Monocrystalline vs Polycrystalline Solar Panels
The honest answer: monocrystalline has won. The price gap has narrowed to the point where polycrystalline panels are rarely the better choice for residential installations in 2026. But here's what the specs actually mean.
| Property | Monocrystalline | Polycrystalline |
|---|---|---|
| Efficiency | 19–23%+ (standard); 25%+ (HJT/TOPCon) | 15–17% |
| Price per watt | ~€0.65–1.10/W | ~€0.45–0.75/W (diminishing) |
| Temperature coefficient | Better (−0.25 to −0.35%/°C) | Worse (−0.35 to −0.45%/°C) |
| Space required | Less (higher efficiency) | More (lower efficiency) |
| Appearance | Black uniform cells | Blue speckled cells |
| Lifespan | 25–40 years | 25–30 years |
| Low-light performance | Better | Good |
The efficiency gap matters more on smaller roofs
Monocrystalline panels produce more watts per square metre. If your roof is small or partially shaded, you need to maximize output from available space — monocrystalline wins here. On a large unobstructed roof with room to spare, polycrystalline's lower efficiency is less important.
Why the price gap has closed
Manufacturing improvements have made monocrystalline silicon nearly as cheap to produce as polycrystalline. In 2026, most Tier 1 manufacturers have shifted production almost entirely to monocrystalline (mono-PERC, TOPCon, HJT). The era of polycrystalline as a meaningful budget option is largely over.
TOPCon and HJT: the new premium tier
Within monocrystalline, TOPCon (Tunnel Oxide Passivated Contact) and HJT (Heterojunction) represent the current efficiency frontier — 22–25%+ efficiency with better temperature coefficients and lower degradation. These are the panels at the top of our efficiency rankings and perform particularly well in northern European climates where diffuse light conditions are common.