Solar and water heating — price, types and what to check
Rooftop solar, water heaters, geysers and backup.
Rooftop solar and solar water heaters cut bills sharply across sunny India. Planning the roof structure and conduits during construction avoids breaking waterproofing later.
The basics
- On-grid solar exports surplus to the grid through net metering; hybrid systems add batteries.
- Central subsidy is available for residential rooftop solar under PM Surya Ghar — check current rates on the national portal.
- Solar water heaters: ETC for most cities, FPC for hard water.
Solar and water heating types and price ranges in India
| Type | Specification | Best used for | Indicative price |
|---|---|---|---|
| On-grid rooftop solar | 3 kW | Bill savings, net metering | ₹1.8–2.4 lakh |
| Hybrid solar with battery | 3 kW | Power backup | ₹2.5–4 lakh |
| ETC solar water heater | 100–300 L | Hot water | ₹18,000–45,000 |
| FPC solar water heater | 100–300 L | Hard-water areas | ₹25,000–60,000 |
| Storage geyser | 15–25 L, 5-star | Bathrooms | ₹6,000–18,000 |
| Instant geyser | 1–6 L | Kitchen | ₹3,000–9,000 |
| Inverter and battery | 900–1,500 VA | Power backup | ₹12,000–35,000 |
Quality checks before you accept delivery
- Panels must be on the government's ALMM list to qualify for subsidy.
- Mono PERC or TOPCon panels give more power per sq ft.
- Geysers: 5-star rating, glass-lined tank for hard water.
- Panel wattage and serial numbers should match the invoice.
- The inverter should be certified for grid connection.
- The mounting structure should be galvanised.
Pro tips
- 1 kW needs about 100 sq ft of shadow-free roof and yields roughly 4 units a day.
- Face panels south, tilted close to your latitude.
- Leave conduits and a structure base in the terrace slab during construction.
- Keep the inverter in a shaded, ventilated spot.
- Clean panels every 2–3 weeks in dusty seasons.
- Install a lightning arrester and separate earthing for the solar system.
- Check generation monthly in the inverter app.
Mistakes to avoid
- Panels shaded by the water tank or parapet.
- Drilling through terrace waterproofing to fix the structure.
- Cheap inverters without warranty.
- Panels mounted too flat, collecting dust and water.
- Undersized DC cables.
Where you can save
- Size the system to your yearly bill, not the maximum roof area.
- Apply through the national portal with an empanelled vendor to claim the subsidy.
How much you need
A typical 3BHK uses 3–5 kW of rooftop solar.
Brands to know
Tata Power Solar, Waaree, Adani Solar, Luminous, Racold, AO Smith, V-Guard, Havells