Development of highly efficient geothermal probes using nanotechnology

As part of the “NanoGeoTherm” network of the Nanoinitiative Bayern GmbH cluster, SKZ is working together with project partners Gerodur MPM Kunststoffverarbeitung GmbH & Co. KG, the Friedrich-Alexander University of Erlangen-Nuremberg, and Laus GmbH on the “EWS.MWCNT” research project to develop a highly efficient geothermal system based on plastics modified with multi-walled carbon nanotubes (MWCNT) for the production of PE100-RC pipes, thereby achieving significantly increased thermal conductivity. At the same time, all relevant standards and safety requirements are to be complied with.

In addition to developing a suitable manufacturing process, a simplified test procedure for determining thermal conductivity is being developed. This is supplemented by investigations into environmental compatibility and ecotoxicity.
“We not only want to increase efficiency, but also to increase the acceptance of new materials through transparent testing methods. This is a decisive step for the market penetration of innovative geothermal technologies,” says Felix Berthold, project manager at the SKZ Plastics Center.

Greater efficiency, lower costs
This development will reduce the drilling depth and the total amount of material required for the probes by up to 20 percent. Despite higher material costs for the PE-CNT pipes, the total costs will be reduced due to lower drilling costs and lower resource consumption. This will make geothermal energy more economically attractive and, at the same time, more environmentally sustainable.

“With this project, we are laying the foundation for more efficient and cost-effective geothermal energy systems and making an important contribution to decarbonization and the achievement of climate targets in Germany,” says Berthold.

New opportunities for the energy transition
The reduced drilling depth also opens up new applications in regions that were previously considered unsuitable for geological reasons. This facilitates a broader use of geothermal energy and strengthens its contribution as a reliable renewable energy source.

To ensure safe use, the new pipes are being evaluated toxicologically from the outset. In the long term, this could also allow them to be used in other areas such as drinking water supply. The toxicity assessment method developed can also be transferred to other nanocomposites, thereby generally increasing the safety of modern nanomaterials. In addition, the targeted adjustment of thermal conductivity enables the design of geothermal probes to be tailored to the location and requirements – a further step towards more efficient and sustainable geothermal systems.

This project is funded by the Federal Ministry for Economic Affairs and Energy (BMWE) as part of the Central Innovation Program for SMEs (ZIM) with the funding code 16KN102921 from December 1, 2024, to May 31, 2027.

Further information on materials development at SKZ