| Abstract |
Australia continues to make modest use of its geothermal energy resources. The only electric power generation from geothermal energy currently in operation in Australia is the 150 kW binary cycle plant at Birdsville in SW Queensland. This plant uses 98 C artesian water from the Great Artesian Basin to generate much of the town's annual power requirements. Direct use of geothermal waters continues to be an important source of energy in the city of Portland in western Victoria. Water pumped from a 1400 metre deep bore at a temperature of 58 C is used to heat many of the municipal buildings and public facilities. Geothermal waters are also used for spas at Moree, near Barradine and at Lightning Ridge in New South Wales and at two developments in Victoria on the Mornington Peninsula, south of Melbourne. Ground source heat pumps are also finding increased use in Australia in both commercial and residential applications. Significant research and development of Hot Dry Rock (HDR) energy is underway and a number of companies have been formed to explore for and develop this form of geothermal energy. Most advanced is an HDR project in the Cooper Basin region of north east South Australia. Here a 4.4 km deep borehole has been drilled as part of an extensive commercial project. An extensive underground heat exchanger has been created in granite at this depth with in-situ temperatures >250 C. The drilling of a second deep borehole in 2004 is to be followed by a planned circulation test in early 2005. The known scale of this resource is so large that it could meet all of Australia's electricity generation requirements for centuries. The main purpose of the current work is to evaluate the likely economics of such a development. Other HDR projects, including one in the Hunter Valley of New South Wales, have also been active in the period 2000-2005. |