Biomass refers to renewable, plant-derived organic materials other than fossil resources. Biomass energy is obtained from organic waste that has traditionally been difficult to process, such as wood building materials, paper, foodstuffs, human waste and raw sewage, rice straw, and rice husks. These are burned or used to produce gas as recycled material. It is an eco-friendly, clean energy source that also contributes to the creation of a recycling-oriented society.