The answer is blowing in the wind

Sydney Morning Herald
29/05/2007 Page: 13

You can install your own wind farm but its effectiveness will depend on where it is and even the time of the year.

Locals in Camden have dubbed it the twin toilet roll but it is more properly known as the vertical axis wind turbine. And those involved in the trials of the device perched atop a tower at Camden High School are hoping it will revolutionise wind energy. The school's principal, John Jarvis, says locating the turbine at his school was a happy accident.

He had introduced solar energy at his previous school and, because of Camden's windy location, was hoping to install wind energy there. After a few letters and phone calls Jarvis linked up with a local company that had been asked to make an "unusual-looking wind generator" from fibreglass.

The company, Dynamic Systems Australia, was looking for a location nearby to test the new wind turbine and it ended up being the high school. Early results have been exciting, Jarvis says. "When we originally put in to Camden Council, [the tower] was going to be 20 metres or 22 metres," he says, "but when it was that high they found it was so effective that they have actually reduced it to about half that height. So you could quite easily site it somewhere and put trees around it, although you'd have to be careful about the trees affecting the wind catchment. But it could be disguised totally. "The remarkable thing about this is that it is actually designed so you can winch it up, and if anything goes wrong with it you can just winch it down and fix the blades and so on. It would also be a relatively inexpensive thing to put into a village in a Third World country or a farm in outback Australia."

Tony Wright, a consultant project manager for Dynamic Systems Australia, says that full-scale tests assessing the power capacity of the vertical axis wind turbine are expected to begin soon. He believes the turbine has "the capacity to produce 80 kilowatts to 100 kilowatts at very low wind speeds - at six metres per second, whereas a traditional turbine would require probably twice that [speed]". (The turbine's capacity is not a rating in kilowatts per hour. This is what the testing will accomplish, taking into account the variations in the wind.)

Small wind turbines have been attracting a lot of attention recently, especially overseas. In Britain, the Conservative Party Leader, David Cameron, famously attached a micro wind turbine to the chimney of his London home, provoking a furious debate there about whether domestic turbines were of any real value. There are plenty of turbine kits for sale in Australia. However, Dr Mark Diesendorf, a senior lecturer from the Institute of Environmental Studies at the University of New South Wales, says wind turbines such as Cameron's would be "almost useless" because they are situated in suburban areas where much of the wind is screened by houses, trees or other obstacles.

"There is a fashion in Britain for people to buy these things and stick them on their chimneys, and in most cases it's a complete waste of money," Diesendorf says. "They would get the same amount of energy [savings] by replacing an incandescent lamp with a fluorescent bulb." However, he says large wind turbines are extremely efficient. They are able to convert more than 45 per cent of the wind that passes through the circle of the blades into energy. He regards the Southern Tablelands, Southern Highlands and parts of the Northern Tablelands as areas with "a lot of potential" for wind farms. But the smaller turbines that would be used in domestic settings are less efficient and, Diesendorf believes, not especially practical. "There will be exceptional cases, usually in places on the coast with a lot of sea breeze exposure, but generally speaking there are much more cost effective ways of reducing greenhouse gas emissions in the home," he says.

On the far South Coast of NSW - where, happily, it often gets very windy - Steve Garrett, the owner of Pyramid Power, has been installing domestic-sized wind turbines for 21 years. He agrees they are not for everyone but says that during the windier months in his area the small 400-watt wind generators he installs are able to provide about two kilowatt hours a day. He estimates this is equivalent to one-sixth of the power used by a reasonably energy-efficient house and 7 per cent of the power in a non energy- efficient house. Of course. in some months there is little or no wind, so no energy is provided. In addition, Garrett says, most domestic turbines are inefficient because they are not placed at a sufficient height above the building.

"You need to get clear air," he says,"so it's more an energy-efficiency flag than an energy-efficiency doer." Garrett has to prepare a council development application for every wind turbine tower over a certain height, so he recommends that people thinking about installing a wind generator at home check their council's regulations regarding height limits. `And it's a really good idea to talk to your neighbours as well".