Renewable Sources of Energy:
Energy derived from the radiation of sun is known as solar energy.It is also known as radiant energy. The earth receives heat and light from the sun. The energy generated by the sun is enormous. It consists of heat radiations called infrared rays, ultraviolet rays and some gamma rays. The earth receives infrared rays and visible light, thus heating up the land-masses and waterbodies.
This energy can be used in cooking with the help of solar cooker, heating water using solar water heater, and in batteries using solar cell.
Plants also need solar energy to manufacture food through the process of Photosynthesis.
The convection current of air is called wind. It is caused by uneven heating of the earth surface by the Sun. Fast moving air possess Kinetic energy. the Kinetic energy can be used to rotate the blades of the windmill. The windmills have been used to pump water and grind grain since a long time. The modern day windmills are used to rotate turbines of electric generators to generate electricity.