Here’s a simple but complete comparison of Mono PERC vs TOPCon vs HJT — the 3 main solar technologies used today.

🌞 1. Mono PERC (Older but still common)

Full form: Passivated Emitter Rear Cell

Type: Mostly P-type silicon

✅ Pros

1. Cheapest technology
2. Proven & widely available
3. Good performance for budget projects

❌ Cons

1. Lower efficiency compared to new tech
2. Higher degradation
3. More power loss in heat

📊 Typical Performance

1. Efficiency: 19–22%
2. Lifespan: 25–30 years
3. Degradation: Higher than N-type panels

Mono PERC adds a reflective layer at the back of the cell to reuse sunlight and improve output compared to old mono panels.

👉 Best for: Low budget residential projects

⚡ 2. TOPCon (Most Popular in 2024–2026 Market)

Full form: Tunnel Oxide Passivated Contact

Type: N-type silicon (advanced)

TOPCon is basically an improved version of PERC with an extra tunnel oxide layer that reduces energy loss and increases efficiency.

✅ Pros

1. Higher efficiency than PERC
2. Better heat performance
3. Lower degradation
4. Good price vs performance balance
5. Becoming industry standard

❌ Cons

1. Slightly costlier than PERC

📊 Typical Performance

1. Efficiency: 22–24% (or more)
2. Lifespan: 25–30 years
3. Better temperature tolerance

Mass-production efficiency of TOPCon cells has already exceeded 25% in some cases.

👉 Best for: Residential + commercial (most recommended today)

🚀 3. HJT (Most Advanced / Premium)

Full form: Heterojunction Technology

Type: Hybrid crystalline + thin-film silicon

HJT combines crystalline silicon with thin-film layers to achieve very high efficiency and low losses.

✅ Pros

1. Highest efficiency
2. Best performance in heat & low light
3. Very low degradation
4. Highest bifacial gain
5. Longer lifespan

❌ Cons

1. Most expensive
2. Limited manufacturers (still growing)

📊 Typical Performance

1. Efficiency: 24–26%+
2. Lifespan: 30+ years
3. Lowest temperature loss

HJT panels degrade slower and maintain better output over lifetime compared to PERC.

👉 Best for: Premium customers / large projects / space-limited roofs

📊 Quick Comparison Table

🧠 Which One is Best?

✔ Budget customer → Mono PERC

✔ Most customers today → TOPCon (Best choice)

✔ Premium / future-proof → HJT

Industry experts expect TOPCon to dominate the market in the next few years, while HJT grows gradually as costs fall.

⭐ Simple Real-World Advice (India Market)

For rooftop solar sales:

1. 5–10 kW residential → TOPCon
2. Commercial / industrial → TOPCon or HJT
3. Subsidy / low budget → Mono PERC