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Wind power - or the lack of it...

Enlightenment from Tim Hunkin.... the key fact is that power is proportional to the cube of the wind speed. So when it’s blowing a gale, wind power is good source of energy. But whenever the wind drops a bit, even if its still a fresh breeze, wind power becomes pathetic. David Cameron (the leader of the UK conservative party) got a lot of publicity for fitting a ‘Windsave’ windmill to his chimney (www.windsave.com). Windsave’s website proudly claims their 2m diameter blades will generate 1Kw of electricity at a wind speed of only 12 meters per second. 12 meters per second is force 6 or almost a gale. By the cube law, a moderate breeze of 6 meters a second would only generate 120 watts, certainly not enough for a freezer let alone anything else that might be switched on, and a light breeze of 3 meters a second would only generate 15 watts, enough for one energy saving light bulb. And David Cameron’s windmill certainly isn’t on a high pole with completely unobstructed windflow so it could only produce much less than Windsave’s quoted figures. I can’t imagine how they claim it can save you 33% of your entire electricity bill. ...

So I now think wind turbines are principally green icons. Until I started playing with wind power I was completely in favour of them. Wind turbines are elegant structures, and its very clever how recent development has converted the relatively slow speed of their blades into significant amounts of power. But if I, who pride myself in having an intuitive sense of what works, can be so mislead by the power of the wind, there’s little hope that most other people are more clued up.

(lots of other good stuff on his web site)


Well done, the first step is always the hardest. You have admitted your problem and it will get better. Now repeat after me:

Organic food does not taste better.
Fair Trade keeps people poor.
Recycling is worst for the environment than landfill.

Wind-power also raises the temperature of the ground beneath, contributing to global-warming and it kills a lot of birds, contributing to species-extinction. At best it might be good for trickle-charging a bank of batteries...

If an intelligent blogger can be so deceived, what hope is there for a dumb polititian?

Welcome to the engineering reality club.

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