The EU co-funded TRANSGEO project has come to a conclusion, generating valuable insights on the opportunities for repurposing disused oil and gas boreholes for geothermal energy generation in the Central Europe region. To this end, Prof. Dr. Hannes Hoffmann of the GFZ Helmholtz Centre for Geosciences and working group leader of the TRANSGEO project shared some of the conclusions from the initiative.
Launched in 2023, the TRANSGEO project aimed to develop concepts and technologies to show ways for an effective repurposing of oil and gas infrastructure. The project involved 11 partner institutions across Germany, Austria, Hungary, Croatia, and Slovenia. It was officially concluded in April 2026.
As Prof. Hoffmann explains, repurposing old oil and gas wells addresses one of the key challenges of geothermal energy by not having to drill new deep geothermal wells. If such a system can be developed, it presents a valuable opportunity for hydrocarbon production regions.
As part of the TRANSGEO project, the team did an extensive inventory of drilling data, geological assessment of potential heat reservoirs, technical tests of reusability, and modeling of the expected heat output. Economic and legal framework were also examined, notably at eight pilot sites, three of which were in Germany.
One demonstration project at the GFZ geothermal research site in Groß Schönebeck in Brandenburg, Germany will be commissioned in the coming summer, in a joint effort with Danish start-up Green Therma. This pilot aims to evaluate heat production from deep, closed geothermal probes using an innovative vacuum-insulated double-pipe system.