Mono vs Poly Panel Comparison

Monocrystalline (Mono PERC) panels are made from single silicon crystals — higher efficiency (20-22%), more uniform colour, better low-light performance. Polycrystalline (Poly) panels are made from multiple silicon fragments fused together — lower efficiency (16-17%) but cheaper per watt.

In most cases yes. Mono PERC gives you 20-25% more power per sq ft of roof, better performance in shade/low-light, and a longer 25-year linear warranty. The price premium is now only 10-15% (down from 40% a decade ago), making mono the better choice for almost every installation.

The newest technology (commercial since 2023). TOPCon uses tunnel oxide passivation on the back of the cell for even higher efficiency (22-23%), lower degradation (0.4%/yr vs 0.5% for mono), better temperature coefficient, and 30-year warranty. Most premium installations post-2025 use TOPCon.

When you have plenty of unshaded roof area AND an extremely tight budget. Poly's 10-15% cost savings can matter for utility-scale ground-mount where land is cheap. For urban/rooftop residential with limited roof area, mono or TOPCon wins.

For a 5 kW system: Mono PERC = 10 panels × 2.58 m² = 25.8 m². Poly = 15 panels × 1.94 m² = 29.1 m². Mono saves ~3.3 m² (12%), important when roof area is the constraint. For TOPCon 580W: only 9 panels, 24.2 m² total.

Panels produce less power as they heat up. Poly loses 0.4%/°C above 25°C; Mono PERC loses 0.35%/°C; TOPCon loses 0.30%/°C. On a 45°C Indian summer rooftop (+20°C above STC), poly loses 8% vs TOPCon's 6% — a noticeable real-world difference.

Poly: 20-25 year linear performance warranty. Mono PERC: 25-year linear. TOPCon: 30-year linear with better degradation curves (80% at year 30 vs year 25 for others).

No. Never mix panel types in the same string — voltage and current mismatches reduce overall array output by 10-20%. Always use identical panels per string, ideally per the whole array.