Due to its nuclear fusion reaction, the sun is continuously pouring huge amount of energy in several forms, including light, heat, radio waves and even x-rays. The Earth, in orbit around the sun, intercepts a very small part of the sun's immense output. On Earth, direct sunlight is available from sunrise until sunset. Solar collectors and modules are designed to capture some of the sun's energy and change it from radiation into more usable forms such as heat or electricity. Infect, sunlight is an excellent source of heat and electricity, the two most important forms of energy we consume. Solar is increasingly popular in remote area electrification in tropical countries like India such as telecommunication, rural electrification, irrigation, solar vaccine refrigeration etc.

In Solar Photovoltaic applications, sunlight is directly converted to electricity by the help of silicon cell modules and stored in batteries for utilisation in night or other usage. In Solar Thermal applications, heat energy of the sun is trapped by the help of solar collectors used for water heating (both domestic and industrial), power generation, swimming pool heating etc.