New public funded project: Universal-EWS develops innovative backfilling methods for borehole heat exchangers

At the beginning of 2026, the joint project “Universal-EWS: New Backfilling Methods to Expand the Use of Borehole Heat Exchangers for Shallow and Medium-Depth Geothermal Energy” officially started. The three-year research initiative is funded by the German Federal Ministry for Economic Affairs and Energy (BMWi) and coordinated by SOLITES. Project partners include EIFER (subproject: “Suspension and Suffusion Behavior of Backfill Materials”), Hans G. Hauri KG, KIT/AGW, and Stephan Schmidt KG.

The project aims to develop new backfilling methods and materials that significantly improve the quality and efficiency of borehole heat exchangers. Laboratory and field investigations will be conducted under realistic subsurface conditions to better understand the main causes of suspension losses, such as filtration and penetration into surrounding rock and their dependence on geological factors. Based on these insights, cost-effective and practical solutions will be designed to make installations more efficient and enhance acceptance among users and approval authorities.

Another key project goal is to make previously unsuitable sites with challenging geological or hydrogeological conditions accessible for geothermal energy use. The project builds on and continues the successful work of the preceding QEWSplus project.