Talk:Wind turbine/Archive 1

Images

Does anyone have some better images? I like this one which I know is from Riverside county, California, but I'm not sure of its provenance. Nrcprm2026 21:58, 22 December 2005 (UTC)

Kirke variable pitch VAWT

This page is completely devoid of anything to do with variable pitch VAWT that have proven ability to start earlier and overcome the first moment of inertia along with improved torque and efficiency. Dr. Brian Kirke in Australia first Patented it but sadly the vibration at high RPM caused destructive shock loads through the device. The Italian Kobold [[1]] has used the variable pitch for several years on a water turbine. Davidson and Hill added a Patented hydraulic dampener that resolved the destructive tendencies but nowhere on the article does anything on variable pitch appear. Being new to Wiki I would edit the page but need some assistance to make it look right. 210.9.237.1 01:06, 21 October 2007 (UTC)

"American-style" windmill invented & used in Australia?

Why would a turbine invented in Australia, and used first in Australia (as explained in the article) be called "American-style"? This makes no sense. Even the caption to the related image calls it American-style, which is what tipped me off. I live in Australia and when I hear "windmill" this style is what I think of. When I saw an image of one, and the caption said it was an American-style windmill in Germany I simply found it baffling. This needs fixing. Also the text mentions "Australian and later American prairie farmers" when there is no such thing as an Austrlian prairie farmer (now an Aussie Dairy Farmer is another thing altogether <g>). I plan on editing this in the next few days if no-one else does. LowKey 02:24, 18 April 2007 (UTC)

Okay, I am about to change the term, but I am a little stuck for an improvement. While I think "American-style" is inadequate and inaccurate, the alternatives are not much better for various reasons. "Southern Cross" is the name that I have always known them by, but that is the primary manufacturer of them in my corner of the world. "New World" doesn't fit, because they have been used extensively in both Africa (Old World) and Australia (Old World, New World or whatever, depending on the context). Considering the Australia/America/Africa usage, I thought of "Colonial" but apart from being offensive to millions (myself included) I have never actually seen that name in use and so it would qualify as original research. "Modern Rural" is the only term that suggests itself as an adequate descriptor. Does anyone object to this? (Does anyone even care?) LowKey 06:25, 30 April 2007 (UTC)

I have changed "American-style farm windmill" to "Modern rural windmill", and I have removed "prairie" from "prairie farmers" so that the term can apply to Australia as well as America (or more precisely USA, I presume).LowKey 00:12, 3 May 2007 (UTC)

I have sorted this section out (with references). The "invented in Australia" part was simply incorrect. Rmhermen (talk) 00:29, 28 January 2008 (UTC)

It looks good. The whole section was a bit a mess for a while there. It probably needs a little further work though, because IIRC Eclipse used an existing, in-use design which they modified slightly (simplified by fixing the blades, I think, making it cheaper & more reliable, though visually very similar). It would be good to mention this earlier rural turbine. LowKey (talk) 02:27, 13 February 2008 (UTC)

NeoAerodynamic

I have removed the reference to NeoAerodynamic in this page, as it constitutes Original Research, is unverifiable, and does not carry any citations. The entry was therefore clearly in violation of WikiPedia content guidelines.

Hello Maury. You should be fair to remove "the windmill with rotation sail...." Are you are one of their employee? FYI: University of Limerick of Ireland is actively work on this. And there will be commercially available no later February by Hilo Energy. —Preceding unsigned comment added by Minhducthandan (talk • contribs) 22:47, 18 December 2007 (UTC)

Regards, Thanks for your effort to keep WikiPedia content guidelines such as "Windmill with rotational sails"

C n thomas 06:34, 11 June 2007 (UTC)

Turbine design and construction section

a VERY interesting NEW concept/idea that should be added in the article: The Wind Energy Skyscrapers Power Plants

this section is quite confusing with only explanations present. would someone with clear understanding of the axial momentum concept please input some diagrams in the section (to do with the turbine) to clarify about how the things actually work? -User:ruolin59 17:52 November 11, 2006 (UTC)

Anyone ever seen a wind turbine like this? Very Large Wind Turbine Design

Wallyflint (talk) 03:40, 16 February 2009 (UTC)

No, never have. Not sure if this even makes much sense really. The turbine is downwind, which is not generally done for reasons stated in the article about HAWTs. Is bending moment/stability even really the problem with large turbine masts? As far as I know, this is not the case, and this seems like a strange way of engineering a solution even if it is.

Regardless, this would constitute independent research and is not eligible for inclusion in the main article. --Tspine (talk) 20:48, 18 February 2009 (UTC)

Bird kills

Ornithologists - and bird societies - have a vested interest in promoting windfarms: wind energy developers hire them as consultants. Windfarms have thus become a goldmine to bird experts, and they won't admit they kill birds "significantly".

To form a balanced opinion on the issue of bird-kills at windfarms, reading the following paper is essential:

www.iberica2000.org/Es/Articulo.asp?Id=1875

It recompiles monitoring studies and birdkill statistics that have been hidden from the public.

Mark Duchamp....... Jan. 26 2006

What evidence is there of birds having been killed? Birds should be more mobile than rotor blades. How many birds have been killed by power stations burning coal or oil? How many birds are being killed every day by cars? Isn't the bird-killing argument just one way of opposing wind power just to secure the gain of the electrical power companies, the oil magnates and such like?

Herwig Wulf, Kirchzarten, Germany

Birds do get killed in wind turbines. They also get killed by autos, airplanes and even from flying into windows. I was in a plant in Seckach, Germany some years ago; the glass windows at the top of the shop area had birds painted on them. I asked a local person why. They said it was to keep the birds from flying into the glass. As far as I can tell, the people who complain about birds being killed by windmills are also people who complain about pollution. They can't have it both ways. -User:RatOmeter

It is not two ways if windmills do not actually mitigate pollution but are themselves just another blight. Kerberos 23:59, 31 December 2005 (UTC)

Two sites with discussion forums for this and other issues with industrial wind power are:

• Greenpeace UK's Yes2Wind (pro)
• the independent clearing house Wind-Farm.org (con)
• windpower.org (actual statistics)
• [htto://www.awea.org/ American Wind Energy Association] (pro.)

At least 200 times more birds are killed by housecats in North America than are killed by wind turbines. Nrcprm2026 23:13, 22 December 2005 (UTC)

And there are 15,000 times more cats than wind turbines. In any case, that's a very weak rationalization. Kerberos 23:59, 31 December 2005 (UTC)

For Herwig Wulf: In our area (Altamont pass wind farm, northern California), the large numbers of low tower, high speed turbines and ground mounted savonius rotors are known locally as raptor cuisinarts. The evidence of bird kills is the large number of traumatized dead birds, mostly raptors - over 300 per year. found around the wind farm. Modern large turbines are slower turning (birds have actually be videotaped flying through the arc of the blades) and as the lower reach of the blade is higher than the normal hunting altitude of the raptor (typically red tail hawk and golden eagle), the birds can share the space with the turbine. Leonard G. 15:53, 27 Aug 2004 (UTC)

The Altamont pass turbines, which are almost 30 years old now, are notorious for killing birds. They are also very noisy. Modern turbines above 100 kilowatts move very much more slowly and kill very few birds. Modern wind turbines in the megawatt range kill almost no birds, and are very quiet. Nrcprm2026 23:13, 22 December 2005 (UTC)

Their rpm is lower, but their speed at the tips is as fast as ever. They do kill birds, and the wind companies don't allow independent research to determine how much. And even the industry is concerned about very high bat kills. Kerberos 23:59, 31 December 2005 (UTC)

Do you have any sources that angular velocity is "as fast as ever" at the center of modern wind turbines? —James S. 06:40, 1 January 2006 (UTC)

It comes out of the aerodynamic theory. The tip speed of a modern 3-blade-turbine is 6 to 7 times as fast a the wind. The maximum at nominal windspeed or higher windspeed is round about 80-90 m/s for the tip. The angular velocity (or rpm) depends on the wind speed and rotor diameter. Hadhuey 20:44, 1 January 2006 (UTC)

Went and researched into it after above poster, because 90 m/s (325 km/h, 200 mph) sounds very fast. Good news is that this only happens in the highest speed wind class locations, or for 2 blade turbines. This site cites the maximum tip speed being limited to 60 m/s (215 km/h135 mph), because the generated aerodynamic noise rises with the 5^th power of linear speed. This speed is still very fast. This other site cites the optimum speed ratio λ≈4π/n, where n is the number of blades, so for 2 blades this becomes about 6x, for 3 blades about 4x, and for 4 blades about 3x the wind speed. So one way to cut bird mortality is to increase the number of blades, but that also puts more stress on the pole and makes the turbine more sensitive to demise under sudden gusts or very fast wind storms, but it also decreases the oscillating imbalance fatigue for whenever a blade passes next to a pole. Another way to cut bird mortality somewhat is to increase the blade size, because the optimum tip speed is constant, so the rpm drops as the radius increases. Basically a 3-blade 200 m or 1m diameter windmill will have their tip moving with the same optimum 24-32 m/s (95-115 km/h, 60-70 mph) speed in a 7.0-8.0 m/s class 5 zone, their respective rpm's being 2.3-2.9 for the 200 m vs. 460-580 rpm for the 1 m turbine. Quite a difference. A 200m turbine hits you quite hard if it hits you with 32 m/s, but at least you get a 1/2.9rpm/3blades=1/9th minute=6 second chance to escape before the very visible next blade comes by, compared to a 1/460rpm/3blades=0.0007 minutes = 43 milliseconds in case of a small turbine's invisibly fast blade hitting you with the same speed, and most likely with a smaller, sharper blade too. Note that you'd have to use approx. 40,000 1-m turbines compared to just one 200-m turbine to cover the same surface area, and thus extract about the same power, and the speeds for these 40,000 turbines would be very fast throughout the whole area, and the blades hard to see, compared to only the tip region for the big turbine with easily seen blades, so the below discussion I wrote earlier is still somewhat relevant asking for big turbines, preferably with more blades for slower speeds. Sillybilly 00:20, 2 January 2006 (UTC)

The optimum Tip speed ratio (λ) for 3-blade turbines is between 6 and 7. For 2-blade it is about 10 and 15 for a one-blade-Rotor. The formula λ≈4π/n is wrong as you can see in the picture on the same website (there the optimum is at λ≈6). Typical nominal speed for a modern turbine is ca. 13 to 14 m/s. Turbines with more than three blades are more expensive (you have to pay for one more blade) and dont have a obvius advantage in their efficiency. Hadhuey 17:27, 2 January 2006 (UTC)

