Why Solar Water Heaters are a Must-Have
In an average Indian household, heating water for bathing is the second biggest electricity consumer after Air Conditioning. An electric geyser (usually 2000W or 3000W) running for just 1 hour a day adds 60-90 units to your monthly bill (approx ₹500-₹800).
How Solar Water Heaters Work
They work on the principle of Thermosyphon. Cold water flows down from your overhead tank into the bottom of the solar collector. As the sunlight heats the water in the tubes/plate, it becomes lighter and rises up naturally into the insulated storage tank. This cycle repeats all day, giving you boiling hot water (60°C - 80°C) by evening, which stays hot till the next morning thanks to PUF insulation.
Hard Water Issues
India suffers from hard water issues (borewell water). Hard water causes scaling (salt deposits) inside heating tubes.
- ETC Systems: The wide glass tubes are less prone to clogging and are easier to clean/replace if scaling happens.
- FPC Systems: The narrow copper capillaries can get choked easily. You must use a heat-exchanger model if you have very hard water.
Cost vs ROI
A typical 200 LPD ETC system costs around ₹25,000 - ₹30,000. It saves you about ₹12,000 per year on electricity bills. This means the system pays for itself in just 2-3 years. After that, you enjoy free hot water for the next 15 years.