Green Therma deploys demonstration of closed-loop geothermal in Groß Schönebeck, Germany

Danish geothermal company Green Therma has announced the demonstration of its Heat4Ever™ technology at the GFZ Helmholtz Centre for Geosciences‘ geothermal research facility in Groß Schönebeck, Germany.

The company’s patented Heat4Ever™ solution is a single-well, closed-loop system that is designed to enable direct heat production from underground hot water reservoirs without the use of heat pumps. An essential component of the system is the vacuum-insulated DualVac™ well solution, designed to minimize heat loss as heat is transported from deep underground to the surface.

With the demonstration well now installed, water is now circulating through the closed system and geothermal heat is being brought up from more than 3 kilometers depth at temperatures high enough for direct use. Now that the system is operational, the continued tests in Groß Schönebeck should provide further data on the system’s long-term performance, stability, and potential for heat recovery under different operating conditions.

“The heat is already underground. We need to get better at exploiting this enormous natural resource and bringing the heat to where people and businesses need it,” said Jørgen Peter Rasmussen, founder and CEO of Green Therma.  

What we have demonstrated in Groß Schönebeck shows that we can harness deep geothermal heat and bring it to the surface at temperatures that can be used directly without heat pumps. 

The cooperation between Green Therma and GFZ, first announced earlier this year, is a good example of collaboration between research and industry. The Groß Schönebeck geothermal research facility, located north of Berlin, provides both infrastructure and scientific expertise and makes it possible to demonstrate new geothermal technologies under actual subsurface conditions.

Green Therma has already also started work on a full-scale project being developed in collaboration with Aalborg Forsyning in Aalborg, Denmark. The project is set to deliver geothermal heat to the local district heating network through a 3o-year heat supply agreement. Drilling for this project is expected to begin in early 2027.

Source: Email correspondence