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Power Science

Radar Could Save Bats From Wind Turbines 116

Posted by kdawson
from the holy-pressure-drop dept.
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."
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Radar Could Save Bats From Wind Turbines

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  • More geeky (Score:2, Informative)

    by Lorens (597774)

    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?

    • Re:More geeky (Score:4, Interesting)

      by waferhead (557795) <waferhead.yahoo@com> on Wednesday July 22, 2009 @02:22AM (#28778745)

      ...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)

      • Re: (Score:3, Interesting)

        by c0p0n (770852)

        ...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.

        Dude, last thing you wanna do is to introduce instability on a 4m long blade by adding uneven weight.

        • by drinkypoo (153816)

          Dude, last thing you wanna do is to introduce instability on a 4m long blade by adding uneven weight.

          I probably shouldn't even justify this comment with a response, but I suspect you could put one on each blade to solve this problem. Or even better, just drill some hole in the end of the blade that would make some fucked up whining noise that would drive away bats. They can go eat bugs someplace else, it would be doing them a favor. The noise doesn't have to be pleasant.

          • by c0p0n (770852)

            Please read the parent post. He mentioned "blade". Individual blades are balanced. It's not just putting one radar each, the blade itself will be out of balance.

          • by Lorens (597774)

            One of the major objections to wind turbines is the noise they make, so anything that increases human-audible noise is out of the question.

        • by Golddess (1361003)
          Who said you only put the speaker on one blade? And even if you did, who said you couldn't do something to even out the weight on the other blades?
          • by c0p0n (770852)

            Who said you only put the speaker on one blade?

            The parent. As I said on another comment, blades are designed with a balance, individually. Plus even if you managed to put the thing on all the blades without altering both their individual balance AND the balance of the whole apparatus (which is what you mentioned), the resulting monster will be heavier thus spinning slower thus generating less power.

            The whole idea is laughable. Wanna go ahead with it, put a machine on a shed, end of story. Don't touch the turbines.

        • by eyrieowl (881195)

          I'd be surprised if they couldn't use some small, lightweight, piezoelectric transducers and keep the weight down while keeping the blade balanced. I'd be floored if this was impossible to engineer.

      • Re: (Score:3, Funny)

        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.
      • by hurfy (735314)

        Have they tried the cheesy little devices they sell on TV that you plug in to keep rodents and stuff out of your house? Keep It Stupid Simple...or something like that ;)

    • by siloko (1133863)

      why not set a device like that to send an amplified return?

      What, and make the bats DEAF!? Are you mad? I for one recommend turning off the wind as soon as bats are in range, that'll sort 'em!

    • Re: (Score:3, Interesting)

      by kinnell (607819)

      Instead of setting a radar to pump out radio waves, why not set a device like that to send an amplified return?

      Yes, let's make bats safer around wind turbines by jamming their sonar ;)

      • by MullerMn (526350)
        >Instead of setting a radar to pump out radio waves, why not set a device like that to send an amplified return?

        Yes, let's make bats safer around wind turbines by jamming their sonar ;)


        This is only effective for the underwater bats and wind turbines. TFA is about the overground kind.
      • by sjames (1099)

        And ampilfied return won't jam their sonar (unless it's excessively amplified), it will just make the prop "look" like a big scary object. Which, for a bat, it is.

    • Re: (Score:3, Insightful)

      by mrphoton (1349555)
      may be the radar is cooking the bats and that is why he is finding less of them!
  • by RsG (809189) on Wednesday July 22, 2009 @02:20AM (#28778741)

    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.

    • by shut_up_man (450725) on Wednesday July 22, 2009 @03:03AM (#28778931) Homepage

      You have to be very careful with sonic systems and creatures like bats and flying foxes. There are arguments afoot here in Australia that many sonic systems are waayyyyyy overpowered, causing bats to freak out and drop their young, or fall straight out of the sky and hurt themselves. Although technically this is a deterrent, it isn't really a good thing for the bats, which is the main point of the system. It might be like trying to keep humans away from an area by blasting our optic nerves with a near-blinding psychedelic lightshow and being a little miffed when the human falls over backwards in shock, tumbles down a hill and breaks their legs. Whoops.

      • by RsG (809189) on Wednesday July 22, 2009 @03:14AM (#28778977)

        Well, to play devils advocate for a minute, if the options are 1) no system, 40% casualties or 2) potentially dangerous system, 5% casualties, then I'd call option 2 an improvement, at least from a conservation standpoint. From an animal rights POV... not so great.

        Anyway, a bat repellent speaker doesn't absolutely have to be a brute force approach. What about broadcasting their own sonar waves back at them, such that they get the mistaken impression there's a solid object in their path, and avoid it accordingly?

        • Re: (Score:3, Interesting)

          by mad_minstrel (943049)
          Echolocation only works when and where you sent out the signal in the first place. A signal sent out from a different location than your current, at an unknown time carries little to no data. Therefore, I don't think you can really impersonate a bat and make it think there's a wall ahead.
          • by sorak (246725)

            Stupid question: Do bats have their own sonar "voice"? I.E., can a bat distinguish it's own sonar from someone else's?

