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Beware windfarms

Proven Energy has announced that it has a problem with one of its popular small wind turbines:

Proven Energy has become aware of a potential manufacturing defect in its Proven 35-2 wind turbine (The Proven 7 and Proven 11 are unaffected). We are investigating this, however, our work to date has now shown that a significant number of shafts may be affected across multiple manufacturing batches.  

With that in mind we are now advising all Proven 35-2 owners to place their wind turbines on brake as soon as it is safe to do so. Under no circumstances should you apply the parking brake whilst the wind turbine is rotating at normal operating speeds since this will place extra stress on the shaft. We will ensure that you receive regular updates in the interim period.  Please accept our apologies for any inconvenience caused.

In other words, that propeller whirling above your farmhouse is in danger of breaking off and turning you into a puree. Oh yes, but you can't switch it off until the wind stops blowing. Round where I live that could be six months or so!

Clearly in green circles, "Proven" means something slightly different to normal usage.

(H/T John Lyon)

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    [...]- Bishop Hill blog - Beware windfarms[...]

Reader Comments (43)

"The wheels on the bus go round and round"

"The blades on the wind turbine go round, and fly off and may kill you"

I hope these risks are drawn to the attention of Planning Officers

Sep 15, 2011 at 4:03 PM | Unregistered Commentergolf charley

I followed your link to Proven, and found that any attempt to explore the site (even to see what "products" they supply), was met by a request to "Log In".

A funny way to encourage custom....

Sep 15, 2011 at 4:24 PM | Unregistered Commenterdave ward

Proven's turbines are not used in commercial wind farms - they're those ~20 feet high things you see in farmer's back yards spinning away with all the charm of a late-summer wasp. More info on the "Scottish Farmer" website:

"SCOTTISH WIND turbine manufacturer Proven Energy was this week teetering on the brink of financial collapse."

If Proven does turn out to be Not Proven, some farmers stand to be left holding a pile of useless junk. Gawd, how my heart bleeds.

NB This address works for me:

The statement is on the home page.

Sep 15, 2011 at 4:28 PM | Unregistered CommenterDaveB

"...but you can't switch it off until the wind stops blowing. Round where I live that could be six months or so!"

6 months constant turning sounds pretty good going for a windfarm! I thought there existed a way to stop turbines when the wind was too high?

Sep 15, 2011 at 4:36 PM | Unregistered CommenterTS

It's hard to follow on a mobile, but the Good Bish is currently demolishing Bob Ward, Doug McNeall and Leo Hickman on Twitter.

Sep 15, 2011 at 4:46 PM | Unregistered CommenterMaurizio Morabito

I thought there existed a way to stop turbines when the wind was too high?

There is a brake, but in this case if you use it the spindle breaks and the blades depart into the distance or take you head off.

Sep 15, 2011 at 4:46 PM | Unregistered CommenterBreathe of Fresh Air

In fairness, finding engineering problems once a product gets into the field is not all that unusual. There are many variables, tolerances, stresses, etc. to take into account, and sometimes you just don't get it right the first time, despite careful design and testing.

What would be more interesting is if this is more than a typical engineering problem. For example, it would be telling if there were evidence of any effort to rush product to the field to meet renewable quotas; whether there were any pressure to use particular suppliers/vendors due to their green footprint; whether any government regulations or lack thereof resulted in special treatment, such as lower standards for renewable products or expediting of permits may have allowed the problem to go unnoticed for longer than usual, etc.

Sep 15, 2011 at 5:02 PM | Unregistered CommenterEric Anderson

The main trouble with these small turbines is that the people buying them have no technical background and only see the money they are promised. They tend to put them in the worst location, i.e. on roofs and behind trees where they experience the maximum turbulence (think "call l me Dave" who was stupid enough to put one on the end of his house).

I gave a talk to our local National Park members a couple of years ago. They had put a small wind turbine at one of their remote visitor centres to reduce usage of the diesel generator. They were most surprised when I told them the ideal location was on top of a nicely rounded hill. They thought it was a good idea to hide it away behind a wall of trees.

