• Geothermal

    Geothermal energy involves extracting the energy stored as heat in the earth. Although geothermal energy is present everywhere beneath the surface, it must be concentrated and close to the surface and energy consumers to be a cost-effective power source.

    Resources in Western Australia

    Western Australia’s geothermal resource falls into two categories – hydrothermal (from hot groundwater) and hot fractured rock.

    Hot fractured rock processes involve pumping water into wells drilled deep underground to access heat from granite rocks. The steam created is used to drive turbines on an electricity generator.

    Hydrothermal processes access existing groundwater resources that are generally shallower and cooler than hot fractured rock geothermal resources. The hot water can be used directly for applications such as heating and cooling buildings or industrial processes. If the temperature is high enough, it can be used to generate electricity.

    Past studies, using data from petroleum exploration, have identified significant potential for geothermal energy in Western Australia. Further information is available from the Department of Mines and Petroleum [external website].

    Current use in Western Australia

    Geothermal energy exploration in Western Australia was legislated in 2008. Since then several companies have been exploring for geothermal energy, mostly in the Perth Basin.
     
    Exploration has been concentrated in areas close to the electricity grid or where significant load growth is more likely in future. The electricity generated could be used to power mining and industrial operations, as well as regional centres, ports and infrastructure.
     
    The Western Australian Geothermal Centre of Excellence [external website], has been focusing on large-scale direct heat applications (e.g. geothermal-powered air conditioning and desalination) in populated centres where there is shallow groundwater of moderate temperature. The Centre completed its major research program in 2012.

    Direct heat applications at relatively small-scale are already used to heat swimming pools around Perth. These include Melville Water Polo Club, Challenge Stadium, Christchurch Grammar School, Claremont Pool, Saint Hilda’s School, Hale School, and the Craigie, Canning and Beatty Park Leisure Centres.

    Future use in Western Australia

    Geothermal energy can potentially be used to generate a non-intermittent power supply, which is not possible with wind and solar technologies without the use of energy storage. Geothermal energy can be used to displace electricity used for large-scale heating and cooling applications. This helps to reduce the need for future investment in electricity generation and network infrastructure used only for a short period each year in which demand peaks. These peak periods generally occur during winter or summer, when electricity is used to control temperature.
     
    Last reviewed: 26 April 2017