EU promotes search for deep geothermal energy
24.10.2024
With the "GeoHEAT" project, the EU is funding the search for geothermal energy sources using radar. The Fraunhofer Research Institution for Energy Infrastructures and Geothermal Energy IEG is researching this.
Geothermal energy is a climate-friendly alternative for heat generation. Investors are still put off by the exploration risk, possible induced seismicity and environmental risks or a lack of social acceptance. The EU project "GeoHEAT - Georadar-aided High-resolution Exploration to Advance deep geothermal energy usage" aims to simplify the search for geothermal energy and make it safer.
The project, led by the Fraunhofer IEG, is being funded over four years with 4.2 million euros from the Horizon Europe Framework Program. "As a CO2-free heat supply, deep geothermal energy can be a decisive building block for the energy and heat transition," explained Professor Erik Saenger, who conducts research at the Fraunhofer IEG and also works at Bochum University of Applied Sciences. "In Germany alone, a quarter of industrial process heat requirements can be covered by geothermal energy," forecasts say.
However, test drillings are expensive, which is why radar investigations are intended to minimize the risk. The participating institutes and companies want to simplify the preliminary investigation of potential reservoirs and improve the quality of the information gathered during the drilling process. This should increase the economic success and social acceptance of deep geothermal energy.
More information before and during the drilling process
The researchers in the Geo-Heat project want to change the workflow of geothermal exploration. By developing new, innovative passive seismic methods and integrating the resulting measurement data with gravity measurements, it should be possible to map deeper structures in the future. At the same time, the data obtained will be incorporated into a probabilistic geological model that also integrates geophysical and conceptual models of the subsurface.
By linking a large amount of data and modeling, many potential geothermal reservoirs could be assessed simultaneously and cost-effectively before a single well is drilled. The drilling process itself also generates information that can provide additional information about the subsurface. To this end, the researchers want to evaluate the drill cores that are brought to the surface as well as rock residues that are washed out when the borehole is flushed.
The numerical analysis of digital geophysical twins will also be used to evaluate the rock properties over every meter drilled. The experts also want to use the reaction of the subsurface to the vibrations induced by the drilling.
Particular attention is being paid to the planned further development of a new type of georadar probe: adapted to the pressure and heat at great drilling depths, this probe should be able to image the subsurface up to 100 meters away from the drill wall. This information ultimately enables well-founded deviation drilling, optimal borehole placement and precise monitoring of the performance and success of the drilling.
Opportunities and risks of geothermal energy
Munich, Paris and Tuscany are examples of successful deep geothermal projects: Münchner Stadtwerke, for example, operates six geothermal plants in the Munich region, including Germany's currently largest geothermal plant in Sendling. In the Paris Basin, 37 geothermal plants are currently in operation. In Italy, forerunners of geothermal energy began as early as 1904. The Italian energy supplier Enel now operates 37 geothermal power plants - covering almost a third of the electricity consumption in Tuscany.
Improperly executed geothermal projects can also trigger induced earthquakes, such as in Switzerland (Basel, 2006 and St. Gallen, 2013) or South Korea (Pohang, 2017). There are also concerns about possible pollution of groundwater or other environmental impacts. These conceivable risks influence the public's acceptance of geothermal projects. The Geo-HEAT project therefore also takes into account the social impact of geothermal energy, which has just as great an influence on success as technical aspects.
Project participants
The project started in June 2024 and will run for a total of 48 months. It receives additional funding from the Swiss State Secretariat for Education, Research and Innovation. Partners in the project are the research institutions Swiss Federal Institute of Technology Zurich (ETH), Delft University of Technology, RWTH Aachen University, University of Pisa, University of Geneva and Fraunhofer IEG as well as the companies Guideline Geo, Bo-Ra-tec GmbH, Advanced Logic Technology, Seismix s.r.l. and Mignan Risk Analytics GmbH.
Author: Susanne Harmsen
Energie & Management GmbH
