Biomass is a renewable energy source from biological elements such as animals, plants and microorganisms. It includes all organic wastes, discharge from industrial activities, sawdust and livestock sludge.

Biomass can be used as various types of energy. Dried wooden biomass is turned into gas directly through combustion, carbonization and pyrolysis. Agricultural products and food waste that contains plenty of carbohydrates can be transformed into ethanol through fermentation. Wastes with a high percentage of water content such as livestock sludge can be transformed into methane gas and used as energy.

Bioenergy is drawing attention as a supplement to fossil fuels due to it being renewable, storable and carbon neutral.