Wind Energy Myths
Noise
Some people are anxious for the sound that wind turbines produce, and that it can go much above save for the human ear level of noise. In fact, thanks to modern technologies used in turbines, todays wind farms are no noisier than a fridge in your kitchen! Morover, the main sound generated by wind machines is only the aerodynamic swoosh when blades pass the tower. To feel even more secure in this matter, each country has strict guidelines on wind turbines and noise emissions. It simply means that the residential amenity in close neighbourhood of wind farms is well protected.
The best thing to do for any doubter is to go and hear for yourself! As long as you stand not closer than 300 meters from the farm, its sound does not exceed 50 *dB* on a scale of 120 *dB range** *of intensities.
Infrasounds
Infrasound is a sound lower in frequency than 20 cycles per second which is the normal limit of human hearing. To be able to perceive them, the sound pressure must be sufficiently high, since hearing becomes gradually less sensitive as frequency decreases. At higher levels it is possible not only to hear, but also to feel infrasound vibrations in various parts of the body.
Eventhough the characteristic 'swish' of the turbine's blades emits low frequency sound while passing the base, there are no proofs to state that we are dealing with infrasounds that endanger our health. It is also important to realise that there is no reliable evidence indicating any effects on humans when infrasound is present at a level below the hearing threshold.
Bird killers
Wind turbines are thought to be harmful to birds and to disrupt bird
migratory patterns. The fact is that they can potentially have impact on
birds through collisions as well as disrupt the habitat. But it is proven
that the impact is still not greater than that of urban sprawl or even home
cats. For every 10,000 birds killed by any human activities, less than one
death is caused by a wind turbine. To compare, 700 birds die because of the
cars and 800 die because of high tension lines.
Harmful to the landscape
Turbines are thought to be harmful to the landscape mainly because of esthetical issues. Let's face it: there are as many opinions as many people walk this earth. And many actually claim wind turbines are majestic. When a wind project is carefully designed it is able to alleviate all visual concerns. Wind farm developers have computer-modeling tools that create simulations of views from given spots in the surrounding area.
Decreasing property value
Those who dread systematic property value decreasing are probably the ones who haven't lived close to any wind farm. Those who live in the wind plants neighbourhood - do not complain. MORI Scotland ws committed to undertake a study examining the attitudes of people living close to wind farms in Scotland. It was decided that the research should focus on the larger sites (farms with nine or more turbines - there were ten of them at the end of 2002). The survey shows that local wind farms had a broadly positive impact on the area according to 20% of residents). Only 7% say that it had a negative impact, and majority (73%) feel that it had neither a positive nor negative impact, or expressed no opinion. Surprisingly, people living closest to the farms tend to be the most positive about them (44% of those living within 5km say it had a positive impact, compared with 16% of those living from 10 to 20km away).
Source: scotland.gov.uk
The survey mentioned above, together with many reports from real estate studies in various locations all across the world, constitute strong arguments against the myth of land and property prices being decreased by having wind farms nearby. One of such study was performed by Poletti and Associates for Invenergy Wind - USA, Illinois, in the White Oak Wind Energy Center. The study compared sales of homes and farmland properties within an area close to the wind farm, to those in an area with similar characteristics but without any neighbouring wind farms. You can read more on reamp.org.
Wind turbines are not safe
'The blades can cause dangerous ice throws' - sounds as unbelievable and unwise as it is in fact. And the fact is that ice throw, while it can occur under certain conditions, is of a very little danger. Setbacks that are normally used to minimize noise, also successfully protect against such danger. Moreover, the ice buildup process slows down a turbine's rotation which is sensed by a turbine's control system, finally leading to the turbine shut down before anything bad can happen.
You have probably heard of some accidents with the blades flying off or the turbine collapse. Blade throws were common in the industry's early years, but do not occur nowadays because of better turbine design and engineering. In addition, utility-scale wind turbines are certified to international engineering standards (e.g. those developed by Germanischer Lloyd or Det Norske Veritas). These standards include ratings for withstanding different levels of hurricane-strength winds, therefore ensure a high level of reliability and safety worldwide.