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Print 38 comment(s) - last by The Raven.. on Nov 4 at 10:28 AM


  (Source: Treehugger)
Raising the cut-in speed to 11 mph could result in as much as a 93 percent reduction in bat-turbine related deaths

Wind power has become an important competitor in the race for clean energy, but like many newer developments, it needs some work. One issue associated with wind power is bat and bird-related fatalities due to the spinning blades of the turbines. However, researchers may have solved this problem with a slight change in speed

Edward Arnett project leader from the Bat Conservation International in Austin, Texas, along with John Hayes, co-author of the study from the University of Florida, have studied bat fatalities associated with wind turbines and concluded that altering the speed slightly would reduce a large percentage of these deaths.

Wind turbines within the United States are programmed to start producing power when wind speed reaches 8 or 9 mph. The speed at which wind turbines begin producing power is the cut-in speed, and those with a low cut-in speed tend to run more often than those with a high cut-in speed because they begin running at lower speeds in the first place. 

Arnett, Hayes and their research team recorded bat fatalities while observing 12 out of 23 turbines at the Casselman Wind Project in Somerset County, Pennsylvania. They stayed for 25 summer and fall nights in 2008 and 2009 (because wind speeds are low this time of the year), and found that the less time a wind turbine is running, the better because bats cannot be harmed by blades that aren't in motion. Following this logic, Arnett suggests raising the cut-in speed of wind turbines to 11 mph, which would result in a reduction of bat fatalities by approximately 44 to 93 percent and an annual power loss of less than one percent. 

"This is the only proven mitigation option to reduce bat kills at this time," said Arnett. "If we want to pursue the benefits associated with wind energy, we need to consider the local ecological impacts that the turbines could cause. We have already seen a rise in bat mortality associated with wind energy development, but our study shows that, by marginally limiting the turbines during the summer and fall months, we can save bats as well as promote advances in alternative energy."

Arnett notes that reducing bat fatalities is essential because bats help with pollination and pest management, making them an important part of ecosystem health nationwide. 

"Rarely do you see such a win-win result in a study," said Arnett. "There is a simple, relatively cost-effective solution here that could save thousands of bats. This is good news for conservation and for wind energy development." 

This study was published in Frontiers in Ecology and the Environment on November 1.



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This is news?
By The Insolent One on 11/2/2010 11:37:18 PM , Rating: 2
Really?




RE: This is news?
By quiksilvr on 11/3/2010 12:03:24 AM , Rating: 3
Yeah, its showing how we made wind turbines slightly more useless to save the lives of bats.


RE: This is news?
By Omega215D on 11/3/2010 2:31:28 AM , Rating: 5
So much for getting rid of my mother-in-law....


RE: This is news?
By MrBlastman on 11/3/2010 9:30:29 AM , Rating: 2
Why? Is she driving you... "batty?"


RE: This is news?
By MrTeal on 11/3/2010 11:10:50 AM , Rating: 1
See, you wouldn't have gotten downrated if you would have tossed a "Yeeeaaaaaaaahhhhh" at the end of that. It's a must.


RE: This is news?
By borismkv on 11/3/2010 1:07:35 PM , Rating: 2
Maybe a Wokka Wokka Wokka or two? Sheesh. Everyone forgets about the Fozz...


RE: This is news?
By sleepeeg3 on 11/3/2010 10:47:05 PM , Rating: 2
Lol!

I'll give TK a break here, since I just read about a more practical method of... er... not killing bats by wind turbines.
http://www.scientificamerican.com/article.cfm?id=c...
Paint them purple. Keeps away the insects that are attracted to these white, 40-story monstrosities like a moth to a... turbine. No insects = no food for bats = less bat deaths.


RE: This is news?
By TheHarvester on 11/3/2010 7:55:40 AM , Rating: 3
This article might actually be useful if some context was given for the actual number of bats that were killed during the period of observation. Reducing the cut-in wind speed reduced the number of bats killed from... 3 to 1? 100 to 6? If 100 bats were dying during a summer by these things, then maybe there's something to talk about here in terms of ecological impact, but if the number of bats that died was like 10, knowing that allows us to effectively weigh the cost of a one percent loss in energy capture and decide the ten bats can snuff it and not jeopardize integrity of our ecosystems.