So much for our wonderful education system.

Sep 15, 2011 at 5:21 PM | Unregistered CommenterPhillip Bratby

"Captain! I cannae hold her any longer!"

Sep 15, 2011 at 5:21 PM | Unregistered CommenterZT

Who will pay compensation for the loss of income to these poor, unfortunate power station owners?

Sep 15, 2011 at 6:14 PM | Unregistered CommenterBrownedoff

Just on PM tonight...... haven't stopped laughing yet.....

Donald Trump is opposing the planning application of an offshore windfarm near Aberdeen because it will spoil the vew from his new 'exclusive ' golf course of which the planning application was opposed by the locals because the site was a place of natural beauty and heritage.

You just can't make this stuff up.......

Sep 15, 2011 at 6:30 PM | Unregistered CommenterLord Beaverbrook

"Captain! I cannae hold her any longer!"

Sep 15, 2011 at 6:42 PM | Unregistered CommenterDon Pablo de la Sierra

Phillip Bratby

It isn't only the average punter who screws up with these things, as my posting above shows. Imagine having THAT in your back yard.

Sep 15, 2011 at 6:45 PM | Unregistered CommenterDon Pablo de la Sierra

LB - welcome to contemporary Scotland, where our two government agencies (SNH and SEPA) both with statutory duty to protect the environment, both took the view that a hydro-electric scheme in the Birks of Aberfeldy, a woodland gorge famous for its waterfalls, (which is also an SSSI, and protected under European law as it is part of the River Tay SAC), was a good idea, and gave approval. As you say, you can't make this stuff up.

Sep 15, 2011 at 6:52 PM | Unregistered Commenterlapogus

And that's just the little ones. What is or should be, the stuff of serious concern is what happens when salt water meets offshore turbines:

As David MacKay informs us:

Offshore wind is tough to pull off because of the corrosive effects of sea water. At the big Danish wind farm, Horns Reef, all 80 turbines had to be dismantled and repaired after only 18 months’ exposure to the sea air. The Kentish Flats turbines seem to be having similar problems with their gearboxes, one third needing replacement during the first 18 months.

It isnae gonna work.

Sep 15, 2011 at 6:56 PM | Unregistered CommenterBBD

Don: Yes that is a very famous video, which creates much mirth. I'd love a translation. I guess he says something like "oh sh1t".

Sep 15, 2011 at 7:10 PM | Unregistered CommenterPhillip Bratby


It isn't worrying RWE npower. They are pushing the benefits to us all of the Atlantic Array. I guess the subsidies are so huge that they can afford to be constantly repairing them; that is if anybody can afford to pay their electricity bills by then. 6.87 million in fuel poverty and rising.

Sep 15, 2011 at 7:16 PM | Unregistered CommenterPhillip Bratby

@ Eric Anderson - this is what engineers try and avoid - it's called infant mortality, and the best example on a large scale I can think of was the Tay Bridge disaster in 1879. That's what engineers are there for, to take into account variables, tolerances, stresses, etc. and make sure there's enough safety & reliabilty margin.

I suspect that in your second para, you've put a finger on one or several of the real causes of the problems, particlularly an effort to rush product to the field to meet renewable quotas.

Sep 15, 2011 at 7:47 PM | Unregistered CommenterPalantir

Message from your friendly WTG manufacturer: Our 'proven' wind turbine generator..........isn't!

Sep 15, 2011 at 8:02 PM | Unregistered CommenterDougS


I think it will end badly - for them, and for the rest of us. And I almost weep at the thought of all the money that we could have invested in nuclear, if it hadn't been committed to phase 3 offshore fantasy farms by a f**k-witted New Labour government 'picking winners' a decade ago.

Sep 15, 2011 at 8:03 PM | Unregistered CommenterBBD

Proven to ..........???

