“Clean wind is clean only until it enters the blades. After that it is dirty wind.”

Apr 5, 2013



Editor’s note:  Wind energy is billed as “clean” by its promoters—as in the slogan “clean, green, renewable.”  The truth of the matter is wind turbines are major “noise polluters.”

Noise engineers Richard James and Robert Rand explain.

Noise polluters is the proper way of framing the issue with wind turbines.  An honest discussion about wind energy that is based on evidence from operating projects would have to say that “clean wind” is “clean” only until it enters the blades.  After that it is “dirty” wind.  The interaction between in-flowing air and the blades of the wind turbines changes the wind from something that is healthy and refreshing to something that causes people and animals to become sick. How can any machine that changes wind from healthy to unhealthy claim to be “Green” or “Clean?”

When nuclear energy was first promoted it, too, was promoted as a safe, clean way to produce electricity.  Even if there had been no risks associated with radiation, there were consequences to the environment which included heating of the water used to cool the reactors, which altered fishing and other natural habitats.

With wind energy production, the turbine blade alters the air moving across it.  The consequences of this change are complex and not always intuitive.  New studies are giving rise to concerns about warming of areas around large arrays of turbines.  In addition, the pressure changes that appear as large wakes propagating at the speed of the wind and also noise emissions which propagate at the speed of sound have been shown to be detrimental to weather radar and have produced radar “blind” spots in communities with big projects.

Both sources of modulating pressure have effects on people, agricultural animals, wildlife, and structures—effects that were not properly accounted for during the design of the machines or mitigated by evidence-based safety margins when siting projects. Given that wind energy is only produced during periods with sufficient upper level winds, there is still a need for backup electric production, with the result that the anticipated benefit of less pollution from coal and gas-fired utilities has not occurred.

In sum, wind turbines are neither “clean” nor “green.”

—Richard James, E-Coustic Solutions (Okemos, Michigan)


“Noise polluters” is an appropriate way to refer to wind turbines and those who operate them with adversely affected neighbors complaining.

Acoustically speaking, wind turbines are “dirty”:  they create noise pollution, also known as unwanted sound.  We know this from reports by affected neighbors.  It is worth noting that the wind coming into the turbines is not always even and smooth; the fuel, as it were, is “dirty,” and the wind turbine acoustic output is also “dirty.”

Just like a gasoline or diesel engine stumbling, thumping, and backfiring on dirty fuel, a wind turbine is noisier when running in turbulent or shearing winds.  Turbulent and shearing winds are the norm in many areas where wind turbines have been located.

However, the wind turbine test standard IEC 61400-11 prevents a full accounting of wind turbine acoustic emissions by (1) requiring testing be done only under very smooth airflow conditions (shear <0.2), and (2) requiring A-weighting which filters out low-frequency emissions from analysis, and (3) requiring time averaging which hides dynamic modulations.

People often ask me, “What is a safe distance for a wind turbine?”  I appreciate the question because it indicates the questioner has some concept that there can be noise pollution problems for people (and animals) near wind turbines. After reading the reports from Australia, and especially since April 2011, when Steve Ambrose and I got clobbered by the wind turbine noise & pressure emissions in Falmouth, Massachusetts, I have been replying that I know of no safe distance from wind turbines at this time.  Ambrose & I suggested in our reports that we experienced a dose-response relationship between the wind turbine pulsations and adverse health effects, with a time onset and a time to recovery, and recovery related to our being many miles away or the wind turbine being off.

—Robert Rand, Rand Acoustics (Brunswick, Maine)


  1. Comment by Marshall Rosenthal on 04/05/2013 at 5:36 pm

    I am neither a physician nor an acoustician. I say this at the beginning of my remarks so that the readers can consider my observations and surmises in the proper light.

    Since 2005, when wind turbine developers came into my town with their dog and pony shows, I have become a keen student of whatever information about this that I could find. Early on, it became clear to me that noise produced by industrial wind turbines was a waste product of their operation. I had the pleasure of meeting with Rob Rand at Shelburne, MA, prior to one of their public educational presentations. When I asked him about this, he agreed with me.

    The noise that is propagated includes the mostly inaudible infra-sounds, low frequency sound, and audible sound. Further, it is modulated, that is, it changes from low intensity to high, to none at all.

    It has profound effects on the human, and most likely, the animal populations that it impacts. In humans, the “fight, flight, freeze” response is repeatedly triggered. Wind turbine neighbors in Florida, MA have remarked on the bird silence and absence of wild animals from their neighborhood. At least they could flee the noise pollution. Not so for house pets who are driven to distraction and unable to escape. The same is true for humans, some of whom do flee and become wind power refugees.

    Dr. Nina Pierpont, MD, has well described the insult to brain caused by the noise, notably the ILFNs and modulation, and has discussed in detail the resultant tinnitus, a ringing in the ears even in quiet environments. This is a sensory anomaly that is comparable to the Love Canal victims being chemically toxified.

    It is my surmise that the offending noise disrupts the functioning of the frontal lobes of the brain, as Dr. Gabor Mate’ states occurs in ADD sufferers, and interferes with the normal firing of the nerves of the sympathetic nervous system. These nerves control the contractions of the smooth muscle substrates throughout the body, the automatic systems that govern heart rate, breathing, peristalsis in the gut, the linings of the arterial circulatory system, the stomach lining, and all the secreting organs, like pancreas, liver, etc.

    This would help to account for the sleeplessness, the terrific headaches and migraines, tummyaches, nosebleeds, and earaches of the Fairhaven, MA school children placed in the new school less than 2000′ from their 1.5 MW turbines.

    If any of you readers are beginning to put this together, now might be the right time to present yourselves to your local, and sadly clueless, emergency medical facilities.

    You see, the time now upon us that this disparate, BUT IDENTICAL, set of maladies and miseries assumes its correct position in the understanding of the clinical community as the terrible environmental assault on human rights that it is.


  2. Comment by sue Hobart on 04/06/2013 at 11:43 am

    Thanks Marshall and Rob…. Now we have to prove it to the governments and have them take these things out. But it’s a Monsanto kind of thing; the developers have infiltrated and have the control.

    But all I can say to ANYONE living under or in threat of a new turbine going up near their homes is GET OUT NOW!… Because after the fact, if the turbines don’t kill you the fight probably will. In 2 years my whole life was turned upside down and dumped out.

    I got out at great cost to both health, heart and well being. Now my future holds more hard labor and waiting years for a trial to fight GOLIATH in court.

    Nothing like the little piece of heaven I once had… Can’t justify paving paradise to put up a power plant…. Well, unless you make enough money.

    It’s a deal with the Devil.

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