ABSTRACT
The conversion of solar energy by the fundamental process of photosynthesis is the basis for life. Photosynthesis primarily converts carbon dioxide and water to carbohydrates and oxygen and then the heterotrophs consume the primary producers to sustain their lives, through the food chain or food web. There are three aspects for biomass: overall biomass, production/consumption of food and fiber and bioenergy. Bioenergy shares some of the characteristics of other renewable energy resources. Bioenergy has the advantage that the energy is stored in the biomass, so variability is not the same problem as for solar and wind, although there is the variability of growth and harvest by season for some sources. For bioenergy, the density is low and hence it has to be converted to a different form, for example liquid fuel, and in general the moisture content is a problem. The energy content and logistics are important factors in determining the economics of bioenergy.
