to existing initiatives to use renewable energy, the island will significantly expand its capacity by installing a new, state-of-the-art solar thermal energy system. This project underlines Föhr's commitment to protecting the environment and reducing its ecological footprint. Föhr's island location offers ideal conditions for solar thermal energy, as the solar radiation is above average. 

The district heating network based on solar thermal energy is designed to produce more than one gigawatt hour (GWh) of heat per year. This corresponds to a renewable energy share of > 23% of Energiegesellschaft Föhr eG's total heating requirements. The collectors of the solar thermal system cover a total area of 3,076 m2. Energiegenossenschaft Föhr eG put this large-scale project out to tender and Viessmann Deutschland GmbH came out on top against the other competitors. The contract includes the design and construction of the turnkey solar thermal system, a 500 m3 buffer storage tank and a prefabricated technical building. This will include the solar unit, the heat exchanger and the control system.

Ready for operation as of June 2025

The system is to be fully operational in June 2025 and will lead to a significant reduction in CO2 emissions on Föhr from that point onwards. The system is already the third solar thermal system to be taken into operation by Viessmann Climate Solutions in Germany in June 2025. The construction of the solar thermal systems and other planned projects show that district heating networks and the large-scale use of solar thermal energy as a heat source are becoming increasingly important in Germany.

"We are proud to be able to implement this solar thermal project together with the Energiegenossenschaft Föhr eG. The potential of climate technology as part of the district heating supply in Germany is huge - both from a social and financial perspective. The form of energy is renewable, the technology is reliable and the cost and CO₂ savings are attractive for the system operators," says Dr. Conrad Wiedeler, Managing Director Viessmann Deutschland GmbH.

The system produces district heating from renewable energies - saving many tons of CO₂ emissions every year. Another plus point for the project are the more predictable prices. This new district heating project will enable the Energiegenossenschaft Föhr eG to cover a large part of its annual heating requirements for the next 30 years and calculate costs in advance.

Jan-Hauke Riewerts, Brar Hinrichsen, Dirk Lehmann and Alexander Schweizer, Management Board of Energiegenossenschaft Föhr eG, would like to thank all parties involved for enabling the construction of this important district heating project to begin. They are looking forward to commissioning the new solar thermal district heating system in June 2025. The inauguration ceremony is planned for August 17, 2025.

For more information, please reach out to:

• Thomas Alt, Head of Commercial Business at Viessmann Deutschland GmbH, Phone: +49 151 15168007
• Christian Stadler, Head of Solution Line District Heating & Solar at Viessmann Deutschland GmbH, Phone: +49 170 7628793
• Peter Eijbergen, Head of large-scale solar thermal energy at Viessmann Deutschland GmbH, Phone: +31 6 270 388 40

You can also find further information about the project on the Energiegenossenschaft Föhr eG website at https://energiegenossenschaft-foehr.de/.

About Viessmann Climate Solutions

Founded in 1917 as a heating technology manufacturer, today Viessmann Climate Solutions is a leading global provider of sustainable climate (heating, cooling, water and air quality) and renewable energy solutions. The integrated Viessmann Climate Solutions portfolio seamlessly connects products and systems via digital platforms and services, creating an individualized feel-good climate for users. Viessmann Climate Solutions is part of Carrier Global Corporation, global leader in intelligent climate and energy solutions, committed to creating innovations that bring comfort, safety and sustainability to life. For more information, visit www.viessmann-climatesolutions.com.