Sedimentary basins, occupying a large proportion of the Australian landmass, offer an ideal target to push forward new technologies of direct heat use.
For example, the Great Artesian Basin is one of the world’s largest artesian groundwater basins, underlying one fifth of the Australian continental landmass.
Groundwater from the Basin comes out at wellheads at temperatures up to 100° Celsius. The natural temperature, porosity and permeability of these sedimentary basins may be sufficient to provide usable geothermal power without the requirement of stimulation. It particularly suits the needs of thermally driven geothermal air-conditioning systems.
In the conventional geothermal approach for air-conditioning, the geothermal energy is first converted into electricity which is then used to drive a vapour compression chiller for cooling. However, this method is not economical as more than 70 per cent of the energy is wasted.
An alternative approach using direct heat for air-conditioning is more economically viable as it converts more than 60 per cent of the available thermal power into cooling.
To better understand the design considerations, performance outcomes, underground characteristics and viability of future geothermal cooling, a large-scale district cooling system fuelled by geothermal energy from a hot sedimentary aquifer may commence as early as late 2010 in Perth.
This pilot project will base load to an existing cooling system for UWA's Crawley Campus.