What is the best roof pitch and angle for solar panels?
The best roof angle for solar panels in the UK is around 30 to 40 degrees from horizontal, which most pitched roofs are already close to. Output falls only slightly outside this range, so a typical UK roof pitch is rarely a problem. Flat roofs use tilted mounting frames set to a similar angle.
Why 30 to 40 degrees is ideal
At UK latitudes, a pitch of around 30 to 40 degrees captures the most sunlight across the year and helps rain keep the panels clean. The difference between a 20-degree and a 45-degree roof is small, so most homes do not need to worry about pitch.
Flat and steep roofs
- Flat roofs: panels sit on angled frames, often in east-west rows to fit more in.
- Very steep roofs: still fine, with a slight drop in output.
- Shallow pitches: fine, and self-cleaning is a little less effective.
Frequently asked questions
- Do solar panels work better lying flat?
- No. A tilt of around 30 to 40 degrees outperforms flat-mounted panels and sheds rain and dirt better.
- Can I change the angle of roof panels?
- On a pitched roof the panels follow the roof angle. Only flat-roof systems let you set the tilt with frames.
Related questions
Indicative estimates based on UK average data. Last updated 27 May 2026.