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Interesting? New Wind Turbine Design

10/15/2017 12:31 PM

I ran across this somewhere on CR4 but can't find the original report.

I've pulled some things together for comment.

The Newtonian

Kean Wind Turbines - Buffalo, NY - SmallBusinessBuffalo.com ...

info@keanwindturbines.com

I'm a fan of wind turbines, since I have a place just north of a huge wind farm in Minn. that gets all its power from the wind.

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#1

Re: Interesting? New Wind Turbine Design

10/15/2017 1:08 PM

Sounds like a pyramid scheme....Has all the earmarks.....

..."(The information presented here is based on theoretical extrapolations from wind tunnel tests of our engineering test model. Production models have not yet been tested.)'....

No news for a year or more....no produced product...outrageous claims of efficiency....works alone......nothing for sale after 4 years except shares in the 'corporation'....will only sell to a select few.....Kean W. Stimm, no degrees listed....no work history listed...lists Purdue as school, but no years of attendance.....= scam scam scam

http://www.keanwindturbines.com/news.php

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#4
In reply to #1

Re: Interesting? New Wind Turbine Design

10/15/2017 8:28 PM

Beyond that, the claims make in the video linked in the OP are absurd.

"....3 slender blades turning slowly, 95% of the wind goes between the blades...."

-um, much closer to 100%. Do he think some wind actually passes through the solid blade itself?

"...3 blade turbines create a tremendous amount of turbulence and drag as compared to ours which has no turbulence and drag..."

- claim of a drag-free turbulence-free turbine should be a huge red flag.

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#2

Re: Interesting? New Wind Turbine Design

10/15/2017 3:30 PM

After a quick look online it looks like a classic manufacturing licence-selling/investment scam, I would be very dubious based on what I have found myself.

Link

Patent

Keep digging and let us know what you find, things have been very quiet the last few years as far as I have seen, even on their own site.

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#3

Re: Interesting? New Wind Turbine Design

10/15/2017 3:39 PM

I'm skeptical of his claim that his turbine is 40X as efficient as current 3 blade models.

At first, the 3 thin blades look very inefficient, that the wind just blows between the blades. But when the blades are spinning, a much larger amount of the air interacts with the airfoils as they cut helices out of the moving air mass.

The theoretical maximum amount of energy that can be extracted from the wind is 16/27 the kinetic energy of the air mass intercepting the rotor disk, as dictated by Betz's Law. Modern 3 bladed wind turbines reportedly achieve 75-80% of the Betz efficiency.

https://en.wikipedia.org/wiki/Betz%27s_law

"Efficiency[edit]

Not all the energy of blowing wind can be used, but some small wind turbines are designed to work at low wind speeds.[14]

Conservation of mass requires that the amount of air entering and exiting a turbine must be equal. Accordingly, Betz's law gives the maximal achievable extraction of wind power by a wind turbine as 16/27 (59.3%) of the total kinetic energy of the air flowing through the turbine.[15]

The maximum theoretical power output of a wind machine is thus 16/27 times the kinetic energy of the air passing through the effective disk area of the machine. If the effective area of the disk is A, and the wind velocity v, the maximum theoretical power output P is:

where ρ is the air density.

As wind is free (no fuel cost), wind-to-rotor efficiency (including rotor blade friction and drag) is one of many aspects impacting the final price of wind power.[16] Further inefficiencies, such as gearbox losses, generator and converter losses, reduce the power delivered by a wind turbine. To protect components from undue wear, extracted power is held constant above the rated operating speed as theoretical power increases at the cube of wind speed, further reducing theoretical efficiency. In 2001, commercial utility-connected turbines deliver 75% to 80% of the Betz limit of power extractable from the wind, at rated operating speed.[17][18][needs update] "

https://en.wikipedia.org/wiki/Wind_turbine

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#12
In reply to #3

Re: Interesting? New Wind Turbine Design

10/16/2017 11:24 AM

Yes, right on.

What these people are proposing looks to the wind like a solid plate and the air goes around it not passing through it. A very small amount of air will pass though (2 to max 5% is my guess) but only if the wheel is already turning (which will require power.) It just can't work.

It is a scam.

Windmills are bad. Killing birds as mass and I thought the green promoters are environmentalist? It is an outgrowth of limited minds. Cost / power ratio is high. Fossil fuels are also free. There are no monsters or 'guards' underground demanding pay for taking it.

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#14
In reply to #12

Re: Interesting? New Wind Turbine Design

10/16/2017 12:07 PM

"Killing birds as mass."

