Eight MegaWatt Hours, baby!
We've had solar panels on the roof of our London home for exactly two years. They've just tipped over the 8,000kWh mark. The first question people tend to ask is "how much do they cost?" And the answer is… "It depends." The costs we paid two years ago aren't going to be particularly relevant to you. We have a 3 storey house, so paid a bit more for scaffolding. Our electrics were in a decent state, so we didn't pay for a new consumer unit. I wanted Ethernet on the inverter so paid a bit more for that. We sold the roofing tiles which were removed for a few hundred quid. We paid for a solar battery, but it was at a discount.
What I'm saying is - get a couple of local installers to give you quotes. The technology is improving all the time - but the cost of labour is variable. Expect to pay somewhere between £2,000 and £12,000 depending on how many panels you need and the cost of all the associated extras.
The next question people ask is "how much do you save?" The answer to that is slightly easier to calculate - but highly variable!
On a typical Spring week, the panels generate about 66kWh - with some days generating nearly 18kWh!
We used about 31kWh of electricity directly from the panels that week. At our electricity prices, that's a saving of £6.37.
We also sold the excess 35kWh for £6.23. So that's about £12.60 in total for a bright and clear Spring week.
Across the entire year… Well, it's complicated. Some days are sunny, some aren't. Sometimes we're working from home and consuming electricity in the daytime, sometimes we aren't. The price at which we sell electricity back to the grid is highly variable. Electricity costs have been rising, but maybe they'll go back down again.
Very roughly - and this is going to depend a lot on your local costs and local usage: our 5kW array of solar panels will save us about £800 per year!
That's a saving of £300 from using electricity straight from the panels, and revenue of £500 selling electricity back to the grid.
If electricity prices keep rising, the amount of money we save will also rise.
We're with Octopus Energy - join and we both get £50. They do a specific export tariff which pays a variable price depending on the time of day you sell your electricity. They also have tariffs if you're planning on charging an electric car overnight.
What I'm trying to say is this. Solar isn't the future. It is now!
Richard says:
Can't get my head round why the left arrow on the display points to imp rather than exp. Do they not stand for import and export? Or is it one of those things that requires reverse thinking?
PJ Evans said on twitter.com:
After 8 years we're on the cusp of 30MWh. According to my very dubious maths the panels have now paid for themselves and as I type the house is running 100% on truly free electricity.
Roger Light said on twitter.com:
I was pleasantly surprised how much more affordable they were than I'd expected. Even more so when you can get three years interest free credit. After two months of delays, ours are going up in about two weeks.
Bennycrime said on twitter.com:
Nice. Looking at this at the moment , last blog of yours I read, I got the whole house cabled with Ethernet so I’m probably going to do this as well now arnt I 🤣
Mike Carter said on twitter.com:
They've just announced 0% VAT on solar panels for the next 5 years. That, combined with today's energy prices, makes this a very tempting move.
Martin Pilkington said on twitter.com:
If energy prices stay high over the coming years and the cost of solar, storage, heat pumps, electric cars, etc keep dropping it will be interesting to see how the next decade plays out