            • Re: (Score:2, Interesting)

              by mad_minstrel (943049)
              Common sense suggests they can. If you go into a cave, or anywhere else there's an echo, you can easily distinguish your own voice, even in a crowd of echoes, because you know exactly what you shouted, including timbre, tone, content, rythm, little rasps, etc. You can also approximate when to expect an echo based on whan you shouted and the timing of your previous shouts. And a bat's hearing is a lot better than ours. Then again, whether bats can remember the particular way they had just screached is not ce
            • I would think so, have you ever watched millions of them fly out from under a bridge or cave? They seems to be able to distinguish their own "voice" from others. Come to think of it, maybe that is just timing. They know when they send a chirp, and can expect it back within a certain threshhold. So, basically, I dont know either. Please disregard what you just read...

        • This idea has enough merit to be worth exploring.

          It would require an active system that listened for each bat's vocalizations, then constructed a faux echo that would seem to come from the danger zone by using multiple speakers with carefully tuned amplitudes and delays. The audio pick-ups and speakers don't have to weigh very much or be very powerful: you are attempting to mimic the sounds reflected from a sheet of plywood. So several of these could be mounted within the blades without adding significant

      • by badfish99 (826052)
        So, given the choice between a sonic system with the power turned down to 15 milliwatts, or a 75 gigawatt radar, we should go with the radar?
      • by u38cg (607297)
        One would have thought that it would be sufficient to simply make a distinctive noise that over time, the bats and others can learn to recognise as a danger signal. I wouldn't have thought it necessary for it to be damagingly or unpleasantly loud.
        • by jklovanc (1603149) on Wednesday July 22, 2009 @05:04AM (#28779409)
          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.
          • by beelsebob (529313)

            Having said that, evolution can teach these things -- bats that naturally avoid that sound will be fitter for the environment, and more likely to have offspring.

            • Re: (Score:3, Insightful)

              by Yewbert (708667)

              Right enough in principle, but my first thought in response is, "yeah, like deer have evolved the behavior of not running out in front of cars." Compared to the actual number of bats, the evolutionary pressure exerted on tiny localized populations of them by not-very-numerous wind turbines is probably negligible.

          • by fracai (796392)

            Clearly you've never read the book "The 100th Bat".

          • by gplus (985592)
            That's exactly how brightly colored toxic jungle frogs have taught predators not to eat them. By killing off the stupid and the unlucky until they understand, that the bright colors mean "stay TF away from me".
      • by ukyoCE (106879)

        Foxes can fly???? I WANT ONE

    • by chaim79 (898507)

      It's probably to do with even propagation and loss of volume at distance, they could likely setup a radar transmitter in the middle of the wind farm and have a fairly even spread of radar pulses which evenly drive away the bats no matter the conditions, however with sound it will be effected by air density, wind direction and speed, etc and would be unlikely to have enough of an impact for one unit to cover a large area, they would likely have to set it up on each tower, which would increase the maintenance

    • by Yewbert (708667)

      Yah, like the businesses that blast classical music to keep teenagers from loitering around their parking lots at night,...

      I'm thinking Celine Dion. Drive me batshit, at least. Couldn't be too pleasant for the bats, either.

  • 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.

    • Re: (Score:3, Informative)

      by RsG (809189)

      Nah, nothing so direct.

      Radar pulse hits bat. Pulse generates heat, which produces sound waves, inside the bats head (sounds scary, but we've been operating proximate to radar machines since WWII). I've heard of this effect elsewhere, and can readily believe it might be more pronounced in bats than humans. Sound confuses/diverts/drives off bat - they're not sure how exactly, but any number of theories might explain this behaviour.

    • by adolf (21054)

      Ever heard [wikipedia.org] a meteor shower? I sure have.

    • by GrpA (691294) on Wednesday July 22, 2009 @02:43AM (#28778827)

      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

      • by Cryacin (657549)

        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.

        • by syousef (465911) on Wednesday July 22, 2009 @03:06AM (#28778949) Journal

          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!".

      • 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?

      • by badfish99 (826052)
        At last! Now I know why my tinfoil hat works!
      • No matter how small the radiation level is, it's like microwaving the bats.

        You call it hyper-radiation, I call it good cheap eatin'.

      • by radtea (464814)

        No matter how small the radiation level is, it's like microwaving the bats.

        That would be "like" as in "totally unlike", right?

        There's microwave radiation coming at us all the time from all kinds of sources, natural and artificial. So, being wilfully innumerate, you would say, "No matter how small the radiation level is, it's like we're being microwaved all the time!"

        The energy levels matter far more than the abstract category you assign. "Being microwaved" does not in itself cause harm. "Being microwaved

      • by relguj9 (1313593)

        Fortunately, Bat's can't sue people for exposing them to potentially dangerous levels of radiation, so it's probably just fine.

