The hot spot: Geothermal drilling could solve water woes

Great Southern Star
Tuesday 1/5/2007 Page: 1

A $30 million investment could see South Gippsland become a major producer of clean energy for Victoria. Sydney company Granite Power is set to start drilling geothermal bores in the region after being granted exploration rights for "hot rocks" that lie beneath South Gippsland. And the technology could also provide a solution to the region's water woes, with any energy production expected to fuel waste-water treatment plants for thirsty towns.

Geothermal technology sees water pumped into sub-surface granite, where 200C temperatures superheat the water before forcing it back to the surface. The heated water is then used to spin turbines for electricity production. The clean method of electricity production has been attracting hundreds of millions of dollars in investment funds as the worldwide search intensifies for an alternative to greenhouse-gas producing coal power.

Granite Power managing director Stephen de Belle said the region had massive potential because of its geology and proximity to Melbourne. The company will now use computer modelling to locate South Gippsland's "hot spots", with drilling possible before the end of the year.

The first test holes will be sunk from the south-east fringe of Melbourne to Cape Liptrap, north to Warragul and across to Warburton. "It's an area that has potential for hot rocks at an appropriate depth," Mr de Belle said. "We saw it as having the right combination of location and geology to make it worthwhile."

The first stage of testing would involve a small-scale commercial power plant producing up to 10 megawatts of electricity - enough to power a town like Leongatha. Investment in the mobile plant would top $30 million, with hundreds of millions of dollars to be spent if a full-scale, 120 megawatt plant was built. "A fair bit of that money flows locally, a lot of support and services are required," Mr de Belle said.

The company said South Gippsland geology lent itself to geothermal technology, which is already being successfully trialled in outback South Australia. Hot granite is believed to lie about three to four kilometres below the surface, offering an accessible heat source for the power generation.

"We think there is good potential, we are looking for a combination of hot granite, not too deep and a good insulating layer to keep the heat in over the eons;' Mr de Belle said. "There is evidence that there are heat sources in that area." Mr de Belle said hot rock sites close to major cities had a massive advantage over more remote plants like those in South Australia's Cooper Basin.

"If you compare the cost of delivering a megawatt of power to a town, we could do it at between a third and two thirds of the cost than if it was coming from South Australia" Victorian Energy Minister Peter Batchelor said geothermal energy had the potential to provide clean, reliable and renewable energy to the power grid and help reduce the state's carbon dioxide emissions. "It is vital we explore all means of producing electricity in a more sustainable way and geothermal offers that potential," he said.

"Geothermal energy sources in Victoria have scarcely been explored, but there is a growing awareness of their potential. Victoria has a real advantage over other Australian states in the development of this energy source because of the compact nature of the State and the proximity of potential energy sources to the power grid and prospective markets" A geothermal power station could have the added benefit of providing clean water for the surrounding district.

Mr de Belle said new technology being developed by his company would allow sewage or other unusable water to be processed into clean drinking water. Waste heat from the plant would be used to drive a treatment facility, offering an almost endless supply of usable water.

Meanwhile, Prime Minister John Howard hasn't endeared himself to the federal member for McMillan Russell Broadbent. Receiving the news that Mr Howard had given nuclear power the green light, Mr Broadbent put his body on the line for South Gippsland. "Over my dead body will there be a nuclear reactor in McMillan," Mr Broadbent declared.

Mr Howard said only fossil fuels and nuclear energy were sufficient for running base power stations in the future. Clean coal technology was needed to tackle greenhouse issues, while nuclear power was "cleaner than clean coal".