“Exergy describes the maximum work which can be produced from a system under a given environment. This concept is commonly used in process engineering to estimate (or design) various energy systems such as co-generation systems. Exergy is one of the most widely used goal functions in the structural dynamic modeling.” (Banerjee, Rakshit, and Ray 2019)

Extended Exergy Accounting (EEA) is “a systematic attempt to integrate into a unified coherent formalism both Cumulative Exergy Consumption and Thermo-economic methods, and constitutes a generalisation of both, in that its framework allows for a direct quantitative comparison of non-energetic quantities like labour and environmental impact (hence the apposition ‘Extended’).”

In one case study on the city of Karachi, the main energy supply as well as flows of labour and capital were quantified using extended exergy accounting (Jahangir, Chen, and Wakeel 2016). Other exergy work on an urban level covers Beijing and Castelnuovo Berardenga. However, urban exergy studies are few and far apart, hinting at difficulties in application and limitations in the usefulness.