How Loud is a Wind Turbine?

November 18, 2010

Because wind turbines are such a great source of clean, renewable energy, they’re usually greeted with a great deal of enthusiasm. But some complaints have been made that they can cause too much noise for residents living within a mile of the blades.

So just how noisy are these turbines?

The closest that a wind turbine is typically placed to a home is 300 meters or more. At that distance, a turbine will have a sound pressure level of 43 decibels. To put that in context, the average air conditioner can reach 50 decibels of noise, and most refrigerators run at around 40 decibels.

At 500 meters (0.3 miles) away, that sound pressure level drops to 38 decibels. In most places, according to Keith Longtin of GE Global Research, background noise ranges from 40 to 45 decibels, meaning that a turbine’s noise would be lost amongst it. For the stillest, most rural areas, Longtin says the background noise is 30 decibels. At that level, a turbine located about a mile away wouldn’t be heard.

For a complete run down of louder-than-a-fridge but quieter-than-a-blender context points, check out the graphic below.

Sound check: Click the image to enlarge it.

* Read more ecomagination stories on GE Reports
* Read more Global Research stories on GE Reports

This entry was posted in Ecomagination, Energy, Feature, Global Research, Other, Renewables and tagged Ecomagination, Energy, Global Research. Bookmark the permalink.

Tim Smith

I’m glad to see this information. It’s about one of the questions that I’ve not been able to give a researched answer to. I’ve visited wind farms before and I can tell you from experience, the sound of the natural wind blowing was louder than the “whooshing” sound of the turbine blades and the sound of any electrical component. I’ve featured several specials lately on my blog about wind energy and stay active on wind power forums. There was no “lack of interest” when I attended WindPower 2010 in Dallas this year. Keep up the good work, it’s appreciated. Tim Smith
Tom Saidak

While the graphic diagram looks great, I think a better idea would be a series of sound files (mp3 preferred) that actually gave one the sound vs distance where one could hear it.
Mohhan

Even i work in GE….IAm bery glad to work with type of company which is trying solve world’s toughest problems…..
After seeing this Image abt Wind Energy…we need to.promote this type…because with this we can Generate a lot of power..not only with water……this way we can save some of the water…..but hw ever GE is doing a lot GOOOOOOOOOOOOD …………………..Mohhan
Mohhan

if this wind Enrgy fans come as regular fans which we will use in our homes…..
it should come in that at the height of 15-20ft high….if we can palce them in town ships….apartments….so there we can produce some of the electricity..n we can use…
James Walsh

How would the graph appear if there were five turbines at 500m?
Pete

Five turbines would increase the noise by 7dB to 45dB(A)
Alec Salt

(Mod: Prior comment was truncated and should be deleted)
A key part of this graphic that most people will not appreciate is the “A” after dB (i.e. dB (A)). This means that all the infrasound (less than 20 Hz) generated by the turbine, which undoubtedly affects the ear at levels below those that are heard, is totally ignored by the measurement. This measurement is equivalent to considering only the visible portion of sunlight and concluding that sunlight cannot harm you. We all know that the invisible portion of sunlight (the ultraviolet light) is the cause of skin and eye problems. Similarly, it is the unheard infrasound component of wind turbine noise that causes problems to nearby residents. Until the industry deals with the infrasound component, the problem of wind turbine noise on nearby communities will not be solved. Long term infrasound exposure disturbs sleep and this graphic misrepresents this situation. So the graphic may be visually appealing but it misrepresents the true (infrasound-dominated) nature of wind turbine noise.
Mark

@Tom Saidak – how far up would you know to turn your speakers? What a dumb idea.
BWM

Actually, Mark, Tom Saidak’s idea would work fine if there was a matched local sound embedded so that volumne at the users’ end could be irrelevant. So the MP3 would include wind and turbine noise at x’ (feet) with a known sound. Because it would seem relevant, my MP3 table would include as referent wind noise in open and wooded areas for standard wind speeds that were then matched with turbines operating in those same wind speeds. A little table for turbine brands vs (woods, prairie, suburbs) would be appropriate.

Also, in decision sciences we often use competing standards, so highway noise, rail noise and high-power line hum would be interesting in contrast.
John Perry

Don’t get me wrong. I love the enviro-friendly technology but wouldn’t want to live near a turbine farm even at 43 dB. This is long-term nearly-constant noise whereas all other devices cited cycle on and off – leaving quiet time. Additionally, sound levels that are fine with one person are not necessarily fine with another … e.g. sub-woofers in automobiles. Just guessing but property values go down for homes near turbine farms.

