MELBOURNE - The world's tallest man-made structure could soon be towering over the Australian outback as part of a plan to capitalise on the global push for greater use of renewable energy.
By 2006, Australian power company EnviroMission Ltd hopes to build a 1,000 m (3,300 feet) solar tower in southwest New South Wales state, a structure that would be more than twice the height of Malaysia's Petronas Towers, the world's tallest buildings. Currently, the world's tallest free-standing structure is the Canadian National Tower in Toronto at 553 metres.
The 200 megawatt solar tower, which will cost A$ 1 billion ($563 million) to build, will be of a similar width to a football field and will stand in the centre of a massive glass roof spanning seven kilometres in diameter.
Despite its size, the technology is simple - the sun heats air under the glass roof, which slopes upwards from three metres at its outer perimeter to 25 metres at the tower base.
As the hot air rises, a powerful updraft is also created by the tower that allows air to be continually sucked through 32 turbines, which spin to generate power 24 hours a day.
"Initially people told me 'you're a dreamer', there's no way anything that high can be built, there's no way it can work," EnviroMission chief executive officer Roger Davey told Reuters.
"But now we have got to the point where it's not if it can be built, but when it can be built."
EnviroMission hopes to begin construction on the solar tower before the end of the year and be generating enough electricity to supply 200,000 homes around the beginning of 2006.
The company also hopes the project will save more than 700,000 tonnes of greenhouse gases a year that might otherwise have been emitted through coal or oil-fired power stations.
The company has signed agreements with Australian-listed Leighton Holdings Ltd and U.S.-listed Energen Corp to determine the commercial feasibility of the solar tower, which Time Magazine recently voted among the "Best Inventions of the Year".
The tower has received the support of the Australian and New South Wales governments, which have defined it as a project of national significance.
EnviroMission plans to build the tower in remote Buronga district in New South Wales. The district is near the border with Victoria state and is 25 km (15 miles) northeast of Mildura town.
It will generate about 650 gigawatt hours (GWh) a year towards Australia's mandated renewable energy target, which requires electricity retailers to supply 9,500 GWh of renewable energy a year by 2010.
The Electricity Supply Association has said A$48 billion needs to be invested in electricity infrastructure during the next two decades to meet the country's growing demand. Davey said he is keen to keep the tower's costs as low as possible to ensure its success.
"We have proved that it does work and that it can be built, but what we have got to get a handle on is the cost and we are working very strongly through that now," Davey said.
The tower - originally known as the solar chimney - is the invention of German structural engineers Schlaich Bergerman, who constructed a 200 metre high demonstration power plant in Manzanares, Spain, in 1982.
The 50 kilowatt plant produced electricity for seven years and then closed down after having proved the technology worked. Schlaich Bergerman now work with EnviroMission.
The project has already been given clearance by the Civil Aviation Safety Authority of Australia and will be fitted with high intensity obstacle lights to warn aircraft in the area.