Have you ever seen a dead bird under a wind turbine?

I haven't and I've actually walked around quite a few. That doesn't mean it doesn't happen, but it doesn't seem that bad.

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#15
In reply to #14

Re: Interesting? New Wind Turbine Design

10/16/2017 12:55 PM

I know you said that you like wind turbines.

See this article: Millions a year.

http://savetheeaglesinternational.org/new/us-windfarms-kill-10-20-times-more-than-previously-thought.html

It is all part of the idiocy that CO2 is a pollutant.

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#18
In reply to #14

Re: Interesting? New Wind Turbine Design

10/16/2017 1:18 PM

Denial. A river in Egypt. I wonder which tributary you are on today?

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#19
In reply to #18

Re: Interesting? New Wind Turbine Design

10/16/2017 3:21 PM

I remember seeing a design proposal for a windmill that looked like a giant reel type mower that was supposed to be attached to a stationary blimp at 50,000 ft. I couldn't help but wonder how they planned to get the power down to the ground.

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#20
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Re: Interesting? New Wind Turbine Design

10/16/2017 4:00 PM

Uh, the blimp is stationary, and probaby the cabling would run down the anchor lines. I can just imagine what Benjamin Franklin would think about this when the next storm comes rolling in. True, the wind speeds can be outstanding up there. I don't think the anchor lines could back the blimp though, and the blimp might not have sufficient lift if the anchor lines and cabling were not made out of magic material.

At that altitude, if parked over Florida, it would be guaranteed to collect one heck of a lot of peak power from storms, but maybe not much average power. Lightning being discontinuous and all.

If the blimp was hydrogen-filled, life expectancy might be three whole days.

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#22
In reply to #14

Re: Interesting? New Wind Turbine Design

10/17/2017 12:46 AM

The reason why you don't see any dead birds, maybe you may have seen predators and scavengers in the area...It happens.

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#23
In reply to #3

Re: Interesting? New Wind Turbine Design

10/17/2017 9:43 AM

dP = 0.9 ρ A (v3) dV

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#25
In reply to #23

Re: Interesting? New Wind Turbine Design

10/17/2017 11:44 AM

Correction (dP = 0.9 ρ A (v3) dV) to:

dP = 0.9 ρ A (v2) dV

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#5

Re: Interesting? New Wind Turbine Design

10/15/2017 11:35 PM

Interesting indeed..

Too much ice... In reverse

Tsk tsk tsk

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#6

Re: Interesting? New Wind Turbine Design

10/16/2017 8:38 AM

Friends,

I am curious about one thing. Among the assumptions used to derive the Betz law is the statement that the density of the air downstream is the same as that upstream. This means that the slower-moving air after the rotor automatically occupies a much larger area.

Now, intuitively, this cannot be so. You don't suddenly have an arbitrary disk of air moving at some suitable velocity within a much larger area of air at the same velocity "suddenly" expand in area while its velocity is reduced while the surrounding area's air maintains its velocity and area. I say that the assumption is not valid.

Has anyone done measurements of wind speed immediately before and after a turbine, along with measurements of air density or pressure? If the speed is reduced because of the extraction of energy from the moving air then conservation of mass would suggest that the density must increase (an increase in air pressure) unless (according to the Betz assumptions) the area occupied by the discharged air increases.

Consider the effects of a wind turbine on bats, with the damage to their hearing from rupture of organs--suspected to be caused by sudden changes in air pressure.

Data anyone?

--JMM

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#21
In reply to #6

Re: Interesting? New Wind Turbine Design

10/16/2017 9:40 PM

"... This means that the slower-moving air after the rotor automatically occupies a much larger area ..."

Nope. You are making the mistake of assuming all the parcels stay in their respective lanes....which does not occur. There is plenty of mixing.

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#26
In reply to #21

Re: Interesting? New Wind Turbine Design

10/17/2017 12:07 PM

Friend,

That quote of mine is one of five assumptions on which the calculated 16/27 efficiency is based. Check the original reference. I agree with you that the assumption is not supported in real life.

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#27
In reply to #26

Re: Interesting? New Wind Turbine Design

10/19/2017 10:26 AM

You are quoting a premise of a particular argument/proof, the onus is upon you to provide a link or exact quote.

I suspect your interpretation of the premise is flawed... or perhaps you have it exactly correct...put the same material you are looking at in front of us and it will quickly be sorted.

