Multi-scale extended exergy analysis of the “system Romania”: A tool for monitoring the UN-2030 SDGs

The paper describes an application of the Extended Exergy Accounting method (EEA in the following) to the calculation of the total amount of primary resources used (i.e., consumed) at country level in Romania. A distinctive novelty of EEA is the inclusion in the calculation of the so-called Externalities, i.e., of the monetary fluxes within the system and of the Labour intensity: both quantities are reduced, via an original modelling technique, to flows of primary resources, so that the global consumption of the Country is expressed in terms of the “load” it exerts on the resources available in the Biosphere and in the immediate planetary surroundings. Performing an EEA analysis requires as a first step the calculation of the global mass & energy balances at country level: the results (material and immaterial flows) are then converted into their respective exergy values. Exergy is a non-conserved thermodynamic quantity, and the outcome of this step (Exergy Analysis, ExA) already pinpoints the areas in which irreversibilities affect the conversion of primary resources into final goods and services (e.g., how many kWh of primary energy are embodied in 1 unit of a commodity). The EEA adds another fundamental step: using an ad hoc model to describe the exergy flows in-and-out of the Country, two empirical parameters are derived that account for the primary equivalent exergy required to generate 1 unit of monetary circulation (eeK, kJ/€) and for the primary equivalent exergy required to generate 1 “unit of Labour”, i.e., 1 workhour (eeL, kJ/workhour). For any production line for which sufficiently disaggregated information is available, these two parameters allow for the calculation of a cost proper, expressed in kWh of primary (exergy) resource per unit of any produced commodity. The method applies both to material goods and immaterial “commodities and services”. As an additional feature, EEA uses a remediation model to calculate the primary exergy “cost” of the (near) annihilation of environmental damage caused by the effluents and wastes.