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Versatile Wind Harvester breaks from traditional turbine design


February 22, 2012

Heath Evdemon has designed a new kind of wind turbine based on reciprocating motion that's currently being scaled up into a full-size prototype with the help of the Future Factory project

Heath Evdemon has designed a new kind of wind turbine based on reciprocating motion that's currently being scaled up into a full-size prototype with the help of the Future Factory project

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From huge kites to sea-bound flywheels and roof-top installations to tree-like art creations, we've seen many different approaches to capturing energy from the wind. One design, though, reigns supreme - the tri-blade turbine tower. It's not exactly a trouble-free life at the top and there are those who do not look upon these monsters favorably, most often complaining about the noise and the not so picturesque view. With support from Nottingham Trent University's Future Factory project, Heath Evdemon is currently building a new type of wind turbine called the Wind Harvester that's claimed to be virtually silent, doesn't need to loom high over the landscape and can operate in a variety of wind conditions.

Evdemon first came up with the idea for the Wind Harvester over six years ago but has only recently developed the idea further. The Wind Harvester has horizontal airfoil blades that need only measure one meter (3.28 feet) across and can operate at half a meter (1.64 feet) off the ground on hillsides or outcrops, or can be placed atop domestic, commercial and agricultural buildings.

"The Wind Harvester can be used in locations where it is difficult to install current wind turbine farms," said project supporter Dr Amin Al-Habaibeh from Nottingham Trent University's School of Architecture, Design and the Built Environment.

The system is based on reciprocating motion - as the wind catches a horizontal airfoil (like the ones you might find on aircraft), it's raised until it reaches a certain point, then the angle of the blade alters and it's forced downward, and the process repeats. Unlike the more familiar wind turbine designs where the tip of the blade moves at a different speed to a more central point, all the points on the airfoils of the Wind Harvester would move at the same velocity. This is said to make the unit capable of generating power at low wind speed, as well as continuing through to the kind of higher wind speeds that may result in other systems ceasing operation to prevent damage.

The system is scalable up to blades of about 15 meters (49 feet), and its components can be broken down into bite-sized pieces for ease of installation without the need for heavy machinery.

The frame, rotating base, swinging arms, airfoils, generator and the outer housing of the system are currently being upscaled into a fully working prototype model thanks to funding from Future Factory, the Peak District National Park's Sustainable Development Fund and the Live & Work Rural program.

"We're looking for potential sites within the Peak District National Park at the moment and then we'll turn our attention to industry, but it's a product which could one day be rolled out to farms working towards becoming carbon neutral and homeowners looking for a cheap and sustainable source of power," says Evdemon.

At the time of writing, there's no word on exactly how efficient this new device is expected to be, we'll doubtless have to wait for real world data to be collected at the full-size prototyping stage.

Sources: Nottingham Trent University and Wind Power Innovations

About the Author
Paul Ridden While Paul is loath to reveal his age, he will admit to cutting his IT teeth on a TRS-80 (although he won't say which version). An obsessive fascination with computer technology blossomed from hobby into career before the desire for sunnier climes saw him wave a fond farewell to his native Blighty in favor of Bordeaux, France. He's now a dedicated newshound pursuing the latest bleeding edge tech for Gizmag. All articles by Paul Ridden

It\'s a mechanical nightmare that will break down constantly.


I suspect it was originally to be an Art \"Installation\" but he found there was some unused grant funding in the Alternative Energy kitty.

Who knows? Maybe the walkers in the Peak District will need their iPhones recharged - this should do it.

Pat O'Leary

Like a stalling canard?

Jim Parker

Why is it so trendy and cool to come up with laughably bad alternative power? Does it get chicks?

Todd Dunning

Fine in principle, but as Slowburn says, it will be a a clattering, squeaking with a completely uneccesary amount of components = durability and performance nightmare = not ever going to be cost effective.

I am also keen to understand where this can be installed that would be \'difficult\' for conventional three bladers.