RE: This is news?
By Tiffany Kaiser on 11/3/2010 9:47:10 AM , Rating: 2
The study said Arnett and Hayes recorded bat fatalities for 25 summer nights and 25 fall nights in 2008 and 2009. They found at least one fresh bat carcass every night that the turbines were fully operational as opposed to when the cut-in speed of the turbines increased to 11-14.5 mph, thus running for a shorter period of time. The mortality rate was approximately 3.6-5.4 times higher with a lower cut-in speed.

These were the only figures I could dig up. Hope this helps.


RE: This is news?
By 67STANG on 11/3/2010 11:13:26 AM , Rating: 2
How is this a valid study? Bird, bats, etc. fly into objects all the time. Who's to say that if the turbines they observed were cell towers, they wouldn't have flown into them accidentally and died? I'm sorry, but this is bunk. The same people that do these studies also state that turbines kill birds, when 20x more bird deaths are caused by them flying into sky scrapers.


RE: This is news?
By The Raven on 11/3/2010 3:32:55 PM , Rating: 2
Umm... I'm not down with this hubub either, but the study is not bunk based on your objections.

quote:
The same people that do these studies also state that turbines kill birds


Your comment makes it sound like you think that since more birds are killed by skyscrapers than windmills, you don't believe that bats can be killed by windmills. Windmills do kill birds. And bats too. Unfortunately they don't kill politicians.

And if you know anything about bats it should be the fact that they are blind (hence the saying "blind as a bat"). I think it would be a piece of cake to echo-locate a stationary cell tower as opposed to a moving windmill blade.

So unless you have any other objections, this study seems just fine.


RE: This is news?
By FaaR on 11/4/2010 8:29:05 AM , Rating: 2
Bats use echo-location not because they're blind (which they in fact aren't, seeing as they got eyes), but because bats hunt at night, when there's not much light to be had to see by.

So in other words, the saying which you quote, is - like so many other sayings - nothing but a big ol' load of crap.


RE: This is news?
By The Raven on 11/4/2010 10:10:55 AM , Rating: 2
You are right. I didn't mean for the hyperbole to come off that way. But it must be noted that bats don't have great vision and certainly don't rely on it at night (which is when they are awake). And when they do use their vision, it is poor (though variances exist depending on the species).

And it should also be noted that just because an animal has eyes doesn't mean that it can see. I think moles can see (poorly) but there are other species of animals that live underground and they have non-seeing eyes. Truly blind.
I think they are caught in a point of evolution where they haven't yet "cast off" their eyes.

But my point was that a bat might have issues with these windmills due to the fact that they rely heavily on echolocation. And though they are extremely precise, that skill would be compromised if they were to locate the blades of a quickly spinning windmill.

Point is: this study isn't a "big ol' load of crap" ;-)


RE: This is news?
By The Raven on 11/4/2010 10:28:59 AM , Rating: 2
quote:
For bats, vision is important for foraging and homing, and for predator avoidance. Mesopic vision (at light levels that stimulate both the rods and the cones) is particularly relevant at dusk and dawn and on brightly moonlit nights. For flower-visiting and nectar-feeding bats like those studied here, UV vision should increase foraging success, as many flowers visited by bats show UV reflection.


http://www.sciencedaily.com/releases/2009/07/09072...

This looks like it should be the definitive word that bats aren't as blind as I thought they were.


RE: This is news?
By kattanna on 11/3/2010 11:35:22 AM , Rating: 2
http://www.theresilientearth.com/?q=content/wind-p...

quote:
While the total number of birds killed in the US each year fluctuates, Michael Fry of the American Bird Conservancy estimates that US wind turbines kill between 75,000 and 275,000 birds per year.


the article also talks about previous studies on bats

quote:
Blade rotational speed was a significant negative predictor of collisions with turbine blades, suggesting that bats may be at higher risk of fatality on nights with low wind speeds


but also this

quote:
This followed previous research that showed that bats can have their lungs ruptured from the sudden low pressure of passing turbine blades: the bats are actually drowning in mid-air. It is not necessary for the bats to collide with the turbines, bats don't even need to come in physical contact with the turbine blades. A blade passing close by is enough to be fatal—an unexpected hazard that was previously unsuspected.


