Polycrystalline Panels explained
Polycrystalline panels (also called multicrystalline) are manufactured by melting multiple silicon fragments together to form the panel cells. This process is less precise than growing a single crystal, resulting in a distinctive blue, mosaic-like appearance.
Historically, polycrystalline was the budget option and monocrystalline the premium choice. The performance gap has narrowed, but monocrystalline has largely taken over the market due to falling production costs.
Key characteristics of polycrystalline panels:
- Efficiency: typically 15–18%
- Cost: slightly cheaper per panel than monocrystalline
- Temperature performance: slightly worse in high heat compared to monocrystalline
- Lifespan: 25-year warranties are common, though degradation rates can be marginally higher
In the UK climate, the difference in real-world output between monocrystalline and polycrystalline panels is relatively small — a well-installed polycrystalline system can still deliver excellent value. However, if roof space is limited, the higher efficiency of monocrystalline panels makes more sense. For large open roofs where more panels can be fitted, polycrystalline can be a cost-effective choice.