- At about 25p per kWh, an 800 W kit typically saves £80-170 a year depending on location and mounting.
- Southern England does best; Scotland produces about 20% less.
- Payback is roughly 5-9 years at 2026 kit prices.
- Export payments are not yet available for most plug-in kits.
In this article
What an 800 W kit produces in the UK
| Location | Tilted, south | Vertical, south | Vertical, east/west |
|---|---|---|---|
| Southern England | ~800 kWh | ~580 kWh | ~440 kWh |
| Midlands / North / Wales | ~720 kWh | ~520 kWh | ~400 kWh |
| Scotland | ~650 kWh | ~480 kWh | ~360 kWh |
Estimates without shade. Vertical mounting loses less at UK latitudes than further south.
Savings at 25p per kWh
| Output | 70% self-use | 85% self-use |
|---|---|---|
| 450 kWh | ~£79 | ~£96 |
| 600 kWh | ~£105 | ~£128 |
| 800 kWh | ~£140 | ~£170 |
For context, launch estimates quoted ranged from roughly £70 to £175 a year, which matches these figures.
Payback
With kits at £450-1,100 at launch, payback is about 4-10 years; a mid-range £750 kit saving £110 a year pays back in under 7 years. As prices fall toward the £400-600 the government expects, payback drops to 4-5 years for good sites.
Boosting savings in the UK
- Run washing machines and dishwashers in the middle of the day.
- Pair with a time-of-use tariff carefully: cheap overnight rates reduce the value of daytime solar slightly, but savings remain.
- Keep an eye on Smart Export Guarantee rules; a simplified route for plug-in kits would add value to surplus power.
Estimate for your postcode region with the calculator, and read the UK rules before buying.
Worked example: a flat in Manchester
A single-panel 400 W kit, vertical on a south-west facing balcony: 0.4 kW × 900 kWh/kW × 0.70 ≈ 250 kWh a year. Because it is small, about 90% is used at home: 225 kWh. At 25p, that is roughly £56 a year. A £450 kit pays back in about eight years; at £350, just over six.
How the UK compares with Germany
Germany has similar sunshine to southern England and higher electricity prices (around €0.35 per kWh), which is part of why balcony solar took off there. At 25p per kWh, UK savings per kWh are slightly lower, but the UK started with a clearer product standard and high-street retail from day one. Owners in both countries report that placement matters more than brand. Lessons from Germany.
Five ways to raise UK savings
- Face south, south-east or south-west. Vertical mounting loses less at UK latitudes than further south, so a railing mount is a reasonable choice.
- Avoid winter shade from neighboring buildings; the sun is very low from November to February.
- Run the washing machine and dishwasher at midday on sunny days.
- Keep an eye on export payment rules; a simplified Smart Export Guarantee route would add value to surplus power.
- Buy at the right price. A kit at £450 instead of £750 cuts payback by almost half.
Frequently asked questions
Does the energy price cap change my savings?
Yes. Savings scale with your unit rate. When the cap rises, savings rise; when it falls, they fall.
Is Economy 7 a problem?
On Economy 7, your daytime rate is higher than average, which makes daytime solar slightly more valuable.
Does solar reduce standing charges?
No. Standing charges are fixed; solar only reduces the unit charges for electricity you would otherwise buy.