. Scientific Frontline: Future with geothermal energy

Wednesday, June 22, 2022

Future with geothermal energy

The GeoLaB makes geosciences tangible: the first underground laboratory is being built in the Black Forest / Odenwald, in which researchers can directly observe deep geothermal processes.
Credit: KIT

Local, emission-free and base load-bearing: geothermal energy is an essential component of the energy transition. With GeoLaB, a new and unique underground research infrastructure, the Karlsruhe Institute of Technology (KIT), the German Research Center for Geosciences GFZ and the Helmholtz Center for Environmental Research UFZ now want to accelerate research and prepare the technology for widespread use. The project is to be realized either in the Black Forest or Odenwald, the Helmholtz Association is funding with 35 million euros.

In order to achieve climate neutrality and at the same time become more independent of energy imports, the use of deep geothermal energy is suitable in most regions of Germany. Heat from the subsurface is available regardless of the time of the year and day, which makes geothermal energy suitable for base loads. It is also renewable because heat flows into the reservoir due to the temperature conditions and the transport processes.

“Geothermal energy has huge potential. In Germany alone, we could replace a third of the gas requirements for our heat - and given the climate catastrophe and the geopolitical world situation, we can no longer do without it,” says Professor Holger Hanselka, President of KIT and Vice President for the Energy Research Area of the Helmholtz Association. “So that we can use the necessary technologies safely and that the environmental impact remains minimal, we will now develop geothermal energy accordingly with the help of GeoLaB."

Experiments directly underground

The new large-scale research infrastructure, the Geothermal Laboratory in the Crystalline Basement, or GeoLaB for short, is intended to research fundamental questions of reservoir technology and borehole safety of geothermal plants directly underground. To this end, the project partners of the Helmholtz Association are setting up a new mine in the Black Forest or Odenwald together with external partners under the leadership of KIT. After the expansion, an approximately one-kilometer-long gallery will lead to caverns. From there, controlled high-flux experiments, i.e. flow tests in the rock with flow rates relevant for geothermal energy, are carried out under the thickest possible rock layer of about 400 meters in this world's first underground research laboratory for deep geothermal energy.

As a joint research infrastructure in the research areas of energy, earth and environment, the Helmholtz Association is investing 35 million euros in GeoLaB as a strategic expansion investment. The KIT (as a coordinating Helmholtz Center and representative for the partners GFZ and UFZ) is entering into a cooperation with the Federal Society for Final Storage GmbH (BGE) to establish GeoLaB.

With the participation of the BGE, synergies between the two major social tasks, energy transition and nuclear final storage, are to be used. The mining skills for the construction of the GeoLaB should also be made available to the BGE. However, no repository is being built at the location, a troubled geology like in or on the Upper Rhine Graben would not be suitable for this. Rather, the BGE would like to build up basic experiences and skills when starting a mine in crystalline rock.

Basic research and rapid knowledge transfer

"With the underground laboratory, we are breaking new scientific ground and taking geothermal research a decisive step further worldwide," says Professor Oliver Kraft, Vice President for Research at KIT. “By using the latest methods, we are able to record thermal, hydraulic, chemical and mechanical parameters. In this way we gain a basic understanding of the geothermal transport processes and will also make a significant contribution to safety research for geothermal energy."

With a view to a rapid transfer of the research results into practical application, the scientific director of the German Geosciences Center GFZ, Professor Susanne Buiter, adds: “The heat from the depths is a mineral that we have not yet sufficiently researched, let alone used have brought. However, we not only need the data for this, but also rapid approval procedures and an open dialogue with citizens. Here, too, research in GeoLaB will make important contributions and enable a knowledge-based approach. Different forms of geothermal energy could soon make a major contribution to the heat transition in many urban areas."

Research helps minimize risks

The fact that geothermal energy has so far only been used selectively in Germany is due, among other things, to citizens' concern about artificially caused earthquakes. "These occur primarily when fluids are improperly injected into a reservoir," says Professor Thomas Kohl from the KIT Institute for Applied Geosciences (AGW) and scientific coordinator of the project. Basically, the use of such Enhanced Geothermal Systems (EGS) is necessary in order to make the great potential of geothermal energy economically usable in regions with crystalline basement. These layers of rock have the greatest potential for geothermal energy and are elementary for future energy security.

Most of the time, the necessary flow rates can only be achieved there through appropriate retrofitting measures, the expert explains. "It will therefore be a crucial task of research with GeoLaB to improve the understanding of induced seismicity and to demonstrate measures to prevent it experimentally," says Kohl. He expects the experiments in GeoLaB to significantly expand knowledge about the complex processes in crystalline rock with increased flow rates. The findings would then also be transferable to other crystalline reservoirs worldwide.

Research close to use using modern methods

GeoLaB is therefore also being built specifically in the crystalline subsoil, says Professor Ingo Sass, Head of the Geoenergy Section at the GFZ and Professor of Applied Geothermal Energy at the TU Darmstadt :, “Because we know that the vast majority of German cities have this type of rock in a manner that can be drilled Have depth. The transfer effect of GeoLaB can therefore be of enormous importance for the heat reversal in the metropolitan areas."

"With GeoLaB we also want to set new standards for the digitization of underground laboratories", says Professor Olaf Kolditz from the Helmholtz Center for Environmental Research - UFZ. "With a digital twin (Virtual GeoLaB) there will be modern data storage combined with integrated process models, to plan experiments better, to be able to evaluate and look into the future. Methods of virtual realities are also used, which have already proven themselves in other underground laboratories - also so that the complex processes underground are visible and understandable."

GeoLaB as an investment in the future

"The use and development of the latest observation and evaluation methods with the GeoLaB will shape the safe and ecologically sustainable use of geothermal energy and underground space for generations", says the technical coordinator of GeoLaB, Professor Eva Schill, the geoenergy cluster at the Institute for Nuclear Disposal (INE) of the KIT and also engaged with the TU Darmstadt in GeoLaB. “As an interdisciplinary and international research platform, GeoLaB will create synergies and set standards in research in cooperation with our research partners, industry and specialist authorities."

GeoLaB also ensures the training of a new generation of researchers and technicians, for which various measures are already being planned. In addition, extensive participation opportunities for citizens are created. These can be developed and implemented together with the citizens and interest groups of the region in a co-design process.

Additional Information about GeoLaB

Source/Credit: Karlsruhe Institute of Technology


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