Towards a better understanding of energy systems using emergy-based exergoeconoenvironmental analysis

This paper introduces 'emergy-based exergoeconoenvironmental analysis', a new methodology for improved understanding of energ systems through simultaneous consideration of thermodynamic, financial, and ecological criteria. A new parameter called exergetic ecological emergy/financial emergy ratio is first introduced. This parameter is then used for deriving emergy-based exergoeconoenvironmental balances for an energy system by combining it with exergy cost concepts. The exergetic ecological emergy/financial emergy ratio for all exergy streams of the system is determined using the SPECO approach. The developed approach is applied to a simple cogeneration system of power and steam to demonstrate its general applicability and robustness. The outcomes of the developed method herein are assessed in comparison with those of emergy-based exergoeconomic and exergoenvironmental methods. Overall, the highest total exergetic ecological emergy/financial emergy ratio (13.0841 sej/sej) is observed in the heat-recovery steam generator (HRSG) followed by the air preheater (APH) (10.0379 sej/sej). Even though both emergy-based exergoeconomic and exergoenvironmental methods give the improvement priority first for the combustion chamber (CC), the heat-recovery steam generator is suggested by emergy-based exergoeconoenvironmental analysis. Generally, the hybrid framework developed here appears to be a promising complement to available exergy-based techniques for systematically developing thermodynamically, financially, and ecologically conscious energy systems.