Off the top of my head here, if I were a bird, I think I'd prefer being hit by a big fat pole coming at me so I could bounce from it, plus clearly see it coming at me for a few seconds, instead of a small, thin and sharp blade that gives me less than a second to react, plus it's invisible because of the high speed. Yes, the big turbines also have sharp edges at the very tips, but down toward the center they get fatter, and slower, so the killing zone is only near the tips, over a reduced area. You probably want to compare bird mortality per delivered megawatt - I think many tiny turbines spinning fast, vs. a huge one spinning fast, the tiny ones mince and dice birds up a lot worse for the same swept blade area, or for the same megawatt. Theoretically you could cover each wind turbine with a net, that would cut down efficiency by a lot by hindering the wind, but be safe and keep the birds from getting hit. Question is how much damage you do on the environment in order to sustain your own life - to feed yourself you too kill something, or get others kill something for you - be it chickens (or carrots if you're a vegetarian) - but that does not mean you exterminate them, or live not in harmony with nature, does it? Eskimos and native americans live in harmony with nature, because they respect it. Respect and the attitude is what counts, but they do create casualties, they do inflict damage on other lifeforms, even while feeling respect - but that's life, all around you, in equilibrium, via a food chain. Airplanes have bird casualties too, but we still fly them. Driving on the highway kills lots of mosquitoes too, that are a pain to wash. Life and respect for life is important, but windmills, if properly spaced and designed should not decimate an ecosystem or drive species into extinction, just like driving cars doesn't drive mosquitoes to extinction. I think if we can cut bird mortality from say 100 per megawatt-hour to 0.01 victim per megawatt hour, that'd be a good thing. A zero mortality rate, though a nice target, it's absurd. Windmills provide renewable energy, that would otherwise have to have been obtained by burning fossils, damanging the environment just as much, through global warming, even if that environment is remote from you, such as Lake Chad disappearing, instead of the very near dead birds next to you. You can't win, anything you do has faults - what counts is trying to inflict the least amount of damage in order to sustain yourself, and the actions carried out in a good faith attitude towards this goal. Do you have a better solution to the energy problems? Solar panels just sit and do nothing, and if they don't get hit by hail, after 7 years they return the initial invested energy, and they church out juice from then on, for years and years on, maybe even a century. A payback period of 7 years energy-wise, or 20 years financial wise, is not very tasty, most US businesses won't even consider something that doesnt' repay itself within a year as a viable investment, so we are back to resorting to the more profitable but bird killing windmills, that financially pay back in a year or so. Technically you should be able to add bat sonars the scare off bats, and well designed scarecrows/night flashing strobes to scare off the birds cheaper and more energy efficiently than what it would take to add a net. Anything comes at a sacrifice, at a cost, but losing 1% productivity, getting .99 instead of 1 MW-hour, may or may not be worth cutting the bird mortality rate from 100 to 0.01, in your eyes, morality wise. Or at least you could provide for some benefit in exchange for the birds killed, such as providing birdfeeders away from the windmills, to pay tribute to the birds sacrificed, if that comforts you. Sillybilly 08:54, 1 January 2006 (UTC)

"How many birds have been killed by power stations burning coal or oil?" - I'm not sure, but considering the Nature magazine article showing that "on the basis of mid-range climate-warming scenarios for 2050, that 15−37% of species in our sample of regions and taxa will be 'committed to extinction,'" using over 1100 species world wide, and only estimating for mid-range climate change (it goes up to about 50% for high range), I think it's fairly obvious that the huge number of species saved (by switching to non-greenhouse gas emitting electricity production) is much more important than the relatively small number of birds that die each year due to wind turbines. --naught101 01:32, 2 January 2006 (UTC)

Do a search on the topic of bird kills on www.fieldlines.com (a forum for the amateur construction of RE resources) and you'll find that one of the biggest complaints is that there is very little data, either for or against, bird kills due to wind turbines. 147.145.40.43 23:59, 2 January 2007 (UTC)

It is accurate to assume that the average human being hits more birds with they're car by accident than birds hit wind turbine rotors. If birds hitting rotors deserves a centence on this article, then cars hitting birds deserves an entire article devoted to just that. It is obvious that this is an insignificant issue, and if we don't start using wind turbines amongst other renewable sources of energy, we're going to kill 20-60% of the species of life on the planet according to the IPCC Fourth Assessment Report (2007). For all of you who have those "No bird killing turbines here" signs in your front yards, wake up! Nick carson 13:24, 4 February 2007 (UTC)

Environmental effects of wind power#Birds has some updated, well-sourced content. Note the difference between killing individual birds vs. wiping out entire species. Roaming domestic and feral cats in the U.S. kill more than one hundred million songbirds per year, yet to my knowledge cats have not been implicated in the extinction of any bird species. The most bird-unfriendly wind farm in the world, Altamont Pass Wind Farm, kills up to several hundred raptors per year, but this level of killing has been going on for more than 20 years. If the wind farm were killing birds fast enough to hurt their numbers, we would expect the number of dead birds to decline each year. If the kill numbers are steady, the wind farm is probably not a threat to the species involved. I've seen dead raptors on highways, where they fall victim to the same cars which produce the carrion that attracts them, and yet turkey vultures are not endangered, thanks to the bounty of road kill. The fact that cats and cars kill several orders of magnitude more birds than wind turbines each year is not a reason to ignore the problem with wind turbines, it merely makes obvious the disingenuousness of wind turbine opponents who cite birds as a reason to stop wind power while hypocritically ignoring the vastly greater bird deaths from motor vehicles and cats. If someone really cares about birds, they will object to the other bird killers a few thousand times more often than they object to wind turbines. Consider: I am a fairly informed person, but I had no idea how deadly cars and cats are to birds until wind-NIMBYs started yapping about birds, which motivated me to do some reading. I can't recall hearing anyone invoking the bird argument against cars or cats, suggesting that birds are not the real issue here. Wind power has the least environmental impact of the currently-available large-scale power generation options. The only real objection to them is aesthetic, from the minority of people who don't like their appearance, which again is absurd and hypocritical coming from anyone who doesn't see a problem with the hideousness of automobiles and the resulting sprawl, violence, noise pollution, support for terrorism, etc. Most people don't mind wind turbines, and in fact wind farms are becoming tourist attractions around the world (see Unconventional wind turbines#Wind turbines on public display). Besides, peak oil may sharply curtail recreational motoring soon enough, so the people who depend on automobiles to drive around rural areas to get a cartoon approximation of country living may not be able to get around as much and see all those wind turbines sprouting up. Imagine, living in the country and having to actually see where your energy comes from, instead of blasting the tops off mountains in West Virginia for coal, or supporting the environmental and humanitarian catastrophe in Nigeria resulting from the oil business there. There should be a requirement that people who consume energy at five to ten times the world average should have to see where their energy comes from, rather than forever trying to Environmental justice#export the mess to someone else's backyard (with the someone else usually being disadvantaged in some way). Wind turbines are one of the few power sources benign enough to actually live near. --Teratornis (talk) 04:45, 31 December 2008 (UTC)

questions of bias

Bit of a anti-wind energy pamphlet in it's current form. The tone is already biased and the arguments are one-sided.

Added the opinion of supporters, I think it is a bit more balanced now. By the way, I saw the photo next to the opponent opinion before on a " anti" website. So there might be a copyright issue there. I also have the impression that this a blow up of a piece from a photo taken with zoom-lens. This gives the impression the turbines are closer together than they really are. This a trick is often used by opponents to show how 'horrible' wind parks are (recently used in 'der Spiegel' in Germany).

I will make an excursion soon to take some new pictures - however, don't be suprised if they look quite similar - the packing of these small devices is quite dense - the only significant difference will be the grass color If I do it before the rains come - it will be a golden yellow. I will publish locations, zoom ratio, etc. Leonard G. 01:38, 6 Sep 2004 (UTC)

Yeah , i also felt like the article is a little bit anti-wind energy. May be this perception is because i view wind energy positively. I have to acknowledge though the article is very well written and i shouldn't be whining. gathima 17:22, 27 Feb 2005 (UTC)

Bias?? It's an article about turbines. — Omegatron 21:24, 6 November 2006 (UTC)

prospecting

"The normal way of prospecting for wind-power sites is to look for trees or vegetation that is permanently "cast" or deformed by the prevailing winds."

This is complete and utter nonsense. The wind energy industry is a little bit more advanced than that

--Not at all: I've read an article about a wind prospector, and that's exactly how he described his work. Only after that initial scouting does it become a matter of measurement towers.

In which country? In the Netherlands developers just use data from the meteorological service. Maybe if the measurement network of the meteoservice is very thin, this might be a way. But to write it down as the normal way of doing it?

--The meteorological service provides a general overview of the winds, but for all of the UK, for example, there are but 70 measurement sites -- in the U.S. they are even more far apart -- so to find a specific potential location requires looking at the trees.

There is also a thing as model calculations. Geography, buildings and landuse are put in a computer model together with known wind speeds at higher altitudes. This allows calculations at hub height. Do you have a reference?

--Seattle Times had a big article about the job; "Part science and part black art, prospecting must go beyond maps and weather data to read the face of the land for the mark of the wind. Maps can be wrong, weather data incomplete." And Canadian TV: "So while Thompson uses scientific measurements to chart wind patterns, he also understands the art of wind prospecting, using his instincts to see where gusts are strongest. He says twisted and knotted trees are often a good indicator, as are rocky patches scoured down by years of breezy conditions."

Interesting articles, surely different than it is done here in the Low Lands. Still have the feeling that the text should say that this is A way rather than THE way. World is bigger than the U.S. you know!

--Perhaps there's a mixture of methods, where physical evidence is especially studied in a locale with complicated geography (hilly, mountainous or other features that might cause unpredicable wind patterns). As for meteorological measurements in N. Am, the number of stations and spacing varies greatly but is improving in general. Google "+oklahoma +mesonet" for a good example. User:RatOmeter

• The number of meteorological weather sites in the United States in particular and the world in general is huge. Nearly every single farm in the US has a station because they are paid quite a bit by the NOAA to monitor it (which is very easy). The problem is that even with these stations the mesh of weather models right now have a grid size of approximately 10 km^2. This is great for weather forecasting, which is what they use it for, but knowing that the winds within a 10 km^2 area are somewhat high does not mean that you can simply throw down a windmill wherever. You have to look for high wind locations within that 10 km^2 area. Oh and the reason that weather models use a 10 km (at best) grid size is due to computational complexity, not a lack of data. Is it just me or should this article have a link to the noaa.gov pointing at where to get wind data? --Ignignot 16:59, Aug 17, 2004 (UTC)

I've never been paid by the NWS or NOAA for weather information -- or do you mean "utility-based wind farms"? And, as a former professional meteorologist, I've never heard of NOAA paying for a METAR installation anyway. 147.145.40.43 00:03, 3 January 2007 (UTC)

• I currently work in the wind energy industry, so let me explain how site prospecting is done:

1) Wind map of the continent: theoretical, based on known weather conditions and topography 2) Detailed theoretical study of promising areas, after elimination of areas such as national parks, military zones, areas of outstanding natural beauty. 3) Depending on who is doing the study, approach land owners. 4) Conduct measurement campaign of at least one year, often several years on the proposed site. 5) Correlate measurements with nearby reference stations to make a prediction of long term energy yield.

