A Cooperative Measurement Survey and Analysis of Low Frequency and Infrasound at the Shirley Wind Farm in Brown County, Wisconsin
The purpose was to determine whether infrasound was present in the homes of three families in the footprint of the Shirley Wind project (owned by Duke Energy). These families have reported adverse health effects since the wind turbine utility commenced operation. Two have been forced out of their homes. They report experiencing symptoms of the type associated with wind turbine syndrome. These families are my clients and they offered to act as intervener’s in another Wisconsin case, Highland Wind which is in the application hearing phase. 50 affidavits were filed by them and other residents near the utility describing adverse health effects and home abandonment for the eight turbine Shirley Wind project (click here for video) using Nordex N100 2.5 MW wind turbines.
The above graph shows that wind turbine noise is present outside and inside the residence. The SPL – dB (Sound Pressure Level – decibel) scale on the left hand side of the graph shows low frequency noise levels approaching 80. This is considered a noise level similar to an alarm clock or hair dryer.
Initially the PSC was going to have the study conducted by George and Dave Hessler. This posed a major problem for credibility with the interveners and others who know their position from other projects. The Wis. PSC staffers have a long relationship with them because they have done numerous studies for wind utilities in the state and have always given the utilities’ a clean bill of health claiming that sound levels at complainant’s homes met the state limits and that infrasound and low frequency sound was not a problem. The attorneys for the citizen’s group, Anne Bensky and Peter McKeever for Forest Voice, and Glenn Reynolds, the attorney for the Town of Forest which also opposes the project, wanted the tests to be conducted but were concerned that the Hessler’s would produce a biased study. It was decided that they would push for a study that included four acoustics experts, some on the wind industry side (Hesslers), independents (Schomer and Walker) and one who has demonstrated the ability to find infrasound inside homes (Rob Rand). I was not available on the proposed test dates so I could not participate but Rob Rand was a very good alternative. This also leaves me free to do my own evaluation of the study and collected data and audio files. The participation of the Hesslers and Clean Wisconsin make it much harder for the wind industry trade associations to claim that this work is biased.
The four investigating firms are of the opinion that enough evidence and hypotheses have been given herein to classify LFN and infrasound as a serious issue, possibly affecting the future of the industry. It should be addressed beyond the present practice of showing that wind turbine levels are magnitudes below the threshold of hearing at low frequencies.
That infra and low frequency sound is a primary characteristic of wind turbine acoustic emissions was established by the team. The argument that infrasound produced by modern upwind wind turbines does not have sufficient amplitude to reach the threshold of hearing (set for steady pure tones, not the complex mix of tones emitted by wind turbines) raised by the wind industry through its experts like Dr. Leventhall and the many acousticians and others who parrot his opinion is now discredited. View full report here, pdf file
Paul Schomer, PHD, P.E. letter to Public Service Commission of Wisconsin
Second, the Shirley study fully and completely corroborates Falmouth and fills the knowledge gap suggested by the MA study which was a literature review, not a hands-on field study. There is no reason to corroborate it again.
Third, the measurement of ultra low frequencies produced by mega turbines such as those at Shirley and proposed for Highland are the key to avoiding significant impacts to human health from wind turbines. As the Minnesota study concludes, the low frequencies must be studied further as part of the project planning. In the case of Forest, this study of the low frequency isopleths must be a part of an in-depth EIS, or the project must be redesigned with smaller turbines that are not likely to precipitate such severe health problems that people have no choice but to abandon their homes. These are precisely the studies that we recommended in our Shirley report and the EIS is a perfect way to obtain the information before the project is built; and
Fourth, the record as a whole in this case as well as the literature and case studies all over the world have suggested that people are leaving their homes because they are being exposed to significant levels of pulsating ultra low frequency sound produced by wind turbines.
Sincerely, Paul Schomer, PHD, P.E. Member; Board Certified, Institute of