MELBOURNE (Reuters) - The world's tallest man-made structure could
                               soon be towering over the Australian outback as part of a plan to capitalize
                               on the global push for greater use of renewable energy.

                                                  By 2006, Australian power company
                                                  EnviroMission Ltd hopes to build a 1,000 meter
                                                  (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 meters.

                               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 center
                               of a massive glass roof spanning seven kilometers in diameter.

                               Despite its size, the technology is simple -- the sun heats air under the
                               glass roof, which slopes upwards from three meters at its outer perimeter to
                               25 meters 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 toward 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
                               meter 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.