Visits to the site do not involve examination of wind-swept twigs. They involve assessment of the quality of the installation of meteorological equipment and the location of major features, such as barns, forestry, etc., near the site. User:Waster

At www.fieldlines.com, the typical response for site placement questions includes: desired voltage and wattage output, type of turbine proposed to be installed, installation height, trees/obstruction and their height, average and mean wind speed and direction, and desired tip speed ratio (TSR) of the blades. 147.145.40.43 00:03, 3 January 2007 (UTC)

Maturity

Some of the article needs to be matured-up. The point about wind generators being beautiful art forms right after the picture of wind turbines in CA as an eyesore do not go well together. Personally I think I have some bias that would infect any writing so I will not edit this article, but someone who is more comfortable should. Also, by coincidence, the most efficient number of blades is three, and that lines up with the 120 degree tangential symmetry of three phase power. I believe they mean radial symmetry. I'm not even sure what tangential symmetry is, other than an extremely confusing google hit. However, the comparison between the 3 bladed design and 3 phase power supply is silly, as they have absolutely nothing to do with each other. The reason for 3 blades is explored earlier in the article, the reason for 3 phase power is not that 4 phase would be worse, it is instead that 3 phase is good enough. Also I think that the vocabulary should be moved to everyday, adult, usage. epistimological does not belong in what amounts to a technical article. Most of the article is sloppy, for example 100 m high is used in one sentence and then immediately after 35-m-long is used.

The number of blades has nothing to do with the phase of the electricity being generated (which, from the various forums I've visited, can be 1 to 6, depending on the generator being built and the builder's design goals). The number of blades is a balance between needed torque, wind resistance, blade balance, and wind noise generation. It just so happens that "3" is the best compromise. 147.145.40.43 00:07, 3 January 2007 (UTC)

In case you didn't know...

Just like with a fan, don't put your fingers between the blades because you never know when a strong gust of wind might come. Don't climb the mast unless you really know what you're doing.

Wow. Thanks for the tips. ✈ James C. 07:12, 2004 Sep 4 (UTC) (on a more serious note I found the wind turbines in Ohio to be the most awe inspiring structures I have ever seen) I have been told by Santa that i am immature yes indeed

poetic turbines

Also, by coincidence, the most efficient number of blades is three, and that lines up with the 120 degree tangential symmetry of three phase power. Therefore, there is a poetic narrative that makes a good conversation piece.

What the hell does this mean exactly? I'm sure I could create a poetic narrative on the aesthetics of twin cooling towers in nuclear powerplants. ✈ James C. 01:07, 2004 Sep 6 (UTC)

James, you are quite correct -- this post is meaningless. More and wider blades = slower rotation speed and more torque. An even number of blades causes intertial precession and violent, choppy yaw motion of a wind turbine, which is one reason why 3 blades is a standard for electrical power generation.

The number of blades has absolutely nothing to do with the number of phases in the electrical circuit...that is complete nonsense as you correctly speculate.

DAN Danbob 05:29, 2 Nov 2004 (UTC)

This should be removed. It damages the credibility of an otherwise good article. I find it hard to believe this is a common argument of supporters. If so, it should be cited. Delief 2:49 30 Nov 2004 (NST)

Copenhagen windfarm caption

"Wind often flows briskly and smoothly over water since there are no obstructions. The large and slow turning turbines of this offshore wind farm near Copenhagen take advantage of the moderate yet constant breezes at this location. For wind power, consistancy may be more important than peak power, as consistancy enables the displacement of base load energy generation - typically by nuclear or fossil fuel powered generators. At this site, close to rated power is produced 97 percent of the time. ..."

What windfarm is this that such a claim as this is possible? There is data for the Middelgrunden Wind Turbine Cooperative half of the Copenhagen windfarm at www.middelgrunden.dk/MG_UK/project_info/production.htm. Their 2-MW turbines need a sustained wind over 30 mph to produce at full capacity (which is typical for large turbines). Output falls off quickly at lower wind speeds. In 2001, they produced 19.5% of their rated capacity, in 2002 28.9%, and in 2003 (apparently estimated) 24.7%. Output varied in 2001 from <1 GWh in Jan to >5 GWh in Nov; in 2002 from <3 GWh in Apr, Jul, Aug, and Sep to >6 GWh in Feb; and in 2003 from <2 GWh in Feb to >6 GWh in Dec. This is a month-to-month output from less than 7% to just over 40% of the rated capacity. There is also a day-to-day output graph, showing many days with no output at all. Overall, production is only about 5% (of rated capacity) more than a typical onshore facility in Europe. The page says that "[t]he farm efficiency is estimated to be 93.3%," but this only reflects actual output versus projected output, the latter being 28% of rated capacity. They guarantee an output of about 25% of the rated capacity.

Assuming this is the windfarm in the picture, therefore, it may be misleading to imply that its output is "consistent," and it is certainly wrong to say that "close to rated power is produced 97% of the time." ~~Kerberos, Sep 10

Guys check out these turbines and capacity factors of these windfarms in NZ. Tararua over 48% after more than 5 years, and Brooklyn wind turbine in Wellington. Brooklyn is a single turbine and as far as I am aware it holds the world record for capacity factor, around 60% I think..!!

Dissapointing article

This is a very dissapointing article. Summarizing what proponents and antagonists have said is okay, as far as that goes, but no substantial, neutral facts are presented that could lead an interested reader to any conclusions. Here's what I've found:

• Fact: Western society is power intense, around a kilowatt per person. China and India are heading our way fast.
• Fact: The sun hits the earth with about one kilowatt per square meter at noon. There is plenty of power coming down, the challenge in renewable energy is gathering it.
• Fact: Government agencies in the U.S. and Europe have been mapping wind resources for three decades now. There is good confidence that substantial wind energy exists. Enough in North Dakota yadda yadda yadda. But:
• Fact: Most of the wind energy is class 3 or class 4. Very little is class 6 or class 7. And very little of that is near population centers or near existing or even plausible electrical routes. The enormous class 7 resource along the Aleutian islands might as well not be there.
• Fact: Wind power has a capital cost of about $1/watt -- in class 6 or 7 conditions, and that's peak watts. Wind farms tend to deliver, on average, about 25% of peak, which means the capital cost of average delivered wind power is about $4/watt. The operational cost is around 10% of that, or $0.40/watt delivered.
• Fact: The capital cost to the investor of a natural gas fired turbine/generator is $0.4 - 0.6/watt. The fuel cost is about $0.32/watt per year, and increasing.
• Fact: Various subsidies, many well intentioned, attempting to cancel the effects of hydrocarbon subsidies, etc, have resulted in many of the class 6 and 7 areas (Altamont pass, etc) being built out.

Opinion: Small numbers of wind turbines are pretty to look at from a distance. Large numbers of wind turbines (more than a few dozen) are not pretty, and, though the first turbine is kind of cool to look at up close, they get tiring. In the numbers that are going to be required (see below), turbines are highly objectionable.

What is wind power good for?

• Wind power has historically been cheaper for pumping water, though a century of cheap hydrocarbons and reliable engines has left windmills in the dust.
• For remote locations, wind power is a lot cheaper right now than building long utility connections.
• In the future, wind power might be able to supply a very significant fraction of civilization's power demand, and there are real benefits from that. We could stop financing totalitarian regimes and terrorists, improve our foreign trade deficit, and smooth out a major cause of instability in our economies, for starters. With even larger fractions, we could reduce our CO2 emissions usefully. But, for this to happen, extraction from class 4 wind areas will have to become competitive with hydrocarbon power. Barring a complete rewriting of the wind maps, class 5 is not going to do it.

So what is going to have to happen to get to a significant fraction of grid power coming from wind, in the next 20 years, in order to achieve benefits to ordinary consumers that are worth real amounts of hard-earned money?

• Wind power capital costs per delivered average watt will have to come down 20-50%. This is imaginable.
• Wind turbines will have to be that cost-effective in class 4 conditions rather than class 6 or 7 conditions. This is much harder to imagine, as the available wind power density is 5 times smaller, so the turbines have to be 2.3x bigger and take higher peak loads.
• The problem of connecting an intermittent power source to the grid will have to be solved. This is an excellent R&D project for government to fund, and it is being funded, though probably not at a level consistent with 5% wind power in 2020.
• Once these problems are solved, a fantastic number of turbines will have to be built and installed. For each 1% of grid power for the G-8 (around 18 gigawatts), 20,000 of the largest 3.6 MW turbines will be required, and they will be even bigger than the current 100 m rotors that we see today, so they can work in lighter wind. Those turbines will carpet more than 5,000 square kilometers.

Until this has happened a few times over, the grid-connected turbines you see going up are taxpayer-subsidized R&D projects trying to get more information, and give more power folks practice, at less cost by contributing some useful amount of electricity.

When turbines in class 6 wind areas become economically viable without subsidies (which could happen very soon), those installations are going to be profit-generating facilities for their owners, but are not going to give the consumers of that electricity nor the local residents significant externalized benefit. If the owners of these wind farms pay off the locals in order to get the things installed, then good for them -- but that payoff better exceed the costs to the locals.

Lest I sound like a party pooper, I should add that I'm really jazzed about the idea of windpower. I think profitable offshore wind farms with many thousands of multimegawatt turbines in class 4 conditions are a real possibility. I think that there is a lot of R&D to do to get there, and I think that as a taxpayer it is in my interest to collectively fund that R&D in order to achieve the externalized benefits (security, economy). But I'm not impressed with the idea of subsidizing not-vast-enough eyesores to get that R&D done. I do think that a bunch of corporate profiteers have jumped on the windpower bandwagon and are trying to spin the public into accepting these eyesores so they can gain their subsidized profits.

Also: since there is not enough class 6 and 7 wind to achieve externalized benefits, it's not in my interest to subsidize R&D on turbines for such windy conditions, except as a stepping stone to class 4 generation. Class 6 and 7 is for venture capitalists.

