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Vertical Axis Wind Turbine With Push and Pull
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."
While vertical axis wind generators aren't new - the Soviets utilized vertical designs for the most part - this design is. Wind power usually isn't practical or environmental for large-scale deployment (land usage/kW is too high), and I expect this design won't change that, but it could make wind an even better choice for microgrids.
Shame the article reads like Yet Another Slashvertisment (someone wants venture capital I guess) - I'd like some more details.
Another obvious advantage of this design is that unlike a propeller, you don't have to turn them around when the direction of the wind changes...
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 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?
Being bitter is drinking poison and hoping someone else will die
The entire device looks like a solid structure to passing birds, hence they fly around it. Birds don't fly into solid walls.
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.
From: http://www.windside.com/
"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
A 21st century issue: the irony of technologies of abundance in the hands of those still thinking in terms of scarcity.
And it's all... horseshit.
/. crowd, by pulling us all in to wow at the latest, greatest power generation technique that's going to revolutionize our world.
5 58, or http://www.windstuffnow.com/main/vawt.htm.
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
www.eissq.com/BandP.html Ball and Plate System. Amuse your friends. Crush your enemies.
I think the idea is that it doesn't move as fast as a propeller: From TFA:
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 test site." Likely this is because birds don't normally fly into solid walls.
That is because airospace engineers are the main designers of these kind of machines. They know propellers, have all the systems to calculate what is possible with it, and through old designs of windmills (from 1400AD or even earlier) the principles pretty much stayed the same.
My wife's sketchblog Blob[p]: Gastrono-me
Anyone Remeber the Cousteau Turbo Sail, same principal.
Everything old is new again ? or just a case of two people reaching the same conclusion through trial and error.
Actually, the term Production Prototype *usually* means the first version actually built by manufacturing (as opposed to a hand-built version by R&D) ... so this suggests to me that they are pretty far along - they actually have a manufacturing facility in place, people trained, material lists finalized, procurement contracts, etc. Of course they could just be *calling* it a production proto ...
The more you regulate a company, the worse its products become.
This link is the nicest derivation I have seen online of Betz's law regarding the maximum effiency (16/27 ~= 59%) of any non-compressible mass flow capture device. At least the article doesn't claim to exceed it (40%, I think). But as for high drag-devices getting a better effeciency than a variable-pitch propeller? That sounds pretty suspicious.
http://www.windpower.org/en/stat/betzpro.htm
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.
This design does not create "pull" on the leeward side. There is no such thing as a negative aerodynamic force.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
It always gets dragged up, but does anyone really know how many birds those propellers actually kill? I'm willing to bet it's very low; I also suspect way more birds are killed by flying into vehicles on the highway, or into the sides of highrise buildings (I had one kamikaze into my house last week, and that's not even a high rise).
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.
The enemies of Democracy are
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.
43 - For those who require slightly more than the answer to life, the universe and everything.
Hi,
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
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 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 at this rate.
"You call it a new way of thinking; I call it regression to ignorance!" -- Operation Ivy
The 1000 or so wind turbines on the North Sea coast of Germany near Holtgast have driven the water birds completely out of the area. The problem was not strikes, but the noise and perhaps visual disorientation. In any event over the last 10 years since the installation of the turbines the birds have abandoned the area.
y Id=4975147
There is a recent NPR story on this here: http://www.npr.org/templates/story/story.php?stor
it scales vertically. we built one with 6 55 gallon drums. 3 on the lower tier 3 on the upper tier cut in a way to have 6 blades per tier. all attached to the central shaft using a thrust bearing at the top and botton and then to a pulley that turns the rotor on a home built alternator at 3 times the rpm that the windmill is spinning at.
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.
Do not look at laser with remaining good eye.
Windaus Energy (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.
Right- the AP picked up a story from the Casper Star-Tribune, which then got reprinted by the Seattle Post-Intelligencer, CBS News, Yahoo News, etc. That story was basically coverage of a press conference. I don't imagine there's a whole hell of a lot to cover on any given day in Cheyenne, so of course they'd be there. The fact remains that they don't have a production prototype, and haven't shown anything, so for now they're all talk.
Here are two companies who are offering commercial installations of VAWTs. Although they haven't sold many to date, at least we see that these are both past the R&D phase.
http://web.mckenziebay.com/
http://www.solwind.co.nz/vertical.htm
Your quote of the KE formula is incorrect (KE = 1/2*m*v^2), and your conclusion about cubes vs. squares is wrong, because a mass-flow capture device derives its energy from not just the SPEED but the AMOUNT of mass that goes by per second (i.e. the mass flow). So, if you double the velocity of the wind, the MASS part of the formula doubles as well as the velocity part; that is why the power (energy per unit time) is proportional to the cube, not just the square of the velocity in any mass-flow device.
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 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 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 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.
Sterling Alan http://www.sterlingdallan.com/ is also webmaster of "VaporTechnologies.com"
( it's: Allergy-free cleaning )
"...vertical turbines can never be as efficient as horizontal (propeller style). There's a reason airplanes use horizontal propellers; they're more efficient."
http://www.fanwing.com/
I think you should check your dogma.
When I saw the photo, I immediately thought of my local library's copy of a hippy-era how-to on building a vertical-axis wind generator out of 55-gallon drums, plywood and junkyard auto parts like axle bearings and alternators. It's called "Wind and Windspinners: A Nuts and Bolts Approach to Wind-Electric Systems" by Michael Hackleman.
Basically, you cut the drum in half longways, and then offset the halves from each other to form an "S" shape with the two halves overlapping slightly, so that wind enters the open side, follows its contour into the closed side and exits out the back. The book recommended stacking 3 such drums, offset 60 degrees from each other and with plywood circles between the drums to prevent spilled wind. If you want to get fancy, you build sprung gates into the backs of the drums so they can dump excess wind in a storm. There are some drawings and photos of the design here.
I think Hackleman's reason for championing the Savonius design had nothing to do with efficiency - instead, it was all about cost, simplicity and durability. Fits right into the microgrid idea - a small village in the third world could assemble a few of the cheap homemade versions of these and link them to a battery bank to get themselves some simple, reliable electricity for whatever they needed to power.
6. Audible Alarm (not shown)
-from a Cuisinart product owner's manual.
And it's not even open source. From the article, "TMA is not releasing the most current photos, due to the patent-pending status of some of its aspects."
There are at least two types of verical turbines. In one type, "The Darrieus type is theoretically just as efficient as the propeller type, but in practice this efficiency is rarely realised due to the physical stresses and limitations imposed by a practical design."
In the other type, "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 rotor.
DRM 'manages access' in the same way that a prison 'manages freedom'