Wind turbines are not noisy

[Dearcham]

After visiting the wind farm of Mont Soleil in Switzerland I was amazed by the absence of noise from these monsters of 70 m high: at about fifty meters, the wind in the shrubs covered totally the noise of the blades.

From just below, the noise is about twice as strong as that of a high voltage line but really less stressful.

Here is a small summary of the CLER (Renewable Energy Liaison Committee)

The sound pressure level decreases with distance. The further away from the source, the lower the perceived noise (which is valid for any sound source)
at 10 m of the source, the sound level loses 30 dbA
at 20 m of the source, the sound level loses 35 dbA
at 30 m of the source, the sound level loses 40 dbA
at 100 m of the source, the sound level loses 50dbA

Here is a small table of the sound level of a wind turbine according to the wind speed

Wind speed (km / h) / Ambient sound level (dB (A))
18 / 38
25 / 41
32 / 45
40 / 49
47 / 53
54 / 56


And after ? : the sound level of a wind turbine stabilizes when the wind reaches a certain speed. Beyond this speed, the sound level of the wind continues to increase while that of the wind turbine remains stable. The wind noise then covers that of the wind turbine.


The decibel scale is used to position a certain number of known noise emissions in relation to the average noise emitted by a wind turbine located at a distance of 250 m
10 dB falling leaves
15 dB whispers
30 dB Interior of a bedroom
40 dB wind turbine
50 dB Interior of a house
70dB Office
80dB Interior of a car
90 dB Stereo Music
100 dB Interior of a factory
120 dB Jackhammer
150 dB Jet aircraft

What happens when there are several wind turbines?
The increase of the sound level is in no way proportional but logarithmic. This means that the presence of two identical sound sources does not lead to a doubling of the perception of the loudness. Thus a person placed at an equal distance of two identical sound sources will perceive an increase in the auditory level of 3dB. Four identical sources will increase the level of 6dB.

[Bibiphoque]

What happens when there are several wind turbines?
The increase of the sound level is in no way proportional but logarithmic. This means that the presence of two identical sound sources does not lead to a doubling of the perception of the loudness. Thus a person placed at an equal distance of two identical sound sources will perceive an increase in the auditory level of 3dB. Four identical sources will increase the level of 6dB.

Hi, 3db, it's not exactly double ??
A+

[Dearcham]

the weather is getting bogged down, even our small local seals are losing their bearings

Taking as a basis that a wind turbine produces 40db, if we add a second at the same distance, we could expect a noise of 40 + 40 = 80 db gold, it is not the case, the increase of Sound volume is not 40 db but only 3 which gives us 43 db.
Similarly with 4 wind turbines around we reach not 40 * 4 = 160db but only 46db

Is it better said like that?

[aiolia]

After visiting the wind farm of Mont Soleil in Switzerland I was amazed by the absence of noise from these monsters of 70 m high: at about fifty meters, the wind in the shrubs covered totally the noise of the blades.

From just below, the noise is about twice as loud as that of a high voltage line, but actually less stressful.
...

Indeed, it does not make much noise. But it will risk even less in the coming decades when the scarcity of oil will be responsible for the exponential increase in their cost, making problematic the issue of their profitability.

[Bibiphoque]

the weather is getting bogged down, even our small local seals are losing their bearings

Taking as a basis that a wind turbine produces 40db, if we add a second at the same distance, we could expect a noise of 40 + 40 = 80 db gold, it is not the case, the increase of Sound volume is not 40 db but only 3 which gives us 43 db.
Similarly with 4 wind turbines around we reach not 40 * 4 = 160db but only 46db

Is it better said like that? : P

Hello,
: Angry:
I will not go facher but an increase of 3 db is double! Ndj !, fo review your unit conversions !!!
I quote from wiki:
Call us
An article from Wikipedia, the free encyclopedia.
(Redirected from Decibel)

The beautiful (symbol B), although outside the international system (SI), is in use with him. Bel is used to express the value of logarithmic quantities such as field level, power level, sound pressure level or attenuation. The logarithms of base ten are used to obtain the numerical values ​​of the quantities expressed in bels. For more information, see the International Standard ISO 31.

He was named in honor of physicist Alexander Graham Bell.

It is a logarithmic unit where a difference of 1 bel corresponds to a ratio of 10 in power. It is more commonly used its submultiple the decibel (dB). A difference of a decibel corresponds to a ratio of 101 / 10 is roughly 1,259.

Calculation of a Bel with respect to two values:

bel = log (10) (V1 / V2)
decibel = 10 * log (10) (V1 / V2)
The voltage gain of an amplifier is translated into decibels:

+ 6 dB correspond to a gain almost equal to 2.
+ 20 dB correspond to a gain of 10.
Signal-to-noise ratio S / N (dB) = 10 * Log10 (S / N)


A + B) <_

[Christophe]

Indeed, it does not make much noise. But it will risk even less in the coming decades when the scarcity of oil will be responsible for the exponential increase in their cost, making problematic the issue of their profitability.

Uh, I do not follow you .... can you argue? The problem of profitability is ALREADY present. 15 years of return on investment for a lifetime of 20 years ...

For me, the more expensive the fossils are, the more the renewable ones are profitable because the price of energy (in a general way) is aligned with that of oil ...