Iain McClatchie 07:27, 13 Sep 2004 (UTC)

Good start, but big problems here...

This article has many good points, and many major flaws. I'm going to address them in little bites, from my perspective as a small wind turbine builder an experienced small wind turbine flier. More to come, as I can spare the time.

The biggest problem, and apparently the biggest item of contention in editing, is the major difference between large utility-scale wind power systems and small, off-grid home power type systems. These need to be addressed either in separate article sections, or individually in each section. As far as almost every table of contents header goes, these two issues are apples and oranges. The generator/alternator used and it's method of operation are completely different.

In any case, I'm only just starting out here, from the top, just one section for now--

Location

"prevailing winds" is vague, "average wind speed" is better and ties directly to wind zones. A very important factor is the Rayleigh distribution of the wind speeds--how much of the wind comes to you at 10 mph, and how much at 60 mph--and how much oiwer is available in each? The 60 mph wind certainly has 216 times more power than the 10 mph, but how often does 60 mph happen? And can the wind turbine even harvest that extra energy? Most wind turbines, small or huge, furl or shut down at over 30 mph.

Swept area is the most important factor after wind speed. It is not mentioned. Swept area is the only accurate way to predict potential wind turbine power output, small or large, at any given location.

Tree flagging, laying, carpeting, etc. is generally used only in siting small off-grid wind turbines where the property owner cannot afford the expense and year's time for an anemometer survey tower. How come "anemometer" doesn't appear in this article? And "data acquisition system?"

"Wind power is practical in most areas of the North American great plains..." -- inaccurate. See the NREL wind zone maps, they spell it out very clearly. Some plains areas are really bad, some are great. Same with the mountains. "certain mountain ridges can supply power for the whole continent...." sure, if the wind turbines can even make power with 60mph winds. I don't know of a single turbine that can exploit 60mph winds, small or large....these 'authorities' that are quoted obviously know nothing about wind power and were boasting to the news media.

An incredibly important factor in siting any wind turbine, large or small, is NOT mentioned -- turbulence. For small wind turbines, a well-known rule of thumb is that it must be sited at least 30 feet above any obstruction within 300 feet...some experts say even more. If mounted lower, or on a rooftop, turbulence robs most of the available power, and causes serious stress on the turbine.

"Distributed power", at least as described here, is a very nebulous concept...if you had 100 AIR 403s (at $500 each) on your building roof and the wind speed was 10 mph, your power output would be ZERO since each AIR403 has only a 4 foot diameter rotor, and there's hardly any power available in that tiny swept area--they can't make power at 10 mph since there's not enough power there, even though you spent $50,000. If you instead put up one 10 kW turbine with a 23 foot diameter rotor in the same spot at $15,000, you could be making serious power. Swept area is everything in determining potential power from the wind. Low winds need a big rotor to make any power at all.

The rest of this section seems like an ad for Aeromax and the Lakota. Read the AWEA discussion board on Yahoo for some more info about obtaining a Lakota. C'mon, this is shameless advertising. Or keep the Lakota pic and ditch the shameless advertisements. I don't work for any of them, so I don't care what they think about my comments here.

"dynamic braking" is described very inaccurately in the advertising section about the Lakota. This "dynamic braking" happens with any small-scale, battery-charging wind turbine....it's more accurately called a "dump load". With a small-scale, non-grid-tie turbine, there must always be a load on the turbine--you can't just disconnect the battery bank when it gets full...that would let the turbine overspeed and possibly fail. Instead, after the battery bank fills, a voltage-sensing circuit diverts power to an air- or water-heating element to use up the extra power while keeping the wind turbine under load. And also, grid-tied -- missing definition -- later.

This article REALLY needs to be split up into large-scale wind and small-scale wind. I'll work on it as time permits.

DAN--Danbob 05:31, 2 Nov 2004 (UTC)

Notes

Notes for fixing up this article:

--Danbob 02:26, 19 Nov 2004 (UTC)Add wind power history section. I can help write this.

Take the mapping bit out of Wind Energy and put it into Location

add Raleigh distribution versus actual measured power graph to Wind Energy section (need to find data for actual windpower measurements, probably on NREL site).

explanation of Raleigh distribution: [2]

The Raleigh distribution formula:$F(v)=1-\exp(-{\frac {\pi }{4}}({\frac {v}{\bar {v}}})^{2})$

Paper with actual measured distribution: [3]

Now the cool thing to do will be to plot the ideal and measured distributions together and use that to illustrate Raleigh wind distributions.

discussion of geographic averaging to minimize variability (in Location)

some discussion of maximizing delivered power over windmill cost versus system cost. This gets into the effect of variability on other power plants that have to compensate

add 1/7 power rule to Location section.

discussion of turbulence and increase in maintenance costs and decrease in availability.

add Taxonomy section, with

Drag versus lift devices

Horizontal axis wind turbines

Upwind versus Downwind

Two blade versus three

--Danbob 02:26, 19 Nov 2004 (UTC)vs. one, six, many

Teetering hubs

Danbob 02:26, 19 Nov 2004 (UTC)Does this mean variable pitch, or hinged blade roots, such as downwind machines like the Proven have?

Apparently two-blade HAWTs get a nasty yank on their bearings every time the rotor goes through vertical, because the top blade is in the fastest wind as the bottom blade goes through the forward wind shadow of the tower. Teetering hubs are some sort of hinge, I don't know what, that allows the blades to move instead of resisting the yank. Apparently teetering improves the reliability of two blade machines a lot. Obviously I need to do more research.

Constant speed versus variable speed -- synchronous versus asynchronous generation

Speed limiting via stall versus feathering

Danbob 02:26, 19 Nov 2004 (UTC) and versus folding tail or tilting blade axis

variable pitch

Speed limiting versus shutdown mechanisms

air brakes (maybe put this in wind power history. RE wincharger ;~)

Speed limiting via mechanical brakes or resistive load

Vertical axis wind turbines

Darrieus turbines

scroll-like scoop-wing things --Danbob 02:26, 19 Nov 2004 (UTC)(Savonious)

Danbob 02:26, 19 Nov 2004 (UTC)H-rotor VAWTS

Danbob 02:26, 19 Nov 2004 (UTC)advantages and disadvantages of VAWTS and HAWTS

Danbob, if you want to explain how things are different for large and small turbines, that would be great.

Danbob 02:26, 19 Nov 2004 (UTC)Mostly the huge differences are about being synchronous and grid-tied vs. non-synchronous and off-grid for battery charging, or non-synchronous and grid-tied with or without battery bank. Completely different alternator/generator concept.

Iain McClatchie 08:21, 8 Nov 2004 (UTC)

Could someone explain how a HAWT inherently increases its angle of attack at higher wind speed? I don't quite get it. Is this a constant speed HAWT?

Also, the exact background of the power generation/transfer into a power-grid seems to be missing.

Ec5618 12:58, Apr 5, 2005 (UTC)

Yes, constant speed HAWT. If blade root does not rotate (pitch motor is frozen), and the rotation rate stays constant, then as the wind speed increases the relative wind vector points closer to straight back, which increases the angle of attack.

Of course, big turbines have pitch motors, which is why they can furl. Fixed pitch turbines more naturally stall.

And yes, we need a section on generators and grid intertie. -- I get it now, the constant speed thing, thanks.

notes on the notes

Excellent to see some more input! I added a few notes to your notes and did not delete any. Maybe this article can become a reality. I can't really do more than generalize about utility scale wind power, but I can provide good data about small-scale systems. DANBOB

I was looking at the www.windpower.org site (Danish Wind Industry Association). It's a very good site. I was thinking of how to do a better job than them:

• They keep plugging Danish powerplants. We're already neutral here.
• They only talk about grid-tied systems. We can do both.
• They stick to three-bladed upwind HAWTs, we can present the full panalopy.
• They are relentlessly optimistic, especially in the economics section. I can be more neutral. :)
• They don't present controvery in a neutral way. The current wikipedia page does a clumsy job right now, but it can be made better while still neutral.

But the big thing I realized looking at that site is that there is way more than a single web page of information to be had. I know some folks like to split pages up before they add content. I prefer to add content before I split things up. So the page may get a little big before it gets clean.

Anyway, it's nice to have someone else helping. Thanks. Iain McClatchie 20:01, 19 Nov 2004 (UTC)

Pictures

question about contributing photos

i'd like to contribute some of my photos. though i have a few quick questions.

• my photos has "copyright 2004 xahlee.org" printed on them. Would that be a problem?
• I like to give wikipedia.org right to use but remain the copyright owern of my photo.

what can i do?

i just needed some quick answers or outline by those experienced photo contributors. (as opposed to pointing me to some lengthy wikipedia licensing documents or guides) thanks.

Xah P0lyglut 17:12, 2004 May 6 (UTC)

I use sometimes us cc-nc (enclosed in double braces). That allows use on personal web sites, use as educational materials by teachers, etc. Other people cannot publish to obtain revenue without additional license. This is especially appropriate where the image is of a performer, who would normally expect to recieve revenue from an image of the performace (see Beijing opera). For most other images I contribute, I use cc-sa, (share alike) which simply releases the image for any use by others, but all such releases or derivitive works must also be so released - see Fireboat. These two are the simplest, and (I belive) fairest. There are others, that will require that your credit as image maker follow the image, important only if you wish to present your skills to others for future commercial gain (or if you have a huge ego). Leonard G. 15:53, 27 Aug 2004 (UTC)

pics on commons

Hi, i have put some of my wind power pics from german article on commons (commons:Wind_energy_converter). Can put your pics together with them? i would like to use some of them too :-)) Hadhuey 19:53, 11 Feb 2005 (UTC)

Germany's wind turbines

I am not sure which statement is correct, wikipedia or the BBC article. Wikipedia says "Denmark is especially a leader in the production and use of turbines" while bbc says "Germany already produces 40% of all the world's wind power, and the hope is that by 2010, wind will meet 12.5% of German energy needs." This statements are exclusive, either Dane or Germany is the leader but not both. [4]

I however acknowledge this is a trivia problem. Who cares whether Danes or Germany leads in wind energy production. That explain why i didn't edit the contradiction

both is right Germany is leader in total windpower installation and production, but denmark (still) has got a higher rate of windpower energy relative to their overall production. Hadhuey 19:56, 2 Mar 2005 (UTC)

and Danish company Vestas is leading manufacturer.

Length/Should we split this?

