January 6, 2003. Copyright, 2003, Graphic News. All rights reserved

Australian power tower aims to produce renewable energy
By Joanna Griffin

LONDON, January 6, Graphic News:  An Australian power company plans to construct the worldÕs tallest structure Ð a solar tower Ð as part of global efforts to promote the use of renewable energy.

EnviroMission, based in Melbourne, estimates that its pioneering facility will provide 200 megawatts of electricity, enough to supply more than 200,000 households, by the time it is completed in 2006. 

Rising 1,000 metres (3,300ft) out of the red desert in New South Wales, the proposed tower will dwarf the worldÕs current tallest freestanding building, the Canadian National Tower in Toronto. Its width will be similar in size to a football pitch and it will sit in the centre of a glass roof spanning 7km (4.3 miles), in effect a giant greenhouse.

Though the scale of the project is unprecedented, it relies on technology that could not be simpler: hot air always rises. The sun heats air in the glass roof, causing a 56km/h (35mph) updraft capable of powering 32 turbines. At night the system uses tubes filled with sun-heated water, enabling the spinning turbines to power electricity generators 24 hours a day.

A 200-metre (650-foot) pilot project in Spain worked well between 1982 and 1989. If successful, the tower, designed by German Joerg Schlaich, will not only represent a considerable engineering feat but could revolutionise the production of sustainable energy.

EnviroMission says its tower will save on 830,000 tonnes of greenhouse gases annually, and its plans to build four more towers by 2010. Its A$1 billion (US$560 million) tower has the backing of the Australian government, which set a Kyoto target of cutting greenhouse emissions to within 8% of 1990 levels by the end of the decade.
/ENDS