A study of wind conditions off Australia's coast indicates a resource that probably exceeds that of the North Sea in speed and reliability. Proposals already exist to tap into this abundant energy, and a new report reveals they could achieve outputs exceeding the highest so far tapped worldwide.
Plunging costs have left intermittency as the last great barrier to wind and solar's takeover of electricity generation. This makes the “capacity factor” – the amount a generator produces annually divided by its theoretical maximum – crucial. The first commercial wind farms had capacity factors below 20 percent. This has risen with taller turbines and better placements to the point where the very best locations exceed 50 percent.
Dr Sven Teske of the University of Technology, Sydney has calculated modern wind turbines located off Tasmania's south coast would have an unheard-of capacity factor of around 80 percent. A wind farm there would almost always be producing substantial amounts of power, even if short of full production. Such a location might well prove more reliable than most fossil fuel or nuclear plants since maintenance can be done one turbine at a time.
Aside from the northern part of the North Sea, wind province capacity factors above 50 percent are limited to small hotspots in places like Morocco and Egypt where beneficial geographical factors coincide. Tasmania's southern coast is part of something much larger, edging into the “Roaring Forties” where winds whip around the entire planet with barely a hint of land to stop them.
Teske told IFLScience he is not aware of any proposals to tap into this extraordinary resource, noting: “You need a strong power connection [to make generators economic] and everything pretty much ends at Hobart.” However, some sites under consideration closer to Australia's major transmission lines could still set global records, and new proposals are emerging all the time. The Roaring Forties are probably closer to Ausrtralia's grid than the seas off Iceland are to Europe's, which hasn't stopped some very ambitious plans.
The report refers to 10 proposals with a combined 25 Gigawatts capacity, more than all the coal-fired power stations in notoriously coal-dependent Australia. Yet even while the report was being written, Teske told IFLScience, three more proposals were added.
Teske admitted his estimates of wind strength and consistency have some uncertainty. “Wind data at sea is mostly collected at the deck of a ship around 25 meters above the surface,” he told IFLScience. “From there you model conditions at 100 or 150 meters. These are usually a bit conservative. I modeled potential in the North Sea 15 years ago and the measured data has been better than the estimations.”
On this basis, Teske thinks reality may exceed even the report's optimism. If so, an offshore wind industry might allow Australia to power itself almost entirely with solar and wind with relatively modest amounts of storage. This would serve as a beacon to other countries doubtful such things are possible.
Australia has no offshore wind yet, and only one proposal even close to getting started. Teske and co-authors attribute this to excellent onshore wind and solar resources, and the depth of the ocean relatively close to the coast. He tactfully glossed over the federal government's hostility to non-polluting energy sources.