For an encyclopedia article, I think this is way too long, but the main thing I noticed is that it is sort of talking about different things. It has a bunch of information on the physical properties of wind turbines themselves- how they work, their specs, etc. It also has quite a bit of info on wind power, including a pro-con section (which could be better) as well as history and cost and things like that. I propose we split this into two articles, one on the turbines themselves, and one on wind power as an energy source. Does this sound like a good idea to anyone? --Bonus Onus 21:00, Apr 3, 2005 (UTC)

I'm in favour of decreasing the length, but splitting in the way you suggest seems impossible. Physical properties are directly linked to design, which is linked to pro-con and placement. The article needs to be shorter, but the only segment I can see being cut in the segment on large scale wind mapping. I'm afraid we'll need to compress what we have. --Ec5618 8:45, April 5, 2005 (UTC)

I agree with Bonus Onus: I'd like to see a split into "Wind Turbine", covering the turbines themselves, and "Wind Power", covering the issues of large-scale extraction of wind energy. This seems like a very natural split to me. The current headings "Turbine siting", "Utilization", "Controversy" would go into a "Wind Power" article. --Iain McClatchie 20:57, 5 Apr 2005 (UTC)

I've thought it over, and it should work. There'll be some overlap between the two articles, but it should be more transparent. I'll sleep on it. Ec5618 23:36, Apr 5, 2005 (UTC)

I split it up. Now we have: Wind power, large scale applications, Wind turbine, individual machines, and Wind farm, which should probably be incorporated into the wind power article --Ec5618 06:15, Apr 7, 2005 (UTC)

It's good to see this article, now articles, finally getting some decent structure and clarity. We have a ways to go, still, but... good job. Iain McClatchie 22:11, 8 Apr 2005 (UTC)

I've reworked some sections. I think the part about energy extraction could usefully go into the "wind power" article. The part about generators was wordy, I hope it's less so now ( and the Wikipedia article Generator also needs help, as I discovered when I checked it). Could someone who understands the aerodynamics of the sitation explain how the blades move to furl or to stall (see my comment in that section) ? I can't visualize it from the description, and our proverbial bright 12-year-old would spend a lot of time puzzling it out from what's there now. --Wtshymanski 17:00, 22 Apr 2005 (UTC)

Vaneless ion wind generator - citation please

I've never heard of them. The only things I've turned up on Google point back at Wikipedia. Can anyone show a citation for an "electrostatic" wind generator as described? I think it may be a hoax - the current densities would be pathetic and if anyone was actually building these things, there would be some publicity, I would think. --Wtshymanski 04:13, 24 Apr 2005 (UTC)

I think you're right in that they've never been used practically. I came across the concept on www.halfbakery.com, which in itself does not merit a mention on wikipedia, but I remembered seeing it on a documentary at some point, so I did some (some) checking. Creating a current from moving water and Creating a wind by ionising air. They seemed to be proof of concept, so I added the reference. -- Ec5618 10:16, Apr 24, 2005 (UTC)

Halfbakery is not an authoritative reference. I've heard of the electrostatic water drop generator before but never in the context of making kilowatts - it's more of a lecture hall demonstration than a practical effect. I think this comes perilously close to "orignal research" which is beyond the scope of WIkipedia. I've already seen a few sites making monkey copies of this article as if it was a practical reality - we are going to greatly confuse the proverbial bright 12-year-old by interjecting this into a serious article on wind turbines. The reference would be better in an article on "electrostatic generators" if we have it. --Wtshymanski 15:19, 24 Apr 2005 (UTC)

I never claimed halfbakery is authorative. I claimed that reading about this concept on halfbakery sparked a memory of having seen this concept explained in a documentary. I then did some background reading on the subject, and concluded that, while it may not have been put to practical use, the concept stands. "For another way to convert wind energy to electricity, see vaneless ion wind generator." I suppose "a novelty way to .." would be better, but I don't agree with the removal of the link. Perhaps we should edit the linked page to provide a more balanced view. -- Ec5618 22:15, Apr 24, 2005 (UTC)

On/off/above shore

I've added sections on onshore, offshore and aerial turbines. I think we may need to create a page dedicated to the 'standard wind turbine', consisting of a tower, nacelle and great big horizontal rotorblades. We all know the type, but wikipedia lacks an article on the specific design. A lot of design features, like specific types of generators or twisted blades should be explained on a specific sub-page. The same basically goes for specific offshore designs, and aerial designs, which cannot be explained in full detail on this page.

Embodied energy

Does anybody have good references to research regarding the "embodied energy" in a wind turbine and the time required to break even? I found the below two links, but wondered if anyone else had good links?

(see "EMBODIED ENERGY") http://www.macgen.com/windpower/windfarms/About_Wind_Turbines.html

(see q27) http://www.sd-commission.org.uk/pages/media/list/wind_QAs.html

It's known as Energy Payback in the industry, and the Danish Wind Energy Association has it as a period of a few months: Energy Payback Period for Wind Turbines --scruss 16:51, 18 Jun 2005 (UTC)

Good job

It's nice seeing how much this article has improved, especially with the removal of nonsense (poetic turbines etc.). ✈ James C. 18:34, July 21, 2005 (UTC)

Power Output

How about some stats on what the actual peak output is for a large turbine. Megawatts? Tens of Megawatts? Psychofox 14:14, 21 September 2005 (UTC)

Even some details of the rated size of the turbines would be good! Wind turbine#Turbine size is two paragraphs that contain only two quantitative statements between them, in the first paragraph which states the mass of a turbine is approximately proportional to the cube of its blade-length and wnd power intercepted by the turbine is proportional to the square of its blade-length. These together would indicate that smaller is better, but the second paragraph then points out labor and maintenance costs increase only gradually with increasing turbine size, which indicates bigger is better. There's then a sweeping statement about size limitations which ignores the (interesting) mathematical relationships in the first paragraph. So are these relationships relevant in practice, or not? We can't really have it both ways!

The Danish Wind Power Association claims to have a Reference Manual and other detailed material, and they do indeed, but the rated output of a typical turbine doesn't seem to be stated anywhere. My first Google searches largely turned up sites selling domestic installations of 10-20kW only, a few at 200kW or so. Adding MW to the search helped!

The GE site offers turbines of 1.5 to 3.6 megawatts, and has news items dated up until 21 September 2005, so I'm guessing that's a fairly current figure. But, it doesn't say whether that is what is generated at the turbine head, or what is delivered to the grid, nor does the 3.6 MW details page or the PDF brochure and data pages to which it links. Perhaps with this particular technology, they are the same? With some large turbines these figures used to differ considerably owing to losses in conversion to DC and back to AC, but I may be out of date here. Andrewa 20:06, 8 October 2005 (UTC)

The DOE site is also a good read. Similar figures, they mention the GE 3.6MW unit specifically but call it a prototype while GE say it's a production unit. Andrewa 20:19, 8 October 2005 (UTC)

Is there any info about cost as well? I heard today on the radio that David Cameron, the leader of the Conservative Party in The UK, has applied to put a small wind turbine in front of his house. It's small about 3metres/10foot high and would apparently cost 2,500 UK pounds/about $4000 and would only generate 10% of his household electricity (It's not a huge house) and would take 71 years to pay for itself. So info about cost and power output would be useful especially if we're looking at how good/bad an alternative it is and whether it can be a personal wind turbine or if it has to be a huge industrial wind turbine to be worthwhile. Rcuttill 18:34, 11 July 2006 (UTC)

Check to make sure I reverted it correctly

I just reverted this article backwards several versions due to several successive instances of vandalism. If you have recently edited this article, you may want to check to make sure I got it back to the right version. Please accept my apologies if I accidentally reverted your valid edits and please fix them on my behalf. Joe 13:47, 20 October 2005 (UTC)

Another aspect/example of wind turbines

It looks like the article talks mostly (exclusively?) about big wind turbines; it might be good to mention smaller wind turbines like this one made by Blue Energy, especially in the context of small-scale energy production.

Counter-rotating

A quick Google search on "wind turbine" "counter-rotating" -wikipedia shows a few research papers such as http://eisg.sdsu.edu/shortsums/..%5CSows%5CSOW%2000-09.htm , and one company Web site http://www.eotheme.com/index.htm but they don't seem to have any installations. Reading this paper might provide some facts for the mill. --Wtshymanski 15:13, 15 November 2005 (UTC)

stalling, feathering and maths

I'd call reducing the pitch of a propellor or propelled-or to zero "feathering" it as in aviation. Furling sounds to me like th process that would work on an old Dutch windmill, with the canvas being taken in so that only half the blade was covered by it, analogous to sailing vessels. The maths section looks good, but I think it needs a going over to make it clear what the maths applies to. I can't do that. Midgley 16:47, 26 March 2006 (UTC)

VAWT

At least one site I found claims that VAWT have advantages over HAWT because the blades are simpler and the stresses more constant. I didn't want to modify the main article, however, out of concern I would wrongly classify what variants of the VAWT have this advantage (or if they all do.)--belltower

I wouldn't modify the article on the basis of some Web site item. Empirically, you'll notice that all the commercial-scale turbines being built now are horizontal machines. I've never heard of a megawatt-class vertical-axis machine and I strongly suspect that people who try to make money at building wind turbines know that horizontal machines work better. --Wtshymanski 18:39, 30 March 2006 (UTC)

There are actually several multimegawatt prototype vertical axis machines. If I understand correctly, vertical axis megawatt prototypes were built earlier than horizontal axis prototypes.

But it doesn't matter. The blades are simpler and stresses more constant in the 'horizontal' axis machines, and the vertical axis machines have all failed. Iain McClatchie 05:37, 31 March 2006 (UTC)

Horizontal axis turbines are more efficent and last but not least more cost efficent. Hadhuey 19:30, 26 April 2006 (UTC)

VAWTs do not necessarily have a large swept area. Savonius turbines don't. I removed this statement -"Due to the turbine's large surface area, very little wind is required to turn the rotor blades to generate power." VAWTs can self start with a high solidity of 30% or more. Kjwolf 05:43, 21 February 2007 (UTC)

I removed these two "advantages because the first one isn't an advantage and is wrong. The two types are lift and drag. The second "advantage" doesn't make much sense. HAWTs can use a flexibility of wind speed too. Better torque than HAWTs without sacraficing performance? Huh?

• Vertical wind turbines have two subgroups: Darrieus and Savonius Both were invented for the same multipurpose role of generating electricity in a flat open area far inland to create high torque, also creating a high-voltage output that can power residential and commercial applications, such as televisions and lighting.
• The two subgroups allow a flexibility of wind speed, due in part to the many angles in use that allow a better ratio of torque to output without sacrificing performance. This flexibility of angle configuration can suit any region or environment that has the minimal amounts of wind required to power the generator. The angle configuration of the turbine allows high performance.

