WWII veteran creates bird-friendly wind turbine


September 2, 2012

Military veteran Raymond Green created the Catching Wind Power prototype at an estimated cost of US$550

Military veteran Raymond Green created the Catching Wind Power prototype at an estimated cost of US$550

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World War II veteran Raymond Green, an 89 year old resident of Jackson, California, has created a working prototype of a "bladeless" wind turbine which is bird and bat-friendly, and very quiet in operation. Though still in development at present, Green intends his design to be produced in various sizes, from smaller personal versions to much larger turbines which could be implemented in wind farms.

The Compressed Air Enclosed Wind Turbine weighs 45 lb (20 kg) overall, while the turbine assembly itself measures 12 inches (30 cm) in diameter and the wind sock which surrounds it has a diameter of 31 inches (78 cm) at its widest point. Green explains that unlike traditional three-blade turbines, which can kill birds and bats as they rotate at high speed, his prototype sports no external moving parts, but houses its blades safely within the unit.

In order to test the prototype, Green affixed it to the roof of his truck and drove around, producing enough power to light a bulb.

The prototype’s patented "Inner Compression Cone Technology" draws in wind through its wide entrance, pushing it into the more confined space where the turbine blades are located. Green claims that this system can produce double the output of a typical turbine, even when placed closer to the ground than is usual - an impressive increase indeed, and we're keen to see some hard figures on this as the project matures.

The same wind compression tech is also responsible for enabling the turbine's hidden blades to be shorter than is customary, and this renders it significantly quieter in operation, when compared to a traditional wind turbine.

The Compressed Air Enclosed Wind Turbine was created at an estimated cost of US$550 and in order to bring a product to market, Green has teamed up with Sigma Design Company. The process of perfecting the design and manufacturing is expected to take up to two years.

The short promo video below sheds some more light on the project.

Source: Catching Wind Power, via TreeHugger

About the Author
Adam Williams Adam scours the globe from his home in North Wales in order to bring the best of innovative architecture and sustainable design to the pages of Gizmag. Most of his spare time is spent dabbling in music, tinkering with old Macintosh computers and trying to keep his even older VW bus on the road. All articles by Adam Williams

Studies funded by the Department of Energy over 30 years ago conclusively proved that concentrator ducts don't help. I strongly doubt he really got "double the output" or a measurable increase at all. That's as much exaggeration as the purported output of William Allison's turbine, which nobody else has ever been able to confirm. (Preemptive strike before Island Architect brings up his name for the umpteenth time.) While diffuser ducts do work, the problem remains that a large duct for a large turbine would be heavy and expensive, which is why utility scale turbines haven't been built with those, either.


We are starting to see wind turbine wings 75 meters long - just trying to imagine the size needed for one of these compressor to perform similar makes my head hurt. I simply don't see it especially since the whole concept is questionable.


This gets "invented" several times every year. If people really cared about bird strikes, they'd get serious about painting turbines purple, which makes them stealthy to insects, and thus not worth the risk for hunting birds. Birds are smart enough to not get struck, but the pressure changes from a near miss wreck their lungs.

Bob Stuart

Best say first that I love inventions...but.. Too bad that physics say that the longer the turbine blades are the more efficient the wind turbine gets. And also I am quite sure that when you have a "wind cone" it doesn´t let the air compress it self but makes like an air "bubble" and thus the new air goes around the inlet. (Much like the old "cone goggles" for motor-bikers). Data suggest that turning the cone around and flaring it more will give more help for this turbine. Where the cone creates a low pressure behind the blades and then sucks more air into the turbine. But this is already patented..(sorry).. But to protect bats I'd suggest some type of speaker that operates at the bat range of hearing and thus scares them away. (Is there really any hard data on how many birds and bats that actually die from hitting wind-farms?) The blades spin fast enough that a bat should "see" them even if it goes past fast. Keep trying my fellow inventor, but I do feel like this way is not going to work well enough.

Toffe Kaal

This does in actual fact not compress the air at all. It is called the venturi effect. When air is forced through a narrow section like this, the air speeds up, but both the temperature and pressure drop. It does however increase the yield on the rotor.


I hate to say it: He's not the first to try this approach, won't be the last, and it won't work once again. It may be bird friendly, though it is by no means more efficient: It is simply not possible to draw more than 37% of the energy out of any section of free flowing air: The remaining air is simply going to flow around the obstacle, that is the turbine, or the duct, should there be any. It's just physics and should already have been discovered before WWII.


One of the main objections to the existing 3 rotor based windfarms is their blight on the landscape. Whilst most Doctor Who fans might be thrilled to gaze out at a swarm of flying Daleks hovering menacingly over the English countryside, I can't imagine many other people being delighted at the prospect.


