Updated: Wind turbines louder at night, says expert

By Ellwood Shreve, Chatham Daily News

Wind turbines make more noise at night, according to acoustics expert Rick James.

James provided testimony during the second day of an Ontario Environmental Review Tribunal, held in the council chamber of the Chatham-Kent Civic Centre. He testified on behalf of appellants Katie Erickson and Chatham-Kent Wind Action Inc., who are opposed to the approval of the Kent Breeze Wind Farm in Thamesville, owned by Suncor.

An appeal has been launched against the wind farm project, which is the first to be approved under the Ontario Green Energy Act, on the basis it will cause harm to human health such as sleep disturbances, stress or psychological stress, headaches and loss of enjoyment of life.

James said he has measured differences in sound levels at night and the daytime at other wind farms as well as examined other studies on how the wind speed affects turbine blades at different levels in the rotation.

“It’s not that the wind speed changes, it’s that the difference in the wind speed at different points in the blade’s rotation may be great enough that it’s not possible to set that blade at an angle that is optimal for energy extraction,” James said.

He said in engineering terms, noise is wasted energy.

“When we get to where the blade is in those positions where it’s not at the optimum angle to extract energy we get a little extra noise off of it,” James said. “The more out of alignment the more noise we get.”

He said in the daytime a blade being out of alignment only increases noise by one, two or three extra decibels.

At night, when there are less sounds from other sources to mask the noise, the difference in wind speeds hitting different points in the blade’s rotation can create a thump or a deep whoosh sound, much more intense than what is experienced in the daytime. He noted this could be a 10- to 14-decibel increase.

James studied the Kent Breeze Wind Farm area and figures more than 100 homes in the area of where the eight turbines are to be located will be above the 40-decibel at nighttime, if the increased noise level is factored in.

Albert Engel, lawyer for Suncor, said if the company or another proponent finds that a turbine is exceeding an acceptable noise level, action can be taken to reduce the noise.

James said he is not aware of any mitigation efforts that have reduced the increase in nighttime noise caused by wind turbines.

Andrea Huckins, co-counsel for the Ministry of Environment, pointed out James doesn’t have the medical qualifications to make any conclusions that human health will be impacted by the Kent Breeze Wind Farm.

James said he doesn’t need a medical designation to know people who have been put in a similar situation have made health complaints.

Both Engel and Huckins tried unsuccessfully to convince the tribunal to not allow James to stand as an expert witness, claiming his bias as a board of director of the Society for Wind Vigilance, and the fact he has testified on behalf of several clients opposing wind farms.

The tribunal will resume Feb. 9-11 in Toronto, before returning to Chatham Feb. 15-16. The tribunal will be held in Toronto March 2, 4,11, 25, and move back to Chatham March 22, 23, 29, 30 and 31.

Some of the testimony by witnesses for the appellants will be done in-camera.

Eric Gillespie, lawyer representing the appellants said some information that certain witnesses would like to present is part of a study recently completed in Maine, which looked at the relationship between the location of industrial turbines and health effects on residents.

Noting it is believed to be a first of its kind, Gillespie said the authors of the study want it to try to have it published in a peer-reviewed scientific journal. He added if the information is publicly disseminated through a legal proceeding or other mechanism it could hinder having it published, because it becomes “yesterday’s news.”

14 thoughts on “Updated: Wind turbines louder at night, says expert

  1. How do the turbines make more noise at night? Wouldn’t it be more logical to say people can hear the turbines more at night as there is less other background noise.

  2. From the “Environmental Noise” article from the Owen Sound Sun Times (which comes after the above article):

    “Increases of 5 DB are loud enough to be considered annoying. Increases of 10 DB represent a doubling of volume to the human ear. Therefore, 40 DB is twice as loud as 30 DB to humans. That size of increase changes a sound from noticeable to intolerable.”

    Decibels are based on a logarithmic scale, so something 10 DB louder is TWICE as loud. Factor in the intermittent nature of the sound (the “thump” or “whoosh” mentioned above) and you’ve got a problem.

  3. Relative loudness and dB


    “Poll: Is 3 dB, 6 dB or 10 dB SPL double the sound pressure?

    This is not a trick question. This is not about the subjective perceived loudness of hearing and not how to add sound sources. SPL is the abbreviation for “Sound Pressure Level”.

    The term loudspeaker and amplification is not specifically raised with the previous survey. It’s all about sound pressure.

    There is only one correct answer: Double the sound pressure is a SPL of +6 dB.
    You should go on reading, if you want to know more and want to understand all this.”

  4. It is very disappointing that there are only a hand full of people in the gallery supporting Mr Gillespie. We need to change this there is lots of room and people are welcome to attend. This is a time to for a show of strength from all concerned people in ont.

  5. I thought wind turbines generate electricity on windy days? I know, I know, everyplace is different, but I can’t hear a car coming up our lane way on a windy day.

  6. “I thought wind turbines generate electricity on windy days?”


    The wind doesn’t stop blowing at night. In fact, the movement of air masses through the atmosphere change once the sun no longer heats the ground thereby creating turbulent updrafts of heated air.

