Because of a small crack in a blade of the 2-megawatt Kingston wind turbine Independence, a crew from Hyundai Corp. has undertaken major repairs.
Kially Ruiz, co-manager of Kingston Wind Independence LLC, the developer of the $7 million project, said a surface crack – .04 inches wide – occurred when a blade was twisted during installation.
The Independence stands atop the town’s capped landfill, 475 feet from Route 3 at Exit 8, and has a total height of 403 feet when one of the blades is pointing straight up.
After the crack was analyzed, replacing the blade was considered, but last Wednesday Hyundai engineers decided to remove a section of the blade and replace it with new material, Ruiz said.
“To protect the public we’ve hired an independent engineer to check the repairs,” Ruiz said. “If there are any concerns, we will be getting a new blade. Cost and time are not factors in determining our actions. Safety is our number one concern.”
The turbine is insured and under warranty.
The blades are made of layered composite material, Ruiz said. The composite includes fiberglass and epoxy.
Ruiz said the damage is not delamination, which occurs when layers begin to separate. Some turbine neighbors had voiced concern about delamination.
Ruiz said delamination could occur if there is internal damage from the crack. Although the damage appeared superficial, the decision to remove and replace the entire section was made to prevent any possible delamination from spreading, Ruiz said.
“Delaminating would be a concern if we were just patching it up,” Ruiz said.
The turbine is scheduled to go online by April 15, after being hooked up to the NStar grid, Ruiz said. Once the turbine is generating power, the town’s municipal electric bill will be lowered by 30 percent, he said.
The state Department of Environmental Protection and Department of Public Health commissioned experts to prepare a report titled “Wind Turbine Health Impact Study.” The panel determined that there was limited evidence suggesting an association between exposure to turbines and annoyance, psychological distress or mental health problems. It also determined that noise from some wind turbines could cause sleep disruption.
Ruiz said he doesn’t expect the nearest neighbors, across Route 3, to hear the Independence turbine at all. He said any noise will be masked by the sounds of traffic, the wastewater treatment plant and commuter-rail trains.