If you go to WindSave’s website, you’ll note that their performance claims have gone.
Update, 5 April 2004: I am no longer supplying their PDF brochure. WindSave does not seem keen to back up their product with reliable technical information. If their original dimensions were accurate, here is all you need to know about WindSave’s designs (and why they won’t work) .
Update, May 2005: While it’s true that WindSave appear to have made their device obey the laws of physics (at least according to their published spec), I’m keeping this posting intact.
If the data on their website are to be believed, WindSave cannot generate the figures they claim. There’s much geeky theory involved, but basically, they’re claiming efficiencies that cannot be attained.
In short, they are claiming coefficients of performance of 0.724 and 0.887 for their turbines. Unfortunately, the theoretical maximum efficiency for a wind turbine — the Betz limit — is 0.593. So something, somewhere, is screwy. I’m pretty sure it’s not my sums, as they’ve been verified by an external source.
I worry that the UK energy minister, Brian Wilson, has been taken in by this. Five minutes with a calculator and a wind energy primer shows that these things are too good to be true.
(more…)Leo Marx’s book tells us that, even from Virgil’s time, the rural idyll was far from the reality.
(book details: The Machine in the Garden: Technology and the Pastoral Ideal in America, by Leo Marx. Oxford University Press; ISBN: 019513351X)
On Nov 11, I gave a talk on wind energy and WindShare to the University of Toronto Natural Philosophers’ Club. As there was so much interest, I’ve decided to put up some useful links. Please feel free to comment/add more, and I’ll incorporate them into the body of the entry.
Paul Gipe has written some of the best books on the subject. My favourite book of his is Wind Energy Comes Of Age (John Wiley & Sons, Inc, New York, 1995. ISBN: 0-471-10924-X). It gives a good overview of the technology, and a rare look into the impact on society of wind energy.
If you just want the heavy theory, the Wind Energy Handbook (Burton, Sharpe, Jenkins & Bossanyi. pub John Wiley & Sons, 2001. ISBN: 0-471-48997-2) has everything you need. Based on the famous Loughborough Wind Energy Course (formerly at Imperial College, London, where I took it), it’s absurdly complete.
I find it amusing that, after co-chairing several acrimonious public meetings supporting the development of Dun Law Wind Farm against accusations of it being a potential eyesore, it’s now a tourist attraction — <http://www.discovertheborders.co.uk/places/33.html>