Energy Return on Investment : A Unifying Principle for Socio-Ecological Sustainability

Energy return on investment (EROI) is a biophysical and ecological economics concept that is useful to think about how organisms, ecosystems and societies must obtain enough surplus energy returned from energy gathering activities to live, reproduce, and thrive. EROI can help us overcome the false dualism between nature and society. EROI is a useful metric for economics because it is based on immutable physical laws rather than sometimes arbitrary human preferences. It is essential for assessing useful power, energy trade-offs, efficiencies (and inefficiencies), resource depletion trends, resource quality, and surplus potentials of different fuels and technologies that power, or might power, our socio-economic systems. Apparent inconsistencies in the literature can generally be reduced or eliminated by paying careful attention and explicitly stating boundaries and definitions. We argue that proper use of EROI is critical to understand the interconnections among the environment, energy, and socio-economic development, and inform future energy transitions