The geothermal research site of the GFZ Helmholtz Centre for Geosciences in Groß Schönebeck, in the Schorfheide region of Northern Brandenburg, is celebrating its 25th anniversary this year. In 2001, a former natural gas exploration well dating from the 1990s was brought back into use and converted into a research platform for the development of geothermal technologies. The geology of the North German Basin is typical of many regions in Central Europe. This makes the Groß Schönebeck site both representative and attractive for research. Scientific knowledge has been gathered and technologies have been developed here that are now being used in practice by industry partners worldwide. Currently, the site is being utilised as part of a collaboration with the Danish industry partner Green Therma, which will be testing its newly developed pipe technology here under real-world conditions for the first time anywhere in the world.

At a celebratory event at the Groß Schönebeck site on 30 June 2026, GFZ researchers and guests looked back on the numerous scientific and technological achievements that have been made there, reviewed current projects, and built a bridge to the future – together with representatives from science, industry and politics, as well as the local community.

In the photo gallery above, you will find some highlights from the event. 

Prof. Dr Susanne Buiter, Scientific Director of the GFZ, said in her welcoming address:
“Geothermal energy is and remains highly relevant: we are increasingly seeing how our dependence on fossil fuels makes us vulnerable and harms the climate. With its constant, regional availability, geothermal energy has the potential to become a cornerstone of an alternative, geopolitically independent, renewable energy supply. Our research at the GFZ, and in particular at the Groß Schönebeck site, has helped to lay the essential scientific foundations and establish technological standards for this. And it has paved the way for the transfer of research findings into commercial applications. This has a bright future, and the GFZ can look back on all this with pride.”

Prof. Dr Ingo Sass, Head of GFZ Section 4.3 Geoenergy, which operates the Groß Schönebeck site, says:
“In the international scientific community, Groß Schönebeck enjoys a reputation as a reliable source of knowledge and data, which is drawn upon in numerous publications and research papers. However, successful geothermal research for next-generation geothermal solutions can only succeed if we also work closely with industry, users and local authorities – at both local and international levels. And if we involve the local community. We are also benefiting in many other projects from the positive experiences we have gained in this regard at Groß Schönebeck.”

Jørgen Peter Rasmussen, founder and CEO of Green Therma, comments from a business perspective:
“Our project represents a milestone in geothermal energy extraction technology. By demonstrating the performance of DualVac™ insulation at the GFZ’s geothermal research platform in Groß Schönebeck, we are taking an essential step towards the global, efficient and scalable utilisation of deep geothermal heat.”
 

Background: Geothermal energy and its potential

The heatwave of the past few days hasn’t exactly put us in the mood to think about heating. But the next winter is sure to come. And it’s not just since the wars in Ukraine and Iran that we’ve realised how vulnerable our dependence on fossil fuels makes us. Progressing climate change is also a key driver in the search for alternative, low-carbon solutions for heat supply. After all, it accounts for around half of Germany’s total energy consumption and is still far too under-served by alternatives.

A great treasure lies dormant beneath our feet: the Earth’s heat. Geothermal energy has the potential to become a cornerstone of renewable heat supply: in the ‘Deep Geothermal Energy’ roadmap, experts from GFZ and Fraunhofer estimate that at least a quarter of Germany’s heat requirements could be met by geothermal technologies. And geothermal energy can – speaking of heatwaves – also contribute to efficient cooling.

Geothermal energy is renewable and low in CO₂; it is capable of providing base load power, meaning it is permanently available, regardless of the time of day, season or weather conditions. And it is domestically sourced, independent of geopolitical risks. We can tap into it in many regions of Germany, including here in Brandenburg and Berlin.

Whether and how geothermal energy can be utilised as efficiently as possible, which underground geological formations are particularly promising, and which technologies can be used to operate as efficiently, safely and environmentally friendly as possible – the GFZ has been researching and developing all of this very successfully for decades, including at its Groß Schönebeck research site in Brandenburg’s Schorfheide.
 

The Groß Schönebeck Research Site

In 2001, a former natural gas exploration well from the 1990s in Groß Schönebeck was brought back into use and expanded into a research platform for the development of sustainable geothermal technologies. The geology typical of many parts of Central Europe makes the Groß Schönebeck site representative for investigations under real-world conditions. The findings can be applied to regions with similar geological conditions worldwide.

Commenting on milestones in exploration, Dr Ben Norden, Head of the ‘Exploration Geology’ research group in GFZ Section 4.3 Geoenergy, says:
“In Groß Schönebeck, innovative exploration techniques and their integrated analysis for characterising deep geothermal reservoirs have been tested and further developed. This primarily involves geophysical methods such as magnetotellurics and 3D seismic surveys for more accurate mapping of subsaline subsurface structures, as well as the use of fibre-optic cables in deep boreholes to measure the acoustic properties of the rock. This method allows for improved characterisation of the Rotliegend sandstones, which are otherwise overlain by thick Zechstein salt deposits and are inaccessible to surface-based methods.”

Commenting on milestones in reservoir engineering, PD Dr.-Ing. Guido Blöcher, Head of the ‘Sustainable Production Technologies’ research group in GFZ Section 4.3 Geoenergy, says:
“We have upgraded a former gas exploration well into a geothermal doublet by drilling a second well, enabling the injection of cold water and the extraction of hot water. The development and testing of a hydraulically stimulated multi-fracture system underground has set new standards for the development of low-permeability geothermal reservoirs in Germany and internationally, and has paved the way for the transfer of research findings into commercial application.”

