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The Birdsville Geothermal Power Station - A Beacon For The FutureThe small Birdsville geothermal power station was built in the early 1990's and remains no more than a pimple on Australia’s vast geothermal energy resources. Its well, tapping into the 98C hot water of the Great Artesian Basin, is 1230 metres deep and generates a modest 120 kW net power output. This represents what's known as a geothermal heat pump. 
There are two kinds of geothermal energy: hot rock and hydrothermal. Obviously the Birdsville geothermal power station is the latter. As geothermal plants go it is a low temperature plant. Other hydrothermal plants use water of temperatures around 250C. I have heard once of another "low temperature" kind of "geothermal" heat pump where the warmth of sewerage pipes was used to generated domestic energy. Not quite delving into the bowels of the Earth, but still, well... innovative... Anyway, their genuine geothermal plant saves the outback town of Birdsville's residents about 160,000 litres of diesel fuel annually in otherwise generating electricity – and, importantly 430 tonnes of greenhouse gas emissions. Besides specific information on the Birdsville geothermal power station you can find more general geothermal energy facts here. Some of the advantages that Birdsville residents have been privileged to experience for so long are those offered for the immediate future of this renewable energy:
Birdsville residents have front seats in this highly promising renewable energy source development. Even so, the bulk of their energy requirements still derive from diesel and LPG. However that might change as Ergon, the company that owns the plant is looking at expanding its operation to have the entire town's energy supplied from using its artesian water. By 2007 27 companies had applied Australia-wide for 197 licenses to explore, do flow tests or demonstration projects and received government grants, some up to $5M. If you think $5M is a lot of public money to spend on this, think again. The exploring companies represent a $700M investment over five years. This against the backdrop of the possibility of meeting 6.8% (5.5 GWe) of Australia's energy needs from geothermal power by 2030. It's not just attractive in Australia. Hochtief in Germany for example has announced the first privately funded 5MW geothermal plant to be built in Bavaria, Germany. This makes geothermal power a most desirable object for green investing and has great promise for reducing greenhouse gas emissions. Of course, geothermal power is also a desirable investment target because its customers remain chained to a central grid. So, if you want to get out from under that power you may like to start looking for small, domestic renewable energy generators, like PV solar panels and wind power, and use hotwater solar panels to the max! So, how does the Birdsville geothermal power plant work? Like this: The hot water bore flows at 27 litres per second. The source heat of 98C is transferred to a "working fluid", called isopentane, to a heat exchanger. As the isopentane is made to boil by the hot water from the bore, it is vapourised at around 4 atmospheres pressure. This high-pressure vapour then pushes against the vanes of an expander which converts energy into mechanical power. This power turns the shaft of a generator and produces an 80KW net output. Birdsville, the outback town that's part of the future! Sources:http://www.epa.qld.gov.au/publications/p00834aa.pdf/Birdsville_geothermal_power_station.pdf http://www.pir.sa.gov.au/__data/assets/pdf_file/0016/53071/mj45_geothermal_energy_outlook.pdf |