Library filed under Structural Failure from UK
After the industry's recent boom years, wind power providers and experts are now concerned. The facilities may not be as reliable and durable as producers claim. Indeed, with thousands of mishaps, breakdowns and accidents having been reported in recent years, the difficulties seem to be mounting. Gearboxes hiding inside the casings perched on top of the towering masts have short shelf lives, often crapping out before even five years is up. In some cases, fractures form along the rotors, or even in the foundation, after only limited operation. Short circuits or overheated propellers have been known to cause fires. All this despite manufacturers' promises that the turbines would last at least 20 years.
Repair work is due to begin this week on a wind farm off the coast of Kent which has seen a third of its turbines grind to a halt since early December. Of the 36 turbines erected off Herne Bay - on the Kentish Flats - 12 have experienced gearbox problems. Four have been repaired but the others have been running at reduced efficiency pending a break in the weather. The Danish firm Vestas, which owns and maintains them, said the high failure rate was unusual.
Great Yarmouth, England. Vestas faces another offshore calamity with faulty turbines in the British Scroby Sands farm. Defects have been found in a bearing of the gearboxes of 18 of the 30 V80 machines, the president of Vestas Northern Europe, Tom Pedersen, has confirmed. This is only a year and a half after Vestas was in the headlines with serious flaws in its machines in the Horns Rev farm off the western coast of Denmark. The transformers and generators of all 80 V80 turbines had to be dismantled and repaired on land - at a cost of millions for the world wind industry leader.Pedersen says as a precaution the relevant bearings will be exchanged in all 30 of the Scroby Sands turbines installed in 2003. No such problems were to be expected with North Hoyle, the UK's first major offshore wind farm, inaugurated in November 2003, because the V80 machines installed there have different types of gears, says Pedersen. But damage to bearings similar to that now found at Scroby Sands had occurred in some turbines in the USA and the cause is still being investigated, he added. In addition to the bearings, five generators have to be replaced in Scroby Sands. Pedersen said they'd be taken apart to find the cause. Vestas is lucky inasmuch as the repairs can be done at sea without the nacelles having to be taken down. Weather permitting, the repair campaign is to be completed shortly."This is no new Horns Rev," assures Vestas man Pedersen. But it's still a bad time for his company to be in the news again with damaged components. As recently as the end of November, Vestas shocked its investors with yet another profit warning, explained as partially due to quality flaws in the products of suppliers."Our philosophy 'failure is not an option' must also be implemented by our suppliers,"' Vestas CEO, Ditlev Engel, emphasised in an interview with us a few weeks ago (new energy 6/2005). Now the resolute manager can show sooner than he probably bargained for how he intends to assert that principle.
"Most windfarms are near roads, railways, or walking paths, and the dangers are obvious."
Britain The Times April 16, 2005 Wind farm fears as blade snaps By Katrina Tweedie A TURBINE at a Scottish wind farm has broken down after one of its blades snapped off. The 10-tonne turbine, one of 31 at the £80 million Crystal Rig wind farm near Dunbar, East Lothian, was destroyed last week when a mechanism to stop it spinning too fast failed. Onlookers reported strong winds and said one of the turbine blades flew off and hurtled into the countryside. The 60ft high steel turbines are designed to withstand wind speeds of up to 60 miles per hour and owners, Fred Olsen Renewables, denied the breakdown was wind related. A spokesman said they were investigating the cause and that there had been little risk to people at the remote wind farm. The turbines from German firm Nordex were installed in August 2004. It will cost an estimated £1.25 million to repair. Anti-wind farm campaigners said the incident confirmed their fears about the danger of blades flying off wind turbines. David Bruce, of the pressure group Scottish Wind Assessment Project, said: “There were high winds so the turbines were ‘feathered’, or locked so they couldn’t spin round. It was lucky nobody was walking below. This is only about the second incidence of this in the UK but it shows this is possible.”