Talk:Vertical-axis wind turbine

Useful links[edit]

http://blog.wired.com/wiredscience/2007/08/the-horizontal-.html
http://www.bsi-global.com/en/About-BSI/News-Room/BSI-News-Content/Disciplines/Sustainability/Wind-turbine/
http://earthship.com/vertical-axis-wind-power-generation-final-product — Preceding unsigned comment added by 2601:2:4000:AE0:2DF7:266D:867:CBEF (talk) 19:48, 8 February 2014 (UTC)[reply]

Also, when it comes to filling the expert request, the students that issued the press release and the commenter on Wired that talked about Darwin. MrZaius^talk 00:10, 27 August 2007 (UTC)[reply]

[1], a HAWT for mixing clay.Mion 10:49, 30 August 2007 (UTC)[reply]

Hello. I'm trying to improve this page. Any suggestions are highly apreciated. Also, my english is not optimal. Have mercy. Thank you
Nectanebo80 16:58, 2 September 2007 (UTC)[reply]

I edited the beginning a little bit. There was a mathematical inconsistency in the earlier vesion where the relative wind accross each blade was expressed as:

${\vec {U}}+(-{\vec {\omega }}R)$ .

Assuming that ${\vec {\omega }}$ is the angular velocity vector (which it usually is), then $-{\vec {\omega }}R$ is actually parallel with the vertical axis of the wind turbine. The correct notation is to take the cross product of the angular velocity vector and the position vector from the axis of rotation to the rotating blade. This product is the velocity of the blade, which will be in the tangential direction. This product had magnitude $\omega R$ , but it is actually orientated at right angles to the angular velocity vector.

The drawing correctly labels the magnitude of the velocity. Additional proof-reading may find other errors.138.29.82.6 (talk) 16:57, 7 October 2008 (UTC)[reply]

Vertical[edit]

The title of this article is "Vertical axis wind turbine". A VAWT is a type of axis-perpendicular-to-wind turbine. It would be OK to have a section later to discuss other types of axis-perpendicular-to-wind turbines that are not vertical. It would also be OK to come up with a new article that is about that broader category, and to prominently link to it from here. But that's not what this article is, and there's no reason to redefine the word vertical in the lead. Darrieus's patent does not use the term "vertical axis," so the fact that his patent includes other orientations does not mean that they are VAWTs.Ccrrccrr (talk) 04:15, 3 December 2009 (UTC)[reply]

To change the position of the Darrieus axis from standing vertikal to horizontal position changes physikal parameters too. Gravity, wich is no problem for vertical rotors, becomes a factor to be responded to. Depending on the position of the blades on their way round, Gravity forces change their impact on them, together with different impacts of windpower pending on bladeposition to the wind and the outward Power of the weight of the blades with the spin - all of them interfered by eachother, horizontal position comparing to vertikal axis makes a big diff not just by their position.

To compare: Let your arm hang down a while an then move your arm into a horizontal position. What do you feel after keeping this horizontal position for a few minutes? Maybe you get the feeling of the powerchanges for the turning blades this way.

Therefore, in reality you will not find many Darrieus- or Savonius-rotors (to name just two typical VAWT-types) working on perpendicular systems, most of them have a vertical axis to work with. --Kalinco (talk) 07:58, 27 August 2011 (UTC)[reply]

I like the idea of developing the article more broadly - but as a different article to be linked from this article. MaynardClark (talk) 12:13, 22 December 2017 (UTC)[reply]

why they are better than horizontal[edit]

I found a new study which explains why they may be a more efficient option for windfarms, unfortunately I'm not feeling very eloquent at the moment, feel free to flesh it out as you see fitBack ache (talk) 12:25, 17 February 2010 (UTC) Around the end of the 90's I discussed the pro's and con's with a colleague and a senior lecturer Alex Broadway (now retired) at the Bristol University Electrical & Electrical Engineering Dep't where I worked on the Tech' Staff. He was involved in the choice of the first HAWT's electrical generator machine. He was in complete agreement when I expressed my views on the reliability of the electrical machines & systems exposed to the extremes of environment and weather. He also agreed that the 'vertical axis wind turbine' (VAWT) is in fact in a much better idea*. It's machine & systems can be ground level or even below ground, so it can be better protected and HAWT's are also 'omnidirectional' so no need for repositioning, and all the things you say.[reply]

