This important letter by acoustician Stephen Ambrose explains how two separate court decisions, one in Massachusetts and the other in Michigan, together provide clarity on what the minimum protective noise limits should be when siting industrial wind energy facilities. Mr. Ambrose's letter includes links to the two decisions as well as supporting background information. The content of the letter is shown below. The original can be downloaded from this page.
Documents filed under Noise from Michigan
This important decision by US District Court Judge Thomas L. Ludington addresses two arguments proffered by the wind industry. The first relates to the industry's argument that noise standards for limiting turbine noise emissions that are based on Lmax are not reasonable. The second discusses the argument that restricitve ordinances, in this case an Lmax noise limit, are de facto exclusionay zoning. Judge Ludington takes both claims on and finds the wind company's arguments are without merit. A portion of the decision is provided below. The full decision can be downloaded from this page.
This lawsuit filed against Consumers Energy Company, owner of the Lake Winds Energy Park consisting of fifty-six Vestas V100 1.8 megawatt turbines with a total installed capacity of 100.8 megawatts. An excerpt of the complaint is provided below. The full complaint can be accessed by clicking on the links at the bottom of this page.
This letter was submitted to the Delta County Michigan Building and Zoning Board in reference to noise eminating from the Heritage Garden Wind farm, a 28 megawatt (14 turbine) energy facility sited in Garden Township. The project became fully operational in September 2012 but by October 2012 complaints of noise poured in. The document attached to this page was prepared and signed by 73 residents impacted by the project.
This letter, prepared by acoustics expert Malcolm Swinbanks, addresses three separate issues relating to wind turbines. First, an unresolved issue relating to low-frequency sound generation by wind-turbines. Second, further well-established characteristics of low-frequency noise. Third, the present status of permitted noise levels and setbacks. An excerpt of this letter is provided below. The full letter, as submitted to the State of Michigan, can be accessed by clicking on the link(s) at the bottom of this page.
Low Frequency Noise Low frequency noise is generated at very low frequencies, generally accepted to be at levels below 100 Hz and the audible range. There is presently no commonly accepted metric or standard for measurement, although several have been proposed or used in specific situations. Low frequency noise has been associated with wind turbine developments, as well as road, rail, sea and air traffic and other industrial applications such as cooling towers. It creates a large potential for community annoyance, and it is most often experienced inside of homes and buildings where resonance amplifies the sound, which is less easily heard outside. Because the frequencies are so low, the noise is often “felt” as a vibration or a pressure sensation. Reported effects include annoyance, stress, fatigue, nausea and disturbed sleep. Low frequency noise can be a factor at much greater distances from the noise source than audible noise. A case study in North Carolina in the 1980’s near a wind turbine installation documented low frequency noise problems at residences located over ½ mile from the turbine.2 While the phenomenon was originally believed to be associated with the older, down-wind designed turbines, the problem persists with newer wind farms. It has received particular attention in Denmark, and has been a topic considered in the UK, Scotland and Wales through a commissioned government project in 2001.
Kelly Alexander believed that windpower would be a good energy source. He was told the machines were not noisy. No one told him about the blade flicker that shines even through closed blinds or the low frequency noise that penetrates his home with doors and windows tightly closed and storm windows installed. Recently, the turbine owner visited Kelly and asked what he could do to help the situation. He said, “Stop lying about these turbines. Tell people the truth.”