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. SWHs 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. SWH are active (pumped) and passive (convection-driven). They use water only, or both water and a working fluid. They are heated directly or via light-concentrating mirrors. They operate independently or as hybrids with electric or gas heaters.In large-scale installations, mirrors may concentrate sunlight onto a smaller collector.
Solar water heating is now a mature technology. Wide spreadutilization of solar water heaters can reduce a significant portion of theconventional energy being used for heating water in homes, factoriesand other commercial & institutional establishments. Internationally themarket for solar water heaters has expanded significantly during the last decade.
Aside from cost and greenhouse gas emissions savings, the beauty of a solar hot water system is its relative simplicity and durability!
There are two types of collectors used in a solar hot water service:
1.Flat plate collectors (suitable where tank roof mounting is required)
2.Evacuated tubes (more efficient and great for frost prone areas).
The solar radiation incident on the surface of earth can be conveniently utilized for the benefit of human society.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 panel coated with selected coating transfers the hat to the riser pipes underneath the absorber panel. The water passing through the risers get heated up and is delivered the storage tank.
- Around 60 deg – 80 deg c temp can be attained depeding on solar radiation , weather conditions and solar collector system efficiently.
- Hot water for homes , hostels , hotels , hospitals , industries etc.
- The amount of hot water consumed each day must be replaced and heated.
- Solar water heaters (SWHs) of 100-300 litres capacity are suited for domestic application.