A Set of Coherent Indicators for the Assessment of the Energy Profitability of Energy Systems

The concern on climate change and on the limitations of fossil fuels is leading to the promotion of renewable-based energy options. However, the assessment of the energy profitability of a technology is still a controversial topic, especially when renewable-based systems are compared with non-renewable ones and when the depletion of the stocks of available resources is not accounted properly. As a matter of fact, some popular energy indicators do not seem to cover all the aspects of the problem, with the risk of drawing ambiguous conclusions. A set of life cycle-based indicators is proposed in order to establish a more reliable approach to the assessment of energy products which decouples the different contributions given by renewable and non-renewable resources. The proposed set of indicators has been quantified for different groups of energy products and compared with an energy indicator frequently used (i.e. EROI). A coherent assessment of the depletion of energy resources and of the energy profitability of the products is presented. The indicators could even contribute to understand the feasibility of energy projects and plans by evaluating their impact on the stock of energy resources.