The June 6 Falmouth selectmen’s meeting missed the major wind turbine irritant. The HMMH consultants highlighted their A-weighted sound study and Steven Clark, Executive Office of Energy and Environmental Affairs, said Falmouth’s approach was “right in line” with the administration’s policy. Both represent a waste of Falmouth time and money if NASA’s Technical Paper to the U.S. Department of Energy Wind – HydroOcean Technologies Division (1990) carries weight.
A-weighted sound pressure levels de-emphasizes lower frequencies in evaluating the effects of noise. The more appropriate measure, dB(G), specifically emphasizes lower frequency evaluation (MassDEP, are you listening?). The effect of a turbine wake may take 16 rotor diameters for recovery to the initial free-air flow (Wind Turbine Wakes Control and Vortex Shedding . This represents a 4304’ around Falmouth’s utility sized turbines since each individual machine is an omnidirectional source.
The Environmental Protection Agency in Denmark has developed criteria for low frequency and infrasound (not just for wind turbines) of 85 dB(G), explicitly allowing a 10 dB factor for people more sensitive than the norm. Maybe it’s time Falmouth (let alone county and state) follow Denmark’s lead and ask questions addressing the more accurate problem!