A presentation on Emergy and efficiency analysis of historical bubbles was made at the 10th Biennial Emergy Research Conference, Emergy Synthesis 10, held at the University of Florida in Gainesville, FL, on January 25-27, 2018.
The concept of emergy is essentially the amount of available energy that has been used up to create a present quality of available energy. For example, to produce coal that can be burnt in a power plant, the coal was likely dug out by petroleum-consuming mining equipment, and transported by a petroleum-consuming train. In turn, that petroleum required a lot of energy for exploration, drilling, refining and transport to the mining equipment. Emergy comprises the sum of these energy inputs rather than the available energy in, say, a ton of coal itself. Emergy is useful in studying the flows and consumption of energy in a wide range of systems from swamp ecosystems to the global economy.
If less emery is utilized to produce one ton of coal than another, then one could say that the production process for that one ton of coal was more efficient that the process to produce the second ton of coal. Since the analysis of dynastic and economic bubbles involves efficiency, the emergy approach is of special interest to physical and quantitative history.