Modelling EROEI and net energy in the exploitation of non renewable resources

Recently, Bardi and Lavacchi (2009) showed that a simple system of coupled differential equations can be used for a quantitative description of the exploitation of non renewable resources in a free market economy. The present paper examines how the model describes the behavior of the system in terms of energy return for energy invested (EROEI) and net energy (energy returned minus energy expended). We show that the model generates a behavior of these factors comparable to the results obtained by other methods, for instance for the case of crude oil production in the US. (C) 2011 Elsevier B.V. All rights reserved.