The cheapest solar you can install
Solar water heaters pay back faster than rooftop PV for most households. A 200 LPD ETC system costs ~₹50,000 (₹40,000 after MNRE subsidy) and saves ~₹23,500/year in electric geyser bills. That's a 22-month payback — faster than PV, cheaper upfront, and no batteries or inverters to worry about.
Family size → LPD quick reference
| Family | LPD | Collector Area (ETC) | Net Cost |
|---|---|---|---|
| 2 members | 100 | 1.7 m² | ₹22K |
| 3-4 members | 150-200 | 2.5-3.3 m² | ₹35-42K |
| 5-6 members | 250-300 | 4.2-5 m² | ₹55-62K |
| 7+ members | 400+ | 6.7+ m² | ₹85K+ |
For households replacing both geyser and air conditioning, pair the hot-water sizing with our Solar AC Calculator, and tally the combined electric load using the Appliance Load Calculator.