WESTPORT – Flaws in state and federal wind turbine regulations proved a hot topic at a discussion of turbine noise Thursday night, led by an electrical engineer specializing in industrial wind turbine noise and vibration control.
Michael Bahtiarian, vice president of Billericia-based Noise Control Engineering Inc., presented what he called an “objective look” at noise produced by wind turbines.
Bahtiarian, who has conducted studies of the Falmouth turbines, expressed sympathy for residents living in proximity to the turbines.
“That’s an unfortunate situation for the people who live there,” he said.
There are no federal or state regulations relating to wind turbine noise, Bahtiarian said. In Massachusetts, any noise source is considered in violation of noise regulations if it is more than 10 decibels louder than ambient noise, but Bahtiarian said these regulations do not take into account the complex nature of turbine noise.
“Wind turbine sound is what we call aerodynamic amplitude modulation, which means there is a fluctuation of sound that changes as the blades pass through the air,” Bahtiarian said, describing the technical term for what some people call the “wooshing” nature of turbine sound.
“The Massachusetts noise regulations do not make any accommodations for the different nature of that type of sound,” he said.
He added that in its testing of both the Falmouth and Fairhaven turbines, the technician slightly altered the methodology for testing in an attempt to accommodate turbines’ unique sound qualities but that “there has been no change to the statute.”
Bahtiarian said that in his experience, wind turbines begin to elicit complaints when they are larger than one megawatt, as are the turbines in Fairhaven and Falmouth
More than 30 people attended Bahtiarian’s talk at White’s of Westport, hosted by the Institute of Electrical and Electronic Engineers. The engineers were joined in the audience by members of Fairhaven and Falmouth Windwise, Fairhaven Selectman Bob Espindola and multiple members of the Fairhaven planning and health boards
Institute of Electrical and Electronic Engineers Chairman Sid Martin said the talk was inspired by “the number of instances of turbines in the Southern New England region that have been reported to be intrusive.”
Also present was Steve Ambrose, an acoustician who co-authored a controversial study of infrasound produced by the Falmouth turbines.
Ambrose and Bahtiarian interacted throughout the talk, with Ambrose pointing out numerous times noise regulations were written with urban areas in mind and saying “They are not appropriate for rural settings.”
Bahtiarian also brought up an alternative set of sound regulations put together by some Massachusetts electrical engineers that would regulate infrasound, broadband (or typical audible sound) and aerodynamic amplitude modulation. That regulation would put a sound source in violation if it creates either broadband or infrasound more than 6 decibels above ambient sound. Bahtiarian said the alternate regulations have been proposed both to the Falmouth Board of Health and the Cape Cod Commission.