I heard of a VAWT version of this that failed miserably at the recent PowerFOB MOD trials...

Folly I am afraid..... who\'s money is funding the Future Fund? - hopefully not mine as a tax payer?


Looks like a clumsy reverse-cyclocopter concept. (http://en.wikipedia.org/wiki/Cyclogyro) I agree with what\'s been said: the more moving parts, the more expensive to fabricate and maintain it\'ll be. Additionally, this appears to be uni-directional. How does it turn to face the wind when direction changes?

IMO, the helical vertical-axis eggbeater types are the most appealing for home-owner level implementation.


Looks more like Heath Robinson than Heath Evdemon.

I bet you could put a savonius rotor in the same volume of space this contraption takes up and get more out of it. Also, not only would it be quieter, I suspect, it would be just as safe in a high wind if designed properly.

Mel Tisdale

Can\'t sing? Can\'t Act? Can dance a little? You guys crack me up.

Avril Stalker

No single element in in the engineering world has drawn so many absurd concepts.

I wonder if we can sell that to Sam Williams for his advanced cruise missile engines.

The fact remains that all the goofballs have been following the 1946 NASA design with airfoils when airfoils are used for entirely different purposes. Even the Old Dutch and Aermotor inventors new better.

And the passel of absurd designers have all abandoned any concern for efficiency whatsoever as if engineering princples are frivolous. Never do they test and publish efficiencies. Certifications for nothing mean nothing.

The world needs a test and development centrer where a proper engineering approach to development can be taken.

Politicians promoting and promulgating the 20% efficiency designs are whacked. In Canada their throats were slit. Bill Allison achieved the Betz limit of 59% efficiency. Why doesn\'t someone try and prove him wrong?

Dead flat blades, highly polished SS construction and gaps to eliminate the cone of resistance are necessary.

This is chitty chitty bang bang stuff.

Bill Dickens

Island Architect

Hey, why is everyone attacking a good thing, stop it, Atleast for any good effort or you guys try making it. I once made a similar project. The problems I faced: 1. All parts have to be precise and balanced, otherwise it simply doesn\'t move or moves irratically or inefficiently. 2. Even a small amount of dust or dirt more on one side disbalances it. 3. Birds too sit on it and their dirt also disbalances it. But a larger project can benefit from Wind different between upper and lower levels.

Dawar Saify

Same tired bunch of naysayers always posting here. It gets really tiresome guys. What have you invented lately? A critic without any positive suggestions is one of the lowest forms of life.

The value of this idea is it can be low and unobtrusive, and yes actually fun to watch -- like moving art. Because it moves more slowly, it is not a danger to birds or other wildlife. Another advantage is that it is simple enough that I could build one, or assemble one from a kit in the \"field\" without any special equipment like a crane.

The true value as an energy source will have to wait on field tests and simulations to determine the cost effectiveness of the optimal design. A wide version would likely be effective for prevailing wind over a 90 degree directional range.

As a strictly mechanical device, this could be used as a well water pump for remote irrigation or livestock watering.

It will be interesting to see what kinds of applications the inventors come up with, and what they might do for conversion to generating electricity.

This can serve another niche. Good luck!


Here is a comment from my Canadian Friend....

Don\'t recall whether or not I told you of the news reports up here.

After blowing 18 billion smackeroos on windmills ....and 80% of them aren\'t functioning for a variety of reasons....the power people in Ontario called several states in the US and asked them to buy excess electricity (as you know, you cannot stack electricity like firewood) and negotiated a sale...power free...and Ontario had to pay $ 420,000,000 bux for accepting it.

I am going downstairs to the bar and have several bowls full of Scotch.

The three bladed ones are a disaster from an antique concept that is dead wrong.

Bill Allison tried a similar flapdoodle on his first attempt before switching to a fan design..

Tell us the efficiency of this flapdoodle. Not much for certain.