@Martinkopplow, and Ed. The maximum amount of power that can theoretically be extracted from an area of wind is the Betz limit, and it is 59.3%. If you take more than that, you reduce the local wind speed too much and hit diminishing returns. Shrouded fans are useful for limited spaces, but are otherwise always uneconomic. Adding the shroud material to the blade tips helps more.

Bob Stuart

It's common sense that if you 'funnel' the air you can use a much smaller (and therefore cheaper) turbine, because it will be driven by much faster wind than without the funnel. Look at all the examples above.

This guy's invention isn't particularly brilliant, I and I'm sure thousands of others have thought of exactly the same thing before, but as for Gadgeteer's brilliant comment: "While diffuser ducts do work, the problem remains that a large duct for a large turbine would be heavy and expensive," LOL! Never heard of ripstop nylon? Or Dacron? The problem with 99% of new wind turbine designs is that the designers are unable to think of the magic words 'cost per kilowatt', and instead want their turbine to LOOK 'modern'.

Efficiency is irrelevant, ALL that matters is COST PER KILOWATT. Wind turbines should be made with Dacron and use concentrators made of the same.

Would love to see the 'Department of Energy' papers which claim concentrators don't work! Who do you believe? Me, or your own lying eyes? LOL!

Just look at some of the concepts at

For example, the Circular Wind Dam, an excellent idea. The whole point of using concentrators is that they can be built out of very cheap materials, i.e. Dacron, or bricks, strawbales, etc. thus reducing the size of wind turbine needed to extract the same amount of energy as a much larger, un-'concentrated' one would.

And LOL at the commenters claiming that the wind would just 'go round' the concentrator... LOL!

I can't believe you can't even grasp such a simple concept - if the wind speed is 10mph, the air that enters the concentrator will be moving a lot faster by the time it reaches the turbine at the end. Do you think that sufficient wind will somehow move BACKWARDS and thus go AROUND the concentrator (LOL) to prevent the wind speed at the turbine being much higher than that of the rest of the wind?


Wow seems like a pointless "invention" to me. Are people aware that birds die? I mean they die, period. Sometimes they get the flue, sometimes they fly into windows, sometimes other birds get them.

wind turbines only have value if the produce more electricity then it cost to make. The most cost effective turbines have 3 blades and are as big and high as possible.

If this confuses people, oh well. If you were really concerned about birds you could do more research into blade color, reflective material, sound or "scarecrows" to keep birds away from moving blades.

I am happy this ww2 vet is doing something, but Please don't call something so silly news, its been done before and it wasn't worth noting then.

Michael Mantion

Props to the 89-year old 'inventor' !!! It is good to see that innovation has no age boundaries. I am not a fan of wind-turbines but understand that we have to use the technology available to be ‘greener’ than hydrocarbons. Pardon my physics-handicap, but isn’t flowing water more concentrated in energy than wind and always flowing 24/7? Harness THAT from the ocean currents down where we don’t see it and works silently.


It looks like he's got some more work to do on it. But my burning question is this; why did he have to mount it on his truck to get sufficient air flow through the thing? In the real world, these things are static in relationship to the ground, and so that's where they should be at all times to see what the advantages are and where the disadvantages are. If there isn't enough wind where he's testing the unit out, then he should go near to where we already have wind farms and test it there. Then he'd be talking apples and apples, not apples and oranges.


Expanded Viewpoint

Unfortunately, I have to agree with others on this page.

If reliable and abundant wind power was even remotely possible, Germany would be continuing with their wind power program.

But they are going back to coal fired power because they concluded that fossil fuels are the most reliable and lowest cost way to produce electricity.


There is another design out there that I think the Japanese are working on. It looks similar but the air flows the opposite direction and the cone is somewhat flared at its outer and large opening. This apparently causes a low pressure area inside the much-reduce cone size, causing a vacuum to suck more air in and thus increase the rotor speed. Well, that's the theory anyway. They do have some test models up and running. Either way you look at it, these smaller turbines help but to run a house you practically need a wind farm and I have not seen the cost benefits. The price of these small home unit is so high and the power yield so low, it would take decades just to break even.

Charles Gage

Why not just put nets in front of these things to catch the birds and bats before they get hit...just a simple thought

Daniel Beach

If you're going to focus airflow into a turbine, why not use a Tesla-style disk turbine? If the idea is to smooth out the transition from kinetic to electrical, then Tesla had a pretty good idea.

