"Martin Brown" wrote in message
...
On 02/11/2011 11:23, dennis@home wrote:


"harry" wrote in message
...


The PV panel could be fitted to at least 50% of all houses, there are
few sites for windmills and micro-hydro power. There are FIT payment
for these too but few sites.

These schemes use zero fossil fuel and will be market viable to in the
near future.

that is rubbish.

they use lots of fossil fuel in the manufacture of the panels, and
associated fittings.
they use fossil fuel in their shipping.
they use fossil fuel in their fitting and maintenance.

There is little chance that they will actually return more energy than
was used over their life time.

Wrong - even at our unfavourable latitude the lifetime energy return on a
PV array should be something like 4x that used in its manufacture. It
would be nearer 7x if installed at a more sensible latitude. See:

http://www.inference.phy.cam.ac.uk/w.../page_41.shtml

This is especially true of windmills.

Even more untrue. Any decent large scale windfarm will reach energy
payback inside the first year of operation and with a trailing wind inside
the first six months.


Anyone that thinks they don't use fossil fuels is living in a different
world to the rest of us.

They use fossil fuels to make them but they deliver a leverage of 4-7x for
solar PV depending where they are installed and 20-50x for large scale
wind turbines. The latter is a respectable figure of merit.

I don't believe that and there are no definitive explanations of what energy
is used in order to make that comparison.
I especially don't believe a paper that claims "Wind turbines with a
lifetime of 20 years have an energy yield ratio of 80".