Definition: Kilowatt-peak (kWp) measures a solar system’s maximum output under standard test conditions. A typical UK home system is 3.5-4.5 kWp.

kWp vs real output

Each kWp generates roughly 850-1,050 kWh per year in the UK depending on region, roof pitch and orientation — southern England sits at the top of that range.

Sizing guide

A 4kWp system (about 10 panels) suits most 3-bed homes. Bigger isn’t always better: export rates are lower than import savings, so match size to daytime usage.

Estimate your numbers: try the free savings calculator or browse all upgrade guides.