Renewable energies are created from natural and ecological sources of energy such as sun, wind, water, tide or organic matter. These energies come from natural, regular or constant phenomena that make them inexhaustible. They are also sometimes called "green" or "clean" energies. For example, solar energy is an inexhaustible energy on the human time scale, as are the energies derived from it.
-some advantages of renewable energy sources
In general, renewable energies are cleaner than fossil and fossil fuels currently being exploited worldwide. They are more environmentally friendly, available in bulk around the globe and are "free" once production facilities are profitable.