Current research projects at the Groß Schönebeck site

The EU-funded project “CRM-Geothermal” is taking a holistic approach to investigating the combined extraction of geothermal energy and critical mineral raw materials, such as lithium, from geothermal fluids in Europe and East Africa. These critical raw materials (CRMs) are essential for the energy transition and the digital transformation; however, they have so far been imported predominantly from non-European countries where environmental and ethical standards are less stringent than in the EU. The EU, however, possesses a largely untapped resource in the form of geothermal fluids, some of which contain significant quantities of CRMs. The combined extraction of heat and minerals from geothermal reservoirs offers a number of advantages: it maximises the return on investment, avoids additional land use and minimises environmental impacts.

Commenting on the geochemical potential, Prof. Dr Simona Regenspurg, head of the ‘Geothermal Fluids’ research group in GFZ Section 4.3 Geoenergy, says:
“The thermal water at Groß Schönebeck contains various salts, including critical raw materials, dissolved in high concentrations. Extracting these in an environmentally sound manner requires further research, as these raw materials offer immense economic opportunities when used in conjunction with heat extraction.”

The EU project “TRANSGEO” is investigating how decommissioned boreholes and facilities from gas and oil production can be repurposed for geothermal applications. This is of great interest to industry, as drilling represents the largest cost factor in geothermal projects. The conversion or repurposing of existing boreholes can significantly reduce initial investment costs. Furthermore, the risk of failing to find a suitable reservoir is significantly lower than with a new well, as the records of old wells provide information on the geological conditions. In addition to the borehole itself, existing infrastructure can often be utilised. Reuse also avoids further encroachment on the landscape and thus reduces the carbon footprint.

Prof. Dr Hannes Hofmann, Head of the Helmholtz Junior Research Group ARES “Advanced Reservoir Engineering Concepts for the Controlled Utilisation of Deep Geothermal Energy in Urban Areas” in GFZ Section 4.3 Geoenergy, summarises:
“By overcoming technical, regulatory and economic challenges, the partners have demonstrated that existing borehole infrastructure can be effectively repurposed to support renewable energy generation whilst simultaneously reducing environmental impact and investment costs.”

The Groß Schönebeck site is currently being utilised by the Danish industrial partner Green Therma as part of the TRANSGEO project. There, the company is installing the DualVac™ vacuum pipe system for the first time anywhere in the world; this is designed to transport heat from a depth of more than three kilometres to the surface with minimal losses. All that is required is a single borehole and a coaxial pipe installed within it, which extends vertically downwards and then bends horizontally, where it can run for several kilometres. Cold water flows down the outer section of the pipe; as it passes through the subsoil, it heats up and flows back through the inner section of the pipe. To ensure no heat is lost in the process, the inner and outer sections of the pipe are separated by vacuum insulation.

The duplex pipe is intended to demonstrate, for the first time, how heat can be extracted from such a deep borehole without withdrawing water. “Should the technology prove successful, it could significantly increase the efficiency of deep geothermal plants and tap into renewable heat sources at sites previously considered too difficult or too costly,” says Green Therma.

Further information can be found here.

In general, Brandenburg and the North German Basin are becoming increasingly attractive locations for geothermal energy:

In Groß Schönebeck, work is underway on a concept for a future geothermal heat supply; other large-scale initiatives are taking place in Prenzlau, where a successful drilling operation recently took place, as well as in Schwerin, Neuruppin, Oranienburg and Potsdam (collaboration between the GFZ and Energie und Wasser Potsdam GmbH (EWP) and start of drilling for a second geothermal plant in Potsdam at the Heizkraftwerk Süd site).

Further information:

Further information on geothermal energy can be found on our Spotlight page.

In several podcasts (German only), researchers from the GFZ have recently provided insights into the topic of geothermal energy:

Earth and Environment<u>:</u>

Geothermal Energy

Interview with Prof. Dr Ingo Sass, Head of GFZ Section 4.3 Geoenergy:

How do you extract the naturally occurring heat from the ground and transport it from there to consumers? What technological and other – particularly communicative – challenges are there?

https://erdeumwelt.podigee.io/11-erdwarme
 

Helmholtz Talks – Science and Politics in Dialogue<u>:</u>

Geothermal Energy: The Hidden Key to Our Future?

The 10th episode of the podcast features Prof. Dr Magdalena Scheck-Wenderoth, Head of GFZ Section 4.5 ‘Subsurface Process Modelling’, as a guest. She discusses the topic with Lars Rohwer, the CDU/CSU parliamentary group’s spokesperson on geothermal energy. The discussion examines current political measures, including the Geothermal Energy Acceleration Act and the High-Tech Agenda for Germany.

The podcast is a collaboration between the dialogue platform Helmholtz KLIMA and the RIFS Research Institute for Sustainability at the GFZ.

https://helmholtz-talks.podigee.io/10-geothermie-der-verborgene-schlussel-fur-unsere-zukunft

detektor.fm – Forschungsquartett<u>:</u>

The energy treasure beneath our feet

In conversation with PD Dr. habil. Sven Fuchs, head of the ‘Hydrothermal Geothermal Energy’ research group in GFZ Section 4.3 Geoenergy.

Right beneath our feet lies a vast, climate-neutral energy source that is completely independent of the weather and global market prices. Geothermal energy has great potential to heat our cities sustainably. But why aren’t we already using geothermal energy for heating everywhere?

https://detektor.fm/wissen/forschungsquartett-geothermie