Any engineer with integrity is morally compelled to attack pathetic designs in order to help protect the public. Please tell us about the efficiency of this design particularly in winter conditions... I demand that you give it to us.


Island Architect

re; Island Architect

Quite beating the dead horse. Bill Allison\'s numbers are suspect and at the very least his designs do not scale up.


Dawar, things thing don\'t work should be mocked as this is just a very expensive paperweight.

For $300 in parts I can build a real windgen that actually makes useful power, 1kw in 15mph/ 6.5m/s winds. This unit would be lucky to make enough power to even move. If you want real, cost effective power google axial flux wind generator. Any windgen that isn\'t 2-5 blades horizonal just won\'t make useful power for it\'s cost. It basic physics and if you don\'t know why you should be wasting others time spouting misinformation. jerryd

Some comments on here are funny and i mean really funny

The design works it is tested I've seen it with my own eyes and i was amazed to see it working so well in such a light breese. neither of the models shown are working models only concept models to further better a design of which heath pioneered around 7-8 years ago. what you must realise is they are working at nottingham to create the best gearing mechanism and flip mechanism for the working design to build a product that can be marketed, i mean you cant sell just an areofoil and a few struts and make any sort of money. the design wont be released until its ready to market but the gearing is so simple and yet brilliant it minimises moving parts and unlike standard wind turbines that cost around 3 mill for just the blade the wind harvester blade is looking at a couple of thousand for a large scale aerofoil also the way that an aerofoil works means that you can take out more energy as the aerofoil uses the turbulance in the air and uses it to create the lift and fall in a bi directional manner in other words it rides the air instead of using it to produce drag in turn allowing the air to move freely in comparason to other methods that take the energy from the power of the wind so it works in a completly different way to conventional turbines also there is sight for a housing that would have minimal effect and also funnel the air to produce a better air flow and so the design will be pretty much unefected by weather conditions

i would like to point out that there are many sites across the uk that have turned down the possibility of conventional turbines due to the mark on the landscape and to have the ability to run so close to ground means that its quite likley you will see the wind harvester opening up the market and becoming quite the player in the field of wind energy.

there is also sight in the future to stack the wind harvester and so it wont be waisting any of the valuable wind

i would also like to point out that it wont be anything as near of a mechanichal nightmare as the fast moving high cost imposing monstrosities that they build in the landscape and there is so much more than just the cost of money so cost effective i think so.

and id like to ask the above what are you doing for your world what have you invented what problems have you solved that will affect people a great deal more than just your self.

i can only imagine you must resent yourselves for not thinking of such a simple yet brilliant design. or be ye trollin XD

Robert Hodgetts-Haley

Robert Hodgetts-Hhalley Simple yet brilliant???? Simple yes, brilliant debatable. Wind power is great for small scale, otherwise its a dead horse. Unreliable wind speeds, low efficiency, ridiculous startup costs with a poor true ROI, go nuclear.

Inventing a new windmill that doesn\'t do much is not something to crow about. Those monstrosities have some hope of actually generating power more than a bit here and there. Ground level wind is notorious for low speed, huge fluctuations and constantly changing directions.

Adrian Schuurmans

I\'d be willing to bet that most of the amazing technology you use today was trial and errored through some crazy ideas like these, including medical techniques and drugs. Pretty sure the MRI was a happy accident. And furthermore many if the best were largely funded by taxpayers. Companies like to take credit for \"innovation\" but often they\'ve just combined tech that government funded university projects have perfected over decades - time that private companies can\'t afford to wait on. Even something like the iPhone has its roots in military and university research in almost every component and function, from VLSI and RISC chips to cellular to GPS to BSD Unix, even the first touchscreen was British military. Although I\'m not proud of this one, apparently the money- and job-creating hydrofracking was developed with public money too.

