A conceptual exergy-based framework for assessing, monitoring, and designing a resource efficient agri-food sector

The sustainable development goals (SDGs) are a set of global goals, targets, and indicators set by the member states of the United Nations and which are to be followed by governments, the private sector, and the civil society for the next 15 years. Here, we present a framework in the form of a comprehensive step-wise procedure that will expand the tools of policy makers to develop policies for the improvement of the resource use efficiency of the agri-food sector. Ultimately, these policies will contribute in achieving Goal 12 of the SDGs (ensure sustainable consumption and production patters) while having an indirect impact on Goal 2 (end hunger, achieve food security and improved nutrition and promote sustainable agriculture), and on Goal 13 (take urgent action to combat climate change and its impact). We illustrate the use of the framework on assessing the exergetic performance of a theoretical milk concentration process. The framework can be used to apply exergy-based indicators for pinpointing the hotspots in food production chains where the irreversible consumption of natural resources is substantial, and for comparing the resource use efficiency of different system designs and configurations. Furthermore, we list a number of other exergy-based methodologies that are also of relevance in resource use efficiency assessment because they capture additional aspects (such as economic performance which exergy analysis alone cannot address) and with the potential of being integrated in this (or a different) framework. Finally, we discuss potential policy related implications.