The blades on Hanover’s 165-foot wind turbine are once again spinning.
While the turbine is now operational, the town’s newly hired contractor said several mechanical problems still plague the $790,000 turbine.
Originally slated for completion in February 2012, the machine laid dormant for nearly two years afterward, as issues with its tip-braking system, hydraulic temperature and twisting power cables prevented the turbine from spinning to harness wind energy.
“Right now it is operating as it was designed,” said Timothy Stearns of Aeronautica Windpower. “There are no issues with it and the twist issue is not a function of the design. It’s a function of improper installation.”
The turbine began turning again on July 17 when the town’s new contractor, Plymouth-based Aeronautica Windpower, repaired the issues with its tip braking system. The tip brakes prevent the tri-blade system from spinning out of control in heavy winds.
The turbine shutdown temporarily from July 22 through July 28 so Aeronautica could replace brake pins on the turbines other two blades. Aeronautica engineers found that some of the turbine was improperly assembled and decided to replace all three tip brake pins as a precaution to prevent future problems.
The last problem affecting the turbine’s function is twisting power cables, according Stearns.
“When the turbine chases the wind, the cables are becoming twisted,” he said.
Aeronautica deployed a safety mechanism that restricts the number of times the turbine can rotate in order to prevent further damage. The company is visiting the turbine weekly to physically untwist the power cables. Aeronautica is working with the turbine manufacturer, a German company called Siba, to address the issue.
Siba promised a two-year warranty on the turbine once all repairs are complete. The manufacturer will inspect the turbine sometime in late-September or early-October prior to issuing the warranty, Stearns said.
The town hired Aeronautica to consult on how to mitigate the mechanical repairs and two months ago, the firm replaced the original contractor, Lumos, to complete the project. The surety agency, Hanover Insurance, has covered all costs associated with the repairs over the amount of the original bond.
Aeronautica has experience both in manufacturing turbines and in assembling them. Stearns said he is confident the turbine will generate $50,000 to $60,000 worth of electricity annually, once all repairs are complete.
“We are not seeing problems with this particular model, no,” Stearns said. “We have found discrepancies between the installation manual and what was done. We are correcting those issues.”
At Town Meeting in 2008, taxpayers approved an initial $500,000 bond to erect a turbine that would offset the electricity costs at the town’s Pond Street water treatment plant. An additional $500,000 was allocated at the 2009 Town Meeting after the size of the turbine was increased.
The original contract between the town and Lumus Construction allows for liquid damages in the amount of $1,000 per day past the contracted completion date that the turbine remains inoperable. Town Manager Troy Clarkson said per that contract, the town is owed more than $1 million, but added that it is difficult to collect on liquid damages.
“We are still troubleshooting with Aeronautica, the firm hired by mutual consent of the town and Hanover Insurance,” Clarkson said. “Once the turbine is running consistently, we will sit down and negotiate a financial settlement.”
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