Solar panel calculator
Enter your postcode and answer two questions to estimate your solar generation.
Working out sunlight for this location…
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How this estimate works
Your location sets how much sunlight the panels get. We use long-term average sunlight for your area from PVGIS 5.3, European Commission Joint Research Centre.
Roof direction matters: south-facing roofs generate most, east and west a little less, north the least. If you are not sure, we assume east/west rather than the best case.
A bigger system generates more. Without a size, we use a typical system for the roof size you chose.
Shading from trees, chimneys or nearby buildings reduces output. Allowance is also made for normal wiring and inverter losses.
The electricity value assumes a typical home that is in some of the day, saving the current Ofgem price-cap unit rate, with the rest paid at Octopus Energy Outgoing Smart Export Guarantee (12-month fixed) export rate. These are estimates, not guarantees; an installer's survey will be more precise.
Method version 1.0, checked 2026-10-01. PVGIS · Ofgem typical use