Biomass fuel is fuel produced from organic material of recent biological origin. Biomass suitable for the production of fuels is classified as either bio-mass waste or energy crops.

Biomass waste is any material of recent biological origin that has been discarded because it has no apparent value. Examples of biomass waste include residues from agricultural crops, municipal solid waste, and even sewage. Because this waste originates from biomass that recycles to the environment on a nearly annual basis, it is a sustainable energy resource; that is, the resource will be available for future generations.

Energy crops are defined as plants grown specifically as an energy resource. An energy crop is planted and harvested periodically. The cycle of planting and harvesting over a relatively short period assures that the resource is used in a sustainable fashion. Energy crops include woody crops harvested on a rotation of five...