its good to see more sites talk about this issue. I want to see the enery field be on a level playing field and if any other energy producer was the product of such mass death there would be howls from the econuts. yet wind has seemingly been getting a free pass, even when it comes to killing endangered species

quote:
Yet a July 2008 study of the wind farm at Altamont Pass, California, estimated that an average of 80 golden eagles were killed there by wind turbines each year.


wind power has its place, like most other forms, but it is FAR from the "magic bullet" a lot of greens think it is


RE: This is news?
By FaaR on 11/4/2010 8:32:16 AM , Rating: 2
Wind turbines should preferably be placed out at sea where winds are stronger and more prevalent than over land, or in high, mountainous regions where few birds (and virtually no bats, I presume) fly around to get killed by these things.


but...
By invidious on 11/3/2010 9:18:13 AM , Rating: 5
Technically killing the bats reduces the carbon footpring of the bat, making the turbines even greener than anticipated.




I propose to raise it to 120 mph
By Kakao on 11/3/2010 12:38:08 PM , Rating: 2
so the blades will never turn and there will be no dead bats




By SlyNine on 11/3/2010 3:11:11 PM , Rating: 2
Unless you live here in Cheyenne W.y. I kid I kid.


bats have it rough
By chromal on 11/3/2010 1:50:20 AM , Rating: 2
With white nose syndrome wiping out bats wholesale, and their slow reproduction rate of one 'pup' per female bat per year, I guess they're worried about any practically preventable bat kills in the coming years.

http://en.wikipedia.org/wiki/White_nose_syndrome




By frobizzle on 11/3/2010 9:30:56 AM , Rating: 2
quote:
found that the less time a wind turbine is running, the better because bats cannot be harmed by blades that aren't in motion.

And, let's see...parked cars cause less fatalities than moving cars.

Scientists discover drinking water is less intoxicating than drinking beer.

And this just in....jet travel to Europe faster than going by sea.




my 2 cents
By gjk392 on 11/3/2010 12:52:02 PM , Rating: 2
What about all the insects these things kill? Would it stand to reason that we would need less bats and birds to control the insect population?

I usually find one dead bird a year that flew into one of my windows.And it is always the same window. I guess i should remove the window and spend more money in energy costs.




Solid "Blades"?
By SiliconJon on 11/3/2010 1:28:53 PM , Rating: 2
I haven't seen anything yet regarding thoughts on making the blades on wind turbines solid, or least appearing more solid to our flying cohorts.

Granted this may be significantly uglier and include a great deal more material, though some inginguity may minimize those trade offs.




My cat eats more birds/bats than a wind turbine
By undummy on 11/2/10, Rating: -1
RE: My cat eats more birds/bats than a wind turbine
By ElderTech on 11/2/10, Rating: -1
By cmdrdredd on 11/3/2010 12:08:20 AM , Rating: 1
Stop being a bleeding heart liberal for a second and realize WE are more important than a few bats and such. Maybe then you'll stop crying every time some wacko claims a couple useless animals died through no fault of ours.


By EndlessChris on 11/3/2010 1:17:04 AM , Rating: 2
and your cat is part of the problem. Outdoor cats are a completely wasteful and unnecessary source of predation. They have a huge impact on native natural wildlife populations. There is little we can do about that though, as regulating pet care would be impossible. This is something that can be done easily and have very little impact on our energy production. I don't see why it would be considered a bad idea.


By MrBlastman on 11/3/2010 9:34:03 AM , Rating: 4
You might think outdoor cats are completely wasteful and I wholeheartedly disagree. I completely see a purpose for my cat roaming outside, killing mice, eating birds, chasing squirrels and most importantly, eating bugs... lots and lots of bugs. The end result of my furry friend is reduced pests coming into my home. It is a wonderful relationship we have.

The icing on the cake, of course, is when my cat leaves a dead bird or mouse on my doorstep. It makes me feel good everytime I see it.

I'd much rather have my cat doing their job than my wife constantly freaking out and bothering me about foreign intruders in our house.


By olafmetal on 11/3/2010 10:39:52 AM , Rating: 2
I enjoy when my pet Coyote eats peoples pet cats.


By MrBlastman on 11/3/2010 11:52:48 AM , Rating: 1
I enjoy when I get to plug a Coyote with my Steyr AUG. .223/5.56 mm--the great problem solver, used all around the world for the last several decades. :) The best part is, per my county ordinances, it is perfectly legal to do so, even though I live in a major city.


