Energy-Material Cycles: A materials-based perspective of vehicle energy systems

Abstract

In this article, we propose an Energy-Material Cycles (EM-cycles) model to facilitate communication and comparison of tradeoffs that exist across energy systems. We ask: How would a materials-based perspective on vehicle energy systems change how the life cycle of combustion, non-renewable electric, and renewable-electric vehicles are characterized?We account for equivalent material transformation steps in a way that can be applied to both combustion-based and electrified energy systems. This is important due to the increasing coexistence of fossil and non-fossil systems, and the dominance of fuelsbased perspectives. We apply the EM-cycles model to compare recent vehicle models and draw conclusions for environmental assessment of decarbonization in general. Results show that electrification may present a material efficiency advantage rather than an energy efficiency advantage over combustion - a result that differs from typical energy system classifications. Results motivate a discussion of energy system perspectives and the advantages of a materials-based perspective.