Part of the complete guide: Solar cost (complete guide)
Quick answer
Compare quotes line by line on the same basis: module brand, DCR status and wattage; inverter brand and warranty; structure material; earthing and protection; who handles KSEB/TNPDCL and subsidy paperwork; payment schedule; and written warranties. The cheapest quote is rarely the best value if it omits any of these.
The 12-point comparison table
| # | Check | Good sign |
|---|---|---|
| 1 | Module brand, model, Wp, DCR | Named brand, BIS/ALMM, DCR stated |
| 2 | Number of modules | Matches kW (e.g. 6 × 540 Wp ≈ 3.2 kWp) |
| 3 | Inverter brand, rating, warranty | 5–10 years, local service centre |
| 4 | Structure material | Hot-dip galvanised or aluminium, wind-rated |
| 5 | Cables, ACDB/DCDB, SPD | Copper, proper ratings, surge protection |
| 6 | Earthing and lightning arrestor | Separate earth pits, resistance report |
| 7 | Net-metering and subsidy paperwork | Included, with named responsible person |
| 8 | Subsidy treatment | Quoted at full price; subsidy credited to you |
| 9 | Warranty | 25-yr module performance, ≥5-yr workmanship in writing |
| 10 | Payment schedule | Staged (e.g. 20/60/20), not 100% advance |
| 11 | Timeline | Installation in days; commissioning timeline stated |
| 12 | References | Verifiable installations nearby |
Red flags
- Price far below ₹55,000/kW without explanation
- 'Equivalent' or unnamed modules and inverters
- Subsidy deducted from the quote as a 'discount'
- Full advance payment demanded
- No written warranty or no GST invoice
Get help
We compare quotes for free through installer matching, or audit a quote in detail with the Solar Advisor service.
Always verify. Subsidy, tariff and price figures change. Confirm with the official portal, KSEB/TNPDCL and a written quote before paying any advance. Figures here are indicative for South Kerala & Kanyakumari.
