[QUOTE=Mangetout]
Also, there turbine blades are considerably flexible - they bend back a fair bit when operating at full capacity - a mesh cage to enclose them would have to be big enough to allow them the full range of flexibility. Also, it would make maintenance more difficult, would dramatically increase the cost, would make people consider them even more of an eyesore and would probably reduce their efficiency by attenuating the airflow.
[/QUOTE]
And they would look like big desk fans.
The sheer weight of a mesh cover would require a much larger and stronger structure and the wind resistance of a mesh structure that large would be tremendous in high wind situations.
I’m sure there are more practical methods of detering birds.
As I’m typing this I have the radio tuned to a BBC broadcast and they were discussing bats being endangered by wind turbines in Scotland. One possible solution that’s being considered in placing radar locator beacons on the turbine towers. It seems that bats avoid radar.
I’m curious as to how bats avoid radar. Are we saying that they are capable to perceiving radio waves? That would be quite remarkable.
Anyway, one drawback of placing radar beacons on wind turbines is that they would become even more of a nuisance to radar used for military, shipping and aviation purposes; I understand that there’s enough complaint already in this area, because wind turbines play havoc with radar even when they’re just innocently doing their job.
[QUOTE=Mangetout]
I’m curious as to how bats avoid radar. Are we saying that they are capable to perceiving radio waves? That would be quite remarkable.
Anyway, one drawback of placing radar beacons on wind turbines is that they would become even more of a nuisance to radar used for military, shipping and aviation purposes; I understand that there’s enough complaint already in this area, because wind turbines play havoc with radar even when they’re just innocently doing their job.
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I just caught the end of the interview, it was on but I wasn’t paying attention. The guy did say that they had recently discovered that there were bats in the vicinity of radar installations and preliminary research was showing that the animals seemed to avoid flying in the area of the beams when the sites were active. He also said they were still studying the phenomenon.
Mangetout, we almost double-posted. Since when can animals detect RF radiation?
A.R. Cane, we did double-post.
I’m sure it’s too simplistic an idea to be possible, but I can’t help wondering if it might only appear that bats are avoiding flying through radar beams when perhaps what they’re avoiding is flying in front of parabolic reflectors (which might be doing strange things to their sonar, even when they’re not transmitting any RF)
[QUOTE=Derleth]
Mangetout, we almost double-posted. Since when can animals detect RF radiation?
[/QUOTE]
Why not? Most animals can detect EM radiation of varying wavelengths. There’s no fundamental reason why it can’t happen.
On the other hand they said they avoid radar sites, not that they detect radar. There could be a secondary effect that scares them off. EG a particular sound, given their sensitive hearing.
Of course until we establish the exact mechanism we won’t know if radar is a longterm solution.
[QUOTE=essell]
Why not? Most animals can detect EM radiation of varying wavelengths.
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I assume you’re talking about the kind of EM radiation that we commonly call ‘light’? - if so, there’s quite a good reason for animals to be able to detect it , which I don’t think would necessarily hold true for other parts of the spectrum.
[QUOTE=Mangetout]
I assume you’re talking about the kind of EM radiation that we commonly call ‘light’? - if so, there’s quite a good reason for animals to be able to detect it , which I don’t think would necessarily hold true for other parts of the spectrum.
[/QUOTE]
What, like IR ?
I’m just saying it’s possible given that evidence has been produced which supports the theory. We’ll have to wait and see if they can produce proof.
[QUOTE=essell]
What, like IR ?
[/quote]
Still counts as ‘light’, as far as I’m concerned.
I’m not saying that there’s no way biological systems could ever perceive radio frequencies, it’s just that the apparatus they’d need to do it would be different, and there would have to be some reason why they did it that way. Light is useful for perception because its very short wavelength makes high-resolution imaging possible (useful for organisms to perceive objects that are on their own scale), as well as the fact that there’s lots of light about. The same is not necessarily true of the parts of the spectrum that we call ‘radio’.
I know my favorite Senator Ted Kennedy doesn’t like wind power!
[QUOTE=Sophistry and Illusion]
The bit of information I gleaned from this site that will no doubt stay with me the longest is that there is a place in Vermont called Grandpa’s Knob.
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In Boone, NC lots of folks used to climb up on Howards Knob. Coincidentally, it used to have a windmill on it. It was removed because of the noise.
[QUOTE=Derleth]
Mangetout, we almost double-posted. Since when can animals detect RF radiation?
A.R. Cane, we did double-post.
[/QUOTE]
Beyond the obvious example of light, radio length radiation, no matter the band, is perceived as heat on the skin.
[QUOTE=Queen Bruin]
Most of the invective against turbine farms IME tends to be aimed at the “but it’s an eyesore!” argument. I think they’re less of an eyesore than a coal plant, but what do I know? I like seeing the Tehachapi turbine farm on my morning jogs, though.
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I enjoy looking at the things. I am impressed with them. Invaribly, my first reaction is to think of Don Quoixte seeing multi armed giants in these windmills and rushing at them on the back of Rocinante (sp). I will stand there and visualize it. My next reaction is usually seeing them as H.G. Wells’ invaders from Mars because there is usually a long line of them. In eastern Colorado, farmers continue to farm beneath them.
A wildlife biologist I have talked to on occasion said that most people who point out the dangers of the turbines underestimate the adaptability of birds. He once said they are not the “bird brains” we often make them out to be.
Wind generation is not particularly cost effective, but adding a massive wire mesh around it would make it cost prohibitive even if it could be done effectively.
Wait! Put the wire mesh around the birds!
[QUOTE=VunderBob]
Beyond the obvious example of light, radio length radiation, no matter the band, is perceived as heat on the skin.
[/QUOTE]
That reminded me of the new, non lethal, weapon being tested by the U.S. Army.
"According to documents obtained for Wired News under federal sunshine laws, the Air Force’s Active Denial System, or ADS, has been certified safe after lengthy tests by military scientists in the lab and in war games.
The ADS shoots a beam of millimeters waves, which are longer in wavelength than x-rays but shorter than microwaves – 94 GHz (= 3 mm wavelength) compared to 2.45 GHz (= 12 cm wavelength) in a standard microwave oven."
From here: http://www.wired.com/news/technology/0,72134-0.html
Some sort of 1920’s Non-death Ray?
How about putting scarecrows on the tops of each tower, or even better one of those dancing wind sock men?
No more dead birds.
Case closed.