"pete" wrote in message
...
On Thu, 1 Jul 2010 21:23:55 +0100, tim.... wrote:
I guess that this is off topic but I suspect that I will find some
experts
here.

My sister has had a man around to quote for this and I've been tasked
with
checking out if what she was told makes sense.

She has a bungalow with a shallow sloped roof and the quote was to
install
14 panels on an Easterly facing roof because the Southerly facing one is
shaded by a tree. So the figures a

Expected output 2928 kWh per year.

Returning 41.3 feed in tariff plus a saving on her electric bill of 50%
of
the output at say 12p and the other 50% output gains 3p from the electric
company.

The prices a

a) A "leasing" scheme whereby the householder pays an "installation" fee
of
2610.00 and receives the "free electricity plus the "3p" but the company
receive all of the 41.3 feed in tariff.

b) Outright purchase costing 18237.00 whereby the householder keeps all
of
the returns.

I calculate that (a) returns around 220 pounds (8.4%) and (b) returns
1430
pounds (7.8%).

So the question is, are these figures actually achievable and is the cost
price competitive?

Does anybody know?

tim

How much extra would be gained by chopping the tree down?
i.e. how much is that tree worth.

It's not her tree!

So far as calculating the returns, did you take into account
the "lost" income from having the difference - £15,600 in the
bank earning interest?
Even at 3%, that's nearly another £500 / year.

Obviously one looks at this in totally. That's 6-7% instead of 2-3 %

My inclination would be to let the supplier take the risk
of not meeting the expected output, or of a future govt.
reducing / removing the subsidy (as happened in Spain
recently).