Geothermal Energy-Driven Electricity Generation Model for Singapore

Singapore is exploring potential geothermal reservoirs to reduce its reliance on natural gas and transition towards sustainable energy sources. With only 4% of registered power generation capacity coming from renewables, the city-state aims to achieve net-zero emissions by 2050. The study focuses on harnessing low- to medium-temperature geothermal resources for electricity generation using organic Rankine cycle (ORC), which is a heat-to-power conversion technology. The simulation results project that each Enhanced Geothermal System (EGS) well doublet has an electrical generation capacity of 0.93 MWe, equivalent to about 7 GWh annually. This EGS-ORC system can be scaled up to exploit the heat within Singapore’s granite. Furthermore, the study conducts comprehensive analyses, employing Life Cycle Assessment (LCA) and Life Cycle and Cost Analysis (LCCA) methodologies. LCA reveals that geothermal electricity's global warming potential is significantly lower than Singapore’s current grid emission factor. LCCA estimations show the net-present levelized cost of electricity is competitive with Singapore’s long-run marginal cost and aligns with the Uniform Singapore Energy Price. The rejected hot fluid from the geothermal system can further enhance its economic viability. The study offers valuable insights for urban planners, policymakers, and researchers in Singapore's transition towards resilient and eco-conscious energy systems.