The windmill is back on line after an oil leak forced a temporary shutdown, the latest issue to impact the strucuture.
The south turbine at the Princeton Municipal Light Department wind site off Westminster Road was out of commission for more than 10 months due to a problem with the gearbox.
After months of negotiations with the manufacturer of the gearbox and Fuhrlaender, the German company in charge of the installation, a new gearbox was found, shipped and installed in June. The windmill blades started spinning again on June 23.
But on June 27 the computer shut the windmill down due to a low oil level.
“I check the computer everyday,” said PMLD Manager Brian Allen. “It gives me ‘real time’ about what’s going on with the wind turbines. I can control the windmills from the office on Worcester Road. The computer tells us if there is an error.”
When the computer screen indicated there was an error, Fuhrlaender representatives and a municipal light crew checked out the site.
“They found a 12-inch river of oil coming down the turbine tower. It’s 320-weight oil, thick like molasses so it doesn’t travel very fast,’’ Allen said. “We cleaned up the small amount of oil that made it to the ground and bagged it. We estimate about 50-75 gallons leaked out, the majority of the oil stayed within the belly of the cell.”
The light crew went to the top of the turbine and found the valve on the oil pump in the open position, said Allen. The pump only runs when oil is needed for lubrication, he added. Some ran down the side of the tower and the wind blew it onto the blades. “Someone forgot to close the valve,” said Allen.
“Our agreement with Fuhrlaender is they would deliver me a working gearbox so they are responsible,” said Allen. “I had a PMLD employee on site during the entire gearbox change out, but no PMLD employee went into the turbine or took part in the change out of the gearbox. Our job was to have the road prepared for the crane and get the crane set up for the gearbox changeout. Our responsibility went flawlessly. Fuhrlaender technicians came to me on June 25 and said the gearbox was clean, running and good to go and had been running since June 23,” said Allen.
The light department hired Tighe & Bond, Engineering and Environmental Consultants, to look at the spill since it was more than 10 gallons, said Allen. The state Department of Environmental Protection was notified. “I made it very clear and the Fuhrlaender representative agreed: This is all on them. Tighe & Bond is in contact with Fuhrlaender and told them they had to satisfy DEP requirements. The tower had to be cleaned along with the blades and the interior of the cell.’’
Fuhrlaender technicians fixed the problem and the turbines are back on line. “Right now we’re at full capacity,” said Allen at the July 11 Commissioner’s meeting. “We were sent a one-page commissioning report that we’re not satisfied with,” he added.
Commissioner Christopher Conway requested a report from a licensed site professional on the cleanup.
The barrels of oil are all sealed and Fuhrlaender is making arrangements to have them removed.
Commissioners asked Allen to explore a monitoring plan for the gearbox to avoid any future problems.
“Basically, that’s a frequency test. If there is any level of frequency change we get notified,” said Allen.
Bachmann, Inc. is the best in the business, said Allen. They monitor 1,700 turbines in the United States.
First-year, set-up costs would be $16,000, after that the annual fee is $2,400 per turbine.
Allen will prepare a comparison costs of companies that do monitoring and present it to commissioners at their next meeting.