By TheRoadWarrior on 11/3/2010 2:07:43 PM , Rating: 2
They leave it at the doorstep only because they can't open the door by themselves so they can bring it into the house and finish it ;-)


By smartalco on 11/3/2010 1:48:55 AM , Rating: 2
quote:
And from one of my family members who is an environmental biologist working with oil companies to maintain the raptor population in the northern plain states

Wat?

I'd also be curious as to how exactly they decided that increasing the start speed from 8mph to 11mph only decreased production by 1%


By chromatix on 11/3/2010 6:40:52 AM , Rating: 2
Raptor: bird of prey.

I suspect that the logic includes the low yield of turbines running in low wind speeds. Less wind, less power available. Cutting out the lower speeds could indeed have a smallish effect on total power generation while having a disproportionate benefit in terms of reduced duty cycle.


By Calin on 11/3/2010 7:52:35 AM , Rating: 2
First of all, depends very much on the wind speed in the area. The energy contained in wind depends with the cube of its speed (energy is half the mass multiplied by the speed squared, and mass thru turbine working area varies with velocity).
Assuming the efficiency of the turbine is the same at all speeds, you have the power available at 8, 9, 11 and 50 mph wind speed growing about from 1 to 1.4 to 2.6 to 244 (that is, a wind turbine that is equally efficient at 8mph and 50mph wind speed would produce about 250 times more power at 50 mph wind speed). Realistically, wind turbines are not really optimized for the very low wind speed (as there isn't much energy to be harnessed anyway) and the friction losses are disproportionate at very low wind speeds, and you get a lower power at 8mph wind speeds that what the above ratio suggests.
So, increasing the cut in speed in many cases might be almost free of energy cost, and it might reduce the working time and so increase the maintenance intervals. And if this 90+ reduction in bats killed is true, this might allow installation where a higher total efficiency turbine would be forbidden.


By Calin on 11/3/2010 7:52:47 AM , Rating: 2
First of all, depends very much on the wind speed in the area. The energy contained in wind depends with the cube of its speed (energy is half the mass multiplied by the speed squared, and mass thru turbine working area varies with velocity).
Assuming the efficiency of the turbine is the same at all speeds, you have the power available at 8, 9, 11 and 50 mph wind speed growing about from 1 to 1.4 to 2.6 to 244 (that is, a wind turbine that is equally efficient at 8mph and 50mph wind speed would produce about 250 times more power at 50 mph wind speed). Realistically, wind turbines are not really optimized for the very low wind speed (as there isn't much energy to be harnessed anyway) and the friction losses are disproportionate at very low wind speeds, and you get a lower power at 8mph wind speeds that what the above ratio suggests.
So, increasing the cut in speed in many cases might be almost free of energy cost, and it might reduce the working time and so increase the maintenance intervals. And if this 90+ reduction in bats killed is true, this might allow installation where a higher total efficiency turbine would be forbidden.


By 91TTZ on 11/3/2010 10:25:35 AM , Rating: 2
quote:
Your insensitivity to the natural world is typical of someone uneducated in the impact it has on our existence. Having worked in the petroleum and food business for a long time, I've been exposed to a wide variety of both sides of the issue. I've seen the damage hazardous material pollution can do to people and their living environments, as well as the impact it can have on more natural surroundings and the wildlife population.


^Listen to this guy, he knows what he's talking about. He's the inventor of the peanut butter and petroleum jelly sandwich.


By The Raven on 11/3/2010 3:52:44 PM , Rating: 1
I'm not sure why you were downrated. This actually sounds reasonable. If there are too many bird deaths because of windmills, then rectify it in other ways. Kill/curb population of the number of cats out there since they are the number one killer of birds. Declare feline hunting season open or what not. Hide yo' tabbys, hide yo' calicos, and hide yo' siamese, 'cuz they huntin' everybody out here!

So if there are (hypothetically speaking) 5 bird deaths due to windmills every hour and 1000 due to a cat, then kill a cat every 200 hours to balance out the amount of death.

Same should apply to bats. But I'm not too familiar with what are the big killers of bats. So we could focus on bat breeding programs in addition to/instead of killing a predator.

There are too many cats out there as far as I can tell. I mean, even Bob Barker gets it (err...got it).

But of course using less power in the first place will save bats, birds and a whole lot more.


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