I replaced this unproven VAWT advantage

• Being near the ground allows the turbine to collect extra energy from wind that bounces off a forty-five degree slope from the base of the turbine to the ground; when the wind hits the ground and is directed up the slope, around twenty percent more power is added to the wind turbine.

with

"* Mesas, hilltops, ridgelines and passes can have higher and more powerful winds near the ground than up high because of the speed up effect of winds moving up a slope or funneling into a pass combining with the winds moving directly into the site. In these places, VAWTs placed close to the ground can produce more power than HAWTs placed higher up." You can check with Rich Simon, renown wind industry meteorologist to confirm this.

I removed the statement about VAWTs being worse on birds. This depends on the VAWTs solidity. A Savonius type VAWT appears as a solid object. Windstar VAWTS have a 33% solidiy and their RPM has a blade passing a given spot between 3 and 5 times per second. Depending on the flicker factor of the bird species, these turbines should appear as solid objects as well. A HAWT can have its blades take a second or longer to pass through a given point in its rotation resulting in birds flying into open space and not seeing the blade coming up or down on them.

I changed the previous version that was absolute to one that more correctly explained VAWTs need for a relatively flat piece of land.

"* Most VAWTS need to be installed on a relatively flat piece of land flat and some sites could be too steep for them while available to HAWTs."

Also in VAWT disadvantages, I deleted

"* Instability due to its main center of gravity being in the airfoil. Strong support at the base is required." and replaced it with

VAWTs that use guy wires to hold it in place create serious problems for the bottom bearing as all the weight of the rotor is on it and the guy wires increase downward thrust in wind gusts. Solving this problem requires a superstructure to hold in place the top bearing that also can share the weight of the rotor.

I removed this VAWT disadvantage as it is patently untrue and negates a major advantage listed above

" Must be located in an area with steady prevailing winds.

I removed this because it is untrue

• Economics. Installing a vertical wind turbine is expensive, because they are not as widely used as horizontal wind turbines.

and replaced it with:

• Most VAWTs produce energy at only 50% of the efficiency of HAWTs in large part because of the additional drag that they have as their blades rotate into the wind.

I forgot to sign my name to the above Kjwolf 06:32, 21 February 2007 (UTC)

I've removed.

• Smaller VAWT are easier to install.

I don't think it is obvious that a small VAWT is easier to install than a small HAWT. Matthew —Preceding comment was added at 08:10, 29 February 2008 (UTC)

Is the VAWT vs. HAWT debate a little overblown on this web page? There is a lot of VAWT evangelism from small residential turbine scale manufacturers that touts dubious and unproven "advantages" such as lower cut-in speed. It sounds like some of their talking points, none with references as always, have bled through to this page. 169.234.121.42 (talk) 05:24, 22 September 2008 (UTC)

I've done a couple of edits to the advantages of VAWTs that were obviously redundant, but want confirmation before I remove any more. In particular,

• VAWTs have a higher airfoil pitch angle, giving improved aerodynamics while decreasing drag at low and high pressures.

This doesn't seem correct or meaningful.

• Straight bladed VAWT designs with a square or rectangular cross-section have a larger swept area for a given diameter than the circular swept area of HAWTs.

This seems to be a trivial result of the different design and not an advantage.

• VAWTs usually have a lower tip speed ratio and so are less likely to break in high winds.

This doesn't seem to be correct, as the tip speed ratio should not dictate reliability. A properly designed HAWT (as seen worldwide) is fine in high winds. Tspine (talk) 05:31, 25 December 2008 (UTC)

-- I think the comment about a VAWT having larger swept area than a HAWT is relevant to the fact that a particular VAWT could be more efficient in gathering energy from the wind than a HAWT and that differing efficiency measures are relevant - rather than an aerodynamic measure of efficiency. For example a 2m diameter VAWT of height 10m would, despite a lower aerodynamic efficiency , be better at getting energy than a 2m diameter HAWT - for a similar footprint. —Preceding unsigned comment added by 81.129.224.79 (talk) 16:14, 20 February 2009 (UTC)

Possibly erroneous history

The history states that the first wind turbine was built in Denmark in 1890, but I've seen a few websites say it was first built by Charles F. Brush in 1888. Here and here for example. Could someone double-check this?

Use of English Grammar

The grammar in this article is so poor, it's often difficult to comprehend. A second or third reading is usually required.

Make your writing lucid.

Oh very good. Perhaps you could actually EDIT and help correct the sad state the article has gotten into? Looks like several bad edits have mushed the opening paragraph into worthlessness. I'm shocked at how much the article deteriorated since January! --Wtshymanski 17:47, 8 June 2006 (UTC)

Maglev Wind Turbine

This is an interesting article [5], but I'm not sure where about in this article mention of it would belong Lurker 14:51, 17 July 2006 (UTC)

Much more info: 1 gigawatt turbines, needs to be added

http://www.inhabitat.com/2007/11/26/super-powered-magnetic-wind-turbine-maglev/ MilesAgain (talk) 20:10, 28 November 2007 (UTC)

School Project

I have a school project to do, and I found that these articles are really helping! Actually, I think this whole website is great!... Although, I think that on top of your articles (where 'article', 'discussion', 'edit this page', & 'history' is), there should be something like 'kids explination' or 'simple explination' or something, because I found it hard to understand. Especially with how much there is to read & how long it is!

--61.68.173.65 09:08, 18 July 2006 (UTC)Jemma

That's good. I'm glad. As for simple articles, we do have 'simple.wikipedia.org', though it is far less complete than the full English 'pedia. You may want to check it out, though. Good luck. -- Ec5618 09:20, 18 July 2006 (UTC)

Manufacturers

Don't Boeing make wind turbines? 130.95.128.51 07:51, 27 July 2006 (UTC)

Boing made a wind turbine in the early 1980s or late 1970s that was installed along Hwy 680 in Solano County between Hwy 80 and Benecia. It was about a 1 MW sized HAWT but with steel blades. Rumor was that Boing didn't want the risk to their image of anything bad happening to the turbine so they built it so heavy that it had severe bearing problems and only ran occasionally. It was taken down a few years later. As far as I know, that was Boing's only foray into the wind turbine industry. kjwolf168.150.253.55 08:22, 2 March 2007 (UTC)

I added Gamesa and Iberdrola in the Companies section, together with references about their role in the wind industry from the MIT Technology Review. Can someone let me know why it was erased? boirac[at]yahoo[dot]es

Instructions on how to build a wind turbine

NEED different instructions!!! --Aegisxgundam 04:16, 27 October 2006 (UTC)

visit www.fieldlines.com 147.145.40.43 00:34, 3 January 2007 (UTC)

Cleaned External Links Section

This article is filling up with external links which includes some link spammers. Please review WP:EL. Per WP guidelines, when an article starts attracting numerous links, it should be periodically emptied - Wikipedia:WikiProject Spam. Before adding a new link, suggest it first on this Talk page rather than adding to the links section.

Added the WP suggested DMOZ directory and warning message at top of External Link section. If another category on DMOZ is more appropriate, please modify it accordingly. Calltech 15:16, 21 November 2006 (UTC)

There are a lot of dead internal links under Companies in wind turbine industry section. I went ahead and removed these dead links - also removed external links to help keep this article clean. Recommend if a link to a wind technology company is relevant, please place it on DMOZ instead. Calltech 14:46, 29 November 2006 (UTC)

I've observed this article for awhile and noted that there were many red link terms and companies and that the underlying articles were not being produced. If I removed any such terms or companies for which an editor intended to create an article, please accept my apologies. Because there were so many, I went ahead and either removed the company or the wikilink syntax. Calltech 15:21, 29 November 2006 (UTC)

blade count

i doubt that the efficiency increases with with the blade number monotonously. i could neither find this in the literature nor in the german version of wikipedia. does anyone has a proof for this argument? —The preceding unsigned comment was added by 194.95.147.244 (talk) 17:02, 6 December 2006 (UTC).

depends on what you mean by "efficiency"... Torque increases with additional blades, and harmonic imbalance decreases, but tip speed also decreases. 147.145.40.43 00:35, 3 January 2007 (UTC)

Perhaps it would be better to discuss this in the article in terms of coefficient of power (cP) versus wind turbine designs, instead of vs number of blades. I do have that data from NREL, it's in a graph. I'll post it here in discussion first. DANF Here it is: Source, NREL http://www.otherpower.com/images/033293b-03.jpg 67.142.130.42 03:38, 19 February 2007 (UTC)

Do a search on "solidity" re windmill fan, will answer your questions very nicely - it's also well documented in several of the books you might find on this topic.

=rednecksavant

Advantages/disadvantages section

I have some serious doubts about some information here, with both HAWTs and VAWTs. I will not make any changes until the issues have been discussed here and properly cited from professional books and journals, I'll work on the cititions. This whole article needs lots of them!

To start in small chunks:

   * Due to the turbine's large surface area, very little wind is required to turn the rotor blades to generate
power. Vertical wind turbines have two subgroups: Darries and Savonius. 

--- (Power available in the wind and swept area affects where the turbine starts making power, not surface area (more properly called 'solidity.'). Surface area affects at what wind speed the turbine starts turning, called 'start-up speed.')

I agree with your concern about these "advantages for VAWTs and deleted them. Solidity drives start up ability and the two types of turbines are lift and drag. Kjwolf 06:47, 21 February 2007 (UTC)

   * Both were invented for the same multipurpose role of generating electricity in a flat open area far inland
to create high torque, also creating a high-voltage output that can power residential and commercial 

applications, such as televisions and lighting. ---(Citation? VAWTs are better in high-torque applications like pumping water, HAWTs are better for making electricity due to higher shaft speeds.)

