Plug-in solar · The straight answer
Is plug-in solar worth it in the UK?
A clear answer for UK households — no sales pitch, and no made-up savings figures.
By Mike · Updated 19 October 2026 · 6 min read
So, is it worth it?
It can be — especially if your home already uses electricity during the day.
Plug-in solar makes electricity in daylight. When your home is using electricity at the same time, it can use what the panels produce, so less needs to be bought from the grid. The more electricity your home uses in daylight hours, the more chance it has to use what the panels make.
Every home is different, so no single figure fits everyone. As a rough guide, the Energy Saving Trust estimates a typical 800W kit could cut electricity bills by about £70 to £100 a year — towards the top of that if someone’s at home in the day, and towards the bottom if not.
It depends on
Your daytime electricity use
What the system costs
Where the panels can go
Which way they face
Shade
Local conditions
What it could save
How much could plug-in solar save?
The Energy Saving Trust has worked through a typical example. Treat it as a guide, not a promise: your own saving could be higher or lower.
Energy Saving Trust example
Home in the day
Out in the day
Electricity the panels make
About 700 kWh a year
About 700 kWh a year
Saving on your bills
About £100 a year
About £70 a year
The example is an 800W kit in Manchester, facing south and tilted at 30°, with no shade, in a home that uses 2,500 kWh of electricity a year. It prices electricity at 24.7p per kWh.
Why the difference? Your bill only goes down when your home uses the electricity at the moment the panels make it. If nobody’s in and little is running, more of it flows out to the grid, and you normally aren’t paid for that. By our arithmetic, the Energy Saving Trust’s figures mean roughly 400 of the 700 kWh get used at home when someone’s in during the day, and roughly 280 when they’re out.
With today’s electricity price. Ofgem’s price cap for 1 October to 31 December 2026 is 26.32p per kWh (the average for Direct Debit customers in England, Scotland and Wales). At that price, the same amounts of electricity would save about £107 a year for someone home in the day and about £75 for someone who’s out. These are WattVerdict’s own recalculations, not Energy Saving Trust figures, and they will go up or down as electricity prices change.
Paying for itself
How long does plug-in solar take to pay for itself?
Divide what the kit costs by what it saves each year. With the savings above, it works out roughly like this:
Total cost of your kit
Home in the day
Out in the day
£450
About 4 years
About 6 years
£600
About 6 years
About 8 years
£700
About 7 years
About 9–10 years
Worked out from our updated savings of about £107 and £75 a year, then rounded. With the Energy Saving Trust’s original £100 and £70, each takes a little longer, up to about 10 years. These are simple sums: they assume you save the same amount every year, which you won’t, because electricity prices change.
Count everything you need to get started, not just the price on the box: the panels and inverter, something to mount them on, delivery, and anything else the kit needs. Some kits come without a mount, and some add delivery at checkout. The Energy Saving Trust says compliant kits start from around £450 including the panels, inverter, mounting brackets and cables.
When it might not pay off
Heavy shade from trees, buildings or a balcony above can cut how much electricity the panels make by a lot.
Direction and angle matter. In our modelling, panels facing east or west make about a fifth less than panels facing south, panels hung upright on a railing about a quarter less, and panels facing north about 45% less.
If very little is running in your home in daylight, less of what the panels make gets used, so you save less.
So a kit in a poor spot, in a home that’s empty all day, could take many years longer to pay for itself than the examples above.
For figures by place, direction and season, see how much electricity 800W plug-in solar generates.
● More likely to be worth it
When does plug-in solar make the most sense?
When your home can use the electricity while it’s being made.
Someone is often at home during the day.
There’s steady background use — fridges, freezers, routers and other things that stay on.
You can run appliances like the washing machine or dishwasher while it’s light.
The panels can go somewhere with plenty of daylight and little shade.
The system is competitively priced compared with similar kits.
● Less likely to be worth it
When might it make less sense?
When little of the electricity gets used at home, or the system costs more than it needs to.
Very little electricity is used in your home during the day.
The only available spot is heavily shaded.
The panels can’t be placed where they’d get much daylight.
The system is expensive compared with similar kits.
Before you compare kits
Don’t judge it by the wattage alone
The wattage on a solar kit tells you what it’s rated to produce under set laboratory conditions. It doesn’t tell you how much electricity it will actually produce at your home.
Real output depends on things the label can’t know
Where you live
The time of year
The weather
Which way the panels face
Shade
That’s why no single generation figure fits every UK home. For modelled figures by location, mounting and season, see how much electricity 800W plug-in solar generates.
Before you buy
What should you look at?
01
Your daytime electricity use
How much is usually running in your home while it’s light?
02
Where the panels could go
Is there a practical spot that gets plenty of daylight?
03
Shade
Would trees, buildings or anything else shade them for much of the day?
04
The actual price
What would you really pay for the system today, from a real retailer?
05
Suitability for the UK
Is it intended for the UK market, and what compliance information is available for it?
Related questions
Compare
Which plug-in solar systems can you buy in the UK? →
Compliance status and verified retailer prices, side by side.
Your next step
Find a kit that gives you the most for your money
Our Best Kits page compares compliant kits by price and estimated yearly electricity, and shows whether a mount and delivery are included, so you can work out the full cost.
Sources
Where this information comes from
Energy Saving Trust: Plug-in solar panels
The £70 to £100 yearly saving, the 700 kWh example and the assumptions behind it, and kits from around £450. Page last updated by the Energy Saving Trust on 1 October 2026.
Ofgem: Energy price cap unit rates and standing charges
Electricity at 26.32p per kWh from 1 October to 31 December 2026: the average for Direct Debit customers in England, Scotland and Wales.
WattVerdict: How much electricity does 800W plug-in solar generate?
Our modelled figures for direction, angle and location, from the European Commission’s PVGIS data.
Sources checked 19 October 2026.