Stephen Coyle

Exactly one year ago, I got solar panels installed on my house. I live at a fairly high latitude (55ºN), in a place that isn’t exactly famous for its sunny weather, so naturally I was pretty curious to see if they’d generate enough to be worthwhile. This seems like a good point to check in on that.

The short answer is: yes, they do!

The long answer is yes, but with more numbers. Some stats:

• I have ten panels, with a total nominal rating of 4.25kW, but I’ve seen peak generation of around 4.7kW.
• total generation was 3,054kWh for the year (14/09/23 - 14/09/24).
• lowest daily generation was 0.7kWh on 17 December.
• highest daily generation was 22.9kWh on 1 June.
• I don’t have a battery, so any excess energy is exported back to the grid.

The header image is generated from my actual solar data over the last year. Each circle represents one day, with a blue—yellow gradient corresponding with the lowest—highest values. Unsurprisingly, there’s massive seasonal variation; it’s not hard to spot winter in the image above. Also apparent is that there’s quite a bit of variation throughout the summer. It was (or at least felt like) an exceptionally cloudy summer, and daily breakdowns show that there were no completely cloudless days in May, June, July or August. I’m not going to say it was a worst-case-scenario year, but it probably wasn’t far off it.

Delightfully, though, even in those suboptimal conditions, solar is absolutely worth it. It’s hard to put a precise number on the savings for a number of reasons. First, we only moved into this house six months before the solar installation, so I don’t have a full year of electricity usage to compare against. Second, I got an EV a month before the install, which itself uses almost as much electricity as the rest of the house. Finally, since most of our major electricity uses (car charging, clothes drying, etc) can be done overnight at a cheaper rate, we’ve also pretty drastically altered our electricity consumption habits outside of the contributions from the solar.

Some very rough calculations, though, suggest that our electricity bill for the year is somewhere between one third and half of what it would be without the panels. Multiplying that out, the panels should pay for themselves in 5-7 years. If you're in a position to do so, I'd strongly recommend making use of any available government subsidies, and getting some solar panels of your own.

I'm well aware they aren't a panacea, and that there are plenty of hurdles ahead in making an electric grid that can effectively handle widespread micro-generation, but that's a topic for another time.