Worked examples
These examples use realistic, stated assumptions to make the numbers easier to understand. Actual output varies with location, orientation, weather and shading, while the amount used at home depends on when your household consumes electricity.
Instantaneous demand
Up to 53%
of instantaneous demand could theoretically be offset
At 800W output, solar could offset just over half the demand. The grid supplies the remainder; solar will not produce 800W continuously.
Daytime self-use
240W
of example daytime electricity demand
More daytime electricity use gives the household more opportunity to use solar generation directly. It does not guarantee higher savings.
Always-on demand
Over 5× the example household baseload
150W example baseload • 800W peak solar output
Strong generation could cover this example baseload and offset other demand. Actual baseload varies, and 800W output is not continuous.
Simple payback
Low 7.0 yrs · Typical 4.2 yrs · High 3.0 yrs
Illustrative calculator payback
Using more generation in the home shortens this illustrative payback. These calculator results are not forecasts or guarantees.
The payback example uses the same generation, orientation, self-consumption and electricity-price calculation as the main home solar calculator. The appliance and baseload examples compare watts at one moment; they do not estimate daily energy in kWh.
For broader context, read the 800W plug-in solar guide and check the current UK rules.
Worked examples reviewed 14 August 2026.