Wind Turbines; Distance is not the culprit nor the remedy for health issues

Imagine your home in a quiet rural setting with no neighbours for miles around. At the back of the house is a panoramic window with a view of the countryside. Parallel to that back wall exactly 1km away is a fence row of 5 industrial wind turbines. The turbines are arranged like fence posts 400 metres apart to avoid operational difficulties. Each turbine is rated at a 102 db(A) noise level and the turbine in the middle of the group lines up perfectly with the centre of your panoramic window.

Now let’s advance this entire fence row of 5 turbines progressively closer to the house, up to the point where the cumulative noise of the entire group creates 40 db(A) of noise at the house. At that point, the two turbines on either end of the fence row would be 974m from the house. Moving towards the middle of the fence from both ends the next two turbines would be 684m away. The final turbine in the centre of the fence, aligned with the panoramic window, would be 550m from the house. This is how the 550m setback became a reality.

This distance was not plucked as a magic number from some scientific journal, nor was it arbitrarily picked out of the air. It is the direct by-product of the MOE regulation of a 40 db(A) compliance limit for noise at homes exposed to industrial wind turbines.

If we were to eliminate four of the five turbines and leave the middle turbine at 550m from the house, the predicted noise level at the house would decrease by almost 5 db(A). That change in magnitude could be the difference between health and ongoing disability from noise annoyance. Close proximity to a turbine is not the culprit.

On the other hand, if we removed the turbine at 550m and left the other four in place, thereby increasing the distance to the closest turbines to 684m, the cumulative noise level at the house would only drop by about 2 db(A). That difference in noise volume is barely detectable. Arbitrarily increasing distances to turbines is therefore not a remedy.

Obviously, if we were to increase the size of this fence row with more turbines or increase the sound power level of each above 102 db(A), or both, we would increase the level of noise at the home. As a result, the entire fence row would be moved back to meet the 40 db(A) compliance limit. You would expect therefore as wind projects grow in size with more powerful noisier turbines, that the 550m setback would be rare. In fact, this is precisely what happens. If you were to take a look at any number of wind projects such as Zephyr, Gesner, Conestoga or McLeans Mountain which totally involve dozens of turbines and literally hundreds of non-participating receptors, you would not find one example of a turbine located at 550m from a receptor. The closest turbine to any receptors in these projects varies from just over 600m to 800m away. In my opinion, distance as an issue and 550m in particular, gets more attention than it deserves.

In contrast, the issue that never gets any appropriate level of attention is the cumulative nature of noise predictions. Under the current GEA rules the predicted noise level at any receptor is an aggregate of the noise from the closest turbine plus every other turbine within a 5km distance. The resulting predicted noise level is dependent on the number of turbines clustered in that distance and the sound power level of each turbine.

Due to this aggregate approach, in every proposed industrial wind project under the GEA you will find examples of; a) receptors which are closest to turbines do not have the highest predicted noise levels; b) different receptors whose closest turbine is exactly the same distance away with significantly different noise levels and; c) different receptors whose closest turbines are drastically different distances away with nearly identical predicted noise levels.

A current topical illustration of this is the Cedar Point Wind Project being developed by Suncor. That proposal is for 46 Siemens turbines whose power levels range from 2- 2.3MW which will impact 893 non-participating receptors. Noise predictions unfortunately have not been made public for the receptors located 1500m or more from their closest turbine. However, available data for receptors inside that distance is informative. There are 474 receptors closer than 1500m to their nearest turbine which represents more than half of all impacted receptors.

To highlight how aggregate noise predictions distort the linear relationship between distance and noise consider the following from Cedar Point. There are a dozen different receptors located between 1000m and 1010m from their closest turbine. Noise predictions for this group vary by more than 5 db(A) from 32.6 db(A) to 37.7 db(A). Similarly, the median predicted noise level for all receptors inside 1500m is between 33 db(A) and 34db(A). There are 74 receptors within this single decibel range but the distance to the closest turbine across all these receptors varies by well over half a kilometer, from 804m to 1494m. Suffice to say, that if distance is the key to protecting health which one would be the choice from all these permutations?

Cedar Point is topical because the Mayor of Plympton-Wyoming has committed to enforce a newly created by-law for a 2km minimum setback. This 2km setback figure has gained notoriety as it has been recommended in other parts of the globe. However, the substantiation for why this distance is key, has not been well articulated.

Suncor has been awarded a 100MW FIT contract for Cedar Point. A 2km minimum setback opens the door for Suncor to upgrade their current proposal. Hypothetically, rather than 46 2-2.3MW turbines they could use 33 – 3MW turbines to fulfill their contractual agreement. Admittedly, the entire footprint of the project could be downsized and as a result, somewhat less than 893 receptors may be affected. But it is more than feasible that for those who remain impacted, the larger and noisier 3MW turbines could result in increased predicted noise or at least similar levels to those in the initial configuration, even at a 2km setback distance. By acting only on distance without regard to allowable noise limits, the end result may offer no increased protection against ill-health.

Alternatively, if action was focussed on noise limits that were more aligned to the reality of rural settings, health issues could be minimized. Using our 5 turbine fence row scenario, if the current target of 40 db(A) at any receptor was revised to 25 – 30 db(A) as an example, our entire fence row of 5 turbines would be pushed back. This reduced noise limit would not change the convoluted array of distance relationships between homes and turbines we see in every project, but it would move the chaos further away and it would be done for the right reason, not arbitrary choices. How far away is undetermined but distance is a secondary consideration. It’s the noise level we are trying to deal with.

