Rosher.Net

So the seed has grown and the harvest comes… a bit.

I’ve just received the first cheque from SSE for the electricity generated by the solar roof. Back in Note to Self  I mentioned I had sent off the meter reading, and now the first payment has been received. And it’s nearly what I estimated. Yes, a few quid down, and I asked them why.

The FIT and Export Payment rates went up on 1st April, and they estimated what my meter reading might have been then. If they’d asked, I could have told them it was 577 but they guessed at 805. So I missed the munificence of the difference of half a penny per kWh on a few over 200 kWh… meh.

So, in simple payment terms my first Megawatt-hour, generated over four months, earned me £188.66

If you work that out without any consideration of other factors it would take about eleven years to pay back the cost of the roof…

188.66 / 4 months = £47 per month
£6250 / 47 = 133 months = 11 years

Which is good enough since the FIT is fixed and index linked for twenty years. It’s profitable, no doubt. However, we’ve already done the second Megawatt-hour in only two months, so (obviously) you can’t work it out on the winter-spring generation. Plus (obviously) we’ve been saving on electricity not imported, and you’ve read about how little gas we’re now using to heat our water. Any thought that solar, even on a west facing roof like ours, is not viable… well, think again.

It will be interesting to see how solar changes the game as it spreads across the country. It’s good to see my employer (for the next eight months anyway) is considering the issues of balancing the National Grid. One of the things the green folk often forget when they enthuse about wind turbines is how we’ve often got a coal or gas power station running in the background to pick up the load if and usually when the wind drops, so even when the turbines are turning we’re still burning fossil fuel. And then when the wind picks up again, paying for the fossil station to idle again. We need to stop that, perhaps by selective constraining off of non-essential loads like refrigeration and air conditioning to “peak lop” short duration high demands. Would you allow your own fridge to be turned off remotely (probably using the cellular network) for perhaps half an hour? Wouldn’t harm your fridge or the contents… might allow the Grid to hold off running up a gas station. That’s the future, if we’re serious about carbon influenced climate chaos. Or of course we can just let the lights go out.

I would by far prefer to see fields of solar to hilltops of wind turbines. Germany recently managed to cover half it’s national demand with solar and it’s about on a latitude with England. Ok, on a midsummer day… we’re none of us going to do much in the winter. And it’s windier in the winter… meh, perhaps we do need both. How are we doing today? Half a gigawatt of wind, 37GW of demand.

Miss gives up teaching at the end of this school year. I give up work next spring. I wonder if we’ll use more or less electricity and if the roof will keep our own lights on? Or if we’ll be home enough to notice? 🙂