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  (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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My cat eats more birds/bats than a wind turbine
By undummy on 11/2/2010 11:09:14 PM , Rating: -1
1% loss in thousands and thousands of turbines isn't worth a few birds/bats. Just kill some cats instead and give us the electricity. Or, we can make up for that 1% loss with a couple big coal burning power plants which kinda defeats the purpose of utility scale wind turbines.

Skyscrapers and buildings kill more birds around here. Birds are as 'blind as a bat' and crash into windows all the time.

Anyone think that maybe the byproduct 'pollution', by all the fuel burning power-plants, kill even more?

Maybe we should just outlaw wind turbines all together. Being an eco-greenie is so overrated.




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.


"So if you want to save the planet, feel free to drive your Hummer. Just avoid the drive thru line at McDonalds." -- Michael Asher














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