As the global hunt for greenhouse-friendly power intensifies, Australian scientists have developed a world lead in one of the most promising among the renewable energy sources - wind harvesting.

Dr Peter Coppin, of CSIRO Land & Water, is a "wind prospector", one of a new breed who employ a sophisticated array of sciences to pinpoint the areas of richest energy potential in terms of landscape and prevailing winds.

Indeed, so competitive is wind prospecting becoming that something of a "wind rush" has developed, as energy producers race to identify and secure the best sites, says Dr Coppin.

Working with NSW energy supplier Pacific Power, Dr Coppin and his colleagues have identified a major wind "hot spot" located near Crookwell, in the Southern Tablelands - soon to be the home of Australia's largest and first grid-connected wind farm.

With a good wind, the Crookwell farm will pump out a steady 5 megawatts from eight 600kW propellor turbines, enough to meet the average electricity demand of at least 3500 homes and will reduce greenhouse gas emissions by 8000 tonnes per year through the replacement of fossil fuel power.

Finding a rich wind prospect is a good deal more complex that many people might imagine: it involves a subtle blend of fluid dynamics, topography, meteorology, demography, numerical modelling and statistics. It also involves scores of wind monitoring towers scattered across the landscape, measuring wind speed and turbulence year round.

The key to success is not so much the power of the wind - though that is important - as the need for consistency at medium strength, Dr Coppin says. To do this, he has developed a modelling technique which is winning international recognition as a leader in the field.

"The new modelling techniques enable us to find wind where few people would expect there to be worthwhile resources. It enables us to site the farm, and even individual turbines, for optimum power generation."

While most people consider that Australia's windiest regions lie along its southern coastline, Dr Coppin's technique is demonstrating there are plenty of rich energy resources inland too, mainly along mountain ridges and peaks, where moving air is "squeezed" through a smaller area of atmosphere as it is blocked by the higher topography.

"In the case of Crookwell, there is a large expanse of flat, open country which allows the wind strength to build up, and then a series of ridges, which act almost like huge aircraft wings, kicking the wind upwards and increasing its energy as it passes over the top."

The cost of wind energy - and whether it can compete with coal-fired or other forms of electricity - depends vitally on positioning the turbines correctly where they can draw the most power year-round. A site with an average wind speed of 5 metres per second produces almost double the electricity of one with 4 m/sec.

"We have found that every one per cent lift in performance we can get out of a wind farm by these methods will generate an extra $1 million's worth of energy over its life," he explains.

Wind farms are sometimes criticised for their visual impact, but Dr Coppin says another advantage of his technique is that it enables individual turbines to be "micro-sited" in places where they not only draw the optimum power from the wind but also impinge least on the landscape.

Wind farms are coming into their own worldwide. Denmark, the world leader, now draws almost 5 per cent of its total electricity needs from the wind and plans to move to 40 per cent in the next few decades, exporting its surpluses to the rest of Europe.

Dr Coppin believes that the new methodology for finding wind resources will help make it the most competitive form of renewable energy in Australia, capable of supplying the lion's share of the 2 per cent of national energy needs sourced from renewables under the Federal Government's greenhouse strategy.

In the longer run, wind could provide an even larger slice of the national energy cake.

"The cost of wind-power depends on where you locate the generators. It is costly to transmit power over long distances, so wind farms become a real option for supplying power economically to the outer parts of the national grid," he says.


More information:
Dr Peter Coppin, CSIRO Land & Water 02 6246 5576
Margaret Bryant, CSIRO Land& Water 08 9387 0215