Solar Water Heater
A solar water heater consists of a collector to collect solar energy and an insulated storage tank to store hot water. The solar energy incident on the absorber pipe coated with selected coating transfers the heat to The water passing through the pipe and is delivered to the storage tank. The re-circulation of the same water through absorber pipe raises the temperature to 80 C (Maximum) in a good sunny day. The total system with solar collector, storage tank and pipelines is called solar hot water system.
Evacuated Tube Collectors (ETC) based Solar Water Heaters
Evacuated Tube Collector is made of double layer borosilicate glass tubes evacuated for providing insulation. The outer wall of the inner tube is coated with a selectively absorbing material. This helps absorption of solar radiation and transfers the heat to the water which flows through the inner tube.
Solar water heating is now a mature technology. Widespread utilization of solar water heaters can reduce a significant portion of the conventional energy being used for heating water in homes, factories and other commercial and institutional establishments.
Recommended Capacity
| Capacity(LPD) | No. of Connections | No. of Persons |
| 100 | 1 | 2 |
| 150 | 1 | 2-3 |
| 200 | 2 | 3-4 |
| 250 | 2 | 4-5 |
| 300 | 3 | 5-6 |
| 500 | 4 | 6-10 |
| 1000 | 8 | 12-20 |
Monthly Saving Comparison (all figures are in )
| Electric Heater | LPG | Solar | |
| 100 LPD | 416 | 349 | 0 |
| 150 LPD | 625 | 573 | 0 |
| 200 LPD | 833 | 697 | 0 |
| 250 LPD | 1041 | 872 | 0 |
| 300 LPD | 1250 | 1046 | 0 |
| 500 LPD | 2080 | 1744 | 0 |
| 1000 LPD | 4160 | 3488 | 0 |