Energy Return On (energy) Invested (EROI) and its importance in assessing the performance of energy systems

Meeting the energy needs of our societies, in the context of the fight against global warming and the prospect of depleting stocks of fossil fuels and mineral resources, requires the implementation of low-carbon alternative solutions. The cost per MWh is undoubtedly a useful criterion, but physical criteria are essential for assessing technological solutions and possible energy scenarios. The main of these criteria based on physical quantities is the “Energy Return on Invested” (EROI), which measures the efficiency of a system in providing society with useful energy for sectors other than the energy sector itself. Other aspects must also be considered, such as the availability of resources, the surface areas mobilised, mineral requirements, industrial risks and environmental and health impacts.