Sep 15, 2011 at 8:14 PM | Unregistered Commenterj ferguson

"Round where I live that could be six months or so!" - looks as if you've inadvertently shot yourself in the foot....

Sep 15, 2011 at 8:17 PM | Unregistered CommenterIan_UK

Have politicians ever picked a winner?

Sep 15, 2011 at 8:25 PM | Unregistered CommenterPhillip Bratby

Eric Anderson’s comment asked the right questions about policies. As for the technical aspect, this looks like a supplier quality problem perhaps compounded by a design flaw linked to scaling from smaller models 7 & 11 (rotor diameter 3.5 and 5.5m respectively) to a bigger one, the 35-2 turbine (8.5m).

A bit of background first:

I do understand very well how Proven Energy products work. Indeed, my father with the help of a lawyer deposited patents in France 82-21330 deposited on 20 Dec. 1982, "Wind motor with integrated Anti-squall system", Title holders Marcel Villéger & André Dejoux, Inventors Marcel Villéger & André Dejoux; Patent: WO 86/00115 well before Gordon Proven deposited his Patent: WO 91/12429 and .

In the 1980s my father, an electronic engineer with many company patents to his credit was let go from his Chief of Technical Service position for a US multinational. He used portion of his severance compensation to work on a personal project, a wind turbine that was designed to continue producing electricity despite increasing winds and wind gusts that would have damaged other types of turbines. He was always surprised that wind turbines had to stop when the resource was at its peak. He also noticed that classical designs heavily sponsored by a state sponsored firm named Aerowatt backed up by the French atomic commission and EDF the government run utilities, had the disagreeable tendency to break under wind gusts, just like the one installed in 1979 on Brittany’s Ouessant Island.

He designed, built and patented a system where the rotor would be downwind and the blades would simply be pushed by the gust, as it still rotates, deforming and thus reducing the surface available to the wind through increasing the angle of attack of the blades. He called it “Roseau” (reed) in reference with the La Fontaine fable of “The Oak and the Reed”. This way energy generation would plateau instead of stopping. He also designed a light weight generator (82-19059 deposited on 15 Nov. 1982, "Annular generator", Title holder Marcel Villéger & André Dejoux, Inventors Marcel Villéger & André Dejoux) that would be linked to the rotor by a shaft and be placed upwind, at the head on the turbine. Therefore augmenting the load on the alternator would help slow and ultimately stop the rotor.

We did build 2 prototypes (diameter 3m and 1.6m) together that were tested in the Vendée region where my parents had a small country house. I have countless anecdotes and photos including one that highlights the importance of the shaft and its connection to the rotor and generator. In order to avoid possible vibrations, he started with a flexible connection supposed to minimize these, that proved to be too weak and broke on the very first trial. We had to mechanically stop the rotor (throwing a high tech lasso…) and damage the prototype on the way. The lesson was that he had to use a high spec steel shaft and fittings to solve the problem. My father’s smaller prototype was tested in a wind tunnel 30 years ago this month, delivering on specs and we never had problems with the shaft again. So I do understand where a supplier defect and/or under-engineering and /or a material resistance weakness to torsion would create a serious problem here especially when scaling up models.

How it all ended:

In France, not being an alumnus of Ecole Polytechnique and without real means or connections, his work was ignored as business was hardly encouraged these days. His health and resources did not allow him to defend and pay yearly fees on the patents and as a young professional fresh out of university I was in no position myself to do anything with this. Thus these patents reverted to the public domain starting in 1988.

From what I can read, with minor alterations, it looks as if the Proven patents re-used and adapted the ideas –or perhaps even similar ideas had germinated in his mind? Do not get me wrong, Proven simply recognized a smart design when he saw one and went all the way to industrialization during a different time, in a different country and in my opinion, must be commended for bringing a smart, light, efficient small turbine to market. As much as the efficiency of wind generation on bigger scale is suspect, we all know that in remote locations, small, reliable turbines can be of tremendous utility.

