From Wiki:
My (perhaps erroneous) understanding is you need really, really big blades to maximize wind power efficiency for large scale power production, and these kinds of things are better suited to small scale deployment. Also (again, my understanding) is they are better in variable speed/direction winds, while the large scale ones are better for more constant wind speeds. Take all of my writings (as always :p) with a mountain of salt.
Why not build them with mesh cages surrounding the moving parts, to keep the birds out?
Yes, I understand that putting mesh cages around things screws up the aerodynamics more than one might imagine. (This was discussed in a thread a few [del]months[/del] years ago, in the context of putting mesh screens in front of jet engines to keep the geese out.) And how much extra would it cost to place and maintain such screens?
But if the alternative is to shut down half the turbines half the time, how much is that going to cost in lost power generation and expensive mochines sitting idle (not to mention, that shutting half the machines down would only save half as many birds)? What would be the comparative costs of putting up screens, vs shutting down half the farm all winter?
the blade area is huge. to put up not only a self supporting mesh but one that could handle the wind load would be a tremendous problem.
Exactly. And we can make hydrogen-powered cars that use a little bit of the power generated to hydrolyze more water to make more hydrogen!
Laws of thermodynamics be damned!
From the link:
It’s more like half the turbines for 1/3 of the year. So it’s a 1/6 drop in power production.
Modern turbines are very tall and apparently raptors are less likely to fly into them. The blades of the older ones swing closer to the ground, where raptors tend to swoop. The owners are retiring some 200 of the oldest turbines and are replacing them with higher powered and bird friendlier designs. I speculate that this makes more sense than a screen retrofit.
I agree 100% … it’s just too salty for my tastes, but spot on correct.
Bonneville Power Admin. has installed screens and diversion channels on the Columbia River Hydroelectric dams. It seems to be working keeping the fish safe. Luckily, they were able to pass on the costs to the power they send to California [wolfish grin] so it works great for all parties involved. Smolts have no choice, but birds do. I would think after so many years, the gene pool would purge this tendency to lite on rotating blades.
House cats kill birds by the billions, better to be rid of them than try and screen in a wind mill.
I keep my cat behind a screen door, away from the birds.
Anyway, windmills turn themselves off in high winds, and obviously they’re turned off for curtailment too. The language is misleading- it is the wind you can’t turn off.
Altamont was one of the earliest wind farms. The article upthread notes that we’ve learned a lot from their experience and that more recent windfarms don’t tend to kill a lot of raptors. All technologies involve a learning curve. Managing raptor kills are just another cost or challenge to be managed or overcome. ISTM it’s been far from the largest issue.
I thought the raptor thing was local to the Altamont area. Those populations were hammered by DDT and haven’t fully recovered. I do agree that conservation measures must be taken where and when there is this manner of threat. If raptors are thriving in West Texas, then it’s not a problem there.
But if we’re talking about common starlings, I don’t what to hear it.
Still, those old eggbeater windmills were kind of fun to watch. 
Wind is not strictly a renewable energy source. Once you remove the energy from the moving air (converting kinetic energy to electrical energy), it stays permanently removed and the weather patterns adjust accordingly. The amount of energy that giant unshielded nuclear fusion reactor in the sky radiates onto the planet is pretty much fixed by the surface area of the earth and it’s atmosphere. It’s just a matter of what we use it for.
Much of the electrical energy ends up as visible or infrared light and is radiated out into space. That part that becomes thermal energy (back to kinetic) is dumped back into the atmosphere and through convection can partly become wind again. We seem to be getting better at using greenhouse gasses to trap much of this energy so it is not wasted.
Coal, on the other hand is renewable. You just have to bury enough organic matter deep enough and long enough.
The real trick for us U.S. mid-westerners is to make sure that when climate change raises the ocean levels that it happens fast enough that all those people living on the coasts don’t get a chance to move inland first. I think I will go light a fire in the fire place and turn the air-conditioner down to 65.
