Widespread failure of generators in American wind farms is becoming an increasingly serious issue for the industry, according to Joe Longo of the North American Wind Service Alliance, a network of independent wind energy equipment repair shops. While the industry's notorious and ongoing problems with gearbox failures have received much publicity, the problem of generators is only just coming to light, he says.
Generator failure is affecting the latest turbine designs just as much as old ones, says Longo. His group has observed that generators in wind turbines still under warranty fail as often, if not more so, than those in older units. "These are failing pretty quickly," he says. "There are some quality issues we have seen with some of the designs, and [the manufacturers] are working through those problems." Just as with gearboxes, mechanical wear on bearings is often behind generator failures, Longo adds.
Exacerbating the problem in America is the shortage of generators for wind turbine retrofits, with almost no supply to the aftermarket third-party, repair industry, says Longo. Until the turbine manufacturers get on top of the problem, generator failures will continue to add large sums to wind farm operation and maintenance costs, he warns. The price tag for a generator ranges from $80,000-$120,000, while hiring a crane to lift multiple units into place can run to $40,000.