In a ground breaking study from Wisconsin, new evidence on LFN and infrasound.
Supporters can no longer say that wind turbines do not produce significant levels of infra and low frequency sound just because the sound pressure levels do not rise to the Thresholds of perception of audible sounds.
Thus, “What you can’t hear, can hurt you” is the surviving paradigm.
Richard James, INCE
The argument about whether wind turbines produce infra and low frequency sound and if they do, is it sufficient to cause adverse health effects has taken a big step forward with this conclusion. 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.
This is a major step forward.
Please find attached a report for a wind utility in Wisconsin that was the focus of a study requested by, and partly sponsored by, the Wis. PSC. 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.
Three homes were studied. Two of which I are my clients where I have also conducted sound testing for infra and low frequency sound and confirmed its presence. . R1 is about 3500 feet from the nearest wind turbine. R2 is about 1100 feet and R3 is about 7000 feet away. R1 and R3 are my clients. All three homes were found to have measureable infra and low frequency sound from the wind turbines with levels decreasing as distance increases. The peak acoustic energy was found at the wind turbine’s blade passage frequency which is less than 1 Hz for the Shirley Wind wind turbines. Most modern upwind industrial scale wind turbines, including the 1.5 MW turbines commonly installed over the past 5 years, can operate with hub rotation speeds that are similar to those of the Nordex. As turbine sizes (blade length, tower height, and in general power output) increase the more likely it is that the hub rpm will be in the range similar to that of the Nordex units. Rob Rand has a chart in the Team Report that shows the range of rpm’s against the frequency associated with inducing nausea that shows this trend. This is an important chart for showing how the conclusions for this PSC study of a single wind utility has implications for other wind utilities using other makes and models of wind turbines. A revision to that chart did not make it into the report as posted on the PSC site so I have included it below my email and as an attachment.
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. I believe that 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 purpose of the study was to collect high quality audio samples during periods when the family members were present and “feeling” the wind turbines. Wind speed and direction data at the outdoor microphones and from the wind turbine hub level anemometer was also collected. Wind turbine power production was also collected. The data from wind turbines is under a protective order and only available to select reviewers. The Team Report summarizes the data and protocol. It also includes a Team conclusion and separate appendices from each acoustician providing additional information about what they observed or derived from the study. They can also file follow-up reports as can other qualified experts within the time frame for responses to the PSC.
Mr. Walker’s equipment was the best of any of the acousticians and became the focus for data collection. Unlike the instruments traditionally used by acousticians studying wind turbine infrasound Mr. Walker’s equipment could accurately measure sounds in the lower region of infrasound. It allowed synchronized sampling and recording at multiple sites inside and outside a home over the frequency range from 0.5 Hz to 100Hz. These audio samples have been made available to Wade Bray and I for analysis using Head Acoustics’ software in a similar manner to what was done for the Bray/James study and Noise-Con 2011 paper on the GE 1.5 MW turbine in Ubly, MI. The results of our analysis will be presented to the Wis. PSC as part of the Highland hearing in mid January, 2013. For a limited time (several days max. because of the large file sizes) the audio files are available to qualified reviewer’s from my cloud storage site on YouSendIt. Let me know if you wish to have a copy of some or all of them after reading the attached Team Report.
For details on the Highland case see:
|Docket ID:||2535-CE-100 (Highland Wind Farm) at http://psc.wi.gov/
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