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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."
The guy who noticed this was using a device that detects the ultrasonics emitted by bats.
Instead of setting a radar to pump out radio waves, why not set a device like that to send an amplified return?
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.
From TFA:
"It may be so sensitive that even a tiny amount of sound caused by electromagnetic radiation is enough to drive them out."
Surely if it's sound based, they're reacting to the sound produced by the equipment, not some sort of weird sonic biproduct of light.
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How much damage can a radar-equipped bat do?
The rise of wind farms has already led to complications with current NEXRAD weather radars, and these radars don't even scan that close to the surface â" 0.5 degrees is the lowest tilt. I can only begin to imagine the complications of wind farms interfering with military radars which scan much closer to the Earth's surface.
Now they want to point some sort of radar at a complicated source of ground clutter that's already difficult to detect and remove? I don't see how that's going to fly (no pun intended).
For more information: http://www.roc.noaa.gov/windfarm/how_turbines_impact_nexrad_user.asp
Fortunately, Bat's can't sue people for exposing them to potentially dangerous levels of radiation, so it's probably just fine.
What would Batman do?
Science advances one funeral at a time- Max Planck
This does not solve the problem.By decreasing activity by 30% to 40% will only decreas the deaths by that percentage. That is still quite e few dead bats
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.
and just look at how cute they can be!
what no thisisbatcountry tag?
Slavery is the legal fiction that a person is property; A Corporation is the legal fiction that property is a person.
nuclear powered radar
Radar signals can lead to small but rapid spikes of heat in the head that generate sound waves, which in turn stimulate the ear.
No wonder the doctors always say they can never find the microchip putting voices in my head.
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.
"some researchers have raised concerns that wind turbines inadvertently kill bats and other flying creatures."
Do they think that some wind turbines kill bats and other flying creatures DELIBERATELY???
I remember going in to work and a bird flies from one side of the road to the other. The other side of the road has a wall on it and the bird misjudges its trajectory. And slams straight into the wall.
So we should knock down all walls?
1. Locate wind farm.
2. Fill sack with dead bats from the foot of the turbines.
3. ??????
4. Profit.
You feel sleepy. Close your eyes. The opinions stated above are yours. You cannot imagine why you ever felt otherwise.
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"
It doesn't have to encounter a cat to know to avoid cats. It will avoid a cat on its first encounter.
I will apply to be a Windmill Animal Safety Monitor, and am looking forward to completing my WASMD certification to do exactly that! This must be one of those jobs that can't be outsourced!
My broom, bat eating animal suit, and firecrackers are ready!
This is my sig.
"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"
I am confused. The wind flowing over the blade induces a low pressure and causes the blade to move. The blade does not induce a low pressure from it's own movement. It seems to many people are thinking of these like propellers on a airplane or a window fan.
Maybe that's why there is so much opposition. People hear "wind generator" and they think that's what they do, generate wind. It's the government plan to control weather but utilizing huge over-sized oscillating fans.
Anyway, I think TFA has it backwards. The shape of the blades results in a sudden drop of air pressure when wind flow over them thereby inducing movement. It's not the movement of the blades inducing the low pressure and causing wind.
I read Slashdot for the headlines, because the headlines, unlike the articles, are usually original and never duplicated
You all are missing a simple fact. They are bats! Just let them die. On the other hand... The bat "herd" is thinned by the turbines. The portion of the gene pool removed is the portion more apt to fly into moving objects. By doing so, we will make the bat population more advanced.
There is always a point (nearest approach and furthest approach) where even under worst case (directly from the side) the turbine imparts 0 Hz shift because it's velocity component towards the radar is 0. From other angles the blades move even slower. I doubt that the blades get through doppler filtering. They just aren't moving that fast. Most helicopter blades (except canceled Comanche) show up amazingly well on radar assuming that they are high enough to avoid ground clutter. I suspect that these turbines are:
1) High enough to avoid ground clutter -- easily trackable
2) Lost in ground clutter -- easily ignoreable from a navigation standpoint.
hire back all the men/women that lost their job when the wind turbines were completed, have them take down every single waste of government subsidized pieces of junk, and voila! Solves multiple problems. No more ugly wind turbines killing bats and crapping up the horizon.
