What is resource consumption and how can it be measured?: Theoretical considerations

When analyzing the metabolism of our economy, the usual choice for a measure of resource consumption is the throughput of matter and energy. This, however, cannot be sufficient, since consumption by definition is always relating to the destruction or transformation, and hence a change in quality, not only in quantity, of material or energy flows. Here, an approach is presented that takes the entropy production associated with any process as a measure for the resource consumption of that process. Entropy production is thereby used to approximate the intuitive notion of consumption, which can best be described by the term loss of potential utility. This article delivers theoretical evidence for the validity of this choice, and a second article in a future issue will present an application taken from the metallurgical sector. The related concept of exergy analysis is discussed and compared against the entropy approach.