One thing to note, one assumption upon which Betz's formula is predicated is zero change in density....which doesn't bode well for large changes in space occupied by a mass of air.

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#28
In reply to #27

Re: Interesting? New Wind Turbine Design

10/20/2017 10:49 PM

Truth...,

I appreciate the tone of your reply! I did not attempt to look for the original paper from Betz, but used the Wikipedia reference given by Richter in his post #3. Below is a quote of the assumptions portion of that article:

Assumptions[edit]

  1. The rotor does not possess a hub and is ideal, with an infinite number of blades which have no drag. Any resulting drag would only lower this idealized value.
  2. The flow into and out of the rotor is axial. This is a control volume analysis, and to construct a solution the control volume must contain all flow going in and out, failure to account for that flow would violate the conservation equations.
  3. The flow is non-compressible. Density remains constant, and there is no heat transfer.
  4. Uniform thrust is exerted on the disc or rotor.

My post that we have been discussing is a restatement of assumption #3 and is also shown graphically in an earlier portion of the Wikipedia article, wherein the downstream portion of the flow occupies a greater area than the upstream portion.

We both know that air is a compressible fluid and the portions of air flow that do not pass through the turbine's swept area are going to try to occupy the same two-dimensional space downstream as upstream. If the turbine is removing energy from the air stream and the downstream air is constrained to the same cross-sectional area as the upstream air, the downstream air is either more dense (conservation of mass) or cooler (ideal gas laws), or some midpoint between these two. If the downstream air is more dense, because removal of energy would result in a reduced velocity, then Betz' law is based on an assumption that cannot be supported by real world conditions. If the downstream air in fact occupies a larger cross-section than the upstream, then the air that bypasses must become compressed or speed up, and this opens another entire set of real world conditions that can argue against the validity of assumption #3 under any conditions other than an ideal and limited case.

Thanks--JMM

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#29
In reply to #28

Re: Interesting? New Wind Turbine Design

10/22/2017 8:24 AM

"....portions of air flow that do not pass through the turbine's swept area are going to try to occupy the same two-dimensional space downstream as upstream. If the turbine is removing energy from the air stream and the downstream air is constrained to the same cross-sectional area as the upstream air,..."

.

The lines above contain the assumption on your part that is not included as an assumption on required for Betz law. Furthermore, the assumption you add is not one that holds up well given reasonable scrutiny. There definitely is flow motivated from areas of high pressure to areas of low pressure.

Consider this. If air occupied the same two dimensional space upstream as downstream, a closed parachute would push air downward far, far in advance of its descent, and an absolute vacuum would follow above the parachute.

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#30
In reply to #29

Re: Interesting? New Wind Turbine Design

10/22/2017 3:28 PM

I will not attempt to parse words further than we have done. I maintain my assertion that Betz' law is based on assumptions that are valid only in a theoretical model. Real world (i.e. practical) use of a wind turbine will create conditions that invalidate one or more assumptions behind the calculations in Betz' law. Therefore the limiting value of energy that can be extracted from wind may very well be different than the 16/27 value given by Betz' law.

It would be useful to have data that give speed, temperature, and pressure for the moving air mass at different points upstream and downstream from the plane of the operating turbine, in a grid that extends laterally and longitudinally far enough so its furthest points have measured values that are constants across the lateral direction. Until we have this information (along with the amount of energy being extracted by the turbine, I believe that both of us are "blowing wind".

Thanks--JMM

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#31
In reply to #30

Re: Interesting? New Wind Turbine Design

10/22/2017 6:58 PM

I don't think it helps to leave your first objection to the assumptions used for Betz law open with an outstanding objection to your reasoning.

Your explanation of your objection to the assumptions of Betz law is predicated on wind currents "staying in their lane". You implied universal acceptance of this idea. I am stating this idea is not universally accepted. I am further stating that it is obvious that wind is not in the habit of 'staying in its lane'.

.

Do you maintain wind 'stays in its lane'? If so, could you perhaps provide some support for this assertion?

If not, do you have a different specific objection to the assumptions used for Betz law?

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#32
In reply to #31

Re: Interesting? New Wind Turbine Design

10/25/2017 12:59 AM

In a simplified treatment, I am dividing the entire air flow into two portions--that which passes through the plane of the wind turbine and that which does not. These are the two lanes that I am referring to. Turbulence is being ignored (it has no part to play in the equations used to derive Betz' law). Energy extracted from the portion through the turbine can only come from the wind--no other source is allowed. Therefore, the "lane" passing through the turbine must either slow down or become cooler, or some combination of these two. The calculations supporting Betz' law do not include any allowance for cooling, so I will ignore it. Since Betz' law assumes that density is constant a slower air mass must occupy a larger area on the downstream side. This then impinges on the space that is being occupied by the "lane" that does not pass through the turbine. In doing the calculations for Betz' law, this impingement is being ignored.