        Well said sir... we still really don't know what, if any, level of radiation is "safe".

        Some levels are considered safe, but just because we don't feel it or have immediate and obvious physical reactions doesn't mean it's safe.

        An interesting aside is that research has shown insects to be hundreds of times more resistant to radiation than mammals, so it's not surprising the insects aren't repelled by the radar.

      • by lennier (44736)

        Right, the Frey Effect. http://en.wikipedia.org/wiki/Microwave_auditory_effect [wikipedia.org]

        One thing I've always wondered: where did the long-held literal "tinfoil hat" meme really originate from, and when?

        I know everyone nowadays just uses it as a ha ha joke, but you know what's strange? I've never seen any research or reporting into precisely *which* patients first started seriously claiming this very literal set of symptoms: 'government mind control radiation in my brain which I'm trying to block with metal headgear

  • by djconrad (1413667) on Wednesday July 22, 2009 @02:41AM (#28778813)
    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 int
    • by MichaelSmith (789609) on Wednesday July 22, 2009 @03:01AM (#28778925) Homepage Journal

      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.

    • So you can protect possible targets from radar-controlled missiles by putting wind parks nearby?

      • by azery (865903)
        Now, I do not know about missiles, but wind turbines are a NATO concern: see for instance times online [timesonline.co.uk]
        Note that there are a number of mechanisms by which a wind turbine can interfere with primary radar. It is not only the fact that the energy reflected back on the wind turbine can trick the radar into thinking that he is seeing a genuine target. Wind turbines can by the way also impact secondary radar. See for instance Eurocontrol [eurocontrol.int] for more information.
  • 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
    • Re: (Score:1, Insightful)

      by Anonymous Coward

      Tell that to the 30 - 40% left alive! I'm sure they don't mind this solution.

  • by blind biker (1066130) on Wednesday July 22, 2009 @03:27AM (#28779031) Journal

    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.

    • Re: (Score:3, Informative)

      by Plunky (929104)

      Intrigued, I did some google searching about bladeless wind turbines and there are some links but perhaps not any actual real life comparisons. Do you know of any such?

      It seems to me though, from what I've heard recently, that a bladed wind turbine extracts power from the area that the blades cover whereas a rotating cylinder [ecofriend.org] would only extract power from the area near the cylinder, even if the cylinders were arranged in a more traditional configuration [ecofriend.org] and the catavent [bloggingthegreen.com] system would seem to intercept even l

      • Re: (Score:3, Informative)

        by blind biker (1066130)

        Here you an find a plethora of companies making such devices [ecobusinesslinks.com], I hope this helps.

      • Re: (Score:3, Informative)

        by drinkypoo (153816)

        Actually some bladeless turbines make power through some different principles than bladed ones. For example, the Savonius Vertical Axis Wind Turbine (the romans were using it to pump water using a screw) derives power from planetary swing-by, like a pelton wheel.

        A bladed turbine DOES only generate power from what the blades cover. However, it's from what they cover at any given time. They don't magically catch wind they're not in front of. It's very much based on their area (among other factors) and the sam

    • Bladeless designs may be becoming more popular for small, building-scale turbines, but they are not even on the horizon for large, commercial-scale turbines -- the sort that we could use for a large share of our electricity. As far as I know, every single utility-scale wind turbine on the market today uses a horizontal-axis design with 3 (or occasionally 2) blades. Their speed is lower in RPMs, but the tips are still moving around 150 mph.

      And birds and bats do indeed fly into these things or get injured
    • I'm wondering why the bats can't dodge these blades when they have no problem chasing fast-moving bugs around (if you've ever seen bats chasing bugs you know how fast they can turn). I can't imagine a bug creates a bigger sonar return signal than a wind turbine blade.
      • by prograde (1425683)

        err, RTFS. They don't hit the blades:

        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

      • 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 remov

  • what no thisisbatcountry tag?
  • 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.

  • 1. Locate wind farm.
    2. Fill sack with dead bats from the foot of the turbines.
    3. ??????
    4. Profit.

  • by feargal (99776) on Wednesday July 22, 2009 @07:08AM (#28779797) Homepage

    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.

  • 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!

  • "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,

    • by Chris Burke (6130)

      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.

      What's the fucking difference? In either case you have a pressure drop that exists only because the wind mill is sitting there. Whatever nit you're picking vis-a-vis what causes what, the bats and their exploded lungs don't care.

      Oh, but for the record,

  • 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.
  • Ping? (Score:3, Funny)

    by Misch (158807) on Wednesday July 22, 2009 @09:19AM (#28780633) Homepage

    Give me a ping, Vasili. One ping only, please.

  • 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.

  • 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 [wikipedia.org]
  • 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?

  • "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...

  • There goes the supply to my new franchise: KFB. Sigh, my Solar-Panel-Baked-Beetles didn't work out either.

  • as a result of this, maybe one day we can hopefully remove the rabies virus from the endangered species list.
  • 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?

  • 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, yo

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