Solar savings calculator
Your figures, your assumptions, plain arithmetic
Change every number to match your own home and your own quote. Nothing is sent anywhere and nothing is stored. The defaults are deliberately cautious starting points, not recommendations.
Estimated results
- Self-consumed solar
- 1,190 kWh
- Exported solar
- 2,210 kWh
- Avoided import cost
- £298
- Export income
- £111
- Total annual benefit
- £408
- Simple payback
- 17.2 years
- 10-year gross benefit
- £4,080
- Total upfront cost
- £7,000
On these figures, self-consumed solar covers about 44% of your annual electricity use. Ten-year gross benefit is before degradation, maintenance, inverter replacement, inflation and any tariff changes.
Important
This is an illustration, not a quote and not financial advice. Actual generation, tariffs, panel degradation, maintenance costs and export terms vary and change over time. Simple payback ignores the time value of money, finance costs and any future price movements. Always check current official guidance and your own quotes before committing.
How the calculation works
Self-consumed solar is your annual generation multiplied by the share you use at home, capped at your total annual consumption. Exported solar is whatever generation is left.
Avoided import cost is self-consumed kilowatt hours multiplied by your import price. Export income is exported kilowatt hours multiplied by your export price. Total annual benefit is the two added together.
Simple payback divides the total upfront cost, including any battery, by the total annual benefit. The ten-year figure is the annual benefit multiplied by ten, with no adjustment for degradation or maintenance, which is why we call it gross.
No efficiency fudges, no assumed energy price inflation, no hidden uplift. If you want a gloomier answer, lower the generation figure and the self-consumption share and see what survives.