Betz' law is valid as a theoretical construct. It is erroneous have a hard & fast rule requiring application of Betz' law to real-world conditions because these real-world conditions include interactions that violate the assumptions used to derive it.

Nonetheless, Betz' law does give us a good starting point for assessing the maximum possible amount of energy that can be extracted from a moving air stream. But it is NOT an absolute value.

I think we have gone back and forth long enough on this topic. --JMM

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#33
In reply to #32

Re: Interesting? New Wind Turbine Design

10/25/2017 8:51 PM

I appreciate your perseverence in our discussion. I believe we are very close to seeing eye to eye.

There is only one small portion of what you are saying that is giving me problems:

"...Since Betz' law assumes that density is constant a slower air mass must occupy a larger area on the downstream side....".

.

This, for me, does not follow. Maybe, I am forgetting something fundamental, but I'm not making the jump.

A car at rest takes up a certain area and volume at any given moment. That same car with the same density takes up equivalent area and volume at any given moment when in motion.

The volume and area of some aspect of a helium balloon does not change significantly if the child holding its string slows from running to a walk.

Help me out here. Why must air of the same density occupy more area if it is not moving as fast with respect to the ground?

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#34
In reply to #33

Re: Interesting? New Wind Turbine Design

10/26/2017 11:23 PM

Truth,

Take your car analogy and extend it a little. If you have a group of cars on the road at a constant speed, assume that one care passes you every 5 seconds. If this group is traveling at a faster speed but they are passing you at the same rate then they have to be spaced apart further. Similarly, if they are traveling slower then they are closer together. This is the "density" of the cars on the road.

I think you agree that removing energy from the wind is accompanied with a slower wind speed downstream.

Back to the cars... If they are now traveling slower but in the same lane, then their spacing (density) is higher. In order to get the same spacing you have to put some cars in a separate (presumably parallel) lane. Thus, to get the same "density" downstream as it was upstream you have to spread out the flow into a larger area.

Does this help?

--JMM

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#35
In reply to #34

Re: Interesting? New Wind Turbine Design

10/27/2017 10:17 PM

Not sure the cars analogy helps, but I will interject that traffic is better modeled by supersonic flows (compressible) than subsonic flows. Flow restrictions reduce velocity and do not cause the vehicle to squirt faster past any restriction.

Ignoring relativistic effects, I take a moving volume and a stationary volume are not meaningfully different with respect to the various length width height measurments that might comprise such....regardless the frame of reference in which those measurments are taken.

The timing of how quickly the cars pass does not affect the density, as the cars will pass a stationary point even faster than the cars pass a car going slower yet in the same direction. The density is the amount per volume at a particular time. Being at. particular time actually removes any changes in outcome due to motion. How much in what volume at what instant....

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#36
In reply to #35

Re: Interesting? New Wind Turbine Design

10/28/2017 7:35 PM

Truth,

My cars analogy was treating each car as if it was a molecule of air--blowing up what happens to the macroscopic scale! If the same number of cars/molecules pass the turbine per unit of time and they are moving faster before while they are moving slower after, then they are closer together after and further apart before. OK? This means their density (cars per unit area/volume) is greater after than before. This is a violation of assumption #3 for Betz' law. In order to get them at the same spacing afterwards (same density) as they were before, they must spread out to a wider area as they are moving forward. OK.

My objection to the real-world validity of this assumption is that in the real world you have to consider the presence of a moving stream that surrounds the one passing through the turbine. This surrounding stream would tend to constrain the through stream so its slower speed cannot be fully compensated for by spreading into a larger area. Thus Betz' law is good in theory as a beginning point for work, but cannot be used as a hard-and-fast rule for actual wind turbines in the real world.

This would imply that the original poster's statement that a person has achieved significantly higher turbine efficiency than that given by Betz' law cannot be thrown out automatically. I have my personal doubts that the efficiency will be anywhere near what they were claiming. An extreme claim can probably be classified as "vaporware".

--JMM

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#37
In reply to #36

Re: Interesting? New Wind Turbine Design

10/29/2017 1:28 PM

"... This surrounding stream would tend to constrain the through stream so its slower speed cannot be fully compensated for by spreading into a larger area. ...."

