In Australia, geothermal energy is either volcanic in origin or produced from decay of radio-active materials such as uranium, thorium and potassium contained in hot granite rocks 3.5-5km beneath the surface.
Heat in the form of superheated water and steam is accessed by drilling into the target area, bringing hot fluids to the surface and passing them through a heat exchanger before pumping them back underground to be re-heated. In the heat exchanger, a second fluid is heated, rapidly converted to steam and passed through a turbine before being returned to the heat exchanger for reheating. The scheme comprises two completely enclosed systems. There are no emissions.
Australia is not the only country endowed with hot granite which can be used to generate electricity (France and Germany already do so) but it is unique in having the most extensive and hottest rock (250C) at the shallowest depth (4km) anywhere in the world. Proven and inferred deposits of these rocks, mostly in South Australia (SA) Queensland and the Northern Territory, have sufficient heat to generate national base load electricity needs for hundreds, possibly thousands of years.
This puts Australia in the exclusive position of being able to meet all of its electricity needs from pollution free renewable sources within a decade. No other country is in that position. More than 30 companies are involved in exploring for, delineating and drilling production wells into geothermal heat sources. One of these, Geodynamics, will operate a 1MW pilot plant using geothermal steam. The electricity needs of its drilling operations in the Cooper basin and those of the township of Innamincka will be provided by this plant.
A disadvantage is that the hottest and most accessible granites are located in the north of SA and western Queensland, a considerable distance from major population centres. This necessitates building a connection between the Cooper/Eromanga Basins and the National Grid. Once this is done, it will be possible for Geodynamics and others to construct a series of 50MW or larger power stations operated by geothermal steam.
The private sector is pouring hundreds of millions of dollars into this development. By comparison, governments have assisted with a very modest investment compared with the vast subsidies provided directly and indirectly to assist those producing and using fossil fuels, particularly coal.
Subsidising production of fossil fuels may result in generating cheaper electricity: it certainly increases profitability of coal producers and users but it also helps them increase our CO2 pollution. Government should transfer those subsidies and use more of its multi billion stimulus packages to assist development of geothermal resources. Were this to happen, the speed with which those resources are developed would increase rapidly and be matched by a correspondingly rapid decrease in the use of polluting fossil fuels.
Government has chosen not to adopt this option. It prefers to continue subsidising rather than reducing CO2 pollution, increasing the volume of coal production and increasing dependence on it as a revenue source. It prefers to invest $2 billion in development of clean coal technology, believing that its eventual use will ensure on going reliance on fossil fuels, particularly coal, protecting against any diminution in it use to generate electricity.
It is likely that clean coal technology will prove so expensive that its use increases the cost of electricity produced from burning coal to the point where, by 2020, it is uncompetitive with solar energy. China has already indicated its uncertainty in this regard by its decision to meet growing demand for electricity by building more nuclear fuelled power stations and increasing its budget into development of solar technology.
Australia already has the knowledge needed to produce competitively priced geothermal electricity. It could halve its CO2 emissions by 2020 and be in a position to demand that others make similar reductions. Subject to technology advances, sunlight may compliment but is unlikely to displace geothermal energy as a source of pollution free base load power. Government knows this and that the future of fossil fuels should be in sharp decline by 2015.
Why then do ALP and Coalition parties alike resist the inevitable, knowing the damage their policies, or lack of them, do to global warming and climate change, knowing the catastrophic effects these will have on our planet and its habitability? Our leaders prattle on about the need to prevent transitory job losses in the short term while ignoring the very real possibilities of coastal cities being lost, millions being displaced and economies left in ruins well before the end of this century.
Future generations will not thank them for trying to foist a shonky Environmental Trading Scheme on us, for denying the urgency of action to reduce CO2 emissions, or for rejecting that human activity is the cause of global warming.
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