| Abstract |
Research into the deep, superhot roots of geothermal systems, which potentially host supercritical fluids, has been actively pursued by several member countries of the IEA-Geothermal Technology Collaboration Program (TCP), including USA, New Zealand, Iceland, Italy, Japan, Switzerland and Norway. The tasks, to date, have focused on: a) discovery and delineation of superhot geothermal resources (‘deep roots’) that are prospective and accessible by drilling; b) advancing technology to enable reliable energy production from superhot prospects; and c) assessing the potential thermal energy that could be available from deeper geothermal resources to sustainably support low carbon energy futures. Recent advances have seen significant improvements in knowledge of the geochemical and physical conditions to be expected in these superhot settings through experiments in fluid-rock interactions and advanced simulation models. Improvements in deep drilling and well completion technology are also rapidly advancing. This paper discusses these aspects and summarizes lessons learnt from past superhot geothermal projects. To expand on this work, a new collaboration task on superhot resources was initiated by IEA-Geothermal in 2025. The purpose of the new task is to encourage further collaborative activity to help accelerate development in this area of novel geothermal energy technology. The efforts are focused on >400 oC, although the scope is inclusive of >300 oC research where novel fracture stimulation efforts are informative. The overall goal is to achieve expanding impact by reducing costs and increasing deployment through innovation and demonstration. The group plan to share relevant knowledge acquired, inform interested parties and direct future enquiry. |