Geothermal energy: deep sources in Victoria

Abstract

Geothermal energy is heat stored naturally within the rocks of the earth. The higher the temperature of the rock, the more thermal energy is potentially available. In general, temperature increases with depth so deeper rocks store larger amounts of geothermal energy. Water has a higher volumetric heat capacity than most solid minerals, so saturated porous rocks tend to store larger amounts of heat than non-porous rocks. Under the right circumstances, geothermal energy can be economically extracted and put to use either directly (for example, to heat buildings) or by converting it to electrical energy. There are already two geothermal power generators in Australia (a 120 kWe plant at Birdsville, Queensland, and one 1 MWe plant at Innamincka, South Australia) and a range of direct applications of geothermal energy (heated buildings, swimming pools and spas)