Outback power answer a whole lot of hot air

Sydney Morning Herald
Wednesday 27/10/2010 Page: 2

AN EXPERIMENTAL solar power plant at Newcastle will be the biggest of its type in the world, with a field of hundreds of mirrors "creating electricity out of sunshine and air". Most solar thermal power plants concentrate heat to boil water and spin turbines, but the CSIRO's miniature power station is designed for waterless regions of outback Australia.

The mirrors focus the sun's heat onto a tower that holds compressed air. The air, heated to 900°, drives a turbine motor on top of the tower which produces electricity. The trial plant at Mayfield West, where the first mirrors were installed yesterday, covers about 4000 m² about the size of a shopping centre roof. Even running at low capacity, it willpower about 200 households.

"The best solar regions in the world like north-westAustralia are also the regions with the lowest rainfall", said James McGregor, the CSIRO's project director for solar technology. "A lot of the mining towns in that part of the world rely on diesel for generating electricity, so our initial target market over the next five years will be the mining industry".

The agency has calculated that the energy and carbon emissions embodied in the steel, aluminium and silicon needed to build the plant would be offset within two years, after which it would generate electricity without emitting greenhouse gases or requiring water. Unlike the mostly steam driven solar plants overseas, the design uses smaller, cheaper components that can be mass produced. The curved mirrors for the plant are being made on the central coast by Performance Engineering Group, and the little motors used to guide them to face the sun are sold commercially for $19.95.

The project, which is expected to be built by Christmas at a total cost of $5 million and to generate power by the middle of next year is one of the first fruits of the Australian Solar Institute, a $100 million federal government program to support solar power research. At present, just under 4% ofAustralia's energy comes from renewable sources. The national renewable energy target is to raise that to 20% over the next 10 years.