The energy and digital transitions require a large amount of mineral raw materials which are considered ‘critical’ by the European Union. These Critical Raw Materials (CRM) are predominantly imported from non-European countries where environmental and ethical standards are less strict than in the EU. However, the EU has a largely untapped resource at its disposal in geothermal fluids, some of which contain significant amounts of CRMs.

The EU-funded CRM-geothermal project therefore proposes to combine the extraction of mineral raw materials and geothermal heat, a renewable energy resource from the ground that is independent from environmental conditions such as weather. The technology solution developed by CRM-geothermal will thus help Europe fulfil the strategic objectives of the EU Green Deal and the Agenda for Sustainable Development while reducing dependency on imported CRM. The combined extraction of heat and minerals from geothermal reservoirs offers a series of advantages: It is maximising returns on investment, avoiding additional land use and minimising environmental impact.

GFZ is the coordinator of the CRM-geothermal project. GFZ section 4.8 Geoenergy and section 3.1 Inorganic and Isotope Geochemistry contribute to the research with a focus on the following objectives:

Although the presence of Critical Raw Materials in geothermal fluids is known in principle, there are still many uncertainties concerning their occurrence in different geological settings and the practicability and sustainability of their extraction. The actual extraction process is also a major challenge, requiring the development of new technologies. The Horizon Europe funded CRM-geothermal project therefore aims to:

• establish an overview of the potential for raw materials in geothermal fluids for a large range of CRM elements across the EU and third countries;
• determine the source of selected CRM, their mobility and potential for sustained extraction from geothermal brines;
• develop and optimise innovative extraction technologies for selected CRM from geothermal brines that can form a business case for European SMEs;
• assess the environmental-social-economic viability, create transparent and traceable value chains, and foster ethical sourcing of CRM;
• demonstrate the extraction technology for at least one CRM at a pilot site at the scale of a mini-plant and evaluate the system’s sustainability.