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Tuesday, August 18, 2020

Quick Summary of Problems With Wind Turbine Noise Standards

Wind turbines do not operate at full rated power all the time, so the noise is not constant. There are peaks and troughs, depending on wind speed. The World Health Organization (WHO) 2018 Guidelines did not recognize that reality. 

Health Canada relied upon predicted noise levels. Neither the WHO nor Health Canada identified actual wind turbine noise levels to protect the community from adverse impacts – they used predicted levels without any validation of what the actual noise levels were.

The number of complaints about wind turbines prove there is something wrong with the standards. Residents complain of sleep disturbances and other adverse heath impacts. "Complying wind farms" still create sleep disturbances. One reason is the sleep disturbance criterion was based on traffic noise, not wind turbine noise. 

The WHO 2018 Guideline clearly stated there was insufficient data to provide any advice as to sleep disturbance noise limit because there were no studies on actual wind turbine noise inside homes.

The assumed wind turbine noise levels (used by WHO) were also not validated to exclude the ambient outdoor wind and traffic noise. In fact, infrasound can cause resonances inside a home, that make it louder there, than outside the same home (where wind or traffic noise makes pure  measurements very difficult).

If the goal is to protect against sleep disturbance as a result of wind turbines, how can that be accomplished with no measurements inside actual bedrooms?

The compliance test also uses wind and noise data averaged over a period of time. No one lives with an average wind speed and average wind turbine noise.

The wake from upstream turbines can also affect the operation of a turbine by causing disturbed air, which can cause greater noise levels and/or increased modulation.


Measurements and predictive noise models for wind turbines use the dBA scale, which rolls off the bass frequencies, and is nearly useless for accurate measurement of infrasound, that you feel, but don't hear. 

This audiophile, and do it yourself subwoofer builder, bought his first sound meter, and has avoided dBA scale sound pressure measurements since the late 1960s. Wind turbine noise standards in dBA are grossly inadequate.