Electricity may be generated from a range of biofuels which are themselves derived from a wide variety of biologically based feedstocks. Source materials comprise both biomass of agricultural or forestry origin and waste matter. These sources of energy are becoming increasingly important in both the developed as well as the developing nations, providing viable and environmentally attractive fuels able to compete effectively with more conventional energy sources in niche markets. Given further development, biofuels have the potential to provide a significant fraction of the world's electricity generation needs.