Solar energy is the radiant light and heat from the Sun that has been harnessed by humans since ancient times using a range of ever-evolving technologies. According to the recordation, the utilization of solar energy by human beings has a long history for more than 3000 years. However, the history to utilizing the solar energy as a kind of energy and power alternatives is only limited to 300 years and only a minuscule fraction of the available solar energy is used.

Since 1970s, the solar energy technologies have developed increasingly, and the utilization of solar energy has been variable with each passing day. Recently, it is estimated by some famous analysis and research institutes, multinational companies, solar expertise and governments that solar energy is to occupy 50% of worldwide energy structure including wind energy and biomass energy around the middle of the 21st century (2050). Until that time, solar energy is to be the foundation energy for the worldwide sustainable development.

Solar power provides electrical generation by means of heat engines or photovoltaics. Once converted, its uses are limited only by human ingenuity. A partial list of solar applications includes space heating and cooling through solar architecture, potable water via distillation and disinfection, daylighting, hot water, thermal energy for cooking, and high temperature process heat for industrial purposes.