Solar Reality Check
UK plug-in solar payback estimator
No spreadsheets. No solar jargon. Just a realistic yes/no answer in 30 seconds.
Generation
680 kWh/yr
Likely saving
£95/yr
Payback
6.3 yrs
Your realistic annual saving
£95
Worst
£76
Likely
£95
Best
£124
Worth a serious look
Your setup has a realistic payback window. The numbers look promising if the kit price is accurate.
Calculator inputs
Most plug-in kits are likely to sit around 400W–800W.
Include brackets, inverter, cable, delivery — the real all-in cost.
Use your unit rate from your energy bill.
Panel direction
Daytime usage
The bit most calculators hide
Used
340 kWh/yr
Likely unused
340 kWh/yr
If you run washing machines, dishwashers, dehumidifiers or charging during sunny hours, your savings improve. If the house is empty all day, payback gets worse.
Shareable result
Payback: 6.3 years. Unused energy: 50%. Verdict: Worth a serious look.