Solar water heating is the conversion of sunlight into heat for water heating using a solar thermal collector. A variety of configurations are available at varying cost to provide solutions in different climates and latitudes. Solar water heatings are widely used for residential and some industrial applications.
A sun-facing collector heats a working fluid that passes into a storage system for later use. Solar water heatings are active and passive. They use water only, or both water and a working fluid. They are heated directly or via light-concentrating mirrors.
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 selective absorbing material. This helps absorption of solar radiation and transfers the heat to the water which flows through the inner tube. There are 44 MNRE approved ETC based solar water heating suppliers.