Money · 6 min read

Is Plug-In Solar Worth It in the UK?

The payback sums for a cheap kit, a pricey kit, a sunny spot and a poor one.

The short answer

Yes, for most homes with a sunny spot to put one. A kit costs about £450 to £900 and saves about £70 to £110 a year, going by the government's own figures. A £450 kit pays for itself in about four to six and a half years. It's not worth it in a shaded spot, or at top price on a poor wall.

Plug-in solar won't make you rich. It will quietly knock a chunk off your electricity bill, every year, for no effort at all. Whether that's worth a few hundred pounds comes down to two things: what you pay, and where the panel sits.

How much does plug-in solar save a year?

About £70 to £110. Those are the government's figures for an 800 W kit. You get £110 if the panel faces south and tilts at 30 degrees. You get £70 if it sits flat on a wall facing east or west. Most balconies and fences land somewhere in between. Our cost guide shows where the numbers come from.

How long does a kit take to pay for itself?

Divide the price by the yearly saving. The cheapest kit we've seen planned, at £330, would pay back in three to five years. A £450 kit takes about four to six and a half years. A £669 kit takes six to nine and a half years. An £899 kit takes eight to thirteen years. The first number in each pair is the sunny, tilted spot. The second is the flat east or west wall.

When is plug-in solar worth it?

It works best when four things are true. You have a spot that gets sun for most of the day. You can tilt the panel instead of hanging it flat. Someone uses power at home in the daytime. And you pay a fair price, not top whack. It also suits renters, because it comes with you when you move. A roof full of panels can't do that.

When is it not worth it?

Skip it if your only spot is in shade for most of the day. Skip it if your wall or balcony is on the banned list, such as timber or certain cladding. And think twice if you own a good roof. Rooftop solar costs far more, but it covers most of a home's power, not a slice of it.

Are there any hidden costs?

Not many. There's no installer to pay, because you fit it yourself. You must register the kit with your network operator, and we found no fee for that. The shop price already includes VAT. The one hidden cost is the power you don't use. Spare power flows to the grid, and for now nobody pays you for it.

Will the kit last long enough to pay you back?

Check the warranty before you buy. The test is simple. If your payback is six years, you want a warranty that runs well past six years. If the warranty is shorter than the payback, you're taking a gamble. Put the kit back on the shelf and pick another.

Sunny says

Sunny says: do the sum in the shop. Price divided by 110 is your best case in years. Price divided by 70 is your worst case. If both numbers make you wince, walk away.

The quick version

Expect to save about £70 to £110 a year.
A £450 kit pays back in four to six and a half years.
Shade or a top-price kit on a poor wall spoils the deal.

Common questions

Is plug-in solar worth it in the UK?

For most homes with a sunny spot, yes. A kit costs about £450 to £900 and saves about £70 to £110 a year. A £450 kit pays for itself in about four to six and a half years. After that, the saving is yours to keep for as long as the kit lasts.

How long does plug-in solar take to pay for itself?

Between three and thirteen years, depending on price and position. A £330 kit in a sunny, tilted spot pays back in about three years. An £899 kit flat on an east or west wall takes about thirteen. A £450 kit lands between four and six and a half years.

Is plug-in solar worth it if I'm out at work all day?

It's worth less. The government's savings figures assume someone is home in the daytime. If the house is empty, the panel still covers things that never switch off, like the fridge and the router. But more of its power slips out to the grid unpaid. Running the washing machine or dishwasher on a timer at midday helps.

Is plug-in solar worth it on a north-facing balcony?

Probably not. We haven't found official figures for north-facing kits. But a panel flat on an east or west wall already makes about half of what a tilted south-facing one does. A north-facing spot gets even less direct sun. We wouldn't buy one for that spot.

Is plug-in solar better value than rooftop solar?

It pays back faster, but it saves far less in total. A plug-in kit saves about £70 to £110 a year. A typical rooftop system covers most of a home's electricity. Plug-in solar is the better buy if you rent, live in a flat, or want to start small.