Posted with the permission of The Naples Record, originally published Wednesday June 3, 2009
I attended the public "informational" meeting held by Ecogen LLC in Prattsburgh on May 21, and was appalled, though not surprised, by their shameless attempts to distort the truth and hide embarrassing facts about their proposed Prattsburgh/Italy wind turbine project. Two examples relating to noise illustrate their tactics.
Because of the widespread complaints from neighbors of the Cohocton project, noise was a major concern voiced by members of the audience at the meeting. The company's acoustical consultant, Peter Guldberg, assured us that noise would not be a problem with the Ecogen project because the Siemens turbines they intend to install are "60 percent quieter" than the Clipper turbines used in Cohocton. He made a point of repeating that "fact" numerous times in his presentation. Unfortunately (for us), he was talking about apples when the real issue is oranges.
While "60 percent quieter" seems like a great improvement, because of the way human hearing responds to sound, it is essentially meaningless. When pressed further, Mr. Guldberg was forced to admit that the Clipper turbines have a guaranteed maximum noise level of 109 decibels while the Siemens turbines are guaranteed at 107 decibels. "Sixty per¬cent quieter" translates into 2 decibels! He also failed to mention the fact that, outside of a laboratory, a 3-decibel change in sound level is considered barely discernable. In other words, in spite of being "60 percent quieter", the Siemens turbines will seem just as loud as the Clipper turbines.
Another question was raised concerning a woman who lives 600 meters (2,000 feet) from a Siemens wind turbine who claimed that her house shakes so much that objects rat¬tle on her tables. Mr. Guldberg assured us that her problem could not possibly be due to the low-frequency noise coming from the turbine. At that distance, he claimed, the vibration from the wind turbine at a frequency of 31.5 hertz would be 100 times too small to shake a house. What he conveniently failed to mention was the effect of resonance at lower frequencies.
Resonance is the build-up of small vibrations into a very large response in the resonating object. It is a major principle behind the operation of musical instruments, including the human voice. The vibrating strings of a guitar, violin, or cello could not be heard more that a few feet away if it were not for the amplifying effect of the resonating body of the instrument. In the same way, a resonating house or windowpane can amplify the relatively small (even inaudible) low-frequency sounds coming from a wind turbine. The sound power spectrum of wind turbines increases dramatically with decreasing frequency, and at about 10 hertz, is strong enough to rattle windows and cause other annoying consequences, even at distances exceeding 700 meters. By limiting his answer to 31.5 hertz, Mr. Guldberg conveniently ignored these lower-frequency effects.
That woman's vibration problem is real, as are similar problems mentioned by numerous other neighbors of these projects, including residents of Cohocton. To add insult to injury, these people probably have no recourse because the sound levels measured at their properties are very likely within the limits set by local law. The standards used to measure those sound levels make no mention of low-frequency resonance effects. The low-frequency vibrations that cause these problems are also the ones that carry the farthest (elephants use low-frequency sound to communicate over distances as great as 10 miles). So even if you live in the valley a mile or more from the proposed project, don't be surprised if you are awakened at night by rattling windows even when you can't hear the turbines directly.
These are just two examples of the practices used by Ecogen representatives at that meeting. Even if not lying out¬right, they selectively presented some data and ignored others in an attempt to deceive the audience into accepting their pro¬posed project without understanding the true implications of its impact on our lives.
Michael Herzog, Shay Road, Naples
No comments:
Post a Comment