Andy Champ wrote:
On 09/09/2010 06:56, David Hansen wrote:

Beauty is in the eye of the beholder.

Having been to some of the largest wind farms in the UK I have a
little idea about noise. There is certainly some machinery noise if
one stands directly under the nacelle. By about 10 metres from the
base of the tower it is inaudible. Noise from the blades can be
heard further away, but by the time one is the height of the top of
the blade away one cannot hear it. With a large wind farm, if close
enough one can typically hear noise from the nearest turbine or two
but no others. From outside a wind farm the sound of tractors is the
loudest sound, then other motor vehicles, then humans speaking, then
sheep and then birds. The noise of the wind in the trees is louder
than the noise of the wind farm

Many things could "distract" drivers, including all sorts of things
in the countryside like fields, animals and buildings. The road
"safety" lobby used to remove "dangerous" trees, but campaigning has
reduced this. I did once go to the trouble of debunking one of the
well known anti-wind lists of deaths they claimed were caused by
wind generation. A handful of "distraction" deaths, half of which
were people crashing into lorries carrying parts of wind turbines.
If they had instead crashed into lorries carrying coal or parts of a
steam turbine would the same people have made a fuss about all those
people killed by coal generation? I very much doubt it.


Personally I don't find the odd turbine or two unnattractive. I have
doubts over the numbers required through - the UK peak consumption is
something over 60GW, which means (surely I've got this wrong?) 30,000 of
those 2MW units, each of which is as tall as St Paul's Cathedral.

Hang on, 25% load factor. Make that 120,000, and hope we don't have a
day with less wind than average, or a nationwide gale. That's something
like one every mile over the whole country.

We've got a fair spread of turbines around the country; do you know
what's the lowest load factor they've produced country wide? Because
that's an input into the calculation of how many we'd need.


0.3% Calculations on over all windspeed in the whole county show there
are days when all windmills are essentially becalmed, with just a few at
one end or the other idly turning. Turbine output below the design
plateau speedspeed is proportional to windspeed cubed.


The Dames, who have more peak windpower capacity than their actual grid
total load, see at best about 6% average contribution of windpower. Some
years 8%, some years 4%.

Half the time they are switched off, because no one wanst the power.

The other half they aren't producing near enough.

Its a complete farce.

have, I believe, been the subject of
studies which show that at best, each one will only just about pay the
energy costs used to build it and maintain it over its lifetime.

Instead of believing in "studies" why not take a look at the reports
Vestas commissioned. They are at the bottom of
http://www.vestas.com/en/about-vestas/sustainability/wind-turbines-and-the-environment/life-cycle-assessment-%28lca%29.aspx


I imagine they will be dismissed in a sentence, but a few other
people who I have pointed to the reports have been open enough to
tell me that they covered everything they could think of and seemed
accurate.


"It will generate approximately 113,000 MWh during a 20 year period,
which is 20 years."

I read it, even if their editor's didn't. That's a rather more generous
load factor than experience would suggest. (though it doesn't
invalidate their arguments; but see above)

Nuclear power is by far and away the most sustainable form of
electricity production,

Ignoring all the other problems it can only be sustained until the
uranium runs out. The idea of extracting it from the sea is a
variant of perpetual motion machines.


There's plenty of uranium to last us until we have fusion. Depending on
the numbers you believe we might need to do a bit of breeding and
reprocessing though, which is a rather messy business. We've got so
much U238 that the Yanks are sticking it in bullets to fire at the
Iraqis - it's only U235 that's scarce.

There's more uranium in coal station smoke than seawater.


Plenty of it around for current needs anyway.


Andy