Jim Parker
Years ago i used to put up tarps such that wind from the east would funnel down into a narrow gap of about four feet. The wind speed absolutely increased at the squeeze point and it worked well as I am in an area where winds normally come from some sort of easterly direction. Instaed of sleeping in hot, almost still air I was sleeping in a breeze. That also tended to keep mosquitoes off of me. Some modern motorcycles also use a funnel shape to gain incoming air to feed the engine and it has made a real difference in power production. Obviously the effect is larger at higher speeds and the bikes that use these systems tend to be able to reach radical speeds. Jim Sadler

The basic idea of shrouding a turbine to increase its capture area is sound, but using a scoop like this one doesn't work. If this guy simply turned the shroud around, putting the wider part downstream, he would get better results. Still better results can be had by a slight expansion upstream, a very generous lip radius, and an expanding duct downstream. Counterintuitive but sound.


Love this 89 year guy still thinking and tinkering.

bomberR76: I've seen concepts putting turbines on the seabed in the Gulf Stream. 40 years ago in grad school I wrote a paper on using such devices to crack seawater into H2 and piping it ashore, the idea being to eliminate the need for underwater high-voltage transmission lines, with the attendant losses, etc.


"affixed it to the roof of his truck and drove around, producing enough power to light a bulb" BWAAAHAHAHA what a joke!

"all that matters is cost per kilowatt" ROFPML what a joke! if this were true packoftwenty would be using a home made pedal-powered generator built from old washing machines! ...oh hang on, that's what i do already!


packoftwenty, you display utter ignorance about the field. Unlike you, I've read actual scientific studies and papers from sources like NREL, DOE and SERI reports, as well as places like the Journal of Energy. I place more trust in professional researchers and engineers than in any pie in the sky concept promulgated in anonymous blogs by nontechnical daydreamers. If any those ideas had any merit to them at all, why doesn't he patent them and make his fortune? Do you really think this "simple concept," as you put it, hasn't been tested and re-tested by people with equipment far more advanced than a pickup truck? Especially since there have already been hundreds if not thousands of patented variations? Anyone can throw up a blog or even a website and claim something will work. It's much harder to back it up with hard, experimental data.


I have no idea if his concept can work or not but I think his test platform is flawed. Air displaced by the front of his truck might be going through the turbine. He needs to move the windmill forward so that it is the leading point on the truck and every inch of additional height that it can be given would be good as well.


About time.

Hon. Steven W Lindsey State rep Keene, NH

Taximan Lindsey

Oh dear, Gadgeteer... you sound a bit het up... there there...

" If any those ideas had any merit to them at all, why doesn't he patent them and make his fortune? Do you really think this "simple concept," as you put it, hasn't been tested and re-tested by people with equipment far more advanced than a pickup truck?"

Are you talking about Salient White Elephant? Perhaps he can't afford the tens of thousands of ideas required to patent them? Like 99.9% of the population? Perhaps he just wants to give his ideas away so that somebody can eventually make use of them? Why are you suggesting that I am supporting the 89 year old inventor here? The ONLY good part of his invention is the concentrator/shroud, that's it. The fundamental design is not going to be cheap enough, remember COST PER KILOWATT HOUR, and is therefore pointless.

Please enlighten me and give me some references to papers about the use of sail based wind turbines. Actually, you'll find that virtually NO research has been done on them, because the 'higher ups' (idiots like you, presumably) think they know best, BEFORE even building and testing sail based turbines! They actually claim that they 'can't be as efficient' (which is irrelevant, because the ONLY thing that matters is cost per kilowatt hour) as 'conventional' designs, so they don't bother building or testing them!

But please, enlighten me, show me the 'research papers' which you claim exist - I've been searching for some for years, and haven't found any.

Modern large three bladed wind turbines allow MOST of the air to pass straight through the swept area - it is TOTALLY to do with the wind speed versus the speed the blades move through it. A blade cannot be in two places at once. The wind which moves through a space between two blades, a space that could be 50m wide, cannot be turning those blades...

Has any 'research' been done on that? I thought not.

Anyway, Salient White Elephant has some brilliant ideas, particularly his Circular Wind Dam.

Why do you think that won't work? Where is the 'research' into these concepts? It simply doesn't exist. There is only ONE design of wind turbine 'allowed' nowadays, and that's the stupendously huge, three bladed horizontal axis rubbish which we see everywhere - hugely SUBSIDISED by the public, because it simply isn't cheap enough, PER KILOWATT HOUR, to survive in the open market... LOL.


martinkopplow doesn't seem to understand the basics of physics...

"It may be bird friendly, though it is by no means more efficient: It is simply not possible to draw more than 37% of the energy out of any section of free flowing air: The remaining air is simply going to flow around the obstacle, that is the turbine, or the duct, should there be any. It's just physics and should already have been discovered before WWII. "

Nobody claims to be able to extract more energy out of a given cross section of air - what a concentrator does is allow you to extra energy from a LARGER cross section of air, larger than the swept area of the wind turbine. I take it you realise that it costs more to build a 10m turbine than a 3m one? If you can get more air to go through a 3m wind turbine in a given time just by using a fabric concentrator, you can increase its output for a LOT less money than building a 10m wind turbine.