The surrounding, faster moving stream, does not have a constraining effect, just the opposite. Moving at a higher speed and thus reduced pressure, it has the effect of drawing out the slower stream, widening the path.

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#38
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Re: Interesting? New Wind Turbine Design

10/29/2017 5:01 PM

Not that easy. --JMM

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#39
In reply to #38

Re: Interesting? New Wind Turbine Design

10/29/2017 11:25 PM

Are you also unconvinced of Bernoulli's principle?

How else might you arrive at the conclusion that surrounding streams moving more rapidly would serve to constrain the slower flow?

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#40
In reply to #31

Re: Interesting? New Wind Turbine Design

10/30/2017 9:35 AM

I agree. Not only not "staying in its lane", but control volume analysis applied to a wind turbine is probably a doomed assumption from the outset.

In all physics and chemistry, it is keenly important to define the system (whether closed or open) to the fullest extent, before opening the accounting books on it.

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#7

Re: Interesting? New Wind Turbine Design

10/16/2017 9:46 AM

This claim about the three-blade turbine only "seeing" 5% of the input energy in the wind is totally incorrect. It does turn out the 3 or 4 blade HAWT is the mathematical optimum, proven fact.

I have however seen "bladeless designs" that consist of nested conical helices. No shroud.

Shrouded designs for their peak performance require a duct system that is convergent that increases wind speeds into the turbine to achieve the highest outputs.

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#8

Re: Interesting? New Wind Turbine Design

10/16/2017 9:58 AM

If the pitch of these blades is fixed, how do you control the speed? What happens during a storm and wind gusts hit 100mph? Is it rated for 20,000rpm? Or does he plan to use brakes to control it. I have seen videos on what happens when the brakes stay on too long on wind turbines, poof....

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#9
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Re: Interesting? New Wind Turbine Design

10/16/2017 10:05 AM

I agree, as I saw no pitch control either. If you cannot feather the prop, it will not stop.

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#10

Re: Interesting? New Wind Turbine Design

10/16/2017 10:08 AM

I have no doubt, as more and more countries turn to wind power that the design, efficiency and probably even the turbine itself will undergo changes in technology, design, and construction making them even better at what they do. It's just that the market was not big enough that no one has ever explored this concept on an industrial scale. Wind turbine design is still in its infancy really.

That said, this is not one of those. LoL

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#11
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Re: Interesting? New Wind Turbine Design

10/16/2017 10:36 AM

Yes, regarding changes. I remember seeing a prototype on the Altamont Pass in California that was a long looped cable with panels attached. The wind would push them sideways to rotate the shaft for energy production. Never saw it running, however. Think also about the VAWT, such as the Savonius type. Their big problem was lower speeds close to the ground. Did anyone ever put one on a tall pylon?

--John M.

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#17
In reply to #11

Re: Interesting? New Wind Turbine Design

10/16/2017 12:58 PM

All the VAWT designs have been tried aloft. No advantages, other than one thing: no change in rotation axis required if transmitting mechanical power to the ground level.

HAWT can easily do the same thing using hydraulics with the correct couplings.

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#16
In reply to #10

Re: Interesting? New Wind Turbine Design

10/16/2017 12:56 PM

I think that at very high wind speed, something such as that (except with no more than four blades) will be the most efficient.

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#13

Re: Interesting? New Wind Turbine Design

10/16/2017 11:33 AM

Interesting design, but lots of potential issues. A few:

1. No transmission cost. It's on my roof. - Unfortunately the wind is not necessarily where the power is needed.

2. Efficiency vs area - The 3 blade windmill is 30 ft in diameter or larger. I can't feasibly see a way to build this design 30 feet in diameter due to cost and weight. I also wouldn't want this thing directly over my head all the time if it's 30 ft in diameter and weighs several tons.

3. 50% efficiency - How was it calculated?

4. Environmental concerns - What does this thing do to a honey crested huckleberry sucker if it gets sucked in? What is the climate impact of wind pattern changes? What is the interaction effect of these units if they get put too close together, or can we line them up, one directly behind another?

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#24

Re: Interesting? New Wind Turbine Design

10/17/2017 11:39 AM

Archimedes screw type is good, but not that good

The thing I like about this, is that the basic design should be relatively easy even for a backyard mechanic like me. I was thinking about trying a spiral made from coat hanger wires and plastic tarp material, but aluminum sheet metal would be better.

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