While I understand the data, that data appears to be for a single wind turbine. Since all tubines don’t rotate at the same speed, is it possible that beat-frequencies are generated that could result in amplification of the sound pressure level beyond 43 dB?
Scott

All these concerns about noise……have you been next to a coal fired or natural gas fired power plants? Come on folks………..really.
Jovert Garotti

The effective noise depends a lot on the wind speed and direction, like the noise from a highway.
Bert

The loudest part of wind turbines are the flocks of geese who get shredded when flying into them, followed by dozens of PETA protesters screaming murder.
Terry McCann

The reference above to infra-sound by Alec Salt and by John Perry to sub-woofers is very relevant because the issue is not only decibels but frequency since low frequency does not attentuate very well. What I have read of the objections is that it is the on-going low frequency that gets to people. It concerns me that a lot of the people who are objecting to wind power because of noise concerns are actually eco-savvy, not just nimby-ites. This means that we have to take their concerns seriously. Kudos for the research that has been done on sound pressure; can we expect to see something on the different effects of the sound spectrum and effect on suggested distances from where humans (or animals) live and work? What about the effect of wind turbine noise on dairy cattle milk production? This could be done with recordings over a bracketed period of time with controlled levels of sound pressure.
Mick Patrick

I never heard of anyone abandoning a house because of noise like a refrigerator or a “conversation”. But if you read Dr. Alec Salt’s work, you will understand the reason so many people worldwide find they can not live with the infrasound impacts. It causes sleep deprivation, and a host of illnesses when it is located at setbacks that industry says are “safe”, and frankly, they want to sell the turbines so you have to take their claims with a grain of salt…(no pun intended).

Legitimate property value studies show huge value losses out to 3 miles. Google Clarkson University or Michael McCann. Both are independent and find impact on value out to 3 miles. Industry reports use a lot of wesel-words to qualify thier opinions, and I read they even excluded sales data from near the projects studied because the “deviations” from mean values were too great.

Boy are there ever going to be a lot of lawsuits when the dust settles on the facts.
Suchi

Loved the graph: wonderful clarity on such a debated yet less-known topic!
saptadeep

Worderful depiction and presentaion!!!! We can esily imagine how the clen and greem future would be waiting for us. Lots of Kudos GE.
KBR

Its a very relevant information and well presented in graphical formats.But, what happens when there are large wind warms?? Also if you can throw some interesting info on offshore windfarms!!
R V Almond

I believe most of the aerodynamic noise comes from the blades tips, so I’m sure the design aims to keep the tip angular velocity as low as possible, within (obviously) the operating envelope of the machine.
I assume the blades are fixed pitch, so the turbine rotational speed is dependant on the local air velocity into the blade disc AND the torque on the tubine shaft (electrical load generated).

Off shore (& in-land) wind farms in UK & Europe are common now, with more very large ones planned.
Mike George

I remember from my thermodynamics class many years ago that there is no “free” energy. The wind turbine converts the kinetic energy of the wind into electricity. This wind energy is thus lost to the environment, correct? Have there been any studies on how large scale wind farms affect the local wheather patterns?
Steven

Mike, I suspect that in terms of scale it would be like wondering what the effect of desalinating and drinking seawater would be on the global sea level.

But also, wind is air flowing from a high pressure to a low pressure environment. Conceptually, the fact that you catch some of that movement energy (ie. make it harder for air to go from one place to the other) would not affect that mechanic as it is basic physics.

What you may get I guess (ie. conceptually, because in practise this would be negligeable) is that wind may blow harder around the windfarm because ik seeks the easiest way to the low pressure area. This would be the same effect you get in cities when winds pick up in streets because the mass of air needs to go between the buildings, so more air needs to pass through fewer space.

I am no no way an expert, but think it is a very interesting topic to philosophize on!
Norm

I live in a small Oregon town surrounded by Wind Turbines and I have not heard of anyone claiming they are negatively affected by ‘infrasonic sound’. In my opinion its all a bunch of nonsense spread by nimby’s. Mr Salt has done alot of research into Infrasonics, but I have not seen any references to legitimate double blind studies of individuals claiming to suffer from sleep disturbances (caused by turbines). Are there any such studies, Mr Salt? If not, are there any studies being planned? If not, why? A double blind study would be the best way to prove or disprove what is now theory and conjecture based mostly on anecdotal stories – sorry to dissapoint, but that’s NOT science.

Terry – you are incorrect – lower frequencies attenuate faster than higher frequencies. Thats why when you hear music from a distance, you generally hear the high frequencies first, unless the bass frequencies are VERY loud.
AL

Forget the Wind Turbines and build some Nuclear Plants. They are more reliable and don’t make any external noise.
Russell May

Couldn’t we use some of the free energy for Noise Cancellation, ie invert the Low Fre noise?

This might stop the Opposition to this Clean and Renewable Energy source
Russell May

Ooops!

that should be Low Freq Noise
Glenn

Scott’s comment is absolutely right. Coal fired power plants are extremely noisy. I’ve never been in a nuclear power plant, but, I’m guessing that there is a fair amount of noise from the turbines, etc., but they are inside a fortified building, whereas, the wind turbines are out in the open and spread out over a large area. Also, I see that some have asked about how noisy 5 turbines would be, but, in a wind farm there may be 100 or more. So,how far away would you have to be to live in a comfortable acoustic environment?
Frank

I think some interesting points have been raised. First of all, the graph should indicate the dB of the lawnmower, refrigerator, and air conditioner at a common distance of say 6 feet. The values listed for these items are probably where they are the loudest, and few people put their ears next to the muffer of a lawnmower. Since, the source of the noise seems to be around the shaft of the wind turbine, it seems that much of the noise is gear noise. There is a lot of force at those gears. Those gears have to transfer a MW or so of power from around 10rpm to over 600 rpm. Many people like the sound of a waterfalls, but to tell you the true, even a 6 foot one can over power every other sound in the area. It would be interesting to see a graph of amplitude verses frequency down to 20 hertz. It would also be interesting to see how this varies at several distances, say 300meters, 800 meters, mile, and 2 miles.
Jane

I live near the Rosemount Xcel Energy Coal Power Plant in Rosemount, MN….

