Vertical Axis Wind Turbine With Push and Pull 374
Sterling D. Allan writes "After 10 years of prototyping, wind tunnel testing, patenting, and tweaking, Ron Taylor of Cheyenne (windy) Wyoming is ready to take his vertical axis wind turbine into commercial production. Design creates pull on the back side contributing to 40%+ wind conversion efficiencies. Because it spins at wind speed, it doesn't kill birds, and it runs more quietly. It also doesn't need to be installed as high, and it can withstand significantly higher winds (can generate in winds up to 70 mph, compared to ~54 mph tops for propeller designs). Generating costs estimated at 2.5 cents per kilowatt-hour, putting it in the lead pocket-book-wise not just of wind and solar, but of conventional power as well. Production prototype completion expected in 5-7 months."
Sorry... (Score:5, Insightful)
Re:Sorry... (Score:2, Funny)
Gee, ya think? Next you'll tell me that the interesting newspapers in the supermarket checkout don't perform rigorous fact checking. And I was so hoping to meet Elvis and bigfoot.
Re:Sorry... (Score:2)
Whilst this has a large amount of vapourware about it they do at least have working prototypes. Given the high profile of windfarms in the UK I can see more efficient designs being taken up in a big way. It may be a bit early to bet the farm but I wouldn't be surprised to see these on an off shore site near you in the next few years.
Re:Sorry... (Score:4, Informative)
http://www.fanwing.com/ [fanwing.com]
I think you should check your dogma.
Re:Sorry... (Score:3, Informative)
In the other type [wikipedia.org], "Because they are drag-type devices, Savonius turbines extract much less of the wind's power than other similarly-sized lift-type turbines."
I only skimmed the TFA but the pictures make it look an awful lot like a Savonious rot
Re:Sorry... (Score:3, Interesting)
This has been an epic last few weeks for the ability of crackpots to get pseudo-science posted on here. I suspect its actually just a game the editors are playing -- trying to see how riled up they can get everyone. I suppose, though, its possible its just another example of why Slashdot either needs new editors or story moderation.
Re:Sorry... (Score:5, Interesting)
Re:Sorry... (Score:4, Insightful)
But my question is, if it has a patent pending, why don't they publish? I thought that the whole reason for patents was to encourage people to publish their inventions. If the patent is pending, what's the risk?
Re:Sorry... (Score:2)
Re:Sorry... (Score:3, Funny)
Re:Picked up by mainstream press (Score:3, Informative)
Re:Picked up by mainstream press (Score:4, Insightful)
They're all just regurgitating the same story/press release that originated at the Jackson Hole Star Tribune and was passed along to the AP. All this is is an advertisement for venture capital, the same as the last couple you submitted. Both you and Slashdot should be ashamed at running these adds. as if they were news.
Could be useful for microgrids (Score:5, Informative)
Shame the article reads like Yet Another Slashvertisment (someone wants venture capital I guess) - I'd like some more details.
Re:Could be useful for microgrids (Score:5, Informative)
Although your comments about microgrids are very apt. And since what we truly need in this world are microgrids (encourage conservation of energy, reduce fossil fuel use, provide energy to Africa), I'm very excited about wind's possibilities in this arena.
(Which is why I just started a PhD. in solar and wind microgeneration cells.)
Re:Could be useful for microgrids (Score:4, Interesting)
In case anyone else is interested in what a Savonius windmill is, there's a page with a little simulation of one here [picoturbine.com]. I think they're selling something (model turbines maybe?) although I didn't really check it out.
I have to wonder though whether one of these is really as efficent as a propeller-type windmill, given that a propeller type one can alter its blade pitch and keep the rotational speed relatively constant in different wind speeds. Is there a way to do that with a Savonius design? It doesn't seem like the airfoils are really anything that you could easily change in flight.
I'm not sure if it's true, but I once heard an interesting factoid about Dutch-style propeller windmills, and how they were among the first mechanical devices to implement a "feedback loop"; you have a tail rotor mounted perpendicular to the main rotor, which drives the mechanism that orients the windmill. If the wind isn't blowing at the mill directly from the front, it causes the small rotor to turn, turning the mill into the wind. When the mill is pointing in the right direction, there's no wind on the small rotor, so it stops. Pretty brilliant, for the 17th or 18th century.
