Best Solar Panels UK 2026: Compare Models — comparing the top 17

What to look for in solar panels

Efficiency: Efficiency only matters if your roof space is limited. A slightly less efficient panel on a large unshaded roof produces the same total output as a more efficient one — you just use a few more panels.

Degradation warranty: The long-term performance guarantee matters more than headline wattage. Look for panels warranting less than 0.5% degradation per year — a 30-year guarantee at that rate still leaves you with over 85% of original output at end of life.

N-type vs P-type: N-type cells (TOPCon, HJT) degrade more slowly and perform better in low-light conditions than P-type (PERC). P-type is cheaper and still a solid choice — the gap is real but not dramatic for most UK installs.

Common mistake: Comparing panel wattage without accounting for roof orientation and shading. A well-oriented 350W panel on a south-facing unshaded roof will outperform a 400W panel with partial shading or an east/west split. Stage 5 of the guide explains what actually drives output.