This is one of the more unpleasing of the renewable energies. It is called biofuel. Bio fuel technologies uses biomass (otherwise waste both human and animal and also plants) resources to produce energy. One of the new types of biofuel is biodiesel which will be much more efficient and enviroment safe then fossil fuels. Biofuel ranks only second to hydropower in U.S.A's renewable energy production.

Bio fuel is not only easy to obtain because we make it constantly. It also creates massive amount of energy. Also biomass can be added with fossil fuels to make even more energy. The only big problem with it is that there must be alot of biofuel inorder to create enough energy.