/ 1 January 2002

Australia mulls building green power tower

If it is built, Australia’s kilometre-tall solar tower project will be the biggest single generator of green energy in the world.

Roger Davies, chief executive of Enviro-Mission, the company that owns the local franchise for the experimental German technology, reckons it will get built.

”In the early days people thought ‘Can it be built and does it work?’ but we’ve got over that,” said Davies. ”Yes, it can be built and, yes, it does work.”

The government shares Davies’ confidence. It has put up 800 million Australian dollars ($424-million) in seed capital for the venture. There is also a pledge of help getting over bureaucratic hurdles.

Next up for Enviro-Mission is an environmental impact statement for construction of the power plant in the south-western corner of New South Wales.

The tower itself will have be 300 metres taller than Kuala Lumpur’s Twin Towers, the current highest structures in the world.

Ringing the base of the tower will be solar collector panels with a radius of 3,5 kilometres. Their job is to gather hot air and funnel it through 32 wind turbines, creating 200 megawatts of electricity – enough for 200 000 homes.

So, how exactly does a solar tower work?

Davies explained that the solar panels were like a great big greenhouse, under which warm air collected and could be channelled towards the tower in the centre.

The tower needs to be tall to create a temperature differential that draws air through the system. Like the chimney of a household fireplace, in fact.

The solar tower would cut Australia’s greenhouse gas emissions — on a per capital basis, the biggest in the world — by about 700 000 tons a year.

Davies can’t get away from the fact that it is experimental technology.

The only place where something similar has been tried, a prototype in Spain, was a grave disappointment and has been scrapped. – Sapa-DPA