What I learned from putting solar panels on my roof

I’ll be upfront: this one is personal. I’m not writing about a client’s experience or something I read in an economist’s report. I’m writing about my own house, my own power bill, and what I’ve learned over the past six months since we installed solar panels. I’m sharing it because I think there’s useful stuff here — and because the advice I’d give someone thinking about solar is pretty much identical to the advice I’d give someone thinking about a mortgage. But I’ll get to that…

Why we did it — and it wasn’t about the payback period

When Kirsty and I were deciding whether to install solar, I wasn’t particularly interested in the question most people lead with: how long until it pays for itself? Seven years? Fifteen years? I didn’t really care. What I cared about was self-reliance, and a longer-term calculation. Retirement for me is roughly fifteen years away. By the time I get there, this solar system will be paid off — and from that point, the power is effectively free. When your income drops in retirement, you want your costs to drop too. Installing solar now and paying it off over the next decade and a half felt like a very straightforward decision once I framed it that way. I just needed to know it would work and go the distance.

The numbers, since you’re wondering

We started with ten panels and two batteries, totalling 10 kilowatts of storage — enough to run overnight including the air conditioning and the fridges, with the batteries typically topped back up by midday the following day. After a rainy February showed us that the batteries weren’t filling adequately on overcast days, we added four more panels. Fourteen on the roof now. Our power retailer is Ecotricity. They supply us from the grid when we need it and buy back whatever surplus we generate — at one cent per kilowatt-hour, versus the twenty cents per kilowatt-hour they charge us. I’m exaggerating because I can’t remember what the actual buyback rate is,but the practical upshot is that our February power bill was $24. January $32. And March was…wait for it…$2.25 in credit. Yep, credit. Before solar, we were paying around $180 a month —we’re only a two-person household in a well-insulated, double-glazed home. Not a particularly heavy power user by any measure. From $180 to banking $2. I’ll take that.

It’s not just about the gear

Something I didn’t fully appreciate until we were living it: the equipment is only half the story. The other half is behaviour. We now run the dishwasher and washing machine on a delayed start — set them going when we leave the house in the morning, timed to kick in a few hours later when the panels are generating at full capacity. Using those appliances at ten in the morning costs you nothing. Using them at eight in the evening still costs you something, even if the machines are efficient. It sounds like a small thing. It isn’t. Your behaviour has as much influence on your power bill as the panels themselves.

The technical decision worth knowing about

When you look at solar systems, most have a single central inverter that connects all the panels together. We went a different route — a micro-inverter on every individual panel. The reason is simple. With a single inverter, if one panel fails, the whole system goes down. It’s like a string of Christmas lights — pull one bulb and they all go out. With an inverter on each panel, the one that fails drops out and the rest keep producing. Given we’re talking about equipment on my roof for the next twenty-plus years, that resilience matters.

Take advice. Ignore the sales pitch.

This is where the mortgage parallel comes in. For anyone thinking about getting solar, the process should look a lot like getting a mortgage: take proper advice, and be very wary of anyone who leads with a sales pitch rather than questions. We went with Vital Solar, specifically because their adviser Maryann did neither of those things. The first thing she asked us to do was request twelve months of granular power consumption data from our existing retailer — available as a detailed spreadsheet, right down to thirty-second intervals. From that data, she designed a system matched to our actual usage. No guesswork. No upselling. That’s how we ended up with exactly the right number of panels and the right amount of storage — rather than whatever a salesperson reckoned looked good on a quote sheet.

One last thing

Friends who already had solar warned me I’d become obsessed with the monitoring app — checking generation figures, watching the battery fill up, seeing how much we’d exported to the grid. I dismissed this entirely. I am not, I told myself, going to geek out over a power meter. Reader, I check it every day. If you’re thinking about solar and want to talk through the financing side of things, get in touch — green loans are available, and it’s worth understanding your options before you commit.