Savings calculator
What could a plug-in solar setup save you?
Every number below is an estimate built from stated assumptions, not a guarantee. Adjust the inputs to match your home and read the assumptions before you rely on the result.
Conservative
£90 / year
- Monthly
- £8
- Generation
- 560 kWh
- Used at home
- 347 kWh
- Payback
- 6.7 yrs
- 10-year total
- £1,011
Central
£113 / year
- Monthly
- £9
- Generation
- 700 kWh
- Used at home
- 434 kWh
- Payback
- 5.4 yrs
- 10-year total
- £1,263
Optimistic
£130 / year
- Monthly
- £11
- Generation
- 805 kWh
- Used at home
- 499 kWh
- Payback
- 4.8 yrs
- 10-year total
- £1,453
Cumulative savings vs kit cost
Central scenario, ten years, including assumed electricity price rises and panel degradation.
- Year 1£113
- Year 2£228
- Year 3£347
- Year 4£468
- Year 5£593
- Year 6£721
- Year 7£851
- Year 8£985
- Year 9£1,123
- Year 10£1,263
The vertical marker shows the kit price of £649.
These figures are estimates, not guarantees. Real output depends on weather, exact mounting, shading through the day, inverter behaviour, and how much electricity you actually use while the sun is out. Savings only occur on electricity you consume at the time of generation — plug-in systems do not normally earn export payments.
Assumptions used in this calculation
- Base annual yield
- 875 kWh per kWp
- Regional factor
- 1
- Orientation factor
- 1
- Shading factor
- 1
- Self-consumption share
- 62%
- Annual degradation
- 0.5%
Scenario range applies a 80% conservative and 115% optimistic multiplier to generation.
Want the numbers checked against a real roof?
If your estimate suggests you need more than 800W, a full rooftop system is the honest answer. You can request rooftop quotes or read the how it works guide first.