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Solar heating causes uneven heating of the earth's terrain due to the varying Specific Heat Capacity of the exposed surfaces. This in turn causes convection currents in the atmosphere (ie. wind).

Wind farms harness the kinetic energy of the wind using turbine blades which convert the linear motion of the wind into rotary motion which runs a generator, and outputs electricity.

akf2000 mentions the infeasibility of widespread implementation of wind farms due to their obtrusive nature. Although the energy supplied is from a completely renewable source, the efficiency of these turbines is such that any appreciable power output takes up vast amounts of land area. Land area which becomes rather unattractive.

Thanks to my incredibly slow reading of New Scientist (UK Edition -- are there any others?) I only very recently read the 23 September 2000 issue (No.2257). In it there was an intriguing article titled "Reach for the Sky" (p.36), talking about Bryan Roberts' experimentation with alternatives.

A "gyromill" is "a cross between a helicopter and a kite" which flies at an altitude of 4km, and is tethered to the ground with steel cables (which double as means to transfer the generated electricity down to the ground).

The idea behind the gyromills is that they catch the jet streams in the atmosphere and use the energy from them to firstly stay afloat, and secondly generate electricity. Energy available in the jet streams is up to 17 kilowatts per square meter -- compared to an average of 0.4 at ground level!

Additionally the "wind farms" consisting of these gyromills will be very unobtrusive, if at all noticable!

Unfortunately I was not able to track down this article on newscientist.com as full contents are only available to subscribers! If anyone manages to find the original story somewhere please /msg me!

Despite the sheer terror they induce in the populace, we have wind farms here in New Zealand. There are a couple dotted around the place, but new ones are difficult to build. The reason for this is that we have a lovely little thing called the Resource Management Act, which essentially requires an expensive application to local councils for the right to build things. Anyone can raise objections to proposed construction projects; including corporations, which was probably a stupid idea.

While it's a good idea to let people raise sensible objections to a new sewage processing plant, a tannery, or a stadium, it's slightly more problematic when it comes to modern infrastructure that people fear for no good reason whatsoever. For example, thanks to the resource consent process, one of the proposed wind farms in the Wellington region was allowed sixty-six turbines, less than originally intended. Another facet of the resource consent process for the Makara wind farm (officially it's just part of something called Project West Wind) was that the noise of the turbines must be kept below a maximum of 40 decibels.

I found this out thanks to a wonderful letter printed in the local newspaper. The writer went on to claim that in spite of this extremely quiet threshold: "...the low-frequency, persistent droning of turbines penetrates to the core of brain and marrow, making the residents' situation there utterly intolerable". I suppose that's why there have been so many news stories about Makara Village becoming a ghost town, with its misty lanes haunted by the restless spectres of people who died from Turbine Induced Brain Vibration before the remaining population fled in terror into the night, leaving their half-eaten meals cooling on the kitchen tables.

If you go and look up decibel scales online, you'll find various charts, tables and general guidelines that say 40 decibels is slightly less than a normal conversation. In the case of the Makara wind farm, this 40-decibel limit is the level of sound found at a fixed monitoring point no more than 200 metres from individual dwellings nearby - Nearby being over three kilometres away from the wind farm. It's relatively easy to find this out thanks to the internet.

People have their television louder than 40 decibels. The traffic passing by every single house I have lived in was no doubt louder than 40 decibels, given that it always drowned out conversation. In fact, I once lived on a busy main road, and my brain did not turn to slush from the constant noise of vehicles speeding past. Irritating? Yes. Loud enough to directly affect my brain? No.

Based on living in the hills around Wellington, I would hazard a guess that the noise of the wind at Makara Village is frequently over 40 decibels.

The concerned citizen who wrote the letter detailing the insidious effects of vibrating air on the human brain happens to live in a place called Ohariu - about three or four kilometres from the site of Project Mill Creek - the second of the Project West Wind installations. This not-in-my-back-yard scaremongering looks completely stupid after reading all the Environment Court conditions of consent: There is to be a visitor area installed at the site of the Makara wind farm, doubtless because people might want to see first-hand the marvellous sight of all those blades spinning together to the choreography of the wind. On top of visitor centres, it turns out that both the Project West Wind facilities are built on existing farms, because the land owners see energy production as a viable modern farming practice... and they still live there.

So contrary to the laws of physics and some basic observations about reality, the implication drawn by comparing that crackpot letter and the fact there are people living near wind farms is that these brain-churning, bone-pulverizing vibrations are only felt at great distance from the turbines.

I do not think a modern-day Don Quixote knows more about science than the engineers who build wind farms. That's fine. But I do expect a newspaper editor to actually do some research before publishing letters containing extraordinary claims (which is my subtle way of saying "blatant lies"). While I can - and did - have a good laugh about the idea of a 40 decibel noise pulping people's brains, I realised shortly afterwards the problem is that a large number of people are silly enough to simply accept this and join in tilting at windmills.

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