    The condition is known as “stable atmosphere”:

    “The atmosphere is considered stable when it does not support, in any way, the movement of air molecules upward for a defined area or location.”

    In such conditions, there can be no measurable wind near ground level but at the hub height of a wind turbine, the winds could be sufficiently strong to power the unit at its maximum output.

    The “wind shear” (difference in wind speed relative to height) can be considerable over the 300+ foot diameter of the turbines rotor.

    What we then have is a wind turbine pumping out both maximum power and maximum noise with absolutely NO background noise near ground level to mitigate these ill effects. The difference between ambient noise and that produced by the wind turbine can easily exceed 30dBA.

    This is why the masking effects alluded to by wind proponents are nothing more then wishful fantasy! Additionally, the level of difference between ambient and produced sound will negatively impact ALL life on the planet that possess sensory systems that detect vibrations. On this the body of empirical data is conclusive, overwhelming and freely accessible in the public domain.

    Again, statements made by wind proponents that “only a small portion of the population is adversely affected” is also wishful fantasy! And again, the body of empirical data is overwhelming and conclusive.

    These are the reasons why the wind industry absolutely does NOT want any independent, third party measurements or studies undertaken.

    They are absolutely afraid of the truth!

    And these aren’t even the most major failings of this technology either!


  7. I agree with Fred- bring a van load, heck bring a bus load down to the hearing. There are some not-to-miss witnesses on the stand. Who wouldn’t like to see Colby or the director get grilled for once?

  8. Thank you for your answer, bbw.
    I would like to add, I am a proponent, but am trying to be reasonable.
    I looked up your link, but didn’t research farther into the science, as I would be way out of my depth trying to make sense of most of it. This said, I wonder though, can it be claimed that even in a stable environment, the wind at the height of a hub would have to be moving in a certain direction? this would then also cause sound levels as far as existent to be heard in a quarter or a third of the radius of a turbine, which does leave out a significant chunk of environment that might not hear much? I mean, I have seen from experience that sound carries in one direction better than another. I am also aware, air movement at the heights of turbines is more significant, which would help to explain why they need to be so high.
    Could it be argued, that with the lake effect, we might have stronger air movement from west to east (although these days the opposite might be true) and as such, could, based on studies done for years now, a turbine not be sited closer to homes that are upwind from turbines most of the time?
    I want to also argue that perhaps on windy days, particularly on windy days, a turbines noise is not going to be heard anywhere where there is any significant amount of trees or an odd slanted roof or a leaky window… or perhaps an example from our own farm yard, even the arrangement of buildings can cause wind noise.
    There is, of course, always people living down wind from turbines at some point. But there has got to be a more reasonable answer than to shut down wind development altogether. I heard at a meeting (and I constantly feel to young to attend these) that there is 100/150 people sick from them. this number could double. That is 200/300 people. You might be one of them even, as your user name may suggest. I can’t put myself in your shoes, and you can’t put yourself in mine, so to try and convince each other of the benefits and failings of wind turbines is useless. I am however suggesting that there have got to be constructive ways to tackle turbines and not split communities in half. I am too firm a believer in wind energy that I could possibly give in to the idea of shutting it down. My reasoning is this; My parents went through a nuclear disaster, albeit from 1000km’s away in Tshernobyl. (we are from Western Europe). They lost their fruit and garden crops that year. In the Ukraine, the deficits of nuclear power are still apparent. I wouldn’t compare the standards of security in Tschernobyl to the ones in the Bruce or anywhere else in North America. But could you imagine the disaster if in one of our Nuclear Plants, for any accidental reason at all, at any given time now or in 100(continuous) years, a disaster of that sort occurs? We are mostly farmers around here, and a lost crop like that would really help!! in a radius of 1000km’s, how many hectares of crop land and fruit would maybe be damaged? How many people would be affected? I know today nuclear is safe (from the insight that I’m granted), but we are not Mother Nature, and if a major earth quake or, worse even, a military target was sought by terrorists… would’nt a nuclear plant be a prime location? It’s here now and won’t go anywhere. We are going to use it and it seems to be cheap. But it’s a bit of a odd feeling to know that if it fails (and people never do that), were all going to wonder… well- never mind, it’s an old litany.
    My point is, Solar and Wind will become cheaper over time, the beauty is we can take the large industrial turbines of today down and replace them with better ones down the road for a percentile of the cost that a new reactor would cost. It’s only 2 percent or so right now of our energy. That could change.
    But it won’t solve the problem of those 200 or so people that have health effects.
    I tried to brainstorm some solutions, but they require some a 50/50 approach from both sides. For one, and this is probably the easy way out, Wind companies could cover medical expenses of any sort that come from wind turbine syndrom. There could be programs that help residents closest to the turbines to both re-insulate homes for better sound proofing (and energy saving), installation of new windows (for the same reasons), or doorways. There could be money made available to transplant larger trees into the view lines of homes. Would any of these proposals cater even slightly to the needs of opposed residents?

