Solar water heater (SWH) 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 Heaters are widely used for residential and some industrial applications.
Solar water heating is now a mature technology. Wide spread 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 & institutional establishments. Internationally the market for solar water heaters has expanded significantly during the last decade. It is estimated that over 107 million m2 of collector area has so far been installed worldwide for heating water. In the country, the collector area so far installed for water heating is over 1million m2. Ministry has plans to add another 2 million m2 in next two years.
Solar water heaters (SWHs) of 100 LPD - 500 LPD (liters per day) capacity are applicable for domestic application can be used in independent houses, villas etc.
Solar water heaters (SWHs) of 1000 LPD (liters per day) and above capacity are applicable for commercial application can be used in apartments, hostels, restaurants, hotels, hospitals etc
Evacuated Tube Collector is one of the technology in solar water heater which is economical to use. This is one way to reduce the heat loss inherent flat plates. Since heat loss due to convection cannot cross a vacuum, it forms an efficient isolation mechanism to keep heat inside the collector pipes. Typically, the water piping in an ETC is therefore surrounded by two concentric tubes of glass seperated by a vacuum that emits heat from the sun (to heat the pipe) but limits heat loss. The tube collector is a 3 layered glass tube made of CU, AL, SS. Evacuated tube collector are made of triple layer borosilicate glass tubes which heats water more efficiently even in low temperature.
ETC Solar Water Heater mainly comprises of the storage tank, tank insulation, tubes, electrical backup, supporting structure.
The water heating technology or water heating circulation is known as thermosphyon method.
For domestic systems the tank insulation material is puff insulation.
For commercial systems the tank insulation material is rockwool insulation.
The System temperature output is 60-800 Celsius.
Domestic ETC Solar Water Heaters