Modern biomass energy services have the potential to make a significant contribution to a new energy paradigm. The world currently consumes about 400 EJ (exajoules) of energy per year but generates the equivalent of about 100 EJ of largely unused crop residues. It could produce an additional 180 EJ from energy-dedicated grasses and trees. Despite this potential, bioenergy must be viewed not as the single replacement for oil, but as one element in a wider portfolio of renewable sources of energy.
The production of energy from biomass involves a range of technologies that include solid combustion, gasification, and fermentation. These technologies produce liquid and gas fuels from a diverse set of biological resources — traditional crops (sugarcane, maize, oilseeds), crop residues and waste (maize stover, wheat straw, rice hulls, cotton waste), energy-dedicated crops (grasses and trees), dung, and the organic component of urban waste. The results are bioenergy products that provide multiple energy services: cooking fuels, heat, electricity, and transportation fuels. It is this very diversity that holds the potential of a win-win-win development path for the environment, social and economic development and energy security.
There is a clear link between access to energy services and poverty alleviation and development. The first set of critical energy needs are those that satisfy basic human needs: fuel for cooking, heating and lighting, energy for pumping water, and electricity for health and education services. The second set of critical energy needs are those that provide energy for income-generating activities that help break the cycle of poverty.
The poor rely heavily on biomass as a source of energy, but traditional bioenergy — derived mainly from the combustion of wood and agricultural residues — has severe negative impacts. First, when combusted in confined spaces, these substances produce significant indoor pollution to which women and children are primarily exposed. This exposure has severe health consequences, including respiratory illnesses and premature death. Second, this kind of biomass use puts immense pressure on local natural resources, especially as communities must satisfy increasing demands for energy services.
