Solar panel calculator
Estimate annual generation, bill savings, export income, emissions avoided and simple payback for a rooftop solar system.
Annual saving and export income
£551.81 a year
3,600 kWh generated a year: £379.01 off the bill and £172.80 from exports.
The rest is exported.
| Generated a year | 3,600 kWh |
|---|---|
| Used in the home | 1,440 kWh |
| Exported | 2,160 kWh |
| CO₂e avoided | 783 kg |
Simple payback: 12.7 years. Solar directly covers 48% of annual household use.
How we calculated this
Annual generation is system size multiplied by the yield for your roof and location. The starting yield is an assumption: replace it with a local installer or solar-map estimate.
Self-used generation avoids buying electricity at your current rate. Everything else earns the export rate you enter.
Simple payback divides installed cost by one year’s bill saving and export income. It excludes maintenance, financing, degradation, tariff changes and increases in electricity prices.