David Storfer

I recall a single wing in a vertical orientation flapping radialy around bottom end (simple), could not find it, here\'s some interesting Google Hits of - flapping power generator. That don\'t show up in 6 Gizmag related articles.

http://creativemachines.cornell.edu/node/116 Flapping Piezo-Leaf Generator for Wind Energy Harvesting

http://www.icas.org/ICAS_ARCHIVE_CD1998-2010/ICAS2004/PAPERS/451.PDF MULTI-OBJECTIVE DESIGN STUDY OF A FLAPPING WING GENERATOR - Eriko Shimizu Tohoku University

http://seit.unsw.adfa.edu.au/ojs/index.php/juer/article/viewFile/177/140 Investigating the use of Flapping Foils for Power Generation - Mark D Ripper

http://peswiki.com/index.php/Directory:Wind Pure Energy Systems Wiki

Strikes me as similar to wind generator of this article. http://www.vcstar.com/photos/2007/aug/04/16670/ http://www.vcstar.com/news/2007/aug/05/developers-trying-harness-earths-energy-new-way/ Santa Barbara Based W2 Energy\'s wind \"turbine\" Via Ventura County Star August 2007.

Dave B13

I also recall seeing a pair of flapping blades working quite efficiently on birds and some time ago the pterosaurs demonstrated flapping blades that scaled up to 40ft using organic materials. Not suggesting that this design is good or bad, but there is inspiration from 100\'s of millions of years of evolution of flying designs to draw from in designing flapping machines


Well, I love wind turbines... They are great art pieces on the skyline... Nothing New with this design...

It is really Just a reverse (power in not out) , voith schneider propulsor, with a difference.

The problem with the design as illustrated is that the orientation of the blades will only be used for very slow rotation/low wind, or for starting, once the blades begin moving with any significant rotational speed their angle needs to vary (continuously around the circle) to keep their apparent wind at the correct angle of attack for power production (angle still needs to be varied around the circle).

There have been several patents for variable blade angle/pitch vertical axis wind turbines (this is just a VAWT turned on its side), none of which appear to have been put into production.

Problems are the need to brace the blades which will bend/flex under centripetal acceleration (not centrifugal force).

It is hard to make a VAWT as efficient as a HAWT, partly because of the need to have a mechanical system constantly trimming the blade angles, though I do agree that there is room for improvement, as with a VAWT the blade is all at the same angle of attack (if the wind is uniform along the blade) while with a conventional \"windmill\" the blade twist can only be optimised for one particular rotational speed in one particular velocity of wind, the variable pitch controller is simple able to extract more out of suboptimal situations that a constant pitch system would be able.

This system is likely to not work very well, because we all know that there is more wind up away from the ground and though we have heard stories of fabulous systems obtaining energy from updrafts at the edge of roofs on tall buildings, not many have made it to production (if any in reality) putting the underside close to the ground will mean that the blade coming around the bottom will be fighting against a negative pressure gradient due to ground effect/interference...

Maybe they should stick with improving the efficiency of vertical axis wind turbines and make them competitive with the bird chopping 3 blade horizontal axis turbines.

But then if there weren\'t \"NEW\" \"Amazing\" tech stories what would Gizmag have to write about....


re:- Comment made February 22nd by a certain individual referring to himself (or herself?) as 'Slowburn' re:- Quote Verbatim "It's A Mechanical Nightmare That Will Break Down Constantly." I genuinely have no idea who this Mr Edvemon is, but....I find your comment laughingly fatuous. I state this as I too am in the process of currently attempting to make inroads into an undisclosed market where I seriously believe MY OWN Innovation will eventually result in marked success!

In empathy with Mr Edvemon I too have been on the receiving end of many frankly stupid and annoyingly moronic comments (re:- my own project!).

Yes, of course you are entitled to your opinion(s) as with every other individual I too have personally encountered, but please try and attempt to aspire to be at least decent and fully informed and indeed constructive in posting simplistic 'soundbyte type' comments before fully engaging your brain! It is quite simply unacceptable and annoys the hell out of me when I and other kindred 'inventors' (for want of a better description) have to endure such blatant ignorance. Yours! Mr Peter Bothroyd.