In conclusion we should all wish them to promptly identify the origin of the problem and in what I view as an informed opinion, I find this post a bit disingenuous as manufacturing problems can occur on any man made product. For full disclosure, I am not a shareholder, never did contact or was contacted by Proven Energy and never wished anything but the best of luck to this company.

Sep 15, 2011 at 8:36 PM | Unregistered CommenterM.Villeger

Isn't repair and maintenance of wind-turbines, and the rest of their infrastructure, part of the great green job creation scheme?

Sep 15, 2011 at 9:00 PM | Unregistered CommenterJonathan Drake

@ Dave B - I didn't say the Proven link was faulty, just that all the subsidiary links at the top of the home page only lead to a "Log In" request. It's as if they don't want to give any details of their products or company unless you first give them YOUR details. Sorry, but NO organisation expecting that will ever get any custom from me...

Sep 15, 2011 at 9:01 PM | Unregistered Commenterdave ward

I see other reports of a cash crisis with this firm with LCA indicating that they may have to write off £11m they have invested. The question arises if Proven goes down, will these 600 units that have the problem ever be fixed?

Sep 15, 2011 at 9:14 PM | Unregistered Commenterjohn Lyon

Sep 15, 2011 at 8:36 PM | M.Villeger

Link for specification for this machine:

Proven 35-2 Product Specification

Wind Turbine Type: Down-wind, self regulating rotor. Direct drive with permanent magnet generator.

Rated Power: 12.1kW

Rotor Diameter: 8.5m

RAE: 23,200kWh (based on 5m/s wind speed at hub height)

Tower heights and types: 15m and 20m monopoles gin pole and hydraulic options

Connections: Grid connect

Cut-in Speed: 3.5m/s

Cut-out Speed: None

Sep 15, 2011 at 10:18 PM | Unregistered CommenterBrownedoff

Thank you Brownedoff, btw a google search allowed me to find the PDF specs sheets for the Proven turbines before I wrote my comment.

Sep 15, 2011 at 10:42 PM | Unregistered CommenterM.Villeger

might I ask a very naive question.....why not have a design that does away with with the gearbox, basically a windmiill turning on a vertical axis, with a variable pitch propeller to stop it getting o0ut of control in high winds?

Sep 15, 2011 at 11:56 PM | Unregistered Commenterdiogenes

diogenes, I believe there is no gear box in Proven's designs. As for vertical axis machines, the one in Cap Chat, Quebec is quite renowned -check wiki.

Sep 16, 2011 at 12:29 AM | Unregistered CommenterM.Villeger

To be fair to Proven, their systems have dynamic brakes which short out the alternator, slowing the rotor to the point where the parking brake can be engaged. Their cautionary note just reminds owners not to skip the first step.

Sep 16, 2011 at 1:34 AM | Unregistered CommenterDoug Jones

This was slightly amusing. A meeting to discuss building a wind farm cancelled due to wind..

Sep 16, 2011 at 1:59 AM | Unregistered CommenterGeorge

From the Ecclesiastical Uncle, an old retired bureaucrat in a field only remotely related to climate, with minimal qualifications and only half a mind.

Re M. Villeger. How very interesting! It is very instructive to have a contribution from someone with such close personal involvement in the supply side of this business. Greatly appreciated!

Could you tell us whether you/your late dad originally envisaged that the machines he designed would be employed in remote locations where the cost of connection to a public supply would be prohibitive?

What do you think of the present proposals to build them in locations where the public supply is close in order to reap the benefits of subsidies provided at public cost, rather than to provide economic power. Answer in not more than two sentences from (a) your own personal point of view, and (b) the point of view of the public interest.

