District heating in Geretsried
Overview
In the town of Geretsried, near Lake Starnberg in Bavaria, the Eavor-Loop™ project is set to supply the entire region with district heating and significant electrical energy. This project aims to deliver 65 megawatts of thermal energy and eight megawatts of electrical energy, significantly reducing carbon emissions and contributing to Germany's renewable energy targets. The Eavor-Loop™ technology, successfully tested in Canada since 2019, is now seeing its first commercial deployment in Geretsried, funded by a consortium of banks, including a significant contribution from ING. ING's involvement aligns with its Terra approach, aiming to reduce CO2 emissions from its loan portfolio to zero by 2050.
Local officials and community members have expressed strong support for the project. The potential for affordable, reliable, and sustainable heating solutions is a major draw for the community.
Technical details
The Eavor-Loop™ is a closed-loop geothermal system that operates like a vast underground heat exchanger. It consists of two vertical boreholes connected by 24 horizontal boreholes at depths of 4,500 to 5,000 meters, forming 12 loops in total. A special fluid circulates within this loop, heating up as it travels through the depths of the earth. Thanks to the significant temperature difference between the subsurface and the surface, the heated fluid naturally rises, requiring no additional energy input. Once at the surface, the heat can be directly fed into the district heating network or converted into electricity. The cooled fluid then descends back through the second vertical pipe to be reheated, creating a continuous and efficient cycle.
This innovative approach offers several advantages over traditional geothermal systems. It eliminates the need for thermal water extraction and reinjection, thus minimizing the risk of seismic activity and environmental impact. The Eavor-Loop™ can be deployed in a wider variety of locations because it doesn't depend on specific subsurface water conditions. Moreover, by harnessing heat through conduction rather than relying on fluid movement within the earth, it promises higher efficiency and lower operating costs.
Future developments
The project's success has also sparked interest in neighboring regions. Eavor's recent presentation to the Weilheim City Council discussed a feasibility study for a similar venture in the surrounding area. Dr. Carsten Reinhold, leading the study, expressed optimism about replicating Geretsried's success in Weilheim, citing the favorable geological conditions.
“The ongoing Eavor project in Geretsried is ‘a blueprint’ for the local area with similar [geological] conditions”
Summary
Depth: 4,500 to 5,000 meters
Thermal energy: 65 megawatts