I was looking for a topic to write about for this blog and decided to google “wind farm turbine damages” as that would seem to fit with the theme of this website. Go ahead, try it yourself. Are you as surprised as I was to see (as of today, results may vary in the future) that the top three results and seven out of the ten results on the first page to be about the January 5, 2009 incident at Conisholme, Lincolnshire on the east coast of the UK?
According to The WindPower database, the Conisholme Fen wind farm has 20 Enercon E48/800 turbines with a rotor diameter of 48 m rated at a total installed power of 16 MW and an estimated annual production of 40 GW.h with. In brief, one of the turbines at this Ecotricity-owned wind farm was heavily damaged through loss of one blade entirely and with another badly crumpled in what was described as a collision with an unidentified flying object, (see "Breaking News" from the Grimsby Telegraph). And I do mean UFO! In a Mail Online story you can view photographs of unusual lights in the sky taken by an eyewitness and read reports of strange sightings. They also post the theory offered by the UK Ministry of Defence that a test run by an unmanned stealth bomber known as the Taranis was possibly responsible!
As you can imagine, we don’t often get stories remotely as curious as this when dealing with commercial property losses at Valentine Insurance. Lightning strikes are vastly more common. Mechanical failure of one sort or another even more so. And guess what? According to a February 10, 2009 report in This is Grimsby we learn that, “talk of aliens trashing a wind turbine is a load of hot air, an investigation has concluded.
“The owners of the Conisholme wind farm on Fen Farm have ended speculation surrounding the destruction of two of the propeller blades on one of their wind turbines in January – it was caused by a faulty bolt.
“A spokesperson said: “Following several weeks of forensic examination of the turbine’s components the manufacturer, Enercon, has today ruled out “collision” as a possible cause.
“An interim report has concluded that bolts securing the blade to the hub of the turbine failed due to ‘material fatigue’. “Enercon has ruled out bolt defect due to the nature of the failure and the investigation is now looking into ‘supporting components’ – those parts on either side of the bolts. If one of these supporting components failed it would induce stress in the bolts beyond their design limits and cause failure.”
I’m sure that this report is not why this story ranks so high on that Google results page. Perhaps we will see a clip of a UFO clipping a wind turbine someday on the History Channel’s Ancient Aliens show. Hey, even the “Taranis collides with a wind turbine” storyline is more interesting. Yes, bolt defects are truly mundane and that is why we cover that sort of thing. It could happen to you.
Are your bolts sound and tight?