Brian Sharrock wrote:

however, if I recall correctly he pointed at a URL
http://www.bwea.com/ref/faq.html#payback (?) which seem to claim ...

'The average wind farm in the UK will pay back the energy used in its
manufacture within six to eight months, this compares favourably with coal
or nuclear power stations, which take about six months'

Hmm; talk about 'hand-waving'; Where's the _numbers_?
Fr'instance; a typical wind turbine installation contains n tonne of steel,
n tonne of aluminium, produced from n tonne of ore, x miles of copper .... y
tonnes of concrete ... requiring XXX MegaJoules of input, the power
generated (output) _averages_ at YYY MegaJoules. YYY = XXX at n months.

Ding, bloody Dong! Even the _claim_ from the British Wind Energy
Association - no hint of bias there! - has a variance of thirty-odd percent
! Six months - eight months!
Which is it?

I expect next that David will croon 'Things can only get better!'

There's lies, damm lies and very dodgy statistics ....
six months ... eight months ... ! Imagine an _Engineer_ saying; - "the
bridge will span the gap ... or stop three quarter of the way across" ....
"this aircraft will rotate at 120 Kts ... or it might need 180 Kts' ... !
Yet because it's 'green'; we're expected to gloss over these 'facts', with a
sigh of 'they mean well, Bless them' ?


Wind gens have different sizes and ratings, use different technologies,
go up in different areas with different wind profiles, so its no
surprise they dont all have identical energy payback periods.


NT