Ultra Hot - Supercritical Geothermal - IEA Geothermal Collaboration

Abstract

Several member countries of the International Energy Agency Geothermal Technology Collaboration Program are actively undertaking research into the deep, high-temperature roots of geothermal systems, which potentially host supercritical or ‘ultra-hot’ geothermal fluids. The work is focused on: delineation and identification of locations of ultra-hot geothermal resources that might be prospective and accessible by drilling; advancing technology to enable reliable energy production from the high temperature prospects; and the evaluation of the energy that might be available long term in support of the low carbon energy futures that member countries are actively pursuing. This paper discusses these aspects, in relation to some of the ultra-hot projects, seeking to share knowledge acquired, inform interested parties and direct future enquiry.
The large energy in place in these ‘deep roots’ is undisputed. The aspects that remain to be worked through, apart from resource identification and delineation, are developing reliable technology that can be used in the energy production infrastructure and developing appropriate regulatory regimes that provide adequate certainty to support the investment needed.
Work on this topic undertaken by Working Group 12 of the Geothermal Technology Collaboration Programme is described in the paper, including how the activity of the group is helping advance this area of novel geothermal energy technology development. Recent advances have seen significant improvements in knowledge of the geochemical and physical conditions to be expected in these ultra-hot settings through experiments in fluid-rock interactions and advanced simulation models.