Part of the complete guide: Solar cost (complete guide)
Size depends on your electricity use, not on the size of your house. Start from your monthly units and divide by about 120, the units one kW produces in a month in South Kerala.
| Typical home | Monthly units | System | Panels (540 Wp) | Roof space |
|---|---|---|---|---|
| 1BHK / small home | 100–150 | 1–1.5 kW | 2–3 | 110–160 sq ft |
| 2BHK, 1 AC | 200–300 | 2–3 kW | 4–6 | 215–320 sq ft |
| 3BHK, 2 ACs | 350–500 | 3–4.5 kW | 6–9 | 320–480 sq ft |
| Large house or villa | 600–1,200 | 5–10 kW | 10–19 | 540–1,080 sq ft |
Two things that change the answer
- Kerala's net metering limit: small systems get full credit for exports; larger ones are reported to fall under net billing. Size for daytime use. See the KSEB guide.
- Roof space and shade: a shadow-free roof is the real limit. Use the calculator and add your roof area.
Always verify. Subsidy, tariff and price figures change; confirm with the official portal, KSEB / TNPDCL and a written quote.
