PORTSMOUTH – A major mechanical failure in the town’s wind turbine has shut it down until the town council decides whether to replace the part or first try to find out what caused it to fail.
At Monday night’s meeting, the town council was informed that the gearbox in the 1.5 megawatt turbine has failed. Though the reason for the failure is unknown, oil samples show metal shavings inside the gearbox filter. The turbine has been shut down since June 18.
Replacing the gearbox could cost about $400,000, a quarter of which is the price of a new gearbox and the rest is labor and equipment – the highest cost of which is to get a tall crane to do the work.
The maintenance provider, Lumus Construction, recommends replacing the gearbox on the same day the failed gearbox is taken down for inspection because of the high cost of bringing in a crane.
The turbine’s warranty expired when the manufacturer, AAER, went out of business.
Councilor Keith Hamilton said that the gearbox and the turbine’s engineering should be inspected before replacing the gearbox.
Lumus CEO Sumul Shah told councilors that about 10 percent of all turbine gearboxes fail. The turbine blades may be too big for the gearbox, he said, or it could have been in the way the gearbox was built. But Lumus won’t know until the gearbox can be disassembled and inspected.
Councilor Elizabeth Pedro criticized the maintenance contractor, saying that the turbine had sent repeated notices of error codes to Lumus from February to June.
“This machine is crying for help,” Ms. Pedro said. “This is like a security alarm going off, and it could be a branch on the window or it could be … a break-in.”
The council should pursue litigation against the maintenance provider, Ms. Pedro said.
Mr. Shah said it is common for turbines to find metal shavings in the gearbox filter and for turbines to lose oil. Lumus had followed manufacturer protocols for dealing with error codes, and had thought the problem had been fixed when, after replacing a sensor, the code did not appear for a month. The company did all it could, he said.
Mr. Shah concluded that “if the turbine was, in fact, crying out for help in February that the gearbox had either failed at that point or was about to fail.” He added, “I know the news isn’t pleasant, and I know the natural inclination is to blame the maintenance provider and to blame the manufacturer, but the fact is things do break.”
Town Administrator John Klimm says he is researching gearbox products and reaching out to outside consultants. He’s also looking into buying additional insurance on the turbine’s products. He hopes to have a recommendation for the council at the next meeting on Aug. 14.