It has been just over a year since the solar panels were installed (19th June 2014, and only connected up in the afternoon). Since installation I have:

• generated 2,273.5 kWh of electricity, of which I have
• exported 1,444.0 kWh back to the grid.

This has earned me (up to 31st May) £287.83 from generation and £47.73 from exporting. My panels cost me £6,822, so that is a 4.92% rate of return for the year.

I haven’t been taking regular meter readings for my mains electricity, but looking back at bills for the last couple of years (and using estimates for April and May of this year) in the year before I had the panels installed I bought 2,052 kWh of electricity at a cost of £355.95. This compares to 1,268 kWh bought in the year since installing the panels at a cost of £239.30, so a £116.65 saving on top of the feed-in payments. Adding this to the feed-in payments gives me £452.21 in payments and savings for the year, a rate of return of 6.63%. The current Bank of England base rate is 0.5%.