The rail traffic alone… is just constant.. constant beeping of trucks and heavy machinery… its defiantly louder than 43 decibels, even at 15 miles away!

Oh and of course the smell when the temps dips below -5F… the smell seems to just linger. My family and I have noticeable respiratory problems! My oldest devolved a pretty bad Asthma problem, and according to the Minnesota Department of Health employee I have spoken with told us to stay indoors when it gets “bad”. Thank goodness GE’s parent company makes an awesome air filtration SmartAire purifier!

I am soooo for Wind power!
Herman

I can’t understand why people always protest against something new. What about the constant noise of the sea, yet people build their houses as close to the beach as possible to stay there permanant. Others stay there occasionally.
City noise is not complained about. Sorry, but I really can not see why people are against new technology which is good for Mother Earth. Maybe you should move to an area where there is no wind.
It will take a short while, but you will get used to the noise of wind power generators and later on it will sound like music to the ears. Chill and be happy that it is for our own good. If I had the money I would erect a small one in my town yard.
GO FOR IT GENERAL ELECTRIC!!!!!!!!!!!!!
Tristan

Finally, an advantage of living in the middle of nowhere.
Subra

Would be nice to know the other variables that impact the sound, like length of the blade, RPM at which the turbines are running, closeness to other turbines, etc. I am wondering if the turbines could be placed at a optimal distance to each other such that sound waves from each turbine could potentially cancel each other, resulting in a reduced sound overall !
Robert

I lived on a farm where the only power sources we had were wind, solar, and diesel. During the day the sun charged our batteries, and most nights we had wind. But when all else failed, we ran the diesel generator. That was the noisiest device. We hardly noticed the wind turbine even at high speeds! So there was only one turbine, but I still think the the benefits far out weigh the noise! And believe me, we all slept quite comfortably!
colum joyce

There are studies on low frequency nose and wind turbines. The UK is presently looking at legislation to place limits on it
Glenn

Wind Power makes so much sense. The potential is enormous and the costs are in line with other commonly used generating methods. There is enough potential in the good to excellent land-based wind sites in just 5 states to generate enough electricity to equal the entire useage of the whole country. The good news is that there is also tremendous off-shore potential. When you add up all the good to excellent land-based and off-shore potential, it exceeds the entire electrical AND petroleum based energy consumption in the U.S. !!! Besides the environmental benefits of wind energy, there is also energy independence, which has huge rewards of its own. Think of the problems associated with sending hundreds of billions of $ to oil producing countries that turn around and use that $ against us. Our energy dependence finances the regimes that hate us and we end up getting involved in places that would otherwise be of little consequence. We have spent over a trillion $ on military operations in the Persian Gulf area that we could have saved if we didn’t need the oil – not to mention the lives of our troops. It would be so much better to be able to say, “Keep that nasty oil. We don’t need it.” When all the elements of petroleum vs wind/solar/nuclear/natural gas are taken into consideration, the latter wins hands down. We should make building these non-petroleum energy generating facilities and the infra-structure needed to support them a national priority and build them as fast as possible.

Also, it seems to me that offshore wind would be perfect for providing electricity during high demand and during low demand times splitting water to make hydrogen, which could then be used to either fuel gas turbines to generate electricity during peak times, or, to fuel internal combustion engines for transportation. The engines that we currently have in our cars can run quite well on hydrogen. A number of years ago there was a company in California that converted cars and pick-up trucks to run on hydrogen (unfortuneately, it went belly-up). The biggest challenge with hydrogen is range and the California company had a Ford car that had a range of a little over 200 miles. If hybrid technology were combined with hydrogen power, then the range would improve and the electricity to charge the vehicles batteries could be generated with the non-petroleum methods mentioned above. Everyone wins!!! The environment, the costs are competitive, it’s geo-politically advantageous, and the energy source is sustainable.

So, let’s resolve as nation to convert to non-petroleum energy QUICKLY !!! If we spend $200B/yr (less than our military costs for involvement in the Persian Gulf) we could be totally energy independent in about 10 years.

Let’ DO IT !!!
Barata

sometimes the reason why technology can move our lives to a better place need to be considered that future impact could be worsen if some resources such as gas and oil will be empty someday, this ecomagination about wind turbine will be a game changer in energy resources, and people around the world need to reflect an image a pure air in the atmosphere if there is no more oil and gas burn for waste.

“How Loud is a Wind Turbine?” is a question that will be simply to be forgotten