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Why not use something like those little fan/whistle things they sell to put on your car? The ones that emit a high pitched noise that deters deer and other animals from approaching the road when you drive by. There's obviously already wind available to generate the sound, so just tweak it to emit a pitch only the bats can hear. Zero extra energy requirement.
Many have been killed by wind turbines
Many my ass. The smart ones will learn, the dumb ones won't. How many bats die due to starvation and predation each year compared to the apparently "many" that die from wind turbines? Should we assign a bat guardian to each individual bat to make sure they're safe and spoon feed them if they get too hungry? Come on.
Note they chose to say it uses "radar" rather than "microwaves." A little less scary sounding perhaps?
You should only call it RADAR if you're using it for RAdio Detection And Ranging - not for making bats scream "NO! Get out of my head Charles!"
Also, it sounds like it works a lot like this system - are they sure they're not making the whole bat feel hot?
http://en.wikipedia.org/wiki/Active_Denial_System
Prisencolinensinainciusol. Ol Rait!
All this worrisome talk about green energy killing birds, one question remains: why can't we put screens around these turbines to keep birds from flying into them? This won't solve the air pressure injuries with bats, but with birds why can't a screen solve it?
Likewise, why can't a screen solve the problem with tidal turbine generators grinding up fish, too?
Kriston
"Radar signals can lead to small but rapid spikes of heat in the head that generate sound waves"
The head that makes sound waves as opposed to the other head... Well, you get the point...
http://www.dieblinkenlights.com
There goes the supply to my new franchise: KFB. Sigh, my Solar-Panel-Baked-Beetles didn't work out either.
Table-ized A.I.
as a result of this, maybe one day we can hopefully remove the rabies virus from the endangered species list.
"You can't really dust for vomit" --Nigel Tufnel
RPM or Angular Speed are not the issue with propellers-- its a factor but it is not at all the problem. The center slowly spins around and the farther out from the center the faster it moves. Does not really matter much if you are moving 1 RPM or 100RPM. On the shaft, it is moving as little as possible-- theoretically, an exact center point (a point has no dimensions) would not move at all no matter the RPM. People who were able to play on the playground Merry-go-Round or "Twister" before lawsuits removed them have a 1st hand experience with Angular Velocity and Centripetal force (google those.) Further out from the center the more velocity you get.
The problem with a wind generator is not "slow" but how long the blades are. Bats and birds probably do not have troubles with the 1st few meters which are slow moving; its the 100s of kph speed of the rest of the blade.
To put it another way, a 1RPM blade moves as slow as a second hand of a clock. A second hand seems slow because its only a few cm long. Make that second hand 1 km long and then the tip of it travels 6.3 km in a minute while the 1st few cm are still the "slow" moving second hand. BTW, that tip would be moving at 378kph or 235mph.
a fun question:
At what diameter does the blade length diminish the power?
When the tips are causing sonic booms? don't spoil the question by going into tensile strength or temperature. Does it ever?
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On some futurist show a company invented square, vertical mindmills that birds and bats could see and thereby dodge. They were also more efficient.
Anyone else hear of those and can provide a link?
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The main problem here is that humans want to put windfarms on top of mountains and especially on top of ridgelines.
This is because ridgelines are very good spots for catching the wind, but they also generate their own wind environments from various factors such as ambient temperature, humidity, radiant heating and more. This confluence of factors all combines to draw insects up into the air along ridgelines. If you were to aim a sufficiently sensitive radar as any given ridge in the spring/summer/fall, you'd find it swarming with billions of bugs.
Ridges and mountaintops are the Chiropteran equivalent of the all-you-can-eat buffet.
And we're planning on installing woodchippers in the front door.
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