| Abstract: | Singapore has a high geothermal gradient (～35°C/km) as evidenced by hot springs (70°C) and high heat flow (estimated to be about 130 mW/m2). In this study, ground water models are presented based on AUTOUGH–2 computer modelling. The models show a freshwater lens up to 4.8 km depth under Singapore's land area, whose temperature increases with depth up to 192°C. Three geothermal prospects are identified: an engineered geothermal system (EGS) in hot, wet granite on the main island; an EGS in hot, wet volcanics or granite on Pulau Tekong and hot sedimentary aquifers (HSAs) in the Jurong Formation, both on and off-shore. Geothermal water at 150°C could be used for electricity generation, industrial process heating and desalination. A cost estimate exercise for a district cooling system (DCS) powered by 90°C geothermal water shows that there are significant economic advantages. A feasibility study is required. |
