Daily
Geyser vs solar water heater — when does solar pay back?
A 100-LPD solar water heater costs ₹22,000-30,000 and saves ₹600-900/month. Here is the realistic payback and where geysers still win.
6 May 2026 · 2 min read
Quick frame: A standard 25-litre electric geyser uses ~2 kWh per shower for a hot bath in winter. A solar water heater on the roof eliminates 70-90% of that for ~250 sunny days a year. Whether it pays back depends on your geography and water usage.
Cost comparison
| Item | Cost |
|---|---|
| 25 L electric geyser (Bajaj/Crompton) | ₹6,000-9,000 |
| 100 LPD ETC solar water heater | ₹22,000-32,000 |
| 100 LPD FPC (flat plate) | ₹28,000-40,000 |
| Heat pump (geyser alt) | ₹40,000-60,000 |
100 LPD solar heater is sized for 4-5 person family bathing once a day.
Running cost (winter, 4 baths/day, 4 months heating-heavy)
| Appliance | Annual cost |
|---|---|
| Electric geyser | ₹8,000-12,000 |
| Solar (100 LPD) with electric backup for cloudy days | ₹2,000-3,500 |
| Heat pump | ₹2,500-3,500 (better year-round than solar) |
Use the Geyser vs Solar Tool — it factors in your tariff and family size.
Payback math
Solar water heater:
- Premium over geyser: ₹22,000 (₹28k - ₹6k)
- Annual electricity savings: ₹6,000-9,000
- Payback: 2.5-4 years
- Lifespan: 10-15 years
- Net 10-year savings: ₹50,000-70,000
When solar struggles
- 60+ days of monsoon clouds (Mumbai, Kerala) — backup electric heater required
- Hilly cold regions (Shimla, Manali) — needs FPC type, not ETC
- North-facing roof (low irradiation)
- Apartments without roof access
Heat pump — the dark horse
Heat pumps work like an AC in reverse — they pull heat from ambient air to warm water. Use 1/3 the electricity of resistive geysers, work in cloudy weather, and last 10+ years. Better than solar in monsoon-heavy regions but 3-4× the upfront cost of a regular geyser.
Government subsidy
MNRE offers 20-30% subsidy on solar water heaters in many states (rules vary). Check your state's renewable energy agency website. With subsidy, payback drops to 1.5-2.5 years.
FAQ
Q: Why ETC over FPC? A: Evacuated Tube Collector (ETC) is more efficient in cold weather, freeze-resistant, but tubes can break individually. FPC (Flat Plate Collector) is more durable, better for high-wind coastal areas, but slightly less efficient.
Q: Maintenance? A: Annual cleaning of ETC tubes, checking insulation, replacing anode rod every 5 years. ~₹500-1,500/year.
Q: Can I retro-fit solar to an existing geyser line? A: Yes — installer integrates a 3-way valve. Geyser kicks in only when solar tank is below threshold temperature.
Try the free tool
Geyser vs Solar Water Heater
Electricity vs solar — payback math.
Open Geyser vs Solar Water Heater →