| Title | UNFC Compliant Resource Assessment of Combined Production of Thermal Energy and Minerals from Geothermal Brines |
|---|---|
| Authors | Gioia Falcone |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | critical minerals, lithium, geothermal brine, co-production, UNFC, United Nations Framework Classification |
| Abstract | Open-loop deep geothermal energy systems may produce brines with potentially commercial concentrations of ‘critical’ minerals, e.g. lithium. Committee for Mineral Reserves International Reporting Standards (CRIRSCO)-compliant resource assessments for minerals under the United Nations Framework Classification for Resources (UNFC) informs investors about project viability and maturity across three dimensions: environmental-socio-economic viability, technical feasibility and degree of confidence in the estimate. Industry and stock-markets require CRIRSCO-aligned assessments as basis for investment in minerals activities, but the European Commission expects a UNFC-based resource classification UNFC for strategic purposes. After an earlier 2015 version, the 2025 updated ‘bridging’ document developed by CRIRSCO and the United Nations Economic Commission for Europe (UNECE) aligns the two systems. At the same time, UNECE and the International Geothermal Association agreed to develop a globally applicable harmonized standard for reporting geothermal resources. Specifications for the application of UNFC to geothermal energy resources first became operational in 2016, with an update issued in 2022. Geothermal developments are currently seeking incremental value from minerals co-production. While the UNECE provides separate specifications for the application of UNFC to minerals and geothermal energy, there is no explicit guidance on the combined production of thermal energy and minerals from brines. This paper proposes a conceptual approach to UNFC classification of the combined production that considers existing guidance for the minerals and energy components, while acknowledging the unique challenges, interdependencies and synergies within the integrated project. Such approach aims to provide the basis for aligning reporting of both minerals and energy components to investment markets. |