Many options considered for Fairhaven Wind mitigation 

FAIRHAVEN – Fairhaven Wind developer Sumul Shah, under orders from the health board to address concerns of turbine opponents, is weighing options that include cutting operating hours and paying to insulate and air-condition nearby homes.

“Everything is on the table,” said Shah. “We want to make this situation work.”

The Board of Health told Shah Monday night that he has three weeks to come up with a mitigation plan to deal with noise complaints from some residents.

The action came during the same meeting at which the health board decided to call in the Massachusetts Department of Environmental Protection to conduct sound testing on the turbines.

With the clock ticking, Shah said Wednesday: “We’re still brainstorming. We have two and half weeks left to figure it out.”

He said Fairhaven Wind is committed to finding a plan that works for everyone, especially the DEP.

“We’re taking this very seriously,” he said. “According to our sound model, the turbines should not be in violation of the law. If they are, we want to know that and we want to fix that.”

In Massachusetts, a turbine is considered to be in violation if it is 10 decibels louder than the area’s ambient noise.

Stephen Wiehe, a project manager at Weston & Sampson (the owner and engineer of Falmouth’s two turbines), said the April decision by the Cape Cod community to run only one turbine between 7 a.m. and 7 p.m. was inspired by a mitigation plan his company did in December of 2011.

Research for that plan suggested that if both turbines ran between midnight and 3 a.m., they could be in violation.

“If you turn off just one turbine in those quietest nighttime hours, you’d be fine. Then once the wind picks up to 8 meters per second, it would be loud enough to mask the sound of the second turbine,” Wiehe said.

The town ultimately decided on a “longer window” to keep the turbine off in order to facilitate study of the turbines, Wiehe said.

“My hunch is that once they complete all the testing, they’ll be able to narrow that window back down,” he said.

Officials have previously cautioned against drawing direct comparisons between Fairhaven and Falmouth, citing the different types of turbines in each town.

The blade speed of Fairhaven’s pitch-regulated turbines can be controlled remotely by rotating the angle at which the blades cut the wind. In Falmouth, the stall-regulated turbines’ rotor is shaped so that as wind speed increases, it automatically hits the blades differently.

Stall-regulated turbines are widely regarded to be louder than those that are pitch-regulated, but Wiehe said the difference is only a few decibels and “is not going to make a huge difference if you’re sensitive to turbines.”

Wiehe said Falmouth also considered paying to insulate houses abutting the turbines but that limiting the turbines’ hours of operation was a better solution.

“At some point, if you are compensating landowners, it’s less about the annoyance and becomes ‘What’s in it for me?'” he said.

Money was a factor in creating the Falmouth mitigation plan. According to the plan, the town would lose up to $77,000 in revenue annually from shutting down one turbine between midnight and 3 a.m.

The plan also calculated that shutting off one turbine when wind speeds exceeded 10 meters per second would cost the town an additional $500,000 annually in revenue.

“Not everyone’s going to be happy with wind if it’s in their backyard,” Wiehe said, explaining the balancing act involved in creating a mitigation plan that aims to please abutters without compromising too much financially.

“The main thing to think about is that if you keep a turbine off when it’s windy, what’s the point?” he said.