Kouwen and Weaver

Last year Dr. Kouwen put together a very competent system for measuring noise and wind speed specifically for wind turbines in Ontario.  His first foray into the field demonstrated that the noise from wind turbine projects routinely exceeds both what they predicted and what the Ontario regulations allow.  More recently he took his equipment to another location and found, yet again, these violations.  There is now an unbroken string of measurements (a sampling: Ashbee, Rand, Shirley, Kouwen, Libby) at homes of complaining neighbors that demonstrates, beyond any reasonable debate, that these noise complaints are caused by (drum roll) noise!  I have yet to see a case of a complaining neighbor where there wasn’t some underlying noise or vibration problem that could be traced to wind turbines.  Weaver continues this string.

Kouwen traveled to the Weaver residence, just south of Arthur, Ontario.  The Weavers have the misfortune to live about 700 metres downwind from a wind turbine, with a second one just slightly further away.  Below is an overhead view, with the red line of 550 metres showing the Ontario minimum setback.kouwen-weaver-overheadIn addition to measuring the noise at the Weavers, he also found a similar location away from the turbines to measure the “normal” background levels.  His report presents a number of charts showing various details of his results, and their inescapable conclusion is that the Weavers are being subject to noise above and beyond what was projected and well above the statutory limits.  The most basic display of this is his Figure 5, part of which is shown below.  The light blue lines at the bottom show when the measured noise is above the Ontario limits – some 50% of the time.kouwen-arthur-fig-5The major health issue reported by neighbors is the lack of nighttime abatement of the noise and the disruption of sleep.  Kouwen’s Figure 11 shows that one of the major effects of wind turbines is that they pretty much eliminate quiet nights.  He assembled the nighttime measurements and graphed them against wind speed.  I’ve simplified his Figure 11, shown below.  The turbines move the overall noise level from the dashed black line to the solid black line, and you can see that the increase at low wind speeds is well over 10 dBA, which represents a tripling of the noise level.   A proponent would note that the black line doesn’t go above the red MOE limit “very much” (but recall that NO exceedences are allowed), but that ignores the fact that those lines are averages, with about 50% of the measurements being above the line – which harkens back to the 50% noted above.kouwen-simplified-fig-11

The developers generally state that their pre-project noise predictions are “worst case”.  This is nonsense.  In the Weaver case the “worst case” is violated a full 59% of the time.  The developer and the MOE will try to claim that there’s something (anything!) else besides the turbines that creates the noise – we can see an example of this in the Libby report.  And in fact cars passing or dogs barking or insects insecting can all distort the record.  But it is harder to explain how these distortions always seem to affect the locations where the turbines are close but not, apparently, the locations where they aren’t.  You would think that someone could just listen to the recordings (or better yet, go out and listen) and determine if the turbines were the main cause of the noise.  Apparently it isn’t so easy to listen to snippets of a recording and say for sure the turbines are the cause.

In an effort to get around this problem, Kouwen redraws his charts using the L50 noise number in place of Leq.  The difference between the two is that L50 is the median value while the Leq is the mean (logarithmically).  L50 isn’t “dragged upward” by the relatively loud but infrequent distractions, like traffic.  And, consistent with all the previous measurements (i.e. Libby and Kouwen), it doesn’t change the end result significantly.  They are so far over that there’s no plausible way to explain it away, at least with a straight face – their attempt in Libby is laughable.  Below is Kouwen’s Figure 7, with the red lines at the bottom showing that while the exceedences are less than with Leq, they are still significant.kouwen-arthur-fig-7

One has to wonder how many measurements will it take before the MOE accepts the reality that wind turbines are louder and more disruptive than they’re admitting, and certainly violate their own standards.  Our thanks must go to people like Dr. Kouwen who is willing to put his resources – time and money – towards getting to the truth.  I suspect we’ll be seeing his trailer in action again.  Stay tuned!


Kouwen, Weaver Residence Wind Turbine Noise Assesment

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