Bioenergy is energy from organic matter (biomass), i.e. all materials of biological origin that are not embedded in geological formations (fossilised). Biomass can be used in its original form as fuel, or be refined to different kinds of solid, gaseous or liquid biofuels. Biomass fuels can be produced from agricultural, forestry and municipal wastes and residues, as well as from crops such as sugar, grain, and vegetable oil. Crops grown for use as biomass fuel can be grown on degraded, surplus and marginal agricultural land, and algae could, in the future, be exploited as a marine source of biomass fuel. These fuels can be used in all sectors of society, for production of electricity, for transport, for heating and cooling, and for industrial processes.

Currently, the major use of biomass is in the form of heat in rural and developing countries. About 90% of all the bioenergy consumption is in the traditional use. The primary energy supply of forest biomass used worldwide is estimated at about 56 EJ, which means woody biomass is the source of over 10% of all energy supplied annually. Overall, woody biomass provides about 90% of the primary energy annually sourced from all forms of biomass.