A review of hot sedimentary aquifer geothermal resources in Australia

Abstract

ABSTRACT Numerous currently operating, past and potential future geothermal energy projects in Australia depend on heat from hot sedimentary aquifer (HSA) sources. The relevant aquifers cover a range of geographical and geological settings. Currently operating geothermal energy projects in Australia (excluding ground source heat pumps) predominantly utilise 40–70°C aquifers in the Gippsland Basin, Otway Basin and Perth Basin. Economic assessments have demonstrated that heat from these sources is significantly cheaper than heat from natural gas. Electrical power has previously been generated using 87–99°C water from aquifers in the Great Artesian Basin in South Australia and Queensland, but those generators are now decommissioned. A project to generate power using >150°C groundwater from deep in the Otway Basin in 2010 was suspended and subsequently abandoned when initial production did not meet commercial requirements. Several new projects, particularly in Western Australia, are in the stage of technical and economic pre-feasibility for geothermal power generation from >150°C groundwater. Preliminary techno-economic assessments may be favourable, but existing regulatory constraints pose major impediments to further development of hot sedimentary aquifers in parts of Australia.