(Note - I've seen photos of vertical axis windmill attached to a 'water-screw' raising deep groundwater in the Sahara desert). So I'm in total agreement with you excellent article - it's a 'no-brainer'. My query: - is the VAWT wind farm VAWT design in development - hopefully to replace the HAWT - if not WHY NOT?Ftmazur (talk) 22:28, 10 August 2012 (UTC)[reply]

Forces[edit]

Hi, i want to know more about how to calculate the forces but i dont really understand the formulas. First, it seems that you dont have to know the angle of attack to calculate the forces. But the angle of attack effects the C_l dosen't it? L D T N is the force parameters i think but where can i find the C_l,C_D,C_T and C_N coefficients? —Preceding unsigned comment added by Mattias5891 (talk • contribs) 09:47, 22 March 2010 (UTC)[reply]

In the formula for angle of attack. I can't see what speed has to do with thge angle so why is λ in that formula —Preceding unsigned comment added by Gandalf999 (talk • contribs) 10:07, 22 March 2010 (UTC)[reply]

The diagram in Fig1 is not correct. The lift (L) delivered by the blade is show acting inwards whereas it would in fact act away from the centre. The blade is at a positive angle of attack in this position. Also, if the lift acted as shown, it would provide a clockwise rotation which is contrary to what's been assumed in the diagram. Someone with some expert knowledge needs to either correct this or else provide an explanation. — Preceding unsigned comment added by 109.79.130.153 (talk) 08:50, 8 June 2014 (UTC)[reply]

Efficiency[edit]

The current state of the article seems to show no disadvantages or downsides to vertical axis wind turbines; they're the greatest thing since sliced bread, apparently. How does the efficiency compare to more standard designs? Any other disadvantages or downsides? — Preceding unsigned comment added by Siberx (talk • contribs) 09:37, 18 March 2011 (UTC)[reply]

May I be of some help for You: concerning VAWT tecnology it may be certain, that efficiency does not reach the standards of HAWT technique. There are other Points of view to it: under turbulent windconditions near the ground, close to buildings, between mountains or other disturbing obstacles HAWT technique normaly fails to give good values. There the VAWT technology is better of due to it`s immunity against rapid changes of winddirections and partly, depending on the Type (Savonius or Darrieus) they answer beautyfully to changes of windforce. Savonius is better of in the last, because Darrieus, pending on how the blades are build tends to be slow in reaction to this particular mentioned windcondition.--Kalinco (talk) 07:02, 13 August 2011 (UTC)[reply]

And don´t forget the point of view for other deployments but windpower! Slow watercurrents in rivers or oceans are relayable means to produce energy! Water has about 800 times the density of air and so much energy too! So it does not matter if the current is much slower but wind. And the point of it - VAWT tecnology is just perfect for under water because it can keep the head up in the air. Generators don´t like it to much to be kept under water! Sealings have to be changed often because of pressure under water, electrolytic waste, growth and corrosion of materials. So - to have a bad position to VAWT technic can be a mistake.--Kalinco (talk) 08:13, 27 August 2011 (UTC)[reply]

obviously incorrect[edit]

This: VAWTs offer a number of advantages over traditional horizontal-axis wind turbines (HAWTs). They can be packed closer together in wind farms, allowing more in a given space. This is not because they are smaller, but rather due to the slowing effect that HAWTs have on the air, forcing designers to separate them by ten times their width.

Saying this is like saying using 1 mop to clean a floor is not as efficient as using 10 mops to clean a floor. If a HAWT has a "slowing effect" on air, it means power is being extracted from it. Likewise, if you have 100 VAWT's in a row and the air isn't slowed down at all, it would suggest that the design of VAWT is horribly inadequate to even extract the slightest amount of energy from wind.

