Emergy accounting (EA) is one of the methods in the sustainability assessment toolbox. In its use of stocks and flows of energy and matter it has similarities with e.g. Material Flow Analysis and Life Cycle Assessment, but EA also includes stocks and flows of money and information. In its methodological approach of relating to a global baseline of renewable flows EA is similar to Ecological footprints in that it is not just revealing which of two alternatives is using more or less of different stocks or flows but also comparing the use to available renewable flows on a global annual basis.
This paper address the contribution of three different aspects of EA (emergy analysis, emergy synthesis) to the overarching goal of sustainable development. The discussed aspects were: 1) the Emergy Sustainability Index (ESI), 2) emergy as a normalizing measure, and 3) emergy as a network measure.
It was concluded that the ESI is an interesting measure but does not catch the full range of the sustainability concept. The EA approach, with the ESI as part of it, has more to say about sustainability than what is captured by the ESI alone. An interesting outcome is that the traditional triple-bottom-line of environmental, economic and social sustainability emerges very easily from the emergy assessment conceptual diagram approach. EA holds a promise to classify the economic, social, and socio-economic domains of sustainability, as well as their connection to the ecological/environmental sustainability. The reason why the ESI captures only a small part of what is interesting from a sustainability point of view in the full EA may be that it has the focus on the traditional load and yield components. Many of the interesting parts from emergy evaluations in the sustainability context may instead come from the capability of EA to capture network properties.