Evaluating The Environmental Life Cycle Aspects Of Emerging Technologies – How Can Emergy Analysis Help?

Life Cycle Assessment (LCA) is a popular approach for considering the broader impacts of industrial products and processes. LCA relies on information about emissions throughout the life cycle and their impacts. For emerging technologies or at early stages of engineering design, such detailed information about emissions and their impact is usually not available. However, data about inputs to various industrial processes are much more readily available. This paper discusses a unique role that emergy analysis may be able to play in evaluating emerging technologies such as nanotechnology and green chemistry, with only input-side information. The second law implies that, among different technologies for achieving the same objective, the one with a higher transformity (lower life cycle thermodynamic efficiency) should have a larger environmental impact. However, the life cycle must be broad enough to account for all the thermodynamic processes, including those occurring in ecological systems. Emergy analysis is unique in its ability to meet this requirement. Furthermore, it seems that products with a higher transformity rely more on ecosystem goods and services, and are likely to play a greater role in ecosystem dynamics. These hypotheses, if true would place emergy analysis in a unique position for LCA of emerging technologies and at early stages of decision making. However, these hypotheses need to be statistically validated. This paper presents results for different ways of making electricity which show that if the contribution of ecosystem goods and services is ignored, as in Cumulative Exergy Consumption, the results violate the hypothesis. This indicates the potential unique ability of emergy analysis for evaluating the life cycle environmental aspects of emerging technologies, which we hope will encourage further research in this direction.