Solar generation in the UK varies year to year, but the long-term average is well established. Staffordshire sits close to the UK average for irradiance.
Expected annual output
- 3 kWp system: around 2,400–2,700 kWh/year.
- 4 kWp system: around 3,200–3,600 kWh/year.
- 5 kWp system: around 4,000–4,500 kWh/year.
What drives it up or down
Roof pitch and orientation, shading from trees or chimneys, and panel efficiency. A south-facing roof at 30–40° pitch is the ideal, but east/west splits still generate very well.
How much you actually use
Without a battery, most homes self-consume 30–40% of generation and export the rest. With a battery that rises to 60–80%.