Monocrystalline vs polycrystalline panels: which is best?
Monocrystalline panels are more efficient (around 20% or more), perform better in low light and limited space, and are now the standard choice for UK homes. Polycrystalline panels are slightly cheaper but less efficient and increasingly rare. For most installs, monocrystalline is the better choice, especially where roof space is tight.
How they compare
| Feature | Monocrystalline | Polycrystalline |
|---|---|---|
| Efficiency | ~20%+ | ~15 to 17% |
| Space needed | Less per kWp | More per kWp |
| Low-light performance | Better | Good |
| Cost | Slightly higher | Slightly lower |
| UK availability | Standard | Increasingly rare |
Which to choose
For nearly all UK homes, monocrystalline panels are the right pick: more output from the same roof and strong performance on dull days. The small price premium is usually worth it. Panel brand and the inverter matter more than the mono-vs-poly distinction today.
Frequently asked questions
- Are monocrystalline panels worth the extra cost?
- Usually yes, especially on smaller roofs, because the higher efficiency fits more output into the available space.
- Do panel types affect my warranty?
- Warranties depend on the brand, not the cell type. Look for a product warranty of 12 years or more and a performance warranty of 25 years.
Related questions
Indicative estimates based on UK average data. Last updated 27 May 2026.