Research presented by Dr Eylem Kaya at the 5th Philippine International Geothermal Conference outlined practical pathways toward carbon-neutral geothermal energy.

Dr Eylem Kaya presented research on pathways to carbon-neutral geothermal energy at the 5th Philippine International Geothermal Conference (PIGC5), held at The Fifth at Rockwell, Makati. The presentation, Carbon Neutrality in Geothermal Energy: Establishing a Framework for High-Emission Industries, was delivered to an audience of geothermal operators, researchers, and policy stakeholders from across the Asia–Pacific region.

The presentation responded to the UN COP28 pledge (2023), which calls for tripling global renewable energy capacity by 2030 to limit global temperature rise to 1.5°C. While geothermal energy is already a low-carbon and reliable baseload resource, further emissions reductions are essential – particularly for high-emission geothermal systems – to align the sector with net-zero targets.

A key focus of the work was the reinjection of NCGs produced during geothermal power generation. Reinjection offers a dual benefit: reducing surface emissions while supporting long-term reservoir management. However, its implementation requires careful evaluation of technological, operational, and reservoir-related risks, such as gas breakthrough, surface leakage, pressure impacts, and potential effects on long-term resource performance.

To address these challenges, the RCE team applied an integrated numerical modelling framework. Reservoir flow models were first developed to simulate gas reinjection behaviour under realistic production and reinjection scenarios. These were then coupled with reactive transport models to assess the potential for permanent carbon storage through mineralisation and to evaluate chemical and physical impacts on the geothermal reservoir. Sensitivity analyses further explored how key parameters influence storage potential and reservoir performance.

The work highlights how science-based modelling frameworks can support geothermal operators and policymakers in designing robust, field-specific strategies for emissions reduction, reinforcing geothermal energy’s role as a critical component of a low-carbon and climate-resilient energy future.