Talk:Vertical-axis wind turbine/Archive 1

Efficiency

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)

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)

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)

why they are better than horizontal

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.

• (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)

Useful links

• 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)

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)

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

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)

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)

Forces

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)

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)

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)

Butler Ames of a teaching patent filed in 1908

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)