Yes, mid-western Chambers of Commerce would do well to advertise in the Silicone Valley about the dangers of sea level rise.
The kinetic energy in wind comes from solar radiation. It dissipates when friction turns the wind motion into heat, and then it’s replenished with more solar radiation. The wind turbine just adds a couple more steps. Now it goes from solar to kinetic to electricity to heat. And again, there’s more solar coming in all the time. How is that not renewable?
As for coal, you seem to be using a rather strange definition of renewable. A person might say that, in the big picture, all energy everywhere either comes from a nuclear reaction or it comes from something that came from solar power, which itself is a nuclear reaction, therefore all energy is non-renewable because the amount of nuclear energy in the universe is finite and was fixed at the moment of the Big Bang. But that would be a rather silly definition of renewable because it makes the word totally useless. Why have the word at all if nothing in the universe can be described by the word? On the opposite end of the spectrum, a person could argue that every energy source is renewable in tiny quantities, e.g. if it takes 40 million years to produce 40 million tons of coal then it’s being renewed at a rate of 1 ton per year. But again, that definition is useless because you’ve defined it so that it applies to everything. Why have the word at all if everything in the universe can be described by the word?
Most people use “renewable” to mean that it replenishes itself relatively quickly (less than a human lifespan) and that cycle which drives the replenishment can be expected to continue for a long time (longer than recorded history). By this definition, wind (replenished by solar power on a daily basis)is renewable and coal (replenished by solar power but takes millions of years) is not.
To quote the venerable Fog Horn Leg Horn… “It’s a joke son, a joke. Don’t you know a joke when you hear one?”
Well, maybe one meant to get people to think a bit differently about everyday things. And you hit on a good point that makes me realize “renewable” is the wrong word to use for any energy source. The word has been twisted to simply mean that on a human time scale it is being used at a very small rate compared to the source, and human lifetimes are so very very small compared to history.
When they first starting burning trees, they probably thought “look how freakin huge those forests are. We can cut more whenever we want and it grows back”. When they started mining coal it was “hey, this stuff goes on forever, we can always dig more.” It’s all just a matter of scale, and we keep adding people (energy suckers) to our side of the scale.
Advertising in the Silicone Valley would certainly get a lot of attention. Mainly from men.
[QUOTE=Senegoid]
Why not build them with mesh cages surrounding the moving parts, to keep the birds out?
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The chain link fences around the BART tracks catch enough flying crap like newspapers and grocery bags.
I can envision giant screens around wind turbines getting clogged with the same sort of debris. Besides that, windmills and turbines have a certain grace about them. Erecting huge screens around them would look terrible.
Try living near one of the big wind farms. Whirling blades every where you look in the day time and blinking lights at night. The white strobes are especially annoying.
I lived near some wind turbines in Germany. They were beautiful and peaceful and tranquil. They comforted us as we settled into a blissful sleep at night. They’re like guardian angels. We gave them names.
And run skyclad through them at night, perhaps painted blue? Yeah, that sounds like the life… sigh
So you had no problem coming up with, and keeping straight 100 to 150 names? Apparently you had no appreciation for night-sky viewing (meteors, satellites, the dance of the planets, a thin crescent moon), when a 100 strobe lights are going off every few seconds within a couple of miles of you. Was your view across the land where you could “see for miles and miles” better after the 100 windmills were put up (not to mention the other hundred+ a few miles in the other direction).
Would you have named them and slept as blissfully if they had been among the many abandoned windmills (dead guardian angels)? There is none of your tax dollars available for tearing these things down (like there is to make them “profitable”), and no money set aside to do so. Would you sleep so well in the U.S. knowing that your tax dollars are going directly into the pockets of corporations who build not to help the planet, but only for the money?
Do an internet search on “abandoned wind farms”. You will get a lot of hype and out right lies from both sides of the story, but also a lot of pictures of these “peaceful and tranquil” structures. You can then judge for yourself.
I’d love to save the planet, but wind energy can’t do it, and is sucking huge amounts of money and attention away from research finding ways to really make the difference.