Solar Energy is a direct and perrenial energy source. It is non polluting and is available freely. The technology of converting solar energy into heat and utilizing it for various applications can now be commercially exploited. Solar Energy is received in the form of light and heat radiation. The radiant energy of the Sun can be converted into thermal, electrical, mechanical energy etc. but of all these types of energy in solar radiant energy the thermal conversion mode is the easiest and most convenient. The sun energy can be used to meet the thermal requirements in almost all the temperature ranges in every sector of national economy. The objective of the Solar Thermal Programme of The Department of Non Conventional Energy Sources is to develop and promote use of technologies for conversion of solar energy into thermal energy for supplementing the ever increasing demand for thermal and electrical energy in the developing economy.