Re:Could be useful for microgrids (Score:3, Interesting)
From my readings, and as a pilot, I can hazard a guess that this is because of the enormous complexity both in manufacturing and in mainte
Re:Could be useful for microgrids (Score:4, Insightful)
Re:Could be useful for microgrids (Score:5, Interesting)
Roughly, power = 1/2 * rho * v^3 * a * k * c
where rho is mass density of air, v is windspeed, a is area, and k converts all units to power units. If you use square feet and feet per second as units, and 0.00238 slugs/ft^3, then you need to know that 550 ft-lbs/second will convert to horsepower. "c" is the conversion coefficient, typically around 0.25 for a good bladed rotor, probably closer to 0.1 for a savonious. I have built and seen rotors that did better than 0.3. Factor in loss due to generator power conversion, transmission line losses, etc, and things go downhill from there.
In general, there is a Betz limit that says, mathematically, that the most you can ever harness from a fluid flow such as wind is 59%, though there are suspected ways around that. When these people deride "tip speed ratio" they are giving up the fact that, when you can travel faster than the wind, as does the outer regions of a bladed turbine, you have the opportunity to generate more power due to the lift-to-drag ratio of high aspect ratio blades (wings) providing lots more torque than you would get by mulling along at around the same speed as the wind. Take a look at those multibladed farm water pumpers. They have a tip speed ratio rarely greater than one, and their conversion efficiency is fairly low. They're good for high starting torque to lift water. In electrical generation, you don't worry about starting torque because generators don't "kick in" till you're flying fairly fast. There is one aspect to the claims in the granted patent: he adds external "airfoils" to direct more wind into the central sevonious rotor, speaking of which, it's hard to tell from the pictures, but he may miss one nice point about generalized savonious rotors: the gap in the middle. If he closed that, he loses a lot due to the "airfoil" effect of the retreating (driving) blade directing some of the airflow through the gap into the advancing (dragging) blade (cup if you like).
In some sense, what he claims in his patent is well known in prior art. It's a lot like those dumbass patents the USPTO is granting these days for stuff like "one click", or "shopping carts" -- those folks in the USPTO never go outside and smell the roses. The patent presently granted can be stomped all over with photos from even ths us department of energy archives.
Dumb stuff like this comes along all the time. I don't think this is the work of a charlatan; rather, it really appears to be the work of an honest, but not well educated fellow. Clever, but not original or novel (novel to him, not to the rest of the world). Too bad every time someone comes along with a perpetual motion machine or something close (really cheap energy), they have to slam everything else that's already out there.
An earlier poster here commented on the apparent low quality of the website that printed the press release. Too bad about that. I'm reminded of the somewhat childish but good hearted efforts, long before the web, in the late 70's following the huge gas pump crisis in the U.S. Everybody and his uncle started printing journals, whatever, including The Mother Earth News. Some of it was good, some of it was rubbish, but we all had a ton of fun doing it. Looks like what goes around comes around. Again.
Jack Park
Re:Could be useful for microgrids (Score:2)
Pretty brilliant, for the 17th or 18th century.
I suppose Leonardo da Vinci pretty smart, "for the 15th century".
I'm sure you didn't mean it, but that's pretty patronising. People were making ingenious use of wind power long before the 17th century, for example the use of tacking [asianyachting.com] to sail against the prevailing wind. They only reason ideas like this seem simple to us is because we've had exposure to the creativity of previous generations.
Re:Could be useful for microgrids (Score:2)
That's what I get for speaking out with only a superficial knowledge of turbine design I guess...
Re:Could be useful for microgrids (Score:2)
I don't get it. I looked up Savonius Windmills (with google) and they seem to be different in at least a couple of important points.
Can you explain the differences, and why they don't matter in making this a Savonius windmill?
Re:Could be useful for microgrids (Score:4, Informative)
Re:Could be useful for microgrids (Score:2)
Re:Could be useful for microgrids (Score:2)
Re:Could be useful for microgrids (Score:5, Informative)
I helped erect one in northern Michigan, it can generate 106 watts in the calm days from the natural constant wind going up their hill and generated almost 1.8Kw peak during a storm before it threw the belt off.
no complex wiring to couple a spinnable generator to the power coming down, dirt simple and works at only 40 feet off the ground. if you paint them white they look pretty nice and can be built in a day if you don t build the alternator yourself.
personally I am surprised there are not more of them compared to the highly complex spinning blade setup that must pivot to follow the wind.
Who cares if the more complex is more efficient, if I can build 20 of mine for the price and effort of 1 typical wind generator I'll end up ahead.
Scaling problems (Score:2)
Re:Scaling problems (Score:5, Informative)
works great. put another next to it and now I get 2X the power generating capacity. add 3 I get 3 times the power generating capacity. that's the neat part 1 windmill does not slow down all the wind and scaling up works perfectly when you think of it in a multiples instead of one giant windmill.
a small village trying to be seld sustaining could create a farm of these and generate power. wind is not the only source you need, you have to couple it with solar. because the days it's not windy it's usually very sunny. and all of it needsto go into a storage system.
