Panel type
Polycrystalline Panels
Polycrystalline panels are less efficient than monocrystalline but more affordable. They typically degrade at 0.6–0.8% per year and are more common in older residential installations.
Expected lifespan
25 years
Equipment type
panel
Common issues
Natural panel degradation
All solar panels lose efficiency over time at roughly 0.5–0.8% per year. Accelerated in extreme heat or poorly manufactured panels.
Typical loss: 3–15%
Cell hotspots
Localised overheating in individual cells caused by micro-cracks, shading, or manufacturing defects. Best detected via thermal imaging.
Typical loss: 5–20%
Panel soiling
Dust, pollen, bird droppings, or debris accumulation reducing light absorption. More severe in arid or agricultural areas.
Typical loss: 2–15%
Check your system
Use our free Solar Loss Checker to estimate how much energy your polycrystalline panels system may be losing.
Check my systemBased on conservative solar performance modelling and published degradation data
Updated April 2026 · Structured performance modelling
How we calculate →