Is plug-in solar worth it? What it actually saves
The government says a plug-in kit saves up to £110 a year. Here's what that assumes, what a kit makes in 14 UK cities, and how long it takes to pay for itself.
The government's own figures
South-facing at 30°. 690 kWh a year, 62% used at home (428 kWh).
DESNZ378 kWh a year, 72% used at home (272 kWh).
DESNZWhat the government expects kits to cost. Its initial product life assumption is 10 years.
DESNZOur sum: a £500 kit ÷ £110 a year, before any installation costs.
What a kit saves in your city
Yearly saving and electricity made by an 800W kit, at Ofgem's 26.32p per kWh. It assumes 62% is used at home (72% for upright east or west), as in the government's modelling.
| City | South, 30° | East or west, 30° | South, upright | East or west, upright |
|---|---|---|---|---|
| London | £135 826 kWh | £110 674 kWh | £99 606 kWh | £79 417 kWh |
| Southampton | £142 870 kWh | £116 708 kWh | £102 627 kWh | £83 441 kWh |
| Plymouth | £144 883 kWh | £118 721 kWh | £103 629 kWh | £85 449 kWh |
| Cardiff | £136 836 kWh | £112 687 kWh | £99 605 kWh | £80 424 kWh |
| Birmingham | £128 786 kWh | £105 641 kWh | £95 581 kWh | £75 394 kWh |
| Norwich | £136 831 kWh | £111 678 kWh | £101 616 kWh | £79 417 kWh |
| Nottingham | £129 789 kWh | £105 642 kWh | £96 587 kWh | £75 394 kWh |
| Sheffield | £124 761 kWh | £101 619 kWh | £92 567 kWh | £72 380 kWh |
| Manchester | £116 708 kWh | £94 577 kWh | £86 525 kWh | £67 355 kWh |
| Leeds | £122 749 kWh | £99 607 kWh | £91 560 kWh | £71 375 kWh |
| Newcastle | £123 757 kWh | £99 604 kWh | £94 576 kWh | £73 383 kWh |
| Edinburgh | £119 727 kWh | £94 579 kWh | £90 554 kWh | £70 368 kWh |
| Glasgow | £110 672 kWh | £88 540 kWh | £83 507 kWh | £65 343 kWh |
| Aberdeen | £118 725 kWh | £93 573 kWh | £91 559 kWh | £69 366 kWh |
Our figures from EU PVGIS 5.3 solar data. Your own postcode, shade and price will change them: use the calculator.
How our calculator works
- Solar output comes from the EU's PVGIS 5.3 tool: averages for 2005 to 2023 from satellite solar radiation data (SARAH3), allowing for the shading of hills and the standard 14% system losses.EU PVGIS
- We took PVGIS figures for an 800W kit at 191 points across the UK, about 40 km apart, then averaged the four nearest to your postcode.EU PVGIS
- Direction and tilt use PVGIS figures for 8 directions and 7 angles, at 5 latitudes from Devon to Aberdeenshire.EU PVGIS
- Savings = electricity made × the share you use × your price. We start at Ofgem's 26.32p average (1 October to 31 December 2026) and the government's 62% self-use figure. You can change both.Ofgem, DESNZ
- Your postcode is looked up with postcodes.io to find its location. We don't store it.postcodes.io
kWh used at home
it faces
Fine-tune: shade, price, how much you use
Your own estimate. The solar data allows for hills, not buildings or trees.
Government modelling uses 62% for a south-facing kit and 72% for an upright east or west one. Power you don't use flows to the grid unpaid.
26.32p is Ofgem's price cap average, 1 October to 31 December 2026.
Government modelling expects kits at £400 to £600.
Solar data: EU PVGIS 5.3, averages for 2005 to 2023. How it works
Common questions
Is plug-in solar worth it?
At the government's best case, about £110 a year, a £500 kit pays for itself in about 4.5 years before any installation costs. The government's modelling assumes an initial product life of 10 years. An upright east or west kit saves about £70, so it takes longer.
How much electricity does an 800W plug-in solar panel make?
The government's modelling gives up to 690 kWh a year facing south at 30°, and 378 kWh upright facing east or west. Our PVGIS-based figures give 826 kWh a year in London and 725 kWh in Aberdeen facing south at 30°.
Do I get paid for the electricity I don't use?
The government's savings figures don't include any payment for electricity sent back to the grid. Count only what you use yourself.
Why is your figure different from the government's?
We use location-specific solar data from the EU's PVGIS tool, while the government used two national example set-ups. Both are estimates. Shade, the weather in a given year and how much you use at home all change the real figure.
More guides
Sources
- DESNZ: Plug-in solar final stage impact assessment (July 2026)
- European Commission Joint Research Centre: PVGIS 5.3 (SARAH3 solar radiation data, 2005 to 2023)
- Ofgem: energy price cap unit rates and standing charges (1 October to 31 December 2026)
- GOV.UK: Households can save as plug-in solar panels come to market (26 August 2026)
- postcodes.io: free UK postcode lookup (Ordnance Survey and ONS open data)
Checked 13 October 2026. Spotted something out of date? Email hello@socketpanel.co.uk. How we check