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Radar Could Save Bats From Wind Turbines
mknewman sends in an MSNBC piece on a promising way to keep bats from straying into wind farms — by using radar. "Bats use sonar to navigate and hunt. Many have been killed by wind turbines, however, which their sonar doesn't seem to recognize as a danger. Surprisingly, radar signals could help keep bats away from wind turbines, scientists have now discovered. ...some researchers have raised concerns that wind turbines inadvertently kill bats and other flying creatures. ... The bats might not be killed by the wind turbine blades directly, but instead by the sudden drop in air pressure the swinging rotors induce... The researchers discovered that radar helped keep bats away, reducing bat activity by 30 to 40 percent. The radar did not keep insects away, which suggests that however the radar works as a deterrent, it does so by influencing the bats directly and not just their food. Radar signals can lead to small but rapid spikes of heat in the head that generate sound waves, which in turn stimulate the ear. A bat's hearing is much more sensitive than ours. It may be so sensitive that even a tiny amount of sound caused by electromagnetic radiation is enough to drive them out."
Why not just use a direct sonic system, instead of using radar pulses to generate sound indirectly? Bats have very sensitive hearing, and there are probably ways of generating noises that keep them away, either by interfering with their sonar, or simply generating unpleasant aural input. I seem to recall ultrasonic systems devised for driving off human beings, or other animal species, so it's a demonstrated concept.
Of course, such a system could exist and use more energy, or cost more to implement. Nothing in the article about that however.
Erotic is when you use a feather. Exotic is when you use the whole chicken.
...Or for a tad more energy efficiency vs. using RADAR to heat up the bats skull to produce sound, put some SPEAKERS on the bloody blades.
Or air activated "deer warnings" on the blades, except ones that work for bats.
(Dangerously assuming those worked for Deer, but you get the idea)
How much damage can a radar-equipped bat do?
No, they are actually referring to the radiation causing sound inside the bat's heads...
They figured this out decades ago when they heard sound coming from radar systems that were appropriately modulated.
Then a bunch of nerds (they called them "Air Control Tower Operators" back then) figured they could modulate voice into a radar dish, point it at someone walking over the other side of the field and they would suddenly hear voices in their head... Which I'm sure was really funny for a while.
It's even patented. Microwave induced audio.
But it causes sound by heating, so basically, regardless of the level of radiation, heat generation is needed to induce sound. Consider that for a moment and also that it's microwave radiation.
No matter how small the radiation level is, it's like microwaving the bats.
Fortunately, Bat's can't sue people for exposing them to potentially dangerous levels of radiation, so it's probably just fine.
GrpA
Enjoy science fiction? "Turing Evolved" - AI, Mecha, Androids and rail-gun battles. What more could you want?
I can only begin to imagine the complications of wind farms interfering with military radars which scan much closer to the Earth's surface
Turbines are a problem when they reflect signals back to the radar with sufficient Doppler shift to get past filters for static reflections. The emission from this device won't be near the frequency of the military radars (you would think) so there is unlikely to be a problem.
http://michaelsmith.id.au
Fortunately, Bat's can't sue people for exposing them to potentially dangerous levels of radiation, so it's probably just fine.
Damn! I was about to go out and patent a new set of completely wireless headphones to sell to the Mac crowd.
You still can. Mac zealots have proven they'll take any amount of abuse and still defend Apple's decisions.
"Well yes, they've given me cancer and brain damage (fulfilling the "Think Different" slogan I might add!), but that's the trade off if you want cool stylish things. Anyway the PC version produces twice as much cancer, is buggy, and isn't nearly as cool. This is from Apple so it just works!".
These posts express my own personal views, not those of my employer
The trend is towards larger and slower wind turbines, because they are more efficient. At the same time, slower moving blades are safer (actually, with contemporary wind turbines, completely safe) for birds and bats. Also, bladeless designs are becoming more popular, again because they are more efficient. These bladeless designs are completely safe, regardless of size.
"The agriculture ministry is not in charge of Gundam" - Japanese ministry official.
For a bat to learn that something is dangerous it must encounter the danger. The problem is the only way a bat would know a wind turbine is dangerous is by dying. I can see it now. The bat thinks "that weird noise is connected to that dangerous place. I guess I should avoid it in the future" as it plummets to the ground due to burst lungs. Even if one bat could learn the danger and survive, every other bat would have to go through the same process. When we use distinctive noises to ward off animals we use their already known distress calls. There is no learning on the part of the animal.
All they have to do is build giant concrete walls around the turbines, and stick a roof over the top. So long as they don't put any windows in, it should be safe for bats and birds.
It's crazy that they haven't thought of doing this.
"A goldfish was his muse, eternally amused"
Can't we just put some baseball cards in between the blades? It works on my bike - there are never any bats caught in there.