Biomass for energy—a review

The enthusiasm, in recent years, for biologically derived fuels has not been repaid by the emergence of major new industries. Where they have been adopted, biofuels have needed extensive subsidies or other community support. This review examines the inherent problems of the bioenergy concept, which may ensure that biofuels will never enjoy more than a purely local exploitation. These problems derive from the relatively small usable biomass resource, its high cost and the cost of upgrading biomass to usable fuels, the unfavourable energy balance in converting high entropy feedstocks to low entropy fuels, and the anticipated effects of such processes on the environment.