Small wind turbine owners advised to shut down Proven machines after defect discovered

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The owners of the biggest Proven wind turbines in Shetland were advised to shut down their £60,000 machines last week due to a danger that the rotor and its blades might fly off.

At least six of the P35-2 turbines were in operation around the islands and another is being re-com­missioned. While Sandwick Social Club and Lerwick businessman Steve Henry shut theirs down last Thursday the Leask family on the West Side, who have four, decided to keep theirs turning.

The discovery last week of a flaw in Proven Energy’s flagship P35-2 turbine pushed the Scottish small wind generator company out of business after a city investor took fright and withdrew its funding.

The rapid turn of events initially left turbine owners in the lurch with unanswered questions while those who switched theirs off have been left with no power or income from their machines.

There are also issues regarding the five-year warranties on the P35-2 and whether Proven or their reselling agents are liable as well as the question of insurance cover and compensation for lost earnings and unexpected electricity bills after owners had to switch back to buying power from the Shetland grid.

A week on, they still don’t know when or if their machines will be passed as safe or will require modi­fication to strengthen the weakness, believed to be caused by a weld in a single component.

A number of potential buyers for Proven have emerged since its demise on Friday, including Shetland Wind Power and rival turbine resellers like Icon Energy, seeking to continue Proven’s success in tur­bine development and to tackle customers’ problems.

Several offers where submitted this week to joint receivers Blair Nimmo and Tony Friar at account­ants KPMG. A date for final offers has been set for Tuesday.

However, it could be some time next week before customers with P35-2 turbines find out where they stand.

The two other smaller types of Proven turbine, the P11 and P7, which are more common in Shetland, are not affected by the manufacturing flaw which required urgent action after damage suffered by turbines, including during last week’s gales down south.

In an email issued by Proven last week, and circulated by Shetland Wind Power, customers were told the defect was in the manufacture of the rotor shaft where the spring plate is welded onto the main shaft. It warned: “In a recent storm a rotor travelled a significant distance as a result of such a failure.”

Proven said it had experienced three failures of the weld in three months and analysis had shown that a significant number of shafts may be affected across multiple manufacturing batches. As a result it warned all owners to apply the brake to their turbines as soon as it was safe to do so, when the turbine was spinning slowly.

Proven intended contacting owners again to begin restarting safe machines or to start rectifying the problem. But the firm could not raise cash to work through the crisis, leaving its owners no option but to cease trading.

The local founder of Shetland Wind Power, Michael Anderson, told The Shetland Times his company had been keeping customers with P35-2 machines informed as new information became available with a view to getting them back up and running, possibly within another week.

However, turbines might have to be x-rayed to check their condition or possibly even stripped down, he said. “It could be anything from a week to four weeks.”

He thought there was “a fairly good chance” that P35-2 turbines in Shetland would actually not be affected by the weld problem.

He said: “It’s an external component manufactured outwith their workshop and they’ve identified this manufacturing issue to a batch of these components. But until they get the time to confirm that and identify where every single one of those units has gone it has to be a complete shutdown.”

If Proven was to fold completely then Shetland Wind Power would have to deal with the problem of how its P35-2 customers are compensated, Mr Anderson said. That could involve offering them a different make of turbine.

One of Proven’s marketing pitches has been its patented blade assembly, which allows the blades to pitch and cone when the wind gets strong, enabling its turbines to keep turning in storms which it claimed required other makes to have their brake applied to protect themselves.

But the P35-2 model suffered problems in Shetland with wear and tear and reliability during its development, leading to modifications, shorter blades and a reduction in its rated output. They are known as 15 kiloWatt turbines but in reality have been derated to 12.1kW due to problems with blade noise.

Customers have been attracted to them because they are among the biggest turbines currently certified to qualify for feed-in tariff subsidy from the government and have the potential to earn their owner a greater profit.

Shetland Wind Power held off selling the machine during the early days due to the “teething and niggle problems”, Mr Anderson said. But 18 months ago it was happy to begin offering them.

“We don’t have many of them because we said we wouldn’t sell something unless it was reliable. We were now getting to the stage where we were very confident in the product and this has come as a shot out of the blue.”

Shetland Wind Power has installed them at Sandwick Social Club, the holiday accommodation building at the former Decca station in Lerwick and one for the Duncan family in Ollaberry, which is being re-commissioned.

A Kinross-shire based company Icon Energy installed four of the machines in Aith, Clousta, West Burrafirth and Snarness for the Leask family.

Evelyn Leask said yesterday they were awaiting developments. “I’m not into panicking about things. If you can’t do anything about it you just have to wait,” she said.

Icon has told its customers a technical solution had been proposed for the failed weld. It said it had “the utmost faith” in Proven as a successful worldwide product with over 4,000 installed turbines.

However, the problems have been felt acutely by the Sandwick Social Club which, according to chairman Neville Martin, has been dogged by difficulties with its wind turbine for six years.

Last Thursday the club had thought it was finally in the clear and about to start earning a power subsidy from its fully operational turbine but then the urgent warning came through instructing the machines to be shut down.

“We must be the unluckiest buggers!” Mr Martin said. “It’s just been one technical nightmare.”

The experience has given Mr Martin a more jaundiced view of small-scale wind power developments after years of “hassle”.

Steve Henry, who with his wife Gillian runs the eight-apartment self-catering accommodation called The Decca, has also had problems with his P35-2 over the past two-to-three years, including the loss of the blades and the wrecking of most of the rest of the machine in a severe gale two or three years ago when the brake failed before it even went into service. “It just span itself into obliteration,” he said.

Despite the hassle and the fact that he still hasn’t earned “a ha’penny” from subsidies, Mr Henry said it had not quite put him off, although it was debatable whether he would go through it again. He has at least been able to generate his own heating for his property and has been paid compensation for the technical problems.

Shetland Wind Power has dealt in Proven machines for most of its 18 years and signed a deal in February which further cemented their close relationship. It has also supplied Evance and Westwind turbines.

In December last year Shetland Wind Power was bought over by a Glasgow-based equity company Nevis Capital.

The crisis with Proven’s big turbine is a blow to confidence in the small-scale wind generation sector, as evidenced by the devastating decision by renewable energy investment fund managers Low Carbon Accelerator Ltd to pull out of Proven.

Its instant collapse saw 55 of its workers made redundant with immediate effect with the other 20 kept on to help KPMG prepare the business for sale. It has a factory in Ayrshire and a design office in East Kilbride.

Mr Nimmo said the company had made significant losses while it focused on product development, making it difficult for the business to cope financially with the cost of the failed turbine.


Add Your Comment
  • faye schuyler

    • September 24th, 2011 7:16

    I have been interested in green energy for a long time and have been considering trying to use an alternative source for my home. Do you know of any place to get started with this?


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