Friday, 12 October 2012

Evidence of Ecological Impact?

I learned recently that the European Crane migration is changing. The vast skeins of birds that migrate from the Baltic and Finland across Germany are being disrupted, or at least disturbed, by the hundreds of "Wind Generators" now intruding into the landscape across their flightpath.

They've been observed veering away from clusters of turbines, generally turning back on themselves and circling to gain height and presumably find a route around the turbines. This, despite the fact they generally fly at an altitude that would keep them well above the top of the highest blades. They don't seem to fly over the turbines whether turning or not.

There are two possible explanations according to local observation and research. One is that the movement of the blades is detected by the birds and interpretted as a threat. The second, which I believe is more likely, is that the turbines are causing turbulence i the air above them. Danish research has shown that the 'downwind' turbulence affects the efficiency of turbines placed to leeward in any wind farm, but now it appears the moving blades are generating turbulence above them as well.

Coupled with the known vibration problem in the ground that drives small animals away from these things, I wonder how long it will be before someone does some serious research on this? It is known that the raptor birds are often killed by the turning blades. This is strange, because these birds have incredible agility in flight and eyesight that, in a human, would make telescopes redundant. So why are they not able to avoid the turbine blades? Could there be turbulence that prevents them making an evasion?

Personally I think this needs to be studied as a matter of urgency - preferably before any more of these monsters are erected. The Law of Unintended Consequences suggests that if they are causing a problem for animals, raptors and migratory birds we can expect to see some unwanted effects further down the line unless we are very, very careful.

One thing I learned a long time ago, is that small changes can have large impacts and sometimes the impact is so undesirable it is better not to make the change.

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