How to Compare Solar Systems: Key Metrics
When comparing two solar systems, don't just look at upfront cost. The right metric is LCoE (Levelised Cost of Energy) — the total cost divided by total lifetime generation. A system that costs ₹30,000 more but generates 25% more electricity over 25 years may be far cheaper per unit.
Most Common Comparisons in India
- Mono PERC vs TOPCon: TOPCon costs 8–12% more but generates 5–8% more and degrades slower (0.45% vs 0.55%/yr). Better long-term value for high-tariff states.
- 3kW vs 5kW: If you qualify for only ₹78,000 subsidy at 3kW, the extra 2kW costs full price (₹1.1–₹1.4L more) but generates 67% more. Worth it if you have the load to use it.
- On-grid vs Hybrid: Hybrid adds ₹80,000–₹1.5L for battery backup. Only worth it if power cuts exceed 2 hours/day in your city.