Solar Panel ROI Calculator
Work out how much solar panels will save you and how long until they pay for themselves.
Calculate the return on investment for solar panels on your UK home. Adjust your system size, location, and roof orientation to see annual savings, SEG export income, payback period, and 25-year return.
3 kW (small)6–7 kW (average)10 kW (large)
UK average: ~3,800 kWh/year
Check your energy supplier's SEG rate
Annual generation
3,400 kWh
Total annual benefit
£639
System cost
£6,400
Payback period
10.0 yrs
| Breakdown | Value |
|---|---|
| Annual generation | 3,400 kWh |
| Self-consumed (40%) | 1,360 kWh |
| Exported to grid | 2,040 kWh |
| Annual bill savings | £333 |
| Annual SEG income | £306 |
| Total annual benefit | £639 |
| System cost (inc. VAT @ 0%) | £6,400 |
| 25-year net return | +£9,580 |
* Self-consumption assumed at 40% without battery storage. Solar panels in the UK attract 0% VAT. SEG rates vary by supplier — check your tariff. Generation figures based on MCS irradiance data.