Solar Thermal Energy

The energy from the Sun if and when converted into thermal energy is called solar thermal energy. Its applications are water heating, air heating, desalination, generation of power etc.
The products that are based on Solar Thermal Energy are such as Solar water heating system, Solar cooker, Solar desalination system, Solar hot air system etc.
The solar water heating system consists of a solar collector, toughened glass, insulated storage tank, cold water supply tank and insulated piping. The sun rays penetrate through the glass and fall on the absorber.
The heat of the sunrays is absorbed by the cold water inside the absorber thereby increasing its temperature. The heated water gets collected inside the insulated storage tank either through the thermosyphon or the forced flow system.
In the Thermosyphon system upto 3000 liters per day can be installed, however, for higher capacities it is necessary to use the forced flow system.The water temperature can be raised upto 85C. The solar water heating system can be used for bathing, washing, boilder feed water and similar other purposes where hot water is required in domestic, commercial and industrial sectors.
The cost of the solar water heating system range from Rs.140/- to Rs.220/- per litre, depending upon the capacity of the system and the investment made can be recovered in 4 to 6 years time. The life of the system is around 10 – 15 years if maintained properly. The operation and maintenance cost is negligible. Solar Desalination System means Solar energy can be used for getting distilled water. The device used is called solar still. It is made of fiber glass, with a tapered top surface. A glass is fitted on the top surface. The unit has an area of a sq.m. The daily output from the solar still is 2-2.5 litres.
The Solar Hot Air System:- The solar hot air system can be used for drying of agricultural products like leaves of tea and coffee, groundnuts, seeds, tobacco, chemicals, grapes etc. This way, apart from saving in fuel costs, it is also possible to get a better yield and good product quality by using the solar hot air system.
The system consists of a solar hot water system through which the water temperature can be raised upto 80 C. A liquid-to-air heat exchanger is then used to produce hot air at about 60-70C, which can be supplied for drying purposes.
Thus, Solar Thermal Energy based products are very very useful and they are also cost saving products. Its operation and maintenance cost is very negligible.