The solar energy is one of the ideal sources of renewable energy. This energy can be used incessantly as long as there is sun. It is believed that the earth absorbs nearly 3,850,000 exajoules (EJ) of solar energy. In one hour, the energy absorbed by the planet's oceans and landmasses is more energy than the world consumes in an entire year. With lower costs and increased efficiency of solar technologies, solar energy is becoming a rage in renewable energy market.
Solar energy can be tapped in two ways: Passive and Active. Passive solar techniques include selecting materials with favorable thermal properties, designing spaces that naturally circulate air, and positioning buildings to maximize sun exposure. Active solar techniques use photovoltaic panels, pumps, and fans to convert sunlight into electricity.
Active technologies increase the supply of energy and are considered supply side technologies, while passive solar technologies reduce the need for alternate resources and are generally considered demand side technologies. Investment in solar energy can be done keeping in mind the favorable aspects of tapping sun’s energy and the ways of doing it.