Mainly, Solar energy can be used to convert it into heat energy or it can be converted into electricity. Solar energy can be converted into electricity by means of solar thermal energy and photovoltaic. Through Solar Photovoltaic (SPV) cells, solar radiation gets converted into DC electricity directly. This form of energy can be used to power solar watches, calculators or traffic signals. They are often used in locations that are not connected to electricity grid. Solar heat energy can be used to heat water or space heating which means heating the space inside the building.