    I simply cannot make sense of a land value reduction insurance, or LFN bylaws because it sets such an ugly precedent for agriculture. Or small towns. Take towns with elevators for instance. Or 400 high way communities, or airport region communities anywhere. Maybe the noise is more at one time than another in all these cases, but the same is true of turbines.
    A land value or business value insurance would be a good idea for local coffee shops, if anything. If Tim Hortons opens up nearby, it should pay all other coffee shops a fee to make up the lost business! (Can of Worms).
    I hope not to have wasted your time, and I am not out to get the neighbors or those opposed, but I am as convinced of them as you are not, and I hope your health and community can heal again, as many times before has been the case else were.
    final words; there are problems with the turbines, I know this, it’s flaunted fairly loudly on here! but I am not certain developers will be interested in building them to fall over or be inefficient. But think ahead for a moment. If we can base more fossil fuel activities on electricity, or if we can come up with a way to store their energy (and i have heard of progress), we could be front runners in North America. But the base will be built on power generation.
    Thanks if you took the time to read this.

  9. Johannes, if you haven’t figured it out already, nobody wants to talk to proponents that care diddly squat about people like T3. My guess is you just finished reading CanWea’s handbook on how to ‘deal’ with us opponents and thought you’d try some of the tactics out here. Take a hike.

  10. It’s to no avail, but i’m not familiar with the CanWea handbook. But how can wind energy be rejected by health concerned citizens while nuclear and fossil fuel is not? Am I a villain to think this makes no sense? Is there a correlation between nuclear energy and cancer? Everyone knows someone with cancer, and in many cases it’s much worse. If a study showed that nuclear power was giving us more cancer, then would this site dedicate it’s efforts to shut down the ontario nuclear industry? Or is it proven to be not so by a health study?— If electric cars take off, we can get farther away from fossil fuels and not have to worry about protests in egypt or war in iraq and its effect on price (maybe there wouldn’t have even been a war)/ or oil depletion or spills. if anything, we can stretch those resources to an extent that our kids and grand kids can enjoy them too. Is this insensible gibberish? I didn’t mean to offend anyone… though its probably to no avail to say so.

  11. Can you imagine Joannes cold hearted solution that we insulate our home and get better windows so I can give up sitting on my porch! Give up riding my horse though our woodlot and enjoying the silence! Instead of watching the fireflies in our valley I am forced to watch the flashing red lights on the wind turbines. I would much rather live beside a new modern nuclear facility. I would donate my farm to this cause if it would stop the wind turbines from destroying peoples lives.

  12. Johannes K.: Industrial Wind Turbines do not replace on-demand base load sources of power. IWTs at best were supposed to reduce peak power demand by providing power during peak demand. IWT’s have a poor performance record. The estimated 30% production rate of capacity is a maximum best guess. Most IWT developments are not performing at that level. Also, most power from IWTs is not produced during peak power demand. When power demand is below base load level the excess power has to go somewhere. During lower power demand it is sold for less than cost and many times negative pricing which means someone is paid to take the power.

    IWTs do not produce a steady amount of power over the hour as alluded to by the hourly or yearly production rates but will vary every 5 or less minutes. This is physics and cannot be improved as wind does not have a constant speed over time. Grid stability is necessary. To compensate for the erratic production of IWTs an on-demand source must ramp up and down to maintain grid stability. Not efficient and sources of fuel are consumed at high rates.

    When selling IWT produced wind power a source of on-demand power is needed to stabilize the power sold. Additional fuel consumed; power sold at a loss.

    IWTs are not being built to benefit our power situation or the planet. The IWT companies have done a great job marketing a green dream to make people believe the impossible. IWT companies are focused on making money which is only possible with high subsidizes.

    Anyone has a right to opposed nuclear or coal but should realize when you use power from the grid you become a hypocrite. There is no other concentrated power source like nuclear able to produce power in the amount needed to support the grid. Reading and understanding power production and distribution is needed to make informed comments.

    IWTs are nothing more than pieces of junk with many components destined for landfills.

  13. Johannes K.

    On every energy technology you mentioned, you are egregiously misinformed. Wind and solar are commercially useless due to dismal reliability and energy density. The noise issue is a small symptom of much greater failings, all of which have been beaten to death on this very blog.

    Chernobyl though a hideous travesty to be sure, wasn’t an accident. It was the intentional act of a madman who was warned repeatedly by his own colleagues beforehand what would be the likely result of his actions.

    What it proved was that if you want to make a perfectly good reactor explode by intentionally locking out the very safety systems specifically designed to prevent that very thing, you can.

    Reactor unit one at the Chernobyl facility began operation in 1977 with unit number 4 (the one they blew up) commencing power production in 1983. Incredibly, the other units continued operation for some years afterward.

    By the time of this manufactured disaster on Aril 26, 1986, Mankind already knew how to build passively and inherently safe nuclear reactors. Incredibly, this was proven beyond all shadow of doubt only three weeks earlier.

    Johannes, I actually used to drive out of my way to get ethanol blended gasoline years before the public was aware of it’s existence. Suffice it to say I do no longer.

    My alias is Broke-By-Wind” not because a nearby unit has broken my spirit but because we are all quickly becoming financially “broke” by having our pockets picked to pay for these mendacious, useless monstrosities.

    The truth is out there. But you first have to truly want to learn it.


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