From Exergoeconomics to Thermo-X Optimization of Energy Systems in the transition to a fully renewable system

Exergoeconomics has played an important role in the analysis and optimization of energy systems in the last decades. The idea of using exergy as a “carrier of value” allowed defining an unambiguous criterion to allocate costs among the products of energy systems and paved the way to a deeper analysis of the losses of potential work within the systems. With the development of efficient optimization algorithms, the exergoecomic procedures of analytic optimization and the design improvement procedures based on heuristic exergoeconomic criteria have been gradually replaced by more efficient optimization procedures aimed at minimizing a “cost” objective function, leaving the calculation of exergoecomic costs in the optimum as final step. The increasing attention to the mitigation of the effects of human activities on climate change, together with increasingly higher disparity in the availability and use of energy, enlarged the perspective to a wider set of goals of the energy system designer, which has to consider the energy systems as a part of the whole society. This asks the energy systems designer to move the attention also towards energy users, integrating the design and operation optimization of energy conversion systems with smarter methodologies to reduce energy consumption. Therefore, we propose the Exergoeconomic methodologies to evolve towards ThermoX Optimization methodologies involving a wider set (X) of goals and constraints than the economic ones, to solve the “energy problems” of our society with a wider perspective. The paper briefly summarizes the history of Exergoeconomic analysis and optimization methodologies and outlines the path for developing a general methodology including all the aspects mentioned above.