Navigating geothermal development for Singapore

Singapore relies heavily on energy imports to sustain urban development and ensure energy security, given its absence of extractable natural resources. Currently, natural gas dominates the energy mix. Singapore is considering several clean energy pathways to decarbonise and diversify, including solar photovoltaics, clean energy imports from neighbouring countries, hydrogen-ammonia, and nuclear power. Solar is among the most cost-effective domestic options, yet its extensive land requirements pose challenges for a land-scarce nation. By contrast, geothermal energy warrants investigation as a potential local low-carbon energy source, subject to the confirmation of sufficient subsurface heat resources.

Two deep exploratory slimholes were recently drilled in northern Singapore, reaching depths of 1.12 km and 1.76 km. Their bottom-hole temperatures measured 70°C and 122°C, respectively. From these results, geothermal gradients based on conductive heat transfer evaluated at 40–44°C/km. If such gradients persist to depths of 4–5 km, rock temperatures could exceed 200°C, enabling both electricity generation and direct-use applications. Scenario-based techno-economic and environmental assessments indicate that, if the high geothermal gradients inferred from recent drilling persist to greater depths, geothermal energy could become cost-competitive with existing electricity and cooling supply options under favourable development conditions. Competitiveness is contingent on substantial reductions in well development costs and the successful deployment of advanced subsurface heat-extraction concepts.

Despite these encouraging findings, geothermal remains a nascent technology in Singapore. Research and development are still at an early stage, though the recent drilling campaign marks a revival of efforts first initiated in 2002. Global technological advances in heat extraction and drilling are on the cusp of being demonstrated in the field. Successful deployment could serve as a model for other countries away from tectonic and volcanic settings. However, several challenges must be addressed in Singapore before geothermal can be fully realized. Chief among these are limited data availability and a shortage of local expertise. Building a robust talent pool and expanding the dataset are critical steps to reduce uncertainty and accelerate development. By overcoming these barriers, Singapore can strengthen its position to adopt and assist future geothermal within and in other neighbouring countries, complementing its broader clean energy strategy and enhancing long-term sustainability.