I agree with your concern on this statement. This is not an advantage as if HAWTs didn't have this. This more links to the history of VAWTs as is discussed on pages 44-46 in Peter Asumus' book "Reaping the Wind". Kjwolf 06:47, 21 February 2007 (UTC)

   * The two subgroups allow a flexibility of wind speed, due in part to the many angles in use that allow a 

better ratio of torque to output without sacrificing performance. This flexibility of angle configuration can suit any region or environment that has the minimal amounts of wind required to power the generator. The angle configuration of the turbine allows high performance. --(Citation? I don't understand this)

I agree that this statement doesn't make sense. My reason for deleting it are in the VAWT section above. Kjwolf 06:47, 21 February 2007 (UTC)

   * Vertical wind turbines have a higher airfoil pitch angle, giving improved aerodynamics while decreasing 

drag at low and high pressures. ---(Citation? This does not make sense. Pitch angle simply needs to matched with blade speed; steep pitch near the root, shallow pitch near the tip. And for VAWTs, this only applies with Darrieus 'eggbeater' designs, not drag-based designs. Any pitch angle can be fine, it all depends on how fast the blade is moving, to produce the correct angle of attack)

   * Being near the ground allows the turbine to collect extra energy from wind that bounces off a forty-five 

degree slope from the base of the turbine to the ground; when the wind hits the ground and is directed up the slope, around twenty percent more power is added to the wind turbine. ---(Citation? I've heard this claimed before, and never found any scientific publication that agrees with it. Current literature says that ground friction slows down the air and makes it more turbulent. Please cite a source with good provenance)

I agree with your questioning this. I added my reasons for editing many of the advantanges and disadvantages of VAWTs in the VAWT section above. I replaced this with

• Mesas, hilltops, ridgelines and passes can have higher and more powerful winds near the ground than up high because of the speed up effect of winds moving up a slope or funneling into a pass combining with the winds moving directly into the site. In these places, VAWTs placed close to the ground can produce more power than HAWTs placed higher up.

You can check with Rich Simon (http://windots.com) who is a renown wind industry meteorologist about this. For example, winds are more powerful near the ground in the Altamont pass than higher up. Kjwolf 06:47, 21 February 2007 (UTC)

   * Low height useful where laws do not permit structures to be above tree height.

--(See above, according to current literature all wind turbines need fast-moving, non-turbulent air to maximize power output, whether VAWT or HAWT)

(Sorry it's not catching my username; I can't stay logged in for some reason. My user name is "otherpower.")

66.82.9.46 04:25, 19 February 2007 (UTC)

I removed this advantagte:

• Vertical wind turbines have a higher airfoil pitch angle, giving improved aerodynamics while decreasing drag at low and high pressures.

VAWTS differ greatly between types. Savonius types don't have an airfoil. VAWTs have more drag than HAWTS no matter what thhe airfoil pitch angle. And what does it mean "low and high pressures"? This is not written well enough to be listed on the home page. kjwolf

Wind Star VAWT -- faked picture (NOT!)

This kind of blatant advertising is wildly inappropriate for the Wikipedia, as is the faked picture. I'm shocked that anyone would pollute this extremely important article with such hype. 67.142.130.14 05:19, 21 February 2007 (UTC)

What are you talking about? You can go to the North Palm Drive exit in Palm Springs off of Hwy 10 at the Denny's travel to the west about 1/2 mile where the transmission lines are and see the three Windstar 530G turbines there yourself. These turbines gained Wind Harvest their Vortex Patent (number 6784566). Kjwolf 06:29, 21 February 2007 (UTC)

Sorry about that then, Kjwolf -- there are so many faked VAWT pictures of "proposed installations" around on the web these days that I jumped on it instantly. The resolution was low, so it looked fake. Notice that I didn't touch it or remove it! Glad to see it's for real. 67.142.130.33 06:40, 4 March 2007 (UTC)

HAWT Advantages and Disadvantages

I made the following changes, with much of the information coming from the Wind Power Finance and Investment Summit held in La Jolla CA from Feb 7-9, 2007.

Because it gives the wrong impression, I changed: Ability to fold up the rotor blades in a storm, to minimize damage. to Ability to pitch the rotor blades in a storm, to minimize damage.

In the tall tower advantage I removed the part about offshore and put it in the section on uneven locations. I also cleared up the inaccuracy of the original by changing it to:

• Tall tower allows access to stronger wind in sites with wind sheer. In some wind sheer sites, every ten meters up, the wind speed can increase by 20% and the power output by 34%.

This increase in wind speed is not universal even in high wind sheer locations.

I removed this advantage because HAWT blades are not like pinwheel blades.

• Since the rotor blades are shaped like a pinwheel, the airfoils can withstand greater force from the wind. This allows wind turbines to rotate faster.

I modified these two to make them less absolute.

• Most are self-starting.
• Can be cheaper because of higher production volume.

HAWT disadvantages:

I removed this inaccurate statement:

Poor performance at low altitudes, due to lower wind speed.

and replaced it with:

• Difficulty operating in near ground, turbulent winds because their yaw and blade bearing need smoother, more laminar wind flows.

I removed this statement because it doesn't make sense or its superfluous. All wind turbines locations need good wind that can be considered weather.

• Location is determined by latitude and weather. This can prove a problem in low-lying areas.

I changed this statement to say that it can be a safety hazard

• Height is a safety hazard for low-altitude aircraft.

I added these disadvantages from the Wind Power Finance and Investment Summit

• The tall towers and long blades (up to 180 feet long) are difficult to transport on the sea and on land. Transportation can now cost 20% of equipment costs.

• Tall HAWTs are difficult to install needing very tall and expensive cranes and skilled operators.

• Supply of HAWTs is less than demand and between 2004 and 2006, turbine prices increased up to 60%. At the end of 2006, all major manufacturers were booked up with orders through 2008.

I removed this statement because it doesn't make sense.

• Horizontal wind turbines in urban areas tend to cause a lot of drag that reduces efficiency in power production.

Kjwolf 07:25, 21 February 2007 (UTC)

Excellent changes, Kjwolf. 67.142.130.33 06:43, 4 March 2007 (UTC)

VAWT Guywire Problems

I removed this statement from the VAWT Advantage section:

• Can have a bearing at the top of the vertical axis that is supported by guywires making the design much stronger for little incremental cost.

The experience of Wind Harvest and with the Darrieus type machines (e.g. Flowind) is that guywires attached to a top bearing are problematic. They cause problems for the bottom weight and thrust bearing because no weight is shared by the top bearing, the guywires cause more downward thrust as winds increase, and the guywires allow the shaft to wiggle. All of these combine to create bearing problems at the bottom. Before its R&D on the Windstar 530G turbines (see photo on main page), all Wind Harvest's previous VAWT models had a superstructure that held the top bearing in place and allowed sharing of rotor weight to this bearing. The 530Gs with their guywires allowed for a much less expensive turbine and gained Wind Harvest its proof of the vortex effect when VAWTs are placed close together, but the guywires created bearing problems. So the next Windstar models (the 1500 and 3000) will make use of the vortex effect by being placed closely together with external columns and arms supporting the top bearing.

You can see that SET changed from guywires to an external support structure for the old Darrieus type turbine in their new SES 250 VAWT model which, I believe has gone through the international certification process. (http://www.sustainableenergy.com/SET-wind-turbine/SET-wind-turbine.html) Kjwolf 16:32, 23 February 2007 (UTC)

== Question: How many wind turbines are installed worldwide?

Can anyone hazard a guess based on worldwide installed capacity of Wind power at 74223 MW?

Thanks, --19:16, 24 February 2007 (UTC)Orangehues

:You could find a list of how many were installed each year. Then you could find the average size turbine. So in the early 1980s the turbines average around 150kW (10 to the MW). In CA by 1983 or so, there were around 2000 MW and 14000 turbines installed. In the early 2000s, the average size was around 1 MW. Now it is 2 MW. My guess is that the 15000 MW installed in 2006 resulted in around 10000 - 15000 turbines installed. I would count small house sized turbines in the mix or it would dramatically change the average. So my guess is that, at an average of 500 kW per machine, thereare 150,000 commercial wind farm sized turbines in the world (+ or - 50%) Kjwolf 07:19, 26 February 2007 (UTC)''Bold text''Bold text'Italic text'Italic text'''''''

Thank you so much!

--Orangehues 20:13, 26 February 2007 (UTC)

Just for historical purposes, according to the above estimate there are between 75,000 to 225,000 wind turbines worldwide.

--Orangehues 08:36, 27 February 2007 (UTC)

TMA, Inc. Promotion

Why are there several plugs for TMA, Inc.? I went back 500 revisions and they were still there, so I didn't just rip them out without knowning more. In any case, the article is inconsistent in the plugs. In the first, it says "They report efficiency similar to other wind turbine designs, but with less vertical height and visual impact." But later, it flip-flops into claiming that TMA has overcome the problem of "VAWTs produce energy at only 50% of the efficiency of HAWTs." And finally, they have the only external link to an equipment supplier, which has got to be wrong! The TMA website is a sorry piece of work that's virtually unreadable and seems like a bunch of baseless hype. UncleDouggie 10:24, 1 April 2007 (UTC)

You're right, I've removed all this baseless hype.--Gregalton 07:09, 12 April 2007 (UTC)

removed disadvantage of VAWTs

* A VAWT that uses guy wires to hold it in place puts stress on the bottom bearing as all the weight of the rotor is on the bearing and the guy wires increase downward thrust in wind gusts. Solving this problem requires a superstructure to hold the top bearing in place that can also share the weight of the rotor.

• this doesn't make sense. the guy wires have no effect on the down for on the rotor, otherwise they would stop the rotor from spinning. the guy wires are ALWAYS attached below the rotor, or to a "superstructure" on top. the only down force on the bottom bearing is the weight of the rotor.--60.242.222.210 01:39, 17 April 2007 (UTC)
• that was me: --naught101 01:39, 17 April 2007 (UTC)

Careful using the word always in terms of where guy wires are attached. You will see from photos of the Darrieus/Flowind turbines that they attached guywires to the top bearing. Look at the photo of the Windstar 530Gs and you will see guywires attached at the top. Both of these versions have replace guywires with superstructure to prevent the downward thrust on the bearings that guywires cause in wind gusts. Ask someone who knows about forces and vectors to explain how guywires will translate gusts of wind into a downward thrust. A VAWT that doesn't have some structure attached to the top bearing means that the weight of the entire rotor is only on the bottom bearing. Think of the pressures on the H-Darrieus rotor (see photo or 3-d rendering on main page) in high winds. That will have to be quite a strong shaft and bottom bearing to withstand major gust events. I don't believe that there are any examples of a large rotor swept area VAWT operating successfully in commerical wind conditions that doesn't have a superstructure supporting the top bearing. kjwolf, June 18, 2007

Combined Wind Turbine/Electricity Pylon?

Seeing as how wind power requires additional electrical infrastructure and electricity pylons and utility poles are everywhere, have there been any attempts to combine them? The lower tip of the blades would be at least several feet above the electrical lines for small turbines combined with utility poles and far higher up for large turbines combine with electricity pylons . I don't know what technical challenges this would present, but it sounds like it may have some advantages.

