Or look at this picture
http://www.rnp.org/images/const4.jpg
I can imagine those widely spaced skinny bladed turbines stopping a lot of wind - NOT. They could have got the same amount of power as they get from ten of those from just ONE vertical axis sail based turbine of the same tower height. AND spaced them right next to each other, all along the same path, and got ten times as much energy from the wind.
Just look at this picture:
http://www.biggleszx.com/slashdot/5m_01.jpg
Are you suggesting that if you were on a platform at the height of the generator, a hundred feet downwind of this turbine, that the wind speed would be changed AT ALL when the blades weren't directly in front of you?
If you are suggesting this, can you show me where anybody on the planet has ever tested this?
Obviously, just be looking at the picture of this turbine, you can clearly see that the wind has a big, HUGE space to go through - everywhere the blades AREN'T. This little problem has gone completely unnoticed by the engineers and designers who happily carry on with their 'cult' of horizontal axis blade based designs.
There are two different designs of turbine: one is good for capturing the wind (the vertical axis sail based turbine) and one is good for PRODUCING wind, the horizontal axis two or three BLADE turbine - or PROPELLOR, as I like to call it. That's why propellors have been used on planes since they were invented, and not vertical axis sails.
Perhaps anybody here could prove me wrong by explaining how the blades magically stop any of the wind which they aren't touching...
Obviously they do not.
I'm willing to bet that a vertical axis sail based design (as long as it's my design) would make almost no noise, as the sails would be travelling into the wind WITH the wind on the 'power stroke', and would be parallel to the wind on the 'recovery stroke', thus causing little noise.
Having read through most of the replies to this subject, it seems that the whole world has been brainwashed into believing that inefficient three blade horizontal axis wind turbines are the only possible design for such a machine - they are not.
Well over 90% of the wind passes through the swept area of these turbines completely unused. I was reading about the distance between turbines, and without doing any experiments, they are now spaced apart at ridiculous distances, when you could easily have a hundred in the space they now have ten. Has anybody ever actually bothered to measure the windspeed downwind of one of these large turbines, at the height of the centre of the blades? Obviously not. (Admittedly you'd have to get a mobile tower, etc. to mount your anemometer on, but these 'experts' have taken so much for granted that they probably think they don't even need to bother with real world experiments).
What a load of rubbish.
What studies were done in the 1970s (or any time since) that involved vertical axis sail based designs, that stopped 90% of the air, rather than allowing 90% of it through?
Even a child of five can see, just by looking at any large 3 blade horizontal axis turbine, that most of the wind categorically DOES go through the spaces between the blades without any of its energy being used by the turbine.
In other words, the current design of wind turbines (i.e. they are ALL horizontal axis three blade designs, with very expensive blades, and the generator at the top of the tower, thus making it very difficult to get to) has been decided not by science or facts, but by personal prejudice.
What do you mean by "efficient"? ALL that counts with wind turbines is the cost per kilowatt - NOTHING else. A turbine that offers only a tenth of the 'efficiency' of the current 'trendy but stupid' designs, yet costs one twentieth to build, would obviously produce electricity for HALF the price. Yet this simple fact is simply ignored by the 'three horizontal blades are best' brigade.
If you know of any studies (there haven't been ANY, to my knowledge) involving vertical axis SAIL based turbines, please let us all know. And then we can factor in the massively reduced cost of using sails, rather than costly blades...
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Or look at this picture http://www.rnp.org/images/const4.jpg I can imagine those widely spaced skinny bladed turbines stopping a lot of wind - NOT. They could have got the same amount of power as they get from ten of those from just ONE vertical axis sail based turbine of the same tower height. AND spaced them right next to each other, all along the same path, and got ten times as much energy from the wind.
Just look at this picture: http://www.biggleszx.com/slashdot/5m_01.jpg Are you suggesting that if you were on a platform at the height of the generator, a hundred feet downwind of this turbine, that the wind speed would be changed AT ALL when the blades weren't directly in front of you? If you are suggesting this, can you show me where anybody on the planet has ever tested this? Obviously, just be looking at the picture of this turbine, you can clearly see that the wind has a big, HUGE space to go through - everywhere the blades AREN'T. This little problem has gone completely unnoticed by the engineers and designers who happily carry on with their 'cult' of horizontal axis blade based designs. There are two different designs of turbine: one is good for capturing the wind (the vertical axis sail based turbine) and one is good for PRODUCING wind, the horizontal axis two or three BLADE turbine - or PROPELLOR, as I like to call it. That's why propellors have been used on planes since they were invented, and not vertical axis sails. Perhaps anybody here could prove me wrong by explaining how the blades magically stop any of the wind which they aren't touching... Obviously they do not.
I'm willing to bet that a vertical axis sail based design (as long as it's my design) would make almost no noise, as the sails would be travelling into the wind WITH the wind on the 'power stroke', and would be parallel to the wind on the 'recovery stroke', thus causing little noise. Having read through most of the replies to this subject, it seems that the whole world has been brainwashed into believing that inefficient three blade horizontal axis wind turbines are the only possible design for such a machine - they are not. Well over 90% of the wind passes through the swept area of these turbines completely unused. I was reading about the distance between turbines, and without doing any experiments, they are now spaced apart at ridiculous distances, when you could easily have a hundred in the space they now have ten. Has anybody ever actually bothered to measure the windspeed downwind of one of these large turbines, at the height of the centre of the blades? Obviously not. (Admittedly you'd have to get a mobile tower, etc. to mount your anemometer on, but these 'experts' have taken so much for granted that they probably think they don't even need to bother with real world experiments).
What a load of rubbish. What studies were done in the 1970s (or any time since) that involved vertical axis sail based designs, that stopped 90% of the air, rather than allowing 90% of it through? Even a child of five can see, just by looking at any large 3 blade horizontal axis turbine, that most of the wind categorically DOES go through the spaces between the blades without any of its energy being used by the turbine. In other words, the current design of wind turbines (i.e. they are ALL horizontal axis three blade designs, with very expensive blades, and the generator at the top of the tower, thus making it very difficult to get to) has been decided not by science or facts, but by personal prejudice. What do you mean by "efficient"? ALL that counts with wind turbines is the cost per kilowatt - NOTHING else. A turbine that offers only a tenth of the 'efficiency' of the current 'trendy but stupid' designs, yet costs one twentieth to build, would obviously produce electricity for HALF the price. Yet this simple fact is simply ignored by the 'three horizontal blades are best' brigade. If you know of any studies (there haven't been ANY, to my knowledge) involving vertical axis SAIL based turbines, please let us all know. And then we can factor in the massively reduced cost of using sails, rather than costly blades...