Typically simpler = better. because you can make more of them to compensate for the lack of efficiency that highly complex may or may not give you.
that's the problem with alternative energy, too many people make it complex as hell and scares the realy users away from it. Anyone can create a hang out your window solar heat collector that works fantastically well for about $19.00 in parts and a little time gluing, nailing and painting. But you only see the hyper expensive requires engineers to install systems advertised or talked about. same as solar electricity. you can buy your solar cells for pretty darn cheap, you do not have to pay $5000.00 per panel for new state of the art stuff.
Same as you do not need to be a aeronautical engineer and able to carve an airfoil propeller to make a good working windmill.
Only somewhat (Score:3, Interesting)
Your points are true only on a small scale, they fail on anything large.
All windmills slow the wind. If you add a second windmill, and the wind is blowing such that it would go from one to the next (in absence of any windmills/trees/buildings), the second windmill will see slower wind than the first, and thus generate less power.
All windmills create turbulence zones around them, mostly downwind. This too decreases the efficiency of the windmills downwind.
The only solutions to these problems is to space
Re:Could be useful for microgrids (Score:5, Informative)
Land usage / kW for wind turbines is NOT too high. You only actually need half an acre/MW. The rest of the land is for wind easement, and you can carry on farming/horticulture without much interruption on it. And this is true only for Europe and N. America.
In developing countries, windy land is mostly arid, mountainous, or coastal - nothing much grows there.
Large scale wind developments are economically viable. Wind gets the minimal of governmental support, and look at how it's growing. Lots of free tools are available on the web to see it for yourself - various HAWT models, various sites around the world.
Large scale developments starting from 50 MW parks or higher can enable the manufacturer/service providers to provide efficient erection and commissioning services, on-site round-the-clock Operation and Maintenance services, SCADA operation and data communication to the investor/utility, etc.
Distributed development of wind power projects over geographically distant areas can theoretically reduce intermittency, which is the usual FUD against wind these days. Avian kills are another FUD: what is the extent of ecological damage being caused by your conventional power plants? What is the submergence being caused by hydropower?
About TFA, well, there is a huge amount of development taking place in both HAWT and VAWT technologies, with competition between generator and/or drivetrain philosophies.
HAWTs have a distinct advantage of exploiting the swept area and the power law index by increasing rotor diameters (blade lengths). VAWTs may evolve into simple designs without much need for regulation - there are some that offer inbuilt speed regulation by design. They can generate at any wind speed that the supporting structure can withstand. However, I am yet to see VAWTs catching up with HAWTs having rated capacities of decade-old standards.
Some of the VAWTs of the type in TFA can be well suited for use in defence installations - I've myself suggested one design to a defence research official for distributed, arctic-condition, radar/thermal/sonic neutral generation needs at the world's highest battlefield. I don't know if they have researched it further, but they won't tell
-clueless
Disclaimer: I work for a wind turbine manufacturer. However, I have stayed with them because I like the industry.
Re:Could be useful for microgrids (Score:3, Insightful)
While that may be true in the US, I think you'll find that Wind gets a lot of governmental support in the EU, especially Germany and Britain.
It makes sense, if you think about it. As far north as most of the EU is, Solar isn't as promising for the EU as it is for the US.
Re:Could be useful for microgrids (Score:2)
There's a note on the Wikipedia article you've linked to.
Safer to birds? (Score:2, Insightful)
Birds don't move at wind speed. Sounds like a recipe for a collision!
Worse than that (Score:5, Insightful)
So that little argument is rubbish.
Actually, the whole article is not too bad overall, we certainly see worse in real papers (eg the Guardian's coverage of that hydrogen atom fraud).
Re:Safer to birds? (Score:2, Informative)
One of the primary environmental drawbacks of the propeller wind turbines is that they kill birds. The tips of the blades spin much faster than the wind speed, chopping through the air sometimes at speeds of 200 mph. The birds generally just don't see them coming.
The TMA vertical axis design flows with the wind, at the speed of the wind. "It looks like a building to the bird," said Taylor. "We've never seen a dead bird at our te
Re:Safer to birds? (Score:2)
We can't tell if b > w will always be true, we're pretty sure b w will not always true, but I propose the most definitive statement I can on this subject is b c.
Directionless (Score:4, Informative)
A couple of years ago I talked with an engineer friend about this when we got on the subject of alternative energy. This isn't a new idea of course, variations have been used above chimneys [fluesystems.com] for a long time for instance. He told me then about the large number of advantages to this design. I don't remember if I asked him the question that pops up in my head now - why did the propeller design become the norm?
