Tools / Solar / Solar payback
Solar payback estimator
Drop in your assumptions. The calculator shows every step it takes to get to the payback figure.
Inputs
Total kWp installed
All-in, after VAT
Compass direction
0 = none, 0.4 = heavy
Your tariff's day rate
SEG or smart export rate
Share used directly
Working
Annual generation3,491 kWh
— used at home1,222 kWh
— exported2,269 kWh
Bill savings (yr 1)£336
Export income (yr 1)£340
Year-one total return£677
Headline figure
Payback: 10.0 years
Assuming 0.5% panel degradation per year and stable tariffs in real terms.
Assumptions: generation derived from a UK baseline of 1040 kWh/kWp adjusted for orientation and shading. Real systems vary ±10% against this. We do not factor in inverter replacement at year 12-15.