Biofuels are non-fossil fuels. They are energy carriers that
store the energy derived from organic materials (biomass), including plant
materials and animal waste.
They may be solid, such as fuelwood, charcoal and wood pellets; liquid, such
as ethanol, biodiesel and pyrolysis oils; or gaseous, such as biogas.
Often the term biofuel is used in a narrow sense to refer to
liquid biofuels for transport.
First-generation biofuels are currently produced from food
crops such as sugar cane and rapeseed. They include bioethanol
(made from sugars and starch) and biodiesel (made from
Second-generation biofuels are under development and will be
derived from non-food plant matter such as crop residues and agricultural or
municipal wastes. They include bioethanol made from cellulosic
materials such as straw or wood.
Bioenergy - Biomass - Energy crop - Fossil fuel(s)
To read about this term in context:
GreenFacts Summary on Forests & Energy: