Where there's a wind there's a way

May 30, 2009

With climate emergency rallies on June 13 demanding 100% renewables by 2020, it's important to dispel some myths about alternative energy sources such as wind power.

One myth about is that it can't provide baseload power, the minimum continuous power supply required.

It is said that because the wind doesn't always blow, it's an unreliable source of electricity. But it is wrong to argue that all airflows will completely stop across hundreds of kilometres of coastline and hills. While an individual turbine or wind farm may periodically "stop", this does not rule out its viability.

A 2007 study by Cristina Archer and Mark Jacobson from Stanford University found that appropriately sited linked wind farms can produce 33%-47% of baseload power.

The myth is politically motivated, aimed at preventing debate about renewable power shifting from "can it be done?" to "why isn't it being done?".

Wind technology has evolved massively. The physical size of modern turbines is much greater than just a few decades ago. Stronger, more reliable airflows are available at higher altitudes. The bigger turbines get, the more power they can extract from a given site, and on a more constant basis.

In 1981, high quality commercially available wind turbines had a blade diameter of 15 metres; the hub sat 20-25m off the ground and the turbine had a maximum capacity of 55 kilowatts (kW).

By the mid 1990s, turbines had tripled in size — and with that came an almost twelvefold increase in power. Turbines with a 44m blade diameter would belt out about 600kW in decent breezes. Today there are turbines in operation with a 126m blade diameter, with a peak capacity of five megawatts.

So a single modern five megawatt turbine can produce as much power as an entire wind farm with 90 1981 turbines. And that one large turbine will be getting much better airflow than the 90 small ones.

An April 19 article at RenewableEnergyWorld.com reported that there are now 7.5MW and even 10MW turbines under development. By 2020, there may be giant turbines in production with capacities of 15-25MW or more.

Australian scientists should be funded to develop wind turbine technology as well as other urgently needed alternative energy sources and agriculture methods instead of working on joint strike fighters and other unnecessary garbage.

At the end of 2008, there were 121 gigawatts of wind farms installed worldwide. This figure continues to grow at around 30% per year.

The Chinese government recently announced it was likely to reach its 2020 target (30GW) for wind farms by 2011, and would revise its target to 100-150GW.

Australia has an installed capacity of about 1.5GW, or about half as much output as one large coal-fired power station.

Clearly we need a major expansion. Other places like Germany, Spain, Denmark and California, which are more manufacturing-focused (as opposed to mining-focused like in Australia), have respectable amounts of wind farms installed.

The question is this: how much more wind could be rolled out if there was a genuine political will to rapidly de-carbonise the world's electricity generation?

Wind energy is generally accepted as being able to supply 20% of a given country's electricity needs. In Australia, that figure would likely be higher as we have a relatively small electricity demand compared to our size, and excellent wind resource.

"Smart grid" technology under development will allow wind to play an even larger role in delivering green energy, as will the ongoing development of larger turbines.

It is not unreasonable to project that by 2020, given the investment and political will needed, wind energy could be providing around a third of Australia's energy needs.

If state and federal governments could together commit $3-4 billion per year to direct investment in wind farms over the next decade, we would be well on the way to achieving this.

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