Re:Directionless (Score:3, Informative)
Of course, turning turbines around has been a solved problem since forever. The disadvantage of vertical turbines is that the wind is so much faster at the top than the bottom, which makes half of the turbine essentially useless.
Propeller design as the norm (Score:4, Informative)
Re:Propeller design as the norm (Score:5, Informative)
Modern propeller turbines use lift to generate torque and efficiency scales up with propeller length. Verticle turbines which use drag (as the one in the article does) are not as efficienct to begin with, and their efficiency does not scale as you make them bigger. This is why the engineers don't make modern large scale wind turbines out of them.
Old windmills used wind drag to generate torque. Modern wind turbines use lift to generate torque. Saying the principles are the same is like comparing a glider to fighter jet.
Re:Directionless (Score:5, Informative)
1) These things spin *quickly*. Far faster than the windspeed. Now, that's not so much a problem in a propeller blade because all the mass is on the inside and the blade happens to be strongest here, too. But on a VAWT, all the mass is on the outside, meaning that there is a significant amount of energy stored as they spin round and round. This pull can quickly destroy the windmill, and apparently has caused a couple deaths (Or so I have read in the windmill forums. Caveat reader.).
2) Because of the way the VAWTs spin, the mill is subject to pulsing as the blades change their angle of attack and speed with respect to the wind. Of course, this is reduced by having more blades which are thinner, (the ideal propeller being made out of an infinite number of infinitely thin blades) but the materials have limits and it seems that 2, 3, and 4 blades are all we can reasonably do. So the pulsing motion fatigues the support and can lead to failure.
HAWTs don't suffer from these problems, although they do have other problems-- such as torque applied by gyroscopic precession, torque applied by higher windspeeds at the top of the mill than at the bottom, orientation into the wind-- but they don't seem to be as difficult to overcome as the VAWT ones.
Re:Directionless (Score:4, Informative)
I hate it when people don't read TFA.
Apparently, this thing can handle going with windspeeds of over 154, while props fall must be braked or they'll fall apart. This likely has to do with the materials used.
Also, the wind-tunnel testing gave them a number of 2 blades.
That's the reason this _is_ news. This guy was able to overcome the inherent engineering problems with VAWTs (which are more efficient, but more difficult to design without the failures you described). The Slashdotters may think this is funny, or stupid, but...
It occurs to me that every time a new non-software technology has been reported on slashdot, >50% of those who comment on it are near-psychotic in claiming it's bunk. Why is that?
Re:Directionless (Score:3, Informative)
Re:Directionless (Score:2, Interesting)
Actually, the blades are always moving agains a relative wind. What's tricky about the aerodynamics is that the relative wind constantly changes as you go round the circle. The solution to this is to spin faster, so that the wind component which changes (the real wind itself) is small in comparison to the wind component which doesn't (the relative wind produced tang
Re:Directionless (Score:2)
For some values of "ready" (Score:5, Insightful)
Now being the old fuddy duddy I am (at the tender age of 21) I'm obviously using an old and outdated definition for "ready for commercial production." See, the definition I'm using is one where the prototyping stage is over, and these things are being made in some factory and are about to be sold to companies/people. Now obviously not being up-to-date with the latest definitions, I was quite excited when I read it was ready, only to have my hopes dashed by the end of the summary.
Why don't you call us old-timers when you actually have a commercial product?
Re:For some values of "ready" (Score:3, Informative)
Re:For some values of "ready" (Score:2)
Actually, the term Production Prototype *usually* means the first version actually built by manufacturing
I didn't know that. But even so, it's 5 to 7 months before the production prototype is even built, and they're claiming it's ready to become commercially available NOW. It isn't ready to become commercially available now. It might be ready in 5 to 7 months, but that isn't now.
That was my beef
Re:For some values of "ready" (Score:2)
Its not in-fact a terribly long times, I would say that is it quick. If you sent Boeing a request for 5 planes it would probably take longer before they started any production work.
Let's get this all out of the way at once (Score:4, Funny)
The technology does blow everything else away.
Yes, it will succeed, and not just in vertical markets.
It really took some gust to work on this.
----
Now I have to go back to bed in a fit of self-loathing.
Re:Let's get this all out of the way at once (Score:2)
Re:Let's get this all out of the way at once (Score:2)
--
I'm always serious, never more so than when I'm being flippant. -- Cr. Ziller
Windside has something similar (for twenty years) (Score:5, Informative)
"Windside works, when others don't, with gentle summer breeze and in a violent winter storm. It works, when others are in deep frost. Windside produces electricity at least 50 % more in a year than traditional propeller models. All the year round. Many things make it extraordinary. And therefore it gives the best value for the money."
