There is heaps of useful info in this very long thread on MoneySavingExpert.com: My solar PV first year payback calculation.
Note this post (inconsistent with wth lowcarbonbuildings website):
I have telephoned the Low Carbon Buildings Programme (0800 915 0990) this morning and they confirmed that the grants (Max £2,500) will continue until April 2011 at least. This applies to all the UK.From other things I've read, The Tories are even more commited to FITs in principle than Labour, and the suggested rates (39-44p) are inline with most of Europe (so unlikely to plummet).
Posts 1, 39, 104 and & are all real life examples.
Trying to understand this analogy:
To benefit from selling to the grid (at 9-15p/unit), we would need an export/import meter, too.
A case ctudy from JHS Power Solutions case study is a 2.1kW installation, which they say should produce 1800 units of leccy per year. That equates to around £730/year earnings for the FiT (feed-in-tariff). Full cost to install was £13750 (no grants are available any more)
We might be able to save a fair bit on our leccy bill, especially if we use the immersion heater - might be as high as £150 but that's speculation.
There's also an export rate (ie, stuff we sell to grid) of £0.09p/unit, which would be £100/year assuming we export 60% of the capacity.
Total yearly savings of £980 puts break-even at 14yrs, quite a long payback time. Especially when we don't have much confidence in these FiTs being around in the far future.
Here is what I am asking installers:
We are looking at installing a solar PV array, of the scale given in your case study. We have a 'perfect' roof - modern construction, no dormer windows, south-facing - and with a windsave 1kW wind turbine on one end. There is a clear run down the side of the house to the meter and a location inside for any hardware.
We would obviously need an installation that is eligible for the Feed-in-Tarrif, and also suitable for export (we are already customers of Good Energy, who support this).
We have an invertor unit for the wind turbine, but I assume that you would be unable to re-use that for a solar installation. We have other space for another invertor, if required.
We would expect a 20+ year guarantee on the panels, and would like to know what degradation metrics you have.
Would you be able to quote for this, or is more information (and a survey) required?