Sep 16, 2011 at 3:31 AM | Unregistered CommenterEcclesiastical Uncle

My comment was related to the creative side of wind turbines. Never a business man himself my father did not have a chance to meet with entrepreneurs and market a product. And I am not even talking about the red tape of government innovation incentive back then...
Indeed he thought this design would help in off grid locations. He also designed water pumps that could work with this type of fast RPM wind turbines. Usually water pumping was done through slow moving turbines with many blades and that can start with little wind. In order to counter this he designed and patented a pump whose load on the turbine would vary depending on the wind so it could allow the turbine to start working first. Those applications would be of help in developing countries or remote locations where bringing traditional power would be prohibitive. They were light designs easily operated by one person as opposed to the heavy artillery offered by the state sponsored brand.
As a self made man, an electronic engineer, he was proud of designing efficient products (TV sets) that would require little or no modifications on the assembly line (a rarity in the mid1960s if you ask anyone in the field...). His last design homologation beat the supposed statistical failure rate during testing. Thus he was aware that a successful product should be affordable and reliable, i.e. competitive on a free market.

As for your question, many of those who are involved with those mega projects at least in France are the same who were involved with the Aerowatt company... that says a lot no? LOL
Clearly these are different markets with biased rules, subsidies etc obviously reserved for a few like most state markets are. The leftover crumbs are for suppliers. And yet on a technological viewpoint these monster turbines are dinosaurs. We have all seen the video of disintegrating blades under what looked to be stress from wind gusts. I would argue that his design would improve their reliability and lower their cost.

Sep 16, 2011 at 5:38 AM | Unregistered CommenterM.Villeger

As one of the few Scottish companies involved in wind energy and as one that was repeatedly "outed" from the process by the money grabbing big wind developers, I have to say I feel sorry for Gordon Proven as he has put an awful lot of work into developing his business and I would say he is a model for all Scottish engineering.

He has been in the market for decades, long before the money grabbers came in. His windmills were powering remote farmsteads when all the regulatory framework was against him, and to be frank, it's not his fault that we have such an unscientifically and sycophantic BIG wind policy now.

The proven is undoubtedly one of the most reliable windmills on the market far outperforming any American carp. Wind energy, like wave energy is an incredibly difficult area creating huge stresses on a device that has to be cut down the the bone to save cost. Many have tried to create windmills and almost all have failed.

Proven are one of the few Scottish success stories in the whole sorry saga.

Irrespective of the face most of us are disgusted by our government's irrational "green energy" policy, I can personally testify that Proven is not to blame for that policy and I would ask people to support Scottish engineering, particularly when BIG WIND did to him what they continue to do to us: shaft us!

Sep 16, 2011 at 10:47 AM | Unregistered CommenterMike Haseler

@ Mike, I second your post.

Sep 16, 2011 at 3:31 PM | Unregistered CommenterM.Villeger

Theirs is the first web site I have ever<\em> seen that asks me to log in before even showing me the list of their products. If they fall at the first commercial fence like that they are must be sucking eagerly at the public subsidy teat and are certainly doomed to go bust in spite of it.

Sep 16, 2011 at 3:58 PM | Unregistered CommenterRoy

Just following up my earlier post, it looks like their site is simply messed up. You can't access any links at all without logging in, and you can't create a login. That must be unintentional. If I could get at their phone number I'd call them and tell them.

Sep 16, 2011 at 4:04 PM | Unregistered CommenterRoy

Looks like the 'problem' is terminal......

Sep 16, 2011 at 8:52 PM | Unregistered CommenterD Gill

another naive post...Yes M.Villeger, I have seen windmills with vertical axes...but is there any empirical evidence to say whether they generate more or less power...and whether they need more or less maintenance than the orthodox horixontal-axis turbines?

Sep 16, 2011 at 10:55 PM | Unregistered Commenterdiogenes

Dear diogenes, I am forced to direct you to the wikipedia page on vertical axis wind turbine.

Sep 17, 2011 at 1:12 AM | Unregistered CommenterM.Villeger

The study of genetics is inherently interesting to my students because they can relate to it.-online replica Mido

Sep 19, 2011 at 7:22 AM | Unregistered Commenterlily

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