Avoid witch hunt over gearbox tests

It's nothing more than a numerical milestone, yet it tells a story. This year, in the world's biggest wind market, more wind turbines will come out of warranty than will remain under service guarantee.

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And, as the post-warranty turbines that now dominate the US fleet break down, the witch hunting is likely to begin.

Gearboxes have traditionally been seen as the weak link in turbines. In some cases, turbine makers and operators whose machines fail blame the gearbox manufacturers. Some turbine makers have even sought to cut the gearbox out of the picture altogether by devising direct-drive units. Others have suggested that gearboxes are simply being abused and have become scapegoats. Indeed, as we exclusively report this month, experts say that Winergy is seeking to prove the gearbox's innocence in turbine failures by demonstrating that turbine manufacturers have been placing them under undue stress.

The suspicion is that gearboxes in the field experience greater torque and bending forces than the turbine designers planned for - and that the gearbox makers certified their components for when they were installed. Many investors will find it extraordinary that the sort of real-time load studies being launched by Winergy are rarely undertaken. Given that a turbine typically outlasts its gearbox by around a decade and that gearboxes have consequently become the bete noire of wind technology, it is remarkable that gearbox makers sometimes choose not to go back to operators to check whether their kit is being subjected to inordinate loads.

Therefore, it is perfectly reasonable for Winergy to launch its programme. Companies cannot be expected simply to take the blame for failures they believe are not their fault. The worry is, where will the Winergy tests lead?

There is a danger that, should Winergy uncover evidence of serial over-exertion of turbine gearboxes, the industry could plunge into yet another unseemly legal battle. The clash between Mitsubishi and GE over intellectual property rights (see page 77) has been unedifying enough. A flurry of claims and counter-claims by gearbox makers, turbine makers and manufacturers, each trying to shift the blame for technological failures on to the others, has the potential to be even worse. A spate of court appearances will ultimately serve only to swell the coffers of lawyers, loading in new costs to a price-sensitive sector whose attention should be focused on fighting competition from other energy types, rather than on wrangling with companies within the same industry.

Face challenges together

Instead of causing wind to turn in on itself again, it is crucial that the Winergy tests, and any similar ones carried out in the future, are used to help advance the sector. The wind industry is an adolescent - still growing up, still learning. New data helps. If the Winergy programme does reveal that gearboxes have been over-stretched - and that is far from certain - the industry should come together to improve components or regulate operations, or both, to ensure gearbox lives are extended and turbine downtimes minimised.

Wind is best advised to face up to its challenges as one. The Nobel Prize-winning economist John Nash observed that the market benefits when an individual does what is good for him - and also for the group. Certainly, in this case, an internecine carve-up will be of help to no-one in the wind sector but the lawyers.

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