Peter Bothroyd

re; Peter Bothroyd

It replaces simplicity with complexity, it requires far more parts moving against each other, it reverses motions which increase loads. As I said before "It's a mechanical nightmare that will break down constantly."


The inventors might have missed a bet by making this an oscilatory device. If, instead of having the device bob up and down, they instead had the blades continue on over the top and circle back to their original position the stresses of constantly reversing direction would be eliminated. Connecting the device to a generator would require less complex gearing. In effect, you would have a cyclogyro acting in reverse as a normal wind turbine is a propeller acting in reverse.l


Dear all, Having read all the comments above I must say that some are quite well uninformed and on the other hand some are quite good. If you can get that folks! Dr. Zarkov has a good point, but the fact is that having the aerofoil going back over the top in cyclical motion leads to inefficiency. The aerofoil going over the top leads to drag being the main provider of power and of course when the aerofoil starts to go forwards at the bottom of the motion this also detracts from efficiency battling against the wind and also becoming a drag provider. If Mr Evdemon gets the design right for the flipping of the aerofoil correctly this is a complete winner. I have actually seen film of the prototype model working and even in a light wind it became so frenetic it nearly destroyed itself. Then again it looked like it was made of B and Q wood! Not very good for a prototype I must say! It is slow moving and that is the main point I believe. As one detractor says above, the faster it moves the more you have to change the angle of attack relative to the wind and motion. From what I can see of this device the whole idea is it doesn't move quickly. Therefore you must (Heath) have a generator device that will keep the machine moving at a constant pace, that means coping with various torque loads. There are many generator devices that can do this being variable field, variable torque etc etc. the same in reverse as constant speed electrtical motors. Personally I can see no point in all the detractors of this new device being so negative. If someone comes up with a new idea, don't just slag them off per-se, but open your minds and see the logic, because the logic of the device is very good. To all the small minded people out there, they said a 747 would never fly and Concorde would never work. Aerodynamics is a relatively new concept so all ideas should be open!!!Keep your minds open!!

Pete Wheeldon BSc. Hons. Aeronautical Engineering, Licensed Aircraft Engineer. MRAes

Pete Dunn

Good luck Heath! Oh and if you critical folks are interested I was involved with the original patent of this. You can confirm this fact by searching the patent on "espacenet.com". I have a new patent pending that involves a thermodynamic machine that uses compressed air. This machine could be termed as a version of perpetual motion! It basically removes the latent heat from the air that surrounds us and puts it out at very low temperatures. It will definitely need an enormouse amount of experimental research, but I reckon I may be able to come up with a working model soon! It is mathematically quite complicated, but then again so was the jet engine when Frank Whittle desgned it! Any backers are completely welcome!

Pete Dunn

Bless you Heath . Take no notice of the naysayers, they are jealous that they havn't got the ability to think of innovative projects.You are working along the right lines using a reciprocating mechanism.I have made a one tenth scale model of my reciprocating device and have connected several of them so that all the collected wind energy goes into driving just one generator. My device has the ability to increase the input energy of wind or wave power, several times, prior to giving up it's energy to the single generator. The naysayers have no idea how the wind behaves, unless they have already achieved what I have. If they are still praising the bird mincers, with the outrageous costs and the ability to work only once the wind is blowing above 15mph , which happens on average across the earths surface for just 63 days per annum, then they need to see a head Doctor.A reciprocating device is massively more efficient in every respect but the powers that be will not change to this technology. Here in the UK we have a serving MP that is controlling all aspects of renewable energy, and for the forseeable future this state of affairs will not change while the back handers are still going into his back pocket.Rotary turbines are not fit for purpose and most of you engineers know this. Get yourselves into the 21st century and let go of the past.

Joe Fordham
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