Weekend Australian
Saturday 24/3/2007 Page: 11
Keith Orchison
THE potential of the hot rocks lying deep beneath the surface of central and eastern Australia, says Queensland Energy Minister Geoff Wilson, is big enough to meet all of Australia's power needs for 800 years - if they can be exploited. The effort to exploit this potential is now reaching substantial size: 14 companies have obtained government licences, mainly in South Australia, on commitments to spend $500 million by 2011 on exploration and initial development.
While the task of capturing energy from hot rocks three to five kilometres underground is still in its infancy, Australia is considered to have the best geology in the world for this concept, including temperatures in granites laid down more than 500 million years ago that are up to twice as hot as similar rocks in other parts of the world.
Federal Environment Minister Malcolm Turnbull believes geothermal energy can provide up to 10 per cent of Australia's future electricity needs and substantially reduce greenhouse gas emissions from the power sector. Industry Minister Ian Macfarlane describes the hot rock energy resources as "vast" and potentially providing a new path to a new electricity source.
The Howard Government has given two grants under its Renewable Energy Development Initiative program $6 million to Geodynamics Limited, the first mover in the drive to develop hot rocks power in the Cooper Basin, and a further $5 million in February to Petratherm Limited, which is pursuing shallower geothermal opportunities in South Australia's Flinders Ranges.
"What we hope to see from this," says Macfarlane,"is commercialisation of the technology and then the sale of electricity in to the (national power) grid. It's baseload power and the only renewable energy that can supply power on that basis, so we are keen to see it develop." Adrian Williams, chief executive of Geodynamics, says the next step for his company, which includes big league petroleum players Woodside and Origin Energy among its major shareholders, is to bring a $32 million drilling rig in to Australia from the United States to continue its drilling program and produce the first formal proof of geothermal hot rock reserves.
Having done this, he says, the company intends to develop a 40 megawatt power production project that Geodynamics believes can be delivering electricity in to the grid serving southern and eastern Australia by 2010. "This will be the first step in a 500MW development that will be a flagship project for hot rock geothermal energy in the world and a prelude to Australia accessing thousands of megawatts from this source by 2030," he claims.
Success in commercialising hot rock power is expected to accentuate exploitation of other geothermal resources in South Australia, parts of Queensland, the Hunter Valley in New South Wales and western Victoria.
Geoff Wilson says the Queensland Government is offering 5400sq km of prospective land for geothermal exploration. "Electricity generation from geothermal energy is very environmentally friendly," he adds. " There are no greenhouse gas emissions and no waste materials. The industry will have a future in Queensland because it can produce more baseload power than any other renewable energy source and the land has the right geological environment to develop commercial projects." Notwithstanding the Queensland Government's enthusiasm, it is the Rann Government in Adelaide which has driven the geothermal quest hardest and furthest. The state's Primary Industries & Resources Department says the introduction of legislation in 2000 to facilitate hot rock exploration and development has attracted 12 companies to take up 109 exploration licences.
The firms include Green Rock Energy Limited, which says it aims to build 100MW of geothermal plants near the Olympic Dam copper and uranium mine, and Pacific Hydro, which is exploring the Great Artesian Basin with the aim of establishing a 400MW project.
Adrian Williams says that, in theory, Australia has more thermal energy in hot rocks than it has in black and brown coal reserves put together: How much of this is exploitable and at what production price is the multi-billion dollar question: Williams believes that geothermal electricity can be generated for between $45 and $50 per megawatt hour - significantly lower, he points out, than present projections for clean coal technology with carbon dioxide capture and burial as well as for wind and solar thermal power. Prices at these levels, he adds, would make geothermal energy highly competitive with nuclear power while having none of the waste issues that bedevil the nuclear industry.
"When you look at the size of the prize and its cost, Australia has to invest in geothermal power," he argues.
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