Ecology of scale versus economy of scale for bioethanol production

Sustainability is an essential requirement of biofuel production. The reduction of ecological impact by using renewable resources instead of fossil raw materials is a major driving force for biofuel implementation. The investigation of ethanol production systems on different scales utilizing corn as well as wheat as raw material reveals, however, a strong influence of the size of the plant on the environmental pressure exerted by biofuel production. Comparing different technological options at different levels of production capacity gives insights into the major factors governing ecological as well as economical performance. The trend with regard to economic performance is straightforward and well known: the higher the production capacity of a plant, the lower the costs. The picture is less clear with regard to ecological performance. Increased efficiency of larger plants usually reduces not only the costs but also the ecological impacts. Logistical factors, however, become increasingly important, leading to situations where economy of scale and ecology of scale are in contradiction. (C) 2007 Society of Chemical Industry and John Wiley & Sons, Ltd.