Solar
What would panels make on your roof?
The sun that reaches your postcode, turned into kilowatt-hours: what a typical 4 kWp domestic array would generate over a year on a roof facing south, east or west, what the best possible tilt would add, how the output spreads across the months, and how that compares with what a typical home uses.
- kWh a year by roof direction
- Best tilt & azimuth
- Month-by-month profile
- Against typical home use
How this works
The page runs four layouts through PVGIS, the European Commission Joint Research Centre’s photovoltaic calculator: a 4 kWp crystalline-silicon array at a 35° pitch facing south, east and west, and the same array at whatever tilt and direction PVGIS finds best for the spot. PVGIS uses the SARAH3 satellite record of solar radiation, hour by hour across nineteen years, with temperature and wind from ERA5 and the shading of the surrounding hills from a terrain model, and takes off a standard 14% for the system’s own losses. The answer is what the sky allows at that point; a survey adds what the roof itself does, from its true pitch and any chimney or tree in the way. Answers are cached for a month per two-kilometre cell.
Sources
- PVGIS 5.3, European Commission Joint Research Centre. © European Union, reused under the Creative Commons Attribution 4.0 licence.
- Typical domestic electricity use: Ofgem typical domestic consumption values.
- Postcodes: postcodes.io / ONS Postcode Directory (OGL v3).