How do solar panels actually work on British houses like yours?
Solar panels turn daylight into electricity even when it’s cloudy – I’ve seen them generate power on the greyest Yorkshire mornings. The electricity goes straight into your house wiring to run your kettle, telly, whatever’s switched on. Any leftover power flows back through your meter and the electric company pays you for it.
Been fitting these things for nine years now, mostly around Leeds and Manchester. Every single customer asks me the same thing: “But will they work in this weather?” Course they will – I wouldn’t be in business otherwise.
What actually happens when light hits your panels?
Right, so each panel’s got about 60 little squares in it – that’s the silicon bits. Light hits them, knocks some electrons about, and bosh – you’ve got electricity. Doesn’t need blazing sunshine either. I’ve got panels making power right now and it’s proper overcast.
The panels make what we call DC power – like a car battery. But your house runs on AC mains power. So I stick an inverter box near your fuse board that converts it. Think of it like a translator.
All the electricity goes through your existing wiring. If you’re using power, it feeds your stuff first. If you’re making more than you’re using – like when you’re out at work – it goes back through your meter. The electricity company sees this and pays you for it.
Had a customer in Bramhall, her panels were making 3kW at 11am yesterday. Proper cloudy day too. That’s enough to run her washing machine, dishwasher, and kettle all at once. For free.
Which panels should you actually get?
Three types, really. Most people get the dark blue ones – monocrystalline they’re called. Work best in crap weather, which is handy round here. Cost more but you need fewer of them.
Then there’s the speckled blue ones – polycrystalline. Bit cheaper, don’t work quite as well, but fine if you’ve got loads of roof space. I use these when someone’s watching every penny.
Third type’s the flexible thin ones. Rubbish for houses – you’d need double the roof space. Only good for weird shaped roofs or caravans.
Temperature matters more than people think. These panels actually work better when it’s cooler. That’s why they’re brilliant here – it’s never too hot. I’ve seen panels in Spain that can’t work properly at midday because they overheat.
If your roof’s small, spend the extra on the good ones. If you’ve got a massive roof, save some cash and get the cheaper ones. Either way, you’ll make your money back.
How much roof do you actually need?
About 25-30 square metres for a decent system. That’s enough for 12-16 panels, which should cover most of your electric bill.
I measure every roof before I quote because there’s no point guessing. Got to avoid the chimney, windows, edges where it’s not safe to work. Your actual usable space is always less than the total roof area.
South-facing is best, obviously. But east or west works fine – just need a few more panels. I’ve done loads of west-facing jobs and the customers are happy enough. You make most power in the afternoon when electricity’s more expensive anyway.
Roof angle matters a bit. Steep roofs shed snow better, shallow roofs are easier to work on. Anything between 15-60 degrees is fine really.
Shade’s the killer. Even a small chimney shadow can wreck a whole string of panels. I always check what shadows fall where throughout the day. Takes ages but it’s crucial.
Most semis have enough space. Terraces are tight but usually doable. Detached houses have loads of room – sometimes too much choice of where to put them.
What about the inverter bit?
Inverter’s the box that changes the DC power from your panels into proper mains AC power. Two main types really.
String inverters are cheapest and work fine for most jobs. One box handles all your panels. Costs about a grand, lasts 12-15 years. If you’ve got a simple south-facing roof with no shading issues, that’s what you want.
Power optimizers cost more but work better if you’ve got shade problems or panels facing different directions. Little box on each panel plus a main inverter. Probably £1500-2000 extra but worth it if your roof’s complicated.
I stick the inverter in your garage, utility room, or outside in a weatherproof box. Doesn’t make much noise but does hum slightly. Keep it cool and it’ll last longer.
Some inverters can handle batteries too – hybrid ones they call them. Cost a bit more but save you buying a new inverter if you add batteries later.
How does it connect to your house electrics?
I run a cable from your roof down to your fuse box and connect it like any other circuit. There’s an isolator switch so you can turn the whole lot off if you need to – fire brigade like to see that.
Your meter handles the export automatically these days. Smart meters just measure what goes in and what goes out. Simple.
Older fuse boxes sometimes need upgrading. If you’ve still got the old rewireable fuses or an ancient consumer unit, I’ll need to sort that first. Usually adds about £400-500 but it’s got to be done for safety.
All the metalwork gets earthed properly – panel frames, rails, inverter case, the lot. That’s regulations, not optional.
I test everything twice before I turn it on. Takes longer but I’ve never had a problem with any of my installations because I don’t rush the electrical side.
Do they actually make enough electricity?
Yeah, they do. I’ve got customers who barely pay anything for electric anymore. A 4kW system makes about 3,500kWh a year round here. That covers most houses, especially if you’re not electric heating.
Summer’s brilliant – you’ll make way more than you use. Had one customer in Stockport, her meter was actually running backwards in July. The electric company owed her money.
Winter’s obviously not as good but they still work. Even on a rubbish December day you’ll get a bit. And that’s when electric’s most expensive so every bit helps.
Best bit is when you’re not using much power during the day, it all goes back to the grid and they pay you for it. Currently about 5-15p per unit depending who you’re with. Not a fortune but it adds up.
Most of my customers see their electric bills drop by 70-80%. Takes about 7-8 years to pay for itself, then it’s basically free electricity for the next 20 years.
Do they need much looking after?
Hardly anything really. Rain cleans them most of the time. Maybe hose them off once a year if there’s loads of bird muck or dust.
I tell customers to check their app every month or so, make sure they’re still making power. If generation suddenly drops and it’s not snowing, give me a call.
The panels themselves last 25+ years easy. Inverter might need replacing after 12-15 years but that’s about £1000-1500. Not the end of the world.
Had customers with systems I fitted 8 years ago – still running like new. One lady in Oldham, her panels are still making exactly what I said they would. She’s well chuffed.
Main thing is keeping trees trimmed back if they start shading the panels. And don’t let moss grow on the roof edges where it can shade the bottom row.
What do they actually cost?
About £6,000-£7,000 for a decent 4kW system, all in. That’s no VAT these days which saves you over a grand.
Breakdown roughly:
- Panels and rails: £2,500
- Inverter: £1,200
- My labor: £1,500
- Scaffolding: £500
- Electrician bits: £300
Costs more if your roof’s complicated or your fuse box needs upgrading. Costs less if it’s a straightforward job on a simple roof.
I’ve seen quotes from £4,500 to £9,000 for basically the same job. Cheapest ones usually cut corners somewhere. Most expensive ones are taking the piss. Somewhere in between is about right.
Can get finance if you need it but interest rates are pretty high. Cash is cheapest if you’ve got it.
Look, solar panels work fine in this country. I’ve been fitting them for years and my customers are happy. They cut your electric bills, they last ages, and they don’t need much looking after.
If you’ve got a decent roof and you’re planning to stay put for a few years, they’re worth doing. Just make sure you get someone who knows what they’re doing to fit them.
