Biomass is fuel that is developed from organic materials a renewable and sustainable source of energy used to create electricity or other forms of power. Biomass for millennia has been the primary energy source on the planet. Plants are a common source of biomaterials. Corn, for instance, can be processed to make liquid automotive fuel, and wood can be burned for heat energy. Other sources include residue from forests, such as grass clippings and fallen leaves. Many plants can be turned into industrial fuel, including willow, corn, and hemp.