Dr Eylem Kaya presented RCE research on pathways to carbon‑neutral geothermal energy at the Iceland Geothermal Conference 2024, in a talk titled Carbon Neutrality in Geothermal Energy Production: A Blueprint for Emission‑Intensive Sectors.

The presentation showcased advanced numerical modelling and new insights into the long‑term reinjection of non‑condensable gases (NCGs), including CO₂, H₂S, and CH₄, into geothermal reservoirs to enable predictable, permanent storage.​

Iceland is a global frontrunner in CO₂ mineralisation in geothermal systems through the Carbfix method at the Hellisheiði geothermal power plant, where CO₂ dissolved in water is injected into basalt and rapidly converted to stable carbonate minerals. Building on this experience, our programme is developing high‑resolution predictive models that couple reactive transport, fluid flow, and evolving rock properties to design and optimise controlled mineralisation strategies in geothermal settings. Our work uses these tools to quantify how CO₂‑charged reinjection drives mineralogical and geochemical alteration and to forecast its feedbacks on porosity, permeability, and long‑term reservoir performance and storage security.​

Using large‑scale 3D numerical simulations of liquid‑dominated, basalt‑hosted geothermal systems, the study examines fluid–rock interactions under combined reinjected NCGs and natural magmatic fluxes of CO₂, H₂S, and H₂. Over timescales of up to 100,000 years, the models predict the transformation of primary basaltic minerals into secondary assemblages including albite, chlorite, epidote, quartz, zeolites, and carbonates, consistent with alteration patterns observed in Icelandic geothermal fields. These simulations provide a quantitative basis for tuning injection strategies to steer mineralisation processes, manage porosity and permeability evolution, and evaluate the fate of trace elements.​

As part of the conference programme, Kaya joined a field visit to the Hellisheiði Geothermal Park, which hosts ON Power’s large‑scale geothermal operations alongside Carbfix’s mineralisation site and industrial partners such as Climeworks and VAXA Technologies. This work positions our research programme at the forefront of predictive modelling and controlled CO₂ mineralisation, demonstrating how integrated field data, industry experience, and advanced simulations can inform robust CO₂ management solutions for geothermal systems worldwide.