Wind blowing parallel to the line would make short work of the transmission line (unless the combined towers were made grotestquely high). You'll also note that wind turbine towers are much stronger and much higher than HV transmission line towers. Optimum siting of wind turbines is not the same as optimal siting of transmission towers. --Wtshymanski 17:49, 23 April 2007 (UTC)

Obviously I wasn't talking about blades that could in any way intersect the lines, but would be far above. Already many wind turbine towers are the size of skyscrapers and electrical pylons are often shorter than the lower tips of the blades and for utility poles the same can be said for shorter turbines. Though you wouldn't want to put such combination towers everywhere, where the two locations coincide (ideal wind power location and transmission lines that would be there anyway.), there would be the opportunity for such combo towers. I wasn't proposing that such towers be the same kind of comparatively flimsy steel structure that most electrical pylons are, but rather masts similar to existing turbines' with the electrical infrastructure attached in whatever way needed. And doesn't the presence of a large number of wind turbines guarantee that there will be nearby electrical pylons anyway? Some of those pylons could be combined towers. I'm not saying that the combined turbine/pylon idea is automatically a good one, just that I don't yet know why it would be so impractical to never do it in at least some instances. I suspect it isn't practical and despite the problems of underground transmission, if combined towers offered a compelling benefit, it would already be done somewhere, in the very least in place of the short underground run from the turbine mast to the nearby transmission towers or utility poles.

Function:

Wind turbine works the opposite of a fan. Instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity. The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity.

by alyazia

True, and when the wind drops wind turbines becomes fans. Most are grid connected synchronous machines that all turn at the same speed (or are stopped) so that you cannot tell whether those wind turbines are "generating" or "fanning" by the speed they are turning. Thus they may look as if they are doing something useful even when they are not! GilesW 07:45, 6 September 2007 (UTC)

External link

This appears to be an authoritative site that would be worth adding:

http://www.windpower.org/en/tour/design/index.htm

GilesW 07:45, 6 September 2007 (UTC)

VAWTs

While conducting research on this subject, I came across a different type of VAWT that doesn't seem to appear in your article. It's the Windside turbine made by Oy Windside Ltd in Finland. They've been building them for nearly 30 years and claim some pretty impressive results - oh, and they look kinda cool too! I don't have the technical knowledge or skills to edit the article, but perhaps one of the contributors could have a look at it here: http://www.windside.com/products.html

Hal Crompton General Manager Silent Power Cyprus 88.255.1.125 09:38, 10 October 2007 (UTC)

This is a fairly common modification to the traditional Savonius design. All they have done is "twisted" the cups so they are no longer purely vertical. The basic idea is to spread out the torque, so instead of having a maximum when one of the cups is in the wind and then a minimum when they are end-on, with these versions there's always a portion of one of the cups that's in the wind, so there's always some torque and it's all much smoother. Maury (talk) 00:32, 19 December 2007 (UTC)

SRC Vertical Ltd .......

This is a very informative website about wind turbines from a Russian company (SRC Vertical Ltd.) of former rocket scientists who were funded by the US. Department of Energy to build more efficient VAWT's . The site basically dispels any of the myths about HAWT's being more efficient and a source of cheaper energy . They've built several turbines which are now on the market and have plans for hundred kilowatt and even megawatt size versions . The turbines can remain standing and generating in 130mph (60m/sec) winds . —Preceding unsigned comment added by 86.27.85.8 (talk) 16:04, 30 October 2007 (UTC)

Demonstrating that HAWTs are more efficient than VAWTs takes only a few lines of basic university-level math. The website in question is hardly a counter-argument, none of their turbines are remotely the size of large European designs (30 kW vs 6 MW) and consist of various basic changes to Darrieus/Giromill designs. Maury (talk) 22:09, 18 December 2007 (UTC)

University level maths ( maths short for mathematics , plural ) does not concern itself with REAL wind conditions which are turbulent , which reduces the amount of wind energy that can be captured by an HAWT . Also the ability of SRC's turbines to start generating at 4m/sec and continue generating up to 130m/sec allows much more wind energy to be captured , very impressive i'd say , so it remains to be seen which design is more efficient . Plus , there is no need to be so dismissive of SRC's achievements which are modest at present , however they do have plans for larger and larger turbines . Because the design of SRC's turbines are so simple they may be cheaper to manufacture and construct . Flumstead (talk) 09:03, 26 March 2008 (UTC)

Floating VAWT's.......

Has anybody had the idea of floating VAWT's ? It seems to me that they could potentially be made far larger than HAWT's , possibly hundreds of meters in diameter and height . A circular shaped vessel which rotates with the wind turbine would eliminate the need for a large and expensive bearing . It would have to be sufficiently large for the wave conditions it would be placed in . The vessel could be a doubled hulled , inner and outer ring type , with an air cushion trapped between the two hulls to raise the vessel up and reduce friction . —Preceding unsigned comment added by 82.14.72.244 (talk) 14:32, 12 November 2007 (UTC)

We don't know. We don't do original research here, you'll have to find someone's description of that before we can write about it. -- SEWilco (talk) 02:00, 19 December 2007 (UTC)

There is a patent for a very large , hundreds of meters diameter , VAWT on the WIPO ( World Intellectual Property Organization ) website , much like you describe with enormous yacht type sails . Seems a bit big to be attempted at present tho . Flumstead (talk) 09:12, 26 March 2008 (UTC)

Recent edits

I recently removed some rather ad-like material for a particular style of VAWT that was by no means unique, and moved other content into a new section that I intended to expand. These edits were reverted, manually apparently, with no real checkin notes. I have reverted back to my last version, if the editor wants to revert again, discuss it here first please. Maury (talk) 22:16, 18 December 2007 (UTC)

Small turbines - too American

It's a pity that the section on small turbines seems to see the world as being only the US. I wish someone with the appropriate knowledge could change this. --83.221.81.202 (talk) 07:21, 6 January 2008 (UTC)

You know what to do. Be Bold and add some references for small turbines elsewhere in the world. --Wtshymanski (talk) 15:29, 6 January 2008 (UTC)

DIY small scale windturbine

Perhaps DIY small scale windturbine and -mills can be mentioned in the article. See DIY 1000 Watt windturbine and DIY windmill

Please look into it and perhaps include it into article. Thanks.

KVDP (talk) 09:41, 20 January 2008 (UTC)

Go for it!Write it up - you've already done the hard part, i.e., getting some references. --Wtshymanski (talk) 16:02, 20 January 2008 (UTC)

More references: Builditsolar wind turbines, The Backshed Wind turbines —Preceding unsigned comment added by 87.64.198.157 (talk) 09:22, 18 February 2008 (UTC)

Is it possible that somebody makes an article which compares the diy small-scale windturbines (from kits and completely diy) versus their commercial counterparts ?

There are not many turbines available, so it should be quick. Thanks. KVDP (talk) 09:08, 22 February 2008 (UTC)

Intoduction to the article

I think the intro to the article needs a rewrite. Anyone else think so? § Eloc § 03:26, 21 January 2008 (UTC)

Wind Generator vs Wind Turbine

Hi. IMHO two concepts are a bit too heavily intertwined in this article. Given there are now other types of wind generators, such as the windbelt, I think items related to wind generation should be moved from this article to wind generator while items specific to turbine-style generation should remain here. --Treekids (talk) —Preceding comment was added at 22:40, 27 January 2008 (UTC)

Removal of article sections

Why was the section under VAWT's concerning windstar turbines removed? They have as much a right as all the rest to be there, and there was a bit about them there previously... I would ask whoever took it down to put it back up. If you object to how an article is written, fix it, or post about it here, don't go around deleting work without due cause. -A Concerned Citizen —Preceding unsigned comment added by 69.229.238.165 (talk) 08:20, 12 February 2008 (UTC)

Request for external link

I was about to put a link into the external links section then I read the blurb at teh top, anyway here it is: http://sustainablex.com/index.php/Portal:Wind I think it is a good resource of wind turbines big and small and also has starter guides. —Preceding unsigned comment added by 193.129.65.37 (talk) 14:53, 26 March 2008 (UTC)

Pictures

Y'know, I've got a bunch of vacation pics of wind turbines, too - but I'm not about to put a dozen of them in the article since they add nothing to the understanding of wind turbines. --Wtshymanski (talk) 17:49, 10 April 2008 (UTC)

Image text

The text below the image refers to the door of the turbine which can be barely seen from the image size. I think a different image or removal of this text would be best. —Preceding unsigned comment added by 88.108.121.243 (talk) 22:50, 15 April 2008 (UTC)

But isn't that really the point of the image and caption? The best way to understand the size of these things is to visit one. With a good imagination the picture showing the human-sized door at the base of the tower would let a reader visualize the scale. --Wtshymanski (talk) 14:48, 27 April 2008 (UTC)

Noise

I think there should be a section on noise of wind turbines. This is of concern to many people - sometimes warranted and sometimes not.--Allprogress (talk) 06:59, 10 May 2008 (UTC)

Remove Outdated Ref

Referrences #31 and #32 are for the same article and that information has been removed when you get to the linked page. Can someone remove these 2 referrences. —Preceding unsigned comment added by Tastethefruit (talk • contribs) 19:52, 17 June 2008 (UTC)

Matilda generation claim

The statement "Matilda, was a wind turbine located on Gotland, Sweden. It produced a total of 61,4 GWh in the 15 years it was active. That is more renewable energy than any other single power plant has ever produced" is almost certainly false as it stands. Surely there are large hydro plants, like the Grand Coolee, that have produced many more times this amount of renewable energy. If large hydro is to be excluded in favor of "new" renewables, then that should be explicitly stated. —Preceding unsigned comment added by 72.173.16.123 (talk) 16:00, 20 July 2008 (UTC)

Banesh

who is this mystery Banesh and how his improvements look like? examples needed --discourseur 13:46, 31 July 2008 (UTC)

ok. i found it by accident. alvin BENESH. --discourseur 19:23, 3 August 2008 (UTC)

The Article needs a "History" section

Currently there is a a general "zone" of historical info in the "types" section. The info as it is seems generally a bit untidy, some is inaccurate or oversimplified and some seems to be case-making. The turbines in this 'zone' are also a bit of a mixed bag regarding whether the rig is for generating electricity or pumping. For example, the style of turbine that seems to have been used in the US for electricity generation was (and still is) used in Oz almost exclusively to pump water. The text doesn't really convey this. Also, the "Eclipse" is mentioned as if it were the first of the modern style, whereas it in fact was a modification of an earlier modern style that until then was only moderately successful. I propose a separate "History" or "Development" section to tidy this up and put it into a sensible order. How do we feel about this? LowKey (talk) 01:36, 8 August 2008 (UTC)

Agree: Because what the heck. 70.64.78.207 (talk) 02:24, 26 August 2008 (UTC)