Well actually it’s nearer 7 months as I wanted to announce that we’ve actually had a cheque from SSE Microgen but now I read the small print it seems they allow themselves up to 65 days between receiving our meter reading and paying out the money so I’ll stop holding my breath. Funny how when we pay them for electricity they expect to get their money in advance by direct debit from our bank account or we have to pay an extra 6%!

Anyway I really shouldn’t complain because we are still pretty pleased with our PV installation. Following an exceptionally sunny spring we had a few gloomy weeks, though nowhere near enough rain for the vegetables, and now seem to be having lots of sunshine again as is proper for August. I tweaked my graph a little so the estimated figures better reflect those given by the installers and it seems our total wattage generated to date is a fair bit more than was predicted.

Maybe this surplus is to be expected at first as I suspect the annual estimate is averaged over the lifetime of the installation and the panel output is predicted to slowly decrease by an estimated 0.8% per year. All the same, in a society where commercial interests regularly inflate expectations to get a sale it’s sometimes very pleasing just to know you are getting what you were told to expect instead of the usual disappointment.

Early in July the electricity supplier eventually replaced our old type consumer meter* with one that doesn’t go backwards when the sun shines, over 3 months after we made them aware of the problem. To be fair they didn’t attempt to claw back the money they lost through their tardiness and promptly send us a rebate cheque for the £220 they had taken in debits for power they expected us to use over the first 6 months of the year that failed to register on their meter. The old meter ended up recording us as using only about 25 kWh between January and the start of July.

So how big is this Feed-in Tariff cheque we are waiting for? Well the generation meter* reading I submitted for period to end June was 1194.5 and the reading when installed in January was 1.7 so I think that is about 1193 kWh x 43.3p = £516.57 plus about £17.90 for the estimated power exported to the grid (half the power generated at 3p per kWh unit). £534 – a good start in paying back the £11,000 the system cost us but a long way to go yet.

* Having PV solar installed means you end up with at least 2 electric meters. The consumer meter, which we all have, provides the reading for power used which you get billed for. The generation meter records the power your solar panels generate which you hopefully get your Feed-in Tariff for. In some cases, usually by request, you also have an export meter which records the surplus power your solar panels generate which is sold on via the grid. So you export power generated minus power used at the actual time of generation (ie. you have to boil the kettle when the sun is actually out, not a moment later when it clouds over, as unused power is not stored but immediately sent to the grid for someone else to use). If you don’t have an export meter you are deemed to supply half the power you generate to the grid which is not unreasonable.