That whole sentence is inaccurate, should be removed -- and the [5] and [6] footnotes are used incorrectly (i.e. just because HAWTs slow air does not make them less efficient, the fact that you need less HAWTs makes them even MORE efficient. — Preceding unsigned comment added by 112.198.82.34 (talk) 07:01, 19 October 2013 (UTC)[reply]

This is not related to the fact HAWTs slow the wind more than VAWTs, but that both types of turbines increase the turbulence of the wind. However HAWTs are less capable of using turbulent wind, meaning that HAWTs near other turbines are less efficient than VAWTs near other turbines.86.63.4.191 (talk)

Hi, I would like to add something on the disadvantages of vawt: despite a quite larger variety of designs, VAWTs life span is very poor and unpredictable compared to HAWT; that's why they are not commercialized yet. — Preceding unsigned comment added by 70.75.175.53 (talk) 05:19, 3 January 2014 (UTC)[reply]

Hello! I have spoken about VAWTs with a very knowledgeable coordinator of the Wind Energy Lab here at ISU. He expressed doubts with the accuracy of this article regarding the supposed advantages of VAWTs. Specifically how their "claimed inefficiencies are cancelled out by their abilities to take advantage of turbulent and gusty winds". VAWTs inefficiencies aren't "claimed" they simply are. One major drawback is that they simply aren't as efficient as HAWTs because their blades' swept area is a small fraction of the larger HAWT swept blade area. Additionally, the blades of a HAWT are all simultaneously being pushed by wind and so all contribute to the rotational energy of the shaft. Compare this to the VAWT where only one or two blades are directly being pushed by the wind, and the rest are simply "along for the ride". These two are the fundamental inefficiencies that VAWTs suffer from.

As far as the claim of VAWTs being able to effectively utilize "turbulent and gusty winds", there is some truth to the fact that VAWTs typically don't have the same limitations of HAWTs in that they do not need to adjust yaw or pitch on blades in order to achieve ideal power generation. Because of this, in storms and other periods of unusually high winds (over ~60 mph) HAWTs will activate brakes to avoid damage. While it is possible that VAWTs could continue to generate power during these unusually high wind speeds, simple logic tells us that it is much more likely for wind to not exceed 60 mph. Because of this fact, the argument that VAWTs are more efficient because their inherent inefficiencies are offset by their "storm power" capabilities is one that I would have a hard time believing. — Preceding unsigned comment added by 2610:130:115:701:C0D5:52CC:6857:BCD (talk) 01:31, 14 April 2016 (UTC)[reply]

This article is yet one more example of Wikipedia's inability to deal with controversy. It is highly promotional and unbalanced, and very poorly sourced and documented. 2601:1C0:4D01:7A6B:916:EB1E:7F7E:E53B (talk) 09:36, 19 April 2016 (UTC)[reply]

Butler Ames of a teaching patent filed in 1908[edit]

The traverse-to-wind rotatable airfoil of Congressman Butler Ames was patent-taught in 1908. Such VAWT has not been addressed in the present article. 68.123.235.180 (talk) 20:45, 12 December 2014 (UTC)[reply]

History of VAWTs[edit]

How long have VAWTs been explored? What are the earliest records of VAWTs? I'd like to know more about the long history of VAWTs. Who could enhance that aspect of the article, perhaps to a point of developing a separate specialty article about the history of VAWTs?

The discussion (immediately above) about the traverse-to-wind rotatable airfoil of Massachusetts Republican Congressman Butler Ames in 1908 is one such early historical mention. But surely VAWTs were explored before Congressman Ames in the Bay State. Butler Ames was an alum of the Massachusetts Institute of Technology in Cambridge, Massachusetts. MaynardClark (talk) 12:05, 22 December 2017 (UTC)[reply]

"typhoon turbine"[edit]

Challenergy, a vertical-axis Magnus wind power generator, works via the Magnus effect, where a spinning object directs air around it faster on one side than on the other. [2] [3] Setenzatsu.2 (talk) 21:49, 21 April 2020 (UTC)[reply]