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Radar Could Save Bats From Wind Turbines

Posted by kdawson on 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."

28 of 116 comments (clear)

  1. More geeky by Lorens · · Score: 2, Informative

    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?

    1. Re:More geeky by waferhead · · Score: 3, Interesting

      ...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)

    2. Re:More geeky by c0p0n · · Score: 2, Interesting

      ...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.

      --

      Your head a splode
    3. Re:More geeky by kinnell · · Score: 2, Interesting

      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 ;)

      --
      If I seem short sighted, it is because I stand on the shoulders of midgets
    4. Re:More geeky by mrphoton · · Score: 2, Insightful

      may be the radar is cooking the bats and that is why he is finding less of them!

    5. Re:More geeky by HamburglerJones · · 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.

  2. Potentially silly question... by RsG · · Score: 5, Interesting

    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.
    1. Re:Potentially silly question... by RsG · · Score: 4, Interesting

      Not the issue you might think it is. Bat's hearing includes a whole range of sounds outside of what we mere humans can hear. You could probably make an ultrasonic system that sounds like fingernails on a blackboard to bats, and nothing at all to us.

      --
      Erotic is when you use a feather. Exotic is when you use the whole chicken.
    2. Re:Potentially silly question... by shut_up_man · · Score: 5, Informative

      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.

    3. Re:Potentially silly question... by RsG · · Score: 3, Interesting

      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?

      --
      Erotic is when you use a feather. Exotic is when you use the whole chicken.
    4. Re:Potentially silly question... by mad_minstrel · · Score: 3, Interesting

      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.

      --
      May the source be with you.
    5. Re:Potentially silly question... by mad_minstrel · · Score: 2, Interesting

      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 certain. But if they could, it would probably raise their survivability quite a bit, so I would expect mother nature to have given them that ability, at least to a certain extent. Someone probably already studied this.

      --
      May the source be with you.
  3. Re:Since when does EMR produce sound? by RsG · · Score: 2, Informative

    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.

    --
    Erotic is when you use a feather. Exotic is when you use the whole chicken.
  4. Military applications by djconrad · · Score: 4, Funny

    How much damage can a radar-equipped bat do?

    1. Re:Military applications by RsG · · Score: 3, Funny

      Not nearly as much as one equipped with napalm. I only wish I was joking...

      --
      Erotic is when you use a feather. Exotic is when you use the whole chicken.
    2. Re:Military applications by apoc.famine · · Score: 2, Interesting

      No, he's not joking.

      --
      Velociraptor = Distiraptor / Timeraptor
  5. Re:Since when does EMR produce sound? by GrpA · · Score: 4, Interesting

    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?
  6. I don't like the sound of this... by Schrockwell · · Score: 2, Informative

    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

    1. Re:I don't like the sound of this... by MichaelSmith · · Score: 4, Informative

      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
  7. Re:Since when does EMR produce sound? by syousef · · Score: 3, Funny

    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
  8. It's going to be unnecessary by blind+biker · · Score: 4, Interesting

    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.
    1. Re:It's going to be unnecessary by Plunky · · Score: 2, Informative

      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 would only extract power from the area near the cylinder, even if the cylinders were arranged in a more traditional configuration and the catavent system would seem to intercept even less wind

    2. Re:It's going to be unnecessary by blind+biker · · Score: 2, Informative

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

      --
      "The agriculture ministry is not in charge of Gundam" - Japanese ministry official.
    3. Re:It's going to be unnecessary by drinkypoo · · Score: 2, Informative

      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 same is true of VAWTs.

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
  9. Bats are not linked. by jklovanc · · Score: 5, Insightful

    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.

    1. Re:Bats are not linked. by Yewbert · · Score: 2, Insightful

      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.

  10. The solution is simple by feargal · · Score: 3, Funny

    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"
  11. Ping? by Misch · · Score: 2, Funny

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

    --

    --You will rephrase your request for me to go to hell. Goto statements are not acceptable programming constructs