Not sure what the differences might be. Winside apparently has been producing these vertical axis windmills for extreme environments for, they say, about twenty years. But they do seem costly. They use a helix type design for the blades, see: http://www.windside.com/products.html [windside.com]
Re:Windside has something similar (for twenty year (Score:2)
Lots of details (Score:5, Informative)
What he's proposing is a Savonius windmill. A fancy aenometer. Which we already do much, much better with the Darrius approach. The maximum possible energy that we can get out of the wind is 59%. Savonius windmills are far, far less efficient, as they rely on drag, and not lift.
Of course, he claims that it works off of lift, which-- if his mill even exists in reality-- it probably does, but the fact that it only gets "a little" boost from lift means that it is almost completely drag based.
One problem that people have when visualizing a windmill is the question, "Why not do it like a paddle-wheel? Like on an old steam-boat?" Well, do you still see those old steam-boats tooling up the river and across the ocean. No? Maybe you should wondered why. It's because... surprise, surprise, it's less efficient.
Not to mention the ridiculous claims about hurricane/tornado proof design. And the centripital forces it's have to undergo at these speeds. (Real VAWTs tend to be able to spin at such high speeds that they are explosively dangerous.) And the torque exerted on the bearing coupling of a several story high building when there's 150mph of wind pressing on the top.
opensourceenergy.com seems to be nothing more than a shrewd attempt to make fun of the
For some real information on VAWTs, check out otherpower.com. For instance, http://www.fieldlines.com/story/2005/10/7/63930/5
Re:Lots of details (Score:2)
[Just kidding. Thanks a lot for your thoughts on the new approach. It looks like you think it is more dubious than "Cold Fusion".
Negatives to Vertical WindMills (Score:2)
What I found (and this article leaves out) is that there are a few negatives that need to be considered.
1. To do maintanence, you have to take the entire sucker apart in order to get at the bearings.
2. Height: Wind speeds are not even across various heights. There is a serious potential for nasty stresses when the wind is going faster at the top of this turbine than at the bottom.
3. I don't remember the
Re:Lots of details (Score:2, Funny)
(Has a heart attack and falls over dead)
I'm sorry, you're using correct terminology and appear to know what you're talking about. I'm afraid I'll have to show you the door.
~D
Rotating doors to light the bulbs (Score:3, Funny)
Looks like a TurboSail to me. (Score:3, Informative)
Everything old is new again ? or just a case of two people reaching the same conclusion through trial and error.
Note to critics and skeptics (Score:3, Interesting)
Like a lot of other technologies, this one is going down in price in a predictable way. Check out the wind energy data [earth-policy.org] at earth-policy.org, especially that last figure.
The sector has recently been experiencing Hockey-stick growth [worldchanging.com] in investment. It's pretty much inevitable that this is going to be cheaper than coal- and likely cheap enough to make hydrogen for when wind is low. Cheap, guaranteed price, non-polluting.
Judging from nuclear's track record, it won't come close to wind. These turbines might not be the ones to put nuclear out of its misery- but wind certainly will play a large part (don't discount solar just quite yet).
Re:Note to critics and skeptics (Score:3, Insightful)
So your point is?
Re:Note to critics and skeptics (Score:2, Insightful)
If the design is so revolutionary, more financially viable than conventional power, and better for the environment, then no doubt they'll make a killing financially whether they patent it or not, as th
Betz's law and effeciency - (Score:4, Informative)
http://www.windpower.org/en/stat/betzpro.htm [windpower.org]
On the other hand, if it can endure much higher winds than a prop installation, its OVERALL effeciency might be higher, because the energy in a mass flow is proportional to the cube of the wind-speed; so the 1% high wind speed tail of the distribution contributes a large portion of the total energy captured by the turbine. Of course, having a bit more REAL info would be helpful in determining if this is just slick FUD or something real. And when significant data is not mentioned, it does make one tend to think there is something to hide.
Comment removed (Score:3, Informative)
Re:Vacuum doesn't pull. (Score:3, Informative)
Flawed (Score:4, Interesting)
Also, bird death is about 1 per turbine per year for current technology. This is about 9 orders of magnitude less than bird death from buildings/vehicles/airplanes etc., and that's not considering the enviornmental consequences on bird life of NOT using renewable sources...
Dumpy little vertical axis machines may have limited uses in isolated installation, and for revolving advertising, but they are not practical for large scale generation. The rotor of a modern 5MW wind turbine is about the same size as an athletics track. Imagine how big this vertical axis machine would have to be to match the wind capture of this. If the alternative is to have many small devices, there would be a very large number indeed: this carries costs of electrical interconnection, massive maintenance overhead from trillions of puny alternators and gearboxes, all of which was probably ignored in arriving at the 2.5 cents per kWh.
