Solar energy is energy from the sun in the form of heat and light. The sun’s energy can be used to provide lighting and heat for buildings and to produce electricity. It is also considered a part of hydroelectricity as the sun’s actions on water cause evaporation and rain to fill reservoirs.
Historically, solar energy has been harnessed through passive solar systems. Solar energy can be harnessed only during the day and only if the sunlight.
Today, two active solar technologies that involve electrical or mechanical equipment are becoming more common. First, solar collectors or panels are used to heat water or ventilation air for use in buildings. Second, solar photovoltaic technology uses solar cells to convert sunlight directly into electricity.
Off-grid or grid-tie systems can use battery storage to alleviate the shortfall of darkness interfering in the production of energy. There are other ways to ‘store’ the energy by pumping water to a tank above a micro-hydro generator for later use. Even compressed air can run a back-up generator!