A look at Barbados Light & Power’s proposal – Part 3
First, our apologies to those who sent us articles and materials 3 years ago…
Back in 2007 when BL&P’s proposed wind turbine installation at Lamberts was a relatively new topic, many good folks sent us information, articles and photos. We opened a folder, started some drafts and intended to do a series on the project, but then we had a computer meltdown that lost everything including the wind power files. One thing led to another and we never did recover the files or complete the wind power series – but Shona found the lost files last weekend!
It just goes to show you. In September 2007, Clive burned a CD with some article ideas and brought it to one of our Friday meetings. We took it home and it’s been sitting in a pile of “stuff” on the bookshelf for 3 years. (I know, I know. I really should do a better job of arranging my office.) On that CD was a copy of the wind power materials that we thought were wiped out by the crash.
Some of it might be a little dated now or eclipsed by events, but we hope that publishing the materials now will inspire some discussion in light of the current “Green Economy” push by the Barbados government and the renewed interest in the wind farm proposal at Lamberts. As you can see in the photo at the top where the turbines are creating a vapour trail much like an aircraft at high altitudes, wind turbines are not beneign – they have an impact upon people, environment, economies, land values and so much more.
Can we predict all impacts and mitigate the bad while keeping the good?
That’s a question that deserves open discussion by a well-informed populace.
Barbados Free Press previously published two three wind power articles that I can find right now.
1/ November 14, 2006 Barbados Wind Farm Question: What About Low Frequency Noise?
3/ October 5, 2009 William Kamkwamba – Building windmills from garbage, hope from nothing
Better late than never, here is our 3rd 4th article on Wind Power…
Recommended Distance for placement of wind turbines and the effect if sited in close proximity to dwellings.
The German manufacturers of wind turbines recommend a distance of at least one mile between wind turbines and dwellings. This is only the manufacturers’ recommendation. It is left for individual countries to decide on safe distance from dwellings.
International research shows it is a general protocol to allow a 1.5 mile/2 miles buffer between wind turbines and residents. In New Zealand, not more than a handful of houses were nearer to wind turbines than 1.5 miles. In Riverside County of California, turbines and dwellings must be no closer than two miles. In Germany they are looking at increasing the distance to 1.5 miles.
In the UK and Northern Ireland before awarding contracts to companies erecting turbines, Government stipulates a distance away from dwellings.
In many cases, the companies are advised to place them out to sea.
In Denmark, because of pressure from the population who felt that they were being saturated with wind turbines all over the country side. Government has stopped all wind turbine projects on land.
“There is no universal standard for setbacks…. Some US municipalities have ordinances based on a multiple of the turbine height. Other countries have adopted much greater distances…”
(L&P, Environmental Impact Assessment, for Lamberts East wind Farm April 2007).
Two types of Wind Turbine noise
It is so important that the wind turbines be placed as far away from dwellings as possible because of the noise they produce.
Noise frequency range for hearing is about 0-20,000Hz (20 KHz). Noise below 200Hz is usually known as “low-frequency noise” although this boundary is not fixed. Sounds less than 20Hz, which are just about audible, are known as infrasound.
The perceived loudness of a sound is measured in a unit called decibel (dB). The decibel utilizes a logarithmic scale rather than s linear one as the human ear perceives loudness in a similar manner. This means to a person, that a 3dB increase in sound is equivalent to double the sound level. A 10dB increase sound level is considered two times as loud. I am saying that 40 dB is twice as loud as 30dB.
(Chart courtesy of Wind Turbine Syndrome News)
Wind turbine noise falls into 2 categories. Mechanical noise from the gearbox and generator, and aerodynamic noise, due to airflow around the blades, the airflow from between the blades and the tower as the blades pass. In addition, noise from adjacent wind turbines can “beat” together, raising the noise level downwind. The beat from a base guitar played very loud is difficult to ignore. It also appears to carry further and penetrates buildings more than higher frequencies.
At the Lamberts site there will be an extreme difference in height between the turbine hubs and the dwellings situated to the East side of the turbines. The turbines are to be situated high above the location of the houses, on a plateau.1.5 miles in length. When the wind is light or not blowing where the houses are situated, there will be little or no noise from the wind to mask the noise from the wind turbines. Noise from the turbines will then become noticeable at the sheltered locations where there is little background noise.
Wind farm noise is tonal in character at distance because the higher frequencies are absorbed during transmission.
There are two recognized types of noise produced by the turbines. The one readily associated with it—–thump thump, whoosh whoosh, sometimes described as a cement mixer turning constantly or an express train which never arrives at the station and the low level pulsating noise. The frequency is about one beat per second. Pulsating noise is easily detected and is not readily masked by background noise. When there is a warm layer of air in the atmosphere noise is reflected so one can hear noise that is created a very far distance away. It is most likely this effect will occur with wind farm noise because the air at the height of the blades is cooler than that at the base.
A critique of the EIA noise analysis was undertaken in the USA by an expert on the subject. He concluded…
“The (Environmental Impact Assessment) study was critically flawed and should be repeated with a far better analysis in terms of (a) establishing a reasonable noise criteria that will be protective of the populace. This should include a measurement of ambient background levels using a valid sampling methodology and (b) reasonable computer modeling to show noise contours accounting for likely Atmospheric, ground reflection and modulation effects”.
R. H. Bolton, February 16, 2007.
Light & Power were not aware of any adverse health effects caused by turbine noise when I posed the question to a representative on November 4, 2006. The representative told me he was not aware of any and if I had information I should give it to him.
In a Press Release, May, 31, 2007, Professor Mariana alves-Pereira, Dr. Nuno Castelo Branco,MD, et al, at the centre for Human Performance in Lisbon Portugal concluded that excessive exposure to infrasound and low frequency noise (ILFN) can cause vibro-acoustic disease (VAD).This was after ongoing research since 1980, conducted by a multidisciplinary team of scientists led by pathologist Nuno Castelo Branco, MD.
This is one of the most in-depth and far reaching research papers which “irrefutably demonstrate that wind turbines in close proximity to residential areas produce acoustical environments that can lead to the development of VAD in nearby home-dwellers”.
Indeed this study actually discovered the very marked thickening of the pericardium of the heart in a family living close to this low level noise, even in a child of 10 years of age.
More and more evidence is being produced to show the danger that can result from placing wind turbines too close to people. Government should ensure that there is no danger to the public when perusing these projects.