The only way to make money with this turbine is to be the poor guy's patent attourney.
Re:Flawed (Score:3, Insightful)
Yes, but it looks like a big propeller: the spokes that the wind is pushing on only cover a small part of that circular area at any given time. The rest is clear air.
no more "Open Source Energy" (Score:2, Insightful)
does not kill birds ? (Score:3, Insightful)
just a visual observation, and probably they threw some chickens into their grinder before they claimed that.
Besides being an asshole critic, I really appreciate the aspect of renewable energy paired with not being a traditional meatgrinder
fact: did you guys know that costa rica is only using wind and water power? In fact we produce as much from these sources that CR exports energy to neighbouring countries; clean energy. In fact, while still considered a developing country, electricity coverage is the best in central AM, technically you have electricity everywhere. For US/European readers it is probably normal, but when you drive around in Panama/Nicaragua you canappreciate grid coverage here.
OK, water energy creates some mess with the environment in some cases especially when you have wetlands, because dams can affect these in a bad way, but still better than burning coal or radiating, etc.
What a shame (Score:2)
Why not kill two birds with one stone?
I think Slashdot is being had (Score:5, Informative)
This is the third post I recall by Stirling D. Allan recently, the others being
The first in that list featured complete crackpot pseudoscience. The second seems to be of dubious scientific merit. A quick look at Mr. Allan's website [pureenergysystems.com] shows they are involved with a number of other areas of pseudoscience (or to put it less kindly, scientific hoaxes) such as "magnet motors" and "zero point energy" (as an energy source). That together with the two other submissions he's made leads me to doubt the validity of the information in these "stories". The main problem, however, is that these are not balanced informative articles, but rather they seem to be little more than ads seeking venture capital. Furthermore, it looks like Slashdot is soon to become little more than a mouthpiece for opensourceenergy.org [opensourceenergy.org] at this rate.
Re:I think Slashdot is being had (Score:3, Funny)
Working version from Canada (Score:5, Informative)
Windaus Energy [windausenergy.com] (Ontario, Canada) has developed prototypes of a vertical-axis wind turbine and are looking for places to install working demos.
From an announcement they sent out earlier this year:
Specifications are available on their website, including output, torque, power output. As other people have pointed out, there are some disadvantages to this style of turbine, but there are also some advantages. It looks far more suitable for local micro power than mega wind farms.
Why this design sucks. (Score:4, Informative)
There are several hard problems in wind turbine design. One is that, for large wind machines, wind speed may vary considerably across different parts of the blade area. This produces huge stresses in the blade system. Aircraft propellers and hubs don't have that problem, so technology borrowed from aircraft props didn't quite work. That's been solved, but it took years to get past it.
A basic problem, one which this new design doesn't solve, is overspeed protection. Wind turbines above toy size must be able to deal with high wind conditions safely. Some turn sideways; some turn upwards; some feather the props. Brakes aren't enough. There's no way to feather or turn this new design. Even small turbines [realgoods.com] need, and have, overspeed protection.
There are lots of wind machine designs that more or less work in a small size, but don't scale up to the point where they're worth building. There's a square law; double the blade length and get four times the energy out. So big turbines beat out little ones, once ths scaling problems are solved. Wind turbine size has been creeping up since the 1970s, from about 50KW to a few megawatts.
A 1.5 MW unit [energy.gov] was built in the 1940s, but it suffered a bearing failure within a year, then a loss of blade accident which threw a blade 700 feet. Only in the past decade have reliable wind machines in that size range [gepower.com] been produced in quantity. With 2800 of their 1.5MW units installed, General Electric can be said to have solved that scaling problem.
The big machines aren't simple. They have active yaw control, active pitch control, hydraulic brakes, AC to DC to AC variable frequency conversion, and lightning protection. But, at last, they work.
So these guys are going to beat that with a little tin model that looks like something used to spin a sign in a used car lot. Right.
Re:Doesn't kill birds? (Score:2, Informative)
This is unlike conventional wind turbines that chop through air too quickly for birds to see them.
You haven't RTFA have you? No, of course not, this is Slashdot after all.
Re:Doesn't kill birds? (Score:2)
Uses up the wind (Score:5, Funny)
Re:Uses up the wind (Score:3, Funny)
Though I'd assume more of it would also go towards powering many, many fans.
Re:Uses up the wind (Score:3, Funny)
As I live in Wyoming, we have plenty of wind to spare.
Please take some.
