Thursday, September 11, 2008

Is the answer really blowing in the wind?

As if the constant blather about "clean coal" weren't irritating enough, here's another energy "solution" that has me scratching my head: the flying turbine. Hyped by the Discovery Channel, the project is spearheaded by a dude named Fred Ferguson, a "Canadian engineer specializing in airships." He envisions:
"...launching millions of helium-filled aerial turbines to break the world's dependence on fossil-fueled energy. These turbines, held by tethers, would float up into high-wind conditions where their spin will power generators with electricity flowing through the tethers. By harnessing wind energy properly, the team believes they can reduce the amount of fossil fuel used today. According to their research, 20 percent of the power generated by global winds in a year could meet the world's annual energy needs six times over."
Now, though I love science, I'm not a scientist. What I don't know about science—and pretty much every other subject—could give chronic acid reflux to a black hole (interestingly, a Yale scientist is purporting that black holes have their limits). Still, this idea sounds pretty kooky to me.

Here's what a fellow on a bat Listserve I subscribe to wrote in a recent post to BATLINE:
Of all the farcical ideas we hear, this looks to be on the sillier extreme. Also somebody can't do sums. On inland sites you are lucky to get a wind factor of 20%, say 30% to prevent an argument. Therefore, to supply the UK average load, these would have to have a peak generating capacity of 20% of 40GW times 3.3 equals 26GW. This is about the off-peak "base load" which is already supplied by generators which can't be shut down, so these turbines would have to be shut down (how) in off-peak periods which makes a mess of the wind factor figure above.

In gales, these assemblies would have to be winched down into protective hangars to prevent damage. You can't "feather" a balloon like a turbine blade.

Elementary mechanics show that the torque generated by the horizontal axis turbine (old technology) has to be counteracted to stop the generator spinning as well. More helium balloons and guy wires. Helium leaks through plastic balloon material and would need to be piped up to replace this loss.

Say these were huge and could generate 20 KW, the UK would need 1,300,000 of these with hawsers, cables and pipes up to 300 feet. Apart from the visual amenity question, That would be a considerable human, let alone wildlife, hazard.

Reworking the figures for a more realistic practical wind factor (including gale shutdowns) of 10%, the UK would need more like 4,000,000 balloons, turbines, hawsers, cabling and hangars. And I haven't even started on public health and safety. :-)

David Brinicombe
North Devon, UK
I'm one of those people who "can't do sums," but D.B.'s argument sounds sound.

OK, by now (and probably way before now), you're probably wondering what the hell this photo has to do with turbines? It's Ferguson's turbine "tether test":
"The team tested the strength and conductivity of two competing tethers by using them to lift a string of cars, each car weighing about a ton. The cars were hung from 15-foot sections of steel, then Vectran tethers."
Does anyone else find it ironic that they used automobiles?

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