Calculate your plug-in solar generation, savings and payback
Compare UK plug-in solar system sizes and panel setups using your postcode, panel direction, mounting angle and household electricity use. Get tailored estimates for generation, annual bill savings and payback.
Postcode-level PVGIS solar data
Estimates generation using European Commission PVGIS 5.3 solar radiation data for your UK postcode area and chosen panel capacity, direction and mounting angle, with realistic system losses applied.
Built around the official UK rules
Models plug-in solar system sizes from 400W to 1,200W within the UK compliance limits, applies the 800VA inverter output limit, excludes integrated battery storage and accounts for inverter clipping on larger panel arrays.
Realistic savings modelling
Models household baseload, daytime presence and home-working patterns, values estimated savings using the current Ofgem price-cap electricity rate by default, and accounts for gradual panel degradation over time.
Tell us about your postcode, planned panel setup and household electricity use to see what a compliant UK plug-in solar kit could mean for your home. Your answers and calculations stay in your browser and are not submitted to us.
How it works
How this calculator works
This calculator is designed specifically for the new UK plug-in solar rules. It combines postcode-area solar data with your panel setup and household electricity use, while applying the official system limits and cautious assumptions. The result is a grounded estimate designed to reflect the generation and savings a compliant UK plug-in solar kit could realistically achieve.
Solar generation and system limits
Solar output is estimated using European Commission PVGIS data matched to the user's UK postcode area, with a 15% system-loss allowance, then adjusted for panel size, direction and angle. In line with the current UK plug-in solar rules, the calculator limits systems to four panels, 2,000W of combined panel capacity and 800VA inverter output. Where panel capacity exceeds 800W, the estimate models the inverter ceiling and associated clipping.
Solar used at home
The model first estimates household baseload (fridge, freezer, router etc), using a conservative household-size estimate unless you enter your own figure. It then works out how much estimated solar generation is likely to cover that baseload, and how much spare solar may be used based on daytime presence and work-from-home patterns. Battery storage is not modelled, in line with the current UK plug-in solar rules.
Savings and payback
Savings count only the solar electricity estimated to be used in the home. Export income is not assumed because eligibility for UK plug-in solar systems has not yet been confirmed. Payback is based on the selected kit cost and electricity rate, defaulting to the current Ofgem price-cap unit rate where no custom tariff is entered. Longer-term savings include a 0.4% annual panel degradation allowance after year one to simulate panel ageing.
Daily availability
The hourly chart illustrates how much power the selected kit could produce on a typical clear day in each season, using regional PVGIS profile data. It is not a weather forecast, but it helps show likely peak generation windows, how solar availability changes from winter to summer, and how much output may be absorbed by your household baseload during the day.
!Disclaimer:
We aim to keep the estimates realistic rather than optimistic, but real-world results can still vary with weather, shade, mounting quality, panel specification, inverter performance, appliance timing and how much electricity is used while panels are generating.
Plug-in solar is finally moving from policy idea to UK shop shelves. See the confirmed launch rules, key buyer checks and what the 27 August start date means.