Exergies of natural resources in life-cycle assessment and other applications

The applicability of exergy in the methodology of environmental life-cycle assessment (LCA) is discussed. Exergy consumption (or entropy production) may be used as a measure of resource depletion and competition when performing the impact assessment of an LCA. Exergies of several metal ores and other natural resources are calculated using system boundaries compatible with LCA, i.e. the inflow is the resource as found in the environment. These system boundaries may also be appropriate for other applications of exergy analysis and may yield results different from those in calculations where only a part of the resource has been considered.