When wind enters a concentrator, it SPEEDS UP, so that a given volume of air can move through a smaller area faster than it would move through a larger area. This is basic stuff that even five year olds know.

The book "Wind energy in the built environment":

"This book describes the wind resources in the built environment that can be converted into energy by a wind turbine. It especially deals with the integration of a wind turbine and a building in such a way that the building concentrates the available wind energy for the wind turbine. The three different ways to concentrate wind power are examined: wind turbines on the roof or at the sides of a building; wind turbines between two airfoil shaped buildings; wind turbines in ducts through buildings. "

Which part of that don't you understand? This is hilarious.



"Perhaps he can't afford the tens of thousands of POUNDS required to patent them".

Freudian slip!


I agree with those who say there are thousands of inventors who think they've found the holy grail. True researchers look at an idea, test it, expand from there, test it some more. I see a lot of 'wind turbines' on Youtube that are no more wind turbines than those spinning nylon rainbows on people's lawns. There are all sorts of outlandish claims made on things that are NOT tested, on spinners that are not connected to generators but are called generators. Of course a small device can spin quietly if there is no load on it. If you make the blades smaller, they have to spin faster to make up for the lack of torque produced by larger, higher blades. How does that REDUCE noise? Claims that you can put these closer to the ground do not take into account the way air currents move at that level. Claims that you can just attach these to your house or garage are, in some cases, dangerous, when you take into account vibrations from spin and directional wind changes. And being snarky about how you're a genius and the rest of the world is stupid does not help the cause.

Ron DeMattio

A very simple physics rule is that the energy you get from wind is proportional to the area you collect wind from. How could this funky yogurt pot compete with 70m-long blades, covering areas as large as 15'000 m2 ?

Vincent Rossi

Designs such as these which fall into the ducted turbine genre have commercialized successfully over the past 150 years, not always though as a wind turbine. The first actual ducted turbine was a French ducted "wind-mill" which included a stator preceding the turbine blades, enclosed in a diffusing shroud. The French brothers who designed and invented this machine (Eolienne' Bolle-Sylvain bros) sold 800 of them before grid electricity from fossil fuels marginalized their usefulness based on COE (c. 1860-1890) Yes COE matters, but don't expect new equipment or design to compete against fossil fuel power, even if that new equipment is more efficient. -Concentrator type turbines do work, except they do so at higher true air speeds exceeding 30 mph. That would make this design impractical for most land based locations, barring the Arctic, Antartic and tropical island with tradewinds. It may work as a mobile device attached to a vessel that is traveling fast enough to generate true air speeds in excess of 30 mph. That limits the usefulness of the concentrator approach, but does open a niche market. -All wind turbines are subject to "unsteady aerodynamics", no matter what the design and Kutta Joukowsky condition. It is a fundamental law. -Control volume area (or swept area) in this design is set by the largest diameter of the cone, not the blade or turbine diameter. Cp comes down to earth when this is factored in. -Conversion efficiency (Cp) varies. Theoretically, it is established at. .593 based on the sweep area of the blades or the area of perturbed flow. There is no such thing or claims that wind turbines (of any size, shape or design) can only recover 37% of the kinetic energy or watts per square meter. Rubbish. And the Betz limits applies only to specific conditions and designs, not to every design. For the Betz limit to apply the machine must be: a. Axissymmetrical. or round. b. Unperturbed air flow in the far ahead wake and downstream wake. c. Inviscid fluid and incompressible fluid. (wind or water) d. Flow is subsonic.

One can easily argue that a standard 3 bladed wind turbine properly optimized can exceed the Betz limit, by simply violating the condition used to define the limit. I.E, stick a wind turbine in a mountain pass where the ridge acts as a concentrator, or even in cases where the ground clearance (ground effect-"ballooning") can augment the performace from boosting airflow (ass flow augmentation).

So before those that haven't the slightest clue about aerodynamics and design, comment or post about an invention, I would suggest that you read or go back to school to understand "Fundamentals of Fluid Dynamics" I would say this design has more work to be done, which is what the designer this article is written about is also saying.


If this isn't the way to go as many have expressed then what would you suggest as a way to prevent bird deaths from existing besides a 100' tall scarecrow????

Priscilla Ross-Fox

I would suggest to put vertical type turbines on top stories of tall buildings. Put in vanes that cause bypass air to flow to the down-wind side to cause a low pressure area on the system output. Just like an airplane airfoil. The whole inlet/outlet area can be screened to deflect critters at a small loss in airflow.

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