As Silly as that sounds... (Score:3, Insightful)
About six months past I read in a German paper that in the North where the windmill parks have changed the local climate (http://www.msr.uni-bremen.de/werner/rw/RWOffshore
Re:Uses up the wind (Score:3, Funny)
Birds... (Score:5, Interesting)
The whole bird thing sounds like a convenient excuse invented by people who really oppose windmills because of noise or land use issues, but want a fuzzier, more PR-friendly excuse. The kill zone on a windmill is basically going to be the circle described by the rotor tips as they go through the air, so it's not a huge zone (as you get towards the center they're not moving as fast, tangentially) and at any given time it's not as if just flying into that ring would result in death, you'd have to be at a point at the particular moment in time when the blade moved through it. Last time I checked, birds don't hover, so you have two moving objects that would have to compete against some long odds to end up in the same place at the same time. Also, the turbines are noisy as hell -- something which is a legitimate criticism -- and I find it hard to imagine that birds wouldn't be scared off by the sound, air currents, and motion. (Actually they wouldn't make a bad large-scale scarecrow over farmland...)
Call me overly cynical but I find that particular objection dubious.
Re:Birds... (Score:5, Informative)
If you google for Altamont Pass, you will find reports of what is apparently the most deadly wind farm for raptors in the U.S., and kills about 800-1300 birds of prey a year. It's the farm's location in this pass, a migration path for other birds which makes it a great home for many raptors such as golden eagles, that makes it high risk. It's the small size, tight placement, and old design of the turbines that turns that risk into actual dead birds.
Your intuition is correct here, in that this is a tiny amount compared to the number of birds that crash into windows of buildings in your average city. On a per-turbine basis, cell phone towers kill more birds.
However, many people have taken the issue seriously (the makers of the Altamont Pass turbines were taken to court to force them to reduce the danger of their farms to birds), people like my father who as a bird watcher and conservationist is most concerned about predator populations due to their important role at the top of the food chain. It turns out that these concerns are being addressed, and newer turbines are much less dangerous to birds, in particular raptors. New designs discourage perching on the supports (electrocution of perching birds being a problem apparently), and larger turbines with commensurately slower blades, have proven to reduce bird fatalities.
This is an issue I care about, loving as I do large animals that eat other animals, and I feel it is being duley considered and addressed. Wind farms do less damage to the environment than any other form of power generation other than solar, and kill fewer birds than the windowed office building that would be built to house the adiminstration for any form of power plant. That's no reason not to pressure the makers of the farms to continue to address bird deaths by improving their turbines, but it's also no reason to discourage the construction of wind farms. People who are against wind farms due to bird deaths have in my experience fallen into two categories: concerned environmentalists who aren't aware of the scope of the problem, and industrialists who just want to have something to put in the "negatives of alternative energy" column to line up with "releases more radiation than Three Mile Island on a normal day of operation" in the "negatives of coal" column so they'll both seem equally bad.
More modern turbines (almost) don't kill birds (Score:5, Informative)
Modern turbine designs have taken these problems (and many others) into account and now kill very few birds - probably fewer than are killed by flying into electricity pylons. The main design changes are that they are much larger and slower rotating, so birds tend to judge the motion correctly and avoid them. Correct me if I'm wrong, but I think the Altamont Pass turbines are painted grey to reduce their visual impact against the sky, which also reduces their visibility to birds. Modern ones tend to be painted white, which makes them more visible.
On a recent visit to Denmark I was very impressed by the size and sheer number of turbines, turning gracefully, slowly and fairly unobtrusively. Occasionally there would be a small, faster-rotating one of an older design. These were noticeably more distracting and attention-grabbing - particularly in the peripheral vision (which after all is designed to look for rapid movement from predators). It's these older designs that have lead to most of the complaints from local residents, and understandably so.
Give me a modern turbine at the bottom of my garden any day - they are also virtually silent unlike their older cousins.
Re:More modern turbines (almost) don't kill birds (Score:3, Interesting)
Only to whiny people.
I love the huge turbines. I can see a medium sized wind farm from my home. They're beautiful to me because they represent pure, clean power. Not to mention, they're quite graceful in their movements and fun to watch.
The whiners who oppose them have their heads up their collective rear ends. Ask these people how they prefer to get their electricity and they can't answer you. Wind is ugly and kills birds. Solar is ugly and full of
The Environut-Tape Letters (Score:3, Funny)
Environut: Global warming is going to kill us all. We have to stop the evil oil companies bent of world destruction.
Engineer: Well then, let's invest some money in clean, reliable nuclear power plant design
Environut: Are you kidd
LNG worst case. (Score:3, Interesting)
Actually, the absolute worst-case scenario is a BLEVE, [blazetech.com] which you Do Not Want. When all of the factors are right, heat from a really big fire boils the LNG in its tank, overwhelming the pressure-relief valve. The valve sends up a shrieking tower of flame as it fails to keep up with the rising pressure, and everything that I'
Re:Birds... (Score:2, Offtopic)
Hopefully the moderators will mod you accordingly.
This is a serious issue... (Score:4, Funny)
This is a serious issue and needs to be addressed! How did solar power get away with causing so little damage?? I propose that all solar arrays be built slightly concave, and reflect most of the light they don't absorb (we don't want to reduce efficiency), creating giant death rays. This way we can ignite birds that fly through the kill zone and correct this serious deficiency.
In an unrelated issue, I'd also like some serious effort to be put into breeding chickens that can fly.
Birds are the tip of the iceberg (Score:4, Funny)
1 dead bird
1 dead sheep
From this, we can deduce that wind turbines are equally as deadly to sheep as they are to birds. The 800-1300 sheep killed annually must make the Altamont Pass a bloodbath of truely horrific proportions.
But seriously, folks...
The Altamont Pass is a disaster which was produced by irresponsible economic incentives of the time which put up low quality turbines willy-nilly throughout California. Add to that the fact that many of Altamont Pass's are placed on angle-iron framework towers. These make them ideal nesting grounds--well, if one ignores the 30 m food processor out front. Modern towers take great care in leaving no place for avian habitation.
This park's would otherwise be just a regional problem, but, thanks to more animal-focused environmental groups, and the tabloids who eat up their press releases, that wind park is biting us over here in Europe in the ass.
Altamont Pass is, however, the only wind park on earth with this level of environmental impact. Nothing comes close in these regards. A substantially larger off-shore wind park off the coast of Denmark (Knoetby, I think) actually showed that the birds weren't scared off, but instead kept a distance of about 150 m from the equipment.
Re:Birds are the tip of the iceberg (Score:4, Funny)
1 dead bird
1 dead sheep
Where they near each other? I see two possibilities:
1) Bird gets smacked by turbine blade beak-first into sheep's temple, killing it. The solution to this problem would be to sharpen the blades, so instead of striking the bird like a baseball it would cut them in half so the two halves would fall at normal speed to the ground.
2) The sheep, being of a species well known for their craven cowardice and deep cunning (they only act stupid so as not to appear threatening), saw the dead bird, and upon considering the environmental implications, died of a heart attack. The solution to this problem is to give sheep internet access so they can research the problem themselves.
The Altamont Pass is a disaster which was produced by irresponsible economic incentives of the time which put up low quality turbines willy-nilly throughout California. Add to that the fact that many of Altamont Pass's are placed on angle-iron framework towers. These make them ideal nesting grounds--well, if one ignores the 30 m food processor out front. Modern towers take great care in leaving no place for avian habitation.
Just for everyone's convenience, here's a link [thewatt.com] to a page which shows the old-style tower and the new style and the obvious difference it would make in problems with perching and nesting. There's also the non-obvious scale difference, with the new larger one being much safer due to slower and thus easier to see/avoid blades. It also has per-turbine death rates for birds for various sites, with Altamont being much higher in raptor deaths than the others.
Re:Birds... (Score:2)
There was a problem with some early model wind turbines killing birds. Newer turbines may hit a bird once in a while, but are generally not so hazardous, or at least, that is my understanding of the situation.
Re:Birds... (Score:2)
And car accidents kill less people per year than heart disease. Does that mean we shouldn't try and make cars safer?
Birds don't hover but bats do... (Score:5, Informative)
I was at the UK national Bat conference this years and there were a couple of presentations on bat kills around wind turbines. It turns out that the strange noised attrach insects and therefore bats. Certain wind farms in the use, I forget which, are on migration paths for bats. There is a suggestion that they turn off the wind turbines come migration session.
Since bats are a key part of bug control, particularly in the US, you might want to think about protecting them,
Lonely
Re:Birds... (Score:4, Informative)
There is a recent NPR story on this here: http://www.npr.org/templates/story/story.php?stor
Re:Birds... (Score:2, Flamebait)
As a better question - Why does anyone care?
Stupid birds fly into things. We call that "evolution". The birds without the sense to avoid rapidly moving blades die, the ones with a bit more brains survive, to produce offspring with the sense to avoid giant poultry-processors-of-death.
We haven't banned cars, picture windows, or electric lines yet - Why such a fuss over a technology that has the potential to substantially reduce our
Re:Doesn't kill birds? (Score:3, Funny)
Darwin at work (Score:2)
Re:I dont get this part.. (Score:2)
Re:Put on side of skyscrapers (Score:3, Insightful)
Hmmm--this type of wind turbine could be perfect for the space on top of the planned Freedom Tower in New York Ciy that designers plan to install wind turbines inside that space. It would definitely be less threat to birds flying nearby and the noise level will be substantially lower, too.