Plug-in solar calculator
Work out how much electricity a plug-in solar panel would make where you live, and what it would be worth.
Solar output from PVGIS (European Commission), checked 13 November 2026.
Result
800 W of panels upright, on a wall or railing, facing south in Birmingham, would make about 568 kWh a year. If you used all of it as it is made, that is worth £149.52 a year at the price cap rate of 26.32p per kWh.
kWh a year
| Used in the home | 568 kWh |
|---|---|
| Worth a year | £149.52 |
Show the workings
| Step | Sum | Answer |
|---|---|---|
| Electricity made in a year | 710.1 kWh per kWp × 0.8 kWp | 568 kWh |
| Used in the home as it is made | 568.1 kWh × 100% | 568 kWh |
| Worth, at the unit rate | 568.1 kWh × 26.32p | £149.52 |
What this leaves out or assumes
- PVGIS's long-run average for the place, so a sunny or dull year will differ. Shade from trees or buildings is not counted.
- Electricity that is not used as it is made goes to the grid; no payment for it is counted here.
Where the figures come from
- PVGIS output from 1 kWp in Birmingham, upright, on a wall or railing, facing south: 710.1 kWh per kWp. Source: PVGIS 5.3, European Commission Joint Research Centre. Checked 13 November 2026.
- Electricity unit rate, price cap, Great Britain average, Direct Debit: 26.32p per kWh. Source: Ofgem: Energy price cap unit rates and standing charges. Checked 13 November 2026.
What plug-in solar is
A plug-in solar panel, sometimes called balcony solar, plugs into an ordinary socket and feeds electricity into your home's wiring. Since 27 August 2026 the law in Great Britain allows them if the device's output is no more than 800 watts, it meets the government's Plug-in Solar Device Interim Product Specification, and it does not store electricity taken from the mains. Read the regulations.
How much will it make?
It depends on where you live, which way the panel faces and how it is mounted. A panel tilted at 35° and facing south makes the most. Hung upright on a wall or railing, it makes less: choose "Upright" above to see how much. For 800 W of panels facing south at 35°, PVGIS's average is about 949 kWh a year in Lewes, the sunniest council area, and about 596 kWh in Shetland Islands, the dullest.
What is it worth?
Electricity from the panel saves you buying the same amount from your supplier, but only if something in the home uses it as it is made. The calculator values what you use at your unit rate. Anything you do not use at the time goes to the grid, and this calculator does not count any payment for it. Running a washing machine or dishwasher in the day uses more of your own electricity.
Where the numbers come from
Output comes from PVGIS, the European Commission's solar model, worked out for the centre of each UK council area using its long-run weather data, with PVGIS's standard allowance of 14% for losses in cables and inverters. Council area centres are from the Office for National Statistics. This gives information, not advice.