Study and multi-objective optimization of integrating an energetic solar thermal application, a supercritical process, and a high-temperature electrolyser

Supercritical processes using carbon dioxide reached suitable sustainability in previous research. Hence, the current paper proposes and examines a recompression supercritical carbon dioxide Brayton cycle integrated with a solar power tower. To improve the stability of the solar subsystem for continuous daily operation, two energy storage stages are employed innovatively. In addition, the whole scheme embraces a solid oxide electrolyzer. Therefore, a novel combined electricity and hydrogen cogeneration model based on solar energy is evaluated here. To this end, the en-ergy-, exergy-, sustainability-, and economic-based parametric sