July 15, 2017
Massachusetts, Noise

# Falmouth wind turbines: Decision for larger, overlooked louder

Ambrose, Stephen

[1]

Separation distance is the solitary wind turbine noise control method to assure protections for public health and compatibility with the area. (Two international consensus guidelines may be used to evaluate the effectiveness of a regulatory statute: WHO 2009 Table 1 noise effects on health, and ANSI S12.9, Parts 4 & 5 assessment of compatibility.) A direct relationship connects sound power level (Lw) to noise source distance: ISO 9613-2, section 7.1: Adiv = 20Log(m) + 11 dB. The MassDEP regulates the maximum noise level increase (LI) to more than 10 dB (Lmax) above the baseline ambient (BA) L90, without the noise source when measured (or predicted) at the neighbor’s property line (PL). A simple equation predicts the highest allowed sound power level by distance: Lw = Adiv + LI + BA.

1. Locate Wind-1, Wind-2 and Notus on Google Earth (GE),

2. Using GE’s ruler circle draw, measure each wind turbine distance to the nearest residential property lines.

3. The highest allowed wind turbine sound power levels are shown in the table below comparing manufacturers published noise data.

[2]

## Falmouth Wind Turbines: Cape Cod Commission vs acoustic experts

The Cape Cod Commission recognizes that wind turbines harm public health when installed near residential communities. Unfortunately, wind turbine acoustic experts emphasize sound measurements and noise predictions, omitting assessing for activity disturbance and nuisance. The Commission has chosen an alternative and potentially a more reliable screening tool than blind and deaf noise level predictions, by imposing a mandatory setback distance based on 10 times the rotor diameter. How effective is their approach?

1. Locate Wind-1, Wind-2 and Notus on Google Earth (GE),

2. Using GE’s ruler circle draw, measure each wind turbine distance to the nearest residential property lines.

3. Divide the property line distance by 10.

[3]

4. Use Siemens sound power chart (Low-noise wind turbine design, Stefan Oerlemans, Peter Fuglsang, Siemens Wind Power A/S, 2012 EWEA-Noise-Workshop-Oxford-2012-1-1-Stefan-Oerlemans.pdf (page 11)) to estimate maximum allowable wind turbine sound power level (Lw) from rotor diameter. Compare to wind turbine sound power levels.

[4]

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