Geothermal air conditioning: typical applications using deep-warm and shallow-cool reservoirs for cooling in Perth, Western Australia

Geothermal heat is a sustainable form of alternative energy, commonly associated with the production of electricity along tectonic plate boundaries and in volcanically active zones. Outside of these special regions however it is rare to find a geothermal gradient high enough to achieve pay back on projects for generating electricity. On the other hand regions containing sedimentary aquifers are far more common and these aquifers frequently have a sufficiently high temperature gradient to make direct use of the thermal energy attractive. Meanwhile highly permeable aquifers occurring at shallow depths are possible sources for cooling water or can be both heat sources and sinks when used in combination with heat pumps. We provide a case study for the use of thermally driven absorption chillers on the University of Western Australia campus in Perth and discuss two ongoing projects: one for the heating and cooling of the offices of the Australian Resources Research Council using a reversible heat pump and the other the climate control of the planned Australian International Gravitational Observatory.