There are two forms of bioenergy in use today: “traditional” and “modern”. Traditional use of biomass includes fuelwood, animal waste and traditional charcoal. Modern biomass technologies include liquid biofuels produced from straw and wood, industrial cogeneration and bio-refineries, biogas produced through anaerobic digestion of residues, pellet heating systems and other technologies. Bioenergy as a whole accounted for 12% of the world’s total final energy consumption in 2010, meaning that three-quarters of the world’s current renewable energy use comes from bioenergy as a whole, and more than half from traditional biomass.
Biomass has especially significant potential in populous nations, such as Brazil, India and China. It can be directly burned for heating or power-generation, or it can be converted into oil or gas. Liquid biofuels, a convenient renewable substitute for gasoline, are mostly used in the transport sector.
Brazil is the leader in liquid biofuels and has the largest fleet of flexible-fuel vehicles, which can run on bioethanol — an alcohol made by fermentation that’s mostly from carbohydrates produced in sugar or starch crops such as corn, sugarcane, or sweet sorghum.