Solar Panel Output UK — kWh by Region & Season 2026 Generation Guide
Solar panels in the UK generate 850 to 1,100 kWh per kWp per year depending on location, roof orientation, and shading. A 4kW system produces 3,400-4,400 kWh annually — enough to cover 100-160% of the average UK household electricity consumption of 2,700 kWh. Output varies significantly by region: South England averages 1,000-1,100 kWh/kWp while Scotland averages 850-950 kWh/kWp.
Solar Output by UK Region
Annual generation per kWp (1kW of panels): Cornwall / South Coast: 1,050-1,100 kWh/kWp — best in the UK. London / South East: 1,000-1,050 kWh/kWp. East Anglia / Home Counties: 980-1,020 kWh/kWp. Midlands (Birmingham, Nottingham): 920-960 kWh/kWp. Wales: 900-950 kWh/kWp. North England (Manchester, Leeds): 870-920 kWh/kWp. Newcastle / North East: 850-900 kWh/kWp. Edinburgh / Central Scotland: 850-900 kWh/kWp. Highlands: 800-860 kWh/kWp. For a 4kW system, multiply by 4 to get total annual generation.
Seasonal Variation
UK solar output varies dramatically by season due to day length and sun angle: June (peak): 150-170 kWh per kWp — long days (16+ hours), high sun angle. December (lowest): 15-25 kWh per kWp — short days (7-8 hours), low sun angle. March-September: Produces approximately 80% of annual output. October-February: Only 20% of annual output. This means you will over-produce in summer (export excess via SEG) and under-produce in winter (draw from grid). A battery helps smooth this seasonal variation by storing daytime summer excess for evening use.
Roof Orientation Impact
The direction your roof faces significantly affects output: South-facing (180°): 100% of maximum output — the ideal orientation. South-East or South-West: 95% of south-facing output — still excellent. East or West-facing: 80-85% of south-facing. Generates well but produces less midday peak. East AND West (split array): 85-90% total, with generation spread more evenly through the day — actually better for self-consumption. North-facing: 50-60% of south-facing — generally not recommended unless the pitch is very shallow. Use our Solar Panel Calculator for exact estimates.
Tilt Angle Optimization
The ideal tilt angle for UK solar panels is 30-40° from horizontal, which happens to match most UK roof pitches. 30° tilt: Optimal for year-round energy production. 40° tilt: Slightly better in winter, slightly worse in summer. Good for maximizing winter output. 15° tilt (shallow): 95% of optimum. 50° tilt (steep): 90% of optimum. Flat (0°): 85% of optimum — but panels must be tilted to 10-15° minimum for self-cleaning by rain. Most UK roofs at 30-45° pitch are naturally close to optimal, requiring no adjustment.
| Region | kWh/kWp/yr | 4kW Output | Annual Savings* |
|---|---|---|---|
| Cornwall / South Coast | 1,050-1,100 | 4,200-4,400 kWh | £1,000-1,200 |
| London / South East | 1,000-1,050 | 4,000-4,200 kWh | £950-1,100 |
| Midlands | 920-960 | 3,680-3,840 kWh | £870-950 |
| North England | 870-920 | 3,480-3,680 kWh | £820-900 |
| Scotland (Central) | 850-900 | 3,400-3,600 kWh | £800-880 |
| Scotland (Highlands) | 800-860 | 3,200-3,440 kWh | £750-840 |
Shade and Degradation
Shading: Even partial shade on one panel can reduce output of the entire string by 20-50%. Trees, chimneys, neighboring buildings, and satellite dishes are common culprits. Microinverters or DC optimizers mitigate shade effects by isolating each panel. Always get a professional shade analysis before installing. Degradation: Solar panels degrade approximately 0.5% per year. A panel producing 400W in year 1 will produce about 348W in year 25 (87% of original). All quality panels are warrantied for minimum 80% output at 25 years. Modern panels from LG, Trina, JA Solar, and similar tier-1 manufacturers typically exceed warranty promises.
Disclaimer: For educational reference only. Consult a licensed professional.