These are coal, oil, natural gas, and peat. We can burn them to get energy but one day these sources of fuel will run out. Burning fossil fuels also causes pollution and perhaps Global Warming. Apart from making the solar panels and other equipment to distribute the electrical energy, solar power does NOT casuse pollution. It will NOT run out for millions of years.
Light is an electromagnetic disturbance.
We can think of light as being made of tiny particles called photons, or we can think of it as being made of waves. Both models help us to understand how light behaves. Light is reflected when it falls onto a shiny surface. Light is refracted when it passes from one material into another, i.e. out of the air and into water or in and out of glass. Heat is caused by vibrations of the atoms and molecules of substances.