Sources of Energy
Nearly all energy comes from the sun, either in a roundabout① way or straight from it, in the form of heat rays and light rays. The light from the moon, too, comes from the sun. The moon can be said to be like a large mirror which throws back the sun's light to the earth.
Electrical energy comes from the sun in a roundabout way, e.g.②, it can come from the power of water falling down a mountainside③. The water fell there as rain, and we know that rain is made by the sun's heat evaporating the water on the earth's surface. This water vapour rises, condenses④ on cooling, and falls as rain.
