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Solar PV anyone?
coozer - 28/5/11 at 02:47 PM

Anyone got solar PV?

The figures look very impressive indeed and I'm just wondering if the amount quoted over the 25 years is realistic.

Any experience??


MikeR - 28/5/11 at 02:56 PM

check your mortgage - you sub lease the roof to the solar company. Also check how many mortgages will loan on a roof with panels attached, when they first came out heard on radio4 this could be a big issue with people being stuck unable to sell.


cliftyhanger - 28/5/11 at 03:30 PM

skool has one, I can get the figures from that if you wish.
Hang on, I have some from a few days ago....

startup 10 april 2009, so that is about 745 days.
Total power generation=8191kwh

Panel size 3.74kwh.

Location BN6 8LP

that help?


big-vee-twin - 28/5/11 at 03:31 PM

I design and specify these all the time and the figures do stack up, however sales people do tend to sugar the pill

so,

You will see a PV module rated at 1kWp this means 1 kilowatt in perfect conditions (i.e. peak) or what we call 'in a laboratory'.

In the UK the average KW per meter received from the sun on a cloudless day is around 700 -750Watts/meter/annum so you will never achieve 1kW output

The PV modules themselves are about 12% efficient so you get 12% of 700w or 84watts, you then have an efficiency of the inverter to take account of at 91% so, 76 watts from a 1kWp panel.

This means that you have to put up on the roof 13 panels to get 1kW output which occupies about 7-8 square meters.

You do however get clean energy cash back which is approximately 41 pence per kilo Watt hour generated for a retrofit installation below 4kW in total.

This tariff is paid for 25 years and increases each year with the RPI but the starting point (41 pence reduces every year over 5 years and we are in year 2).

If you export to the grid you get a further 3 pence per kilowatt.

A 1 kWp installation costs around £4-4.5k.

You only lease your roof out to a solar company if you take them on a free installation, for that they keep the tariff and you sign over all your rights to receive the tariff, you still receive the energy though

[Edited on 28/5/11 by big-vee-twin]


jonrotheray - 28/5/11 at 05:01 PM

We've just got solar.
The 3.8kw array has produced 20kwh+ per day on recent sunny days.
We can run the washing machine free on a good afternoon, and get paid 43p -ish per unit generated, whether we use it or not.

The outlay was around 15k, and the payback about 10 years (and I think the government calculation is cautious).

I'm quite impressed so far....


JonnyS - 28/5/11 at 06:21 PM

These guys are not too far from you if you want to take it further:

http://www.thephoenixworks.com/


matt_gsxr - 28/5/11 at 09:11 PM

Be careful when you do the calculations.
Some financial models assume you will get the 43p/kwh for ever.
It is more than likely that this subsidy will disappear long before you have paid off the device.



Schools can get interest free loans for this kind of stuff, and when we ran the calculations the payback would take 13.7years (assuming they don't deteriorate within this period).


Matt


steve m - 28/5/11 at 09:26 PM

My father and I have done some homework, on these panels, and the 10 years it takes to pay off the cost is based on the leccy board paying you 43p ish for all your unused power,

with the current model of 7-9 years time only paying 15p, it really is a con,
also my personol view is the panels look f ing ugly as well, and if i had to look at them all day from my house i would be well pissed off

And as for the mortgage problems, Halifax and Nationwide will not touch a house with panels fitted, (i asked)

steve


MikeRJ - 28/5/11 at 09:26 PM

Also bear in mind the limited life of the panels...


paulf - 29/5/11 at 09:15 PM

What would happen if you had the smallest possible installation and then used the installed meter to feed in power generated by other means such as a combined heat and power generator or maybe battery's charged from mains ?.
Its something I have often wondered and would be a way to get one over the people profiting from this government sponsored money making venture, those of us with out PV will be effectively subsidizing those with as the electricity company's are not going to give it away on the cheap without recovering it from else where.
Paul