Systematically destroying the health and well being of citizens is the problem. Exposure to intrusive environmental noise is the culprit. An educated reduction of current allowable noise limits is the remedy. Haphazardly experimenting with distance limitations doesn’t put us on the road to success, it means we took the wrong turn.

18 thoughts on “Wind Turbines; Distance is not the culprit nor the remedy for health issues

  1. db(a) levels do not capture the reality of wind turbine sound emissions. The dba calculation does not consider the impact of infra- and low frequency sounds.

    Check out the picture at the top of windfarmrealities dot org. Notice the vortex trailing behind each wind turbine.

    The cause-effect relationship is extremely complex. What we understand quite clearly is that the closer people are to wind turbines, the more likely they will experience harms. Fully understanding exactly the complexities may not even be a good use of resources, since these horizatonal axis wind turbines are pathetic contraptions that should be phased out anyway.

    Be careful not to get drawn into overly complex, irrelevant discussions that one could spend a lifetime debating.

    • While everybody debates the pro’s and con’s of wind turbines, and safe and unsafe setbacks, and infrasound, and dirty electricity, and stray voltage, and so on, and so on….real, living, human beings are being treated as guinea pigs, totally without their consent. As a matter of fact, unless they are host farmers, it is usually completely against their will. This must be priority #1, end the pain and suffering that is being inflicted on families that have had these industrial machines thrust into their immediate environment, with no guarantee whatsoever of safety, efficiency, cost-effectiveness, or any other reason why they should be here. The GEA is a travesty of justice, and it makes a mockery of democracy. Shut them all down till further notice.

      • I understand that for Victims, some desperately want to know “what is happening to me?” And others don’t.

        I’m sorry that we may never know…

    • Its unfortunate that this type of subject is seen as ‘irrelevant’. Take a look at ‘LFN from Large Wind Turbines’ Journal; Acoustic Society of America, 129 (6) June 2011, 3727-3744

      • Dan, I thought it was great work. Anytime you can get something in a large newspaper that is great. It is particularly good when it is a newspaper in a Liberal area before an election. Thanks for your work.
        I have noticed that the Star seems to have taken a different attitude towards wind energy lately. Hopefully people will start sending them letters when they see stories. I have started on one and doubt that they will print it but if enough people do it maybe a few will get in there.

  2. I can see the logic of the article, and I agree with suspicious and with Chev.
    OTOH, in much of southern Ontario, a 2km setback from all homes would nearly be the same as saying No Turbines. If the distance is great enough it solves most of the problems. Australia is looking at 5km to 10 km setbacks. That sounds fair. But not in migration paths.
    If they just don’t build them, it solves all the problems. lol
    Just say ‘NO’ to turbines.

  3. Those promoting IWTs have never been made to define what they mean by direct and indirect effects of IWTs
    When an IWT is non-operational with blades not moving there is no “noise” and so no effect.
    When an IWT is operational with blades moving “noise” is produced and this is a DIRECT EFFECT of an IWT being operational.
    Same thing with a light bulb. If a bulb is not lit then no light waves are produced.
    The more light bulbs that are lit then then the more light waves you get from them.

  4. The IWT industry loves to ‘red-herring’ discussions to distraction! There was a video added to this website a while ago, in which a young mouth-piece for the industry was trying to convince attendees at a meeting that her wind turbines would be quieter because they were bigger! Her ‘red-herring’ was that the units’ nacelles would be higher off the ground, so their noise would be further away from receptors. She was creating the ‘straw-man’ argument-of-falsehood that the problem was dBa noise originating directly from the nacelles. She thereby was trying to distract the attendees from the fact that it was the IWTs’ blades that produced sprials of reduced air pressure and the resulting generation of infrasound. Its more of the same old story .. ‘smoke and mirrors, red-herrings, distraction and lies!

    • I must have missed that video…

      That’s a fairly substantial misprepresentation.

      Does anybody know what her name was?
      Or the company?
      Or who was the noise “expert” on hand at that open house?
      (Or the link to the video?)

      • Sounds like the infamous words of Randi Rahahim of N.R.W.C. in West Lincoln. She said that the 3mw turbines that they were installing….had no gears, had special fluid in them, were too high to produce much audible noise, and were MUCH quieter than the smaller ones! What a crock…eh?

      • Yeah! Good old, still battling, and unfortunately still winning, Randi Rhahimin(??)from NRWC. She looked directly into the camera and stated the Enercon 101’s threatened for West Lincoln and Wainfleet(Sadly Haldiman’s politicians have already accepted NRWC’s project as a good thing! :-():
        ‘..would produce less noise because they were higher..’!
        This illustrates the incompetence of the senior management in the Ontario wind energy industry that our politicians, not just the Liberals, but the NDP and Conservatives, are still allowing to control the destruction of rural Ontario.
        I only watched it twice, couldn’t take it any more!
        This woman is the spokesperson for the company planning on building the biggest industrial wind energy project in Ontario to date, and with the biggest IWts to have been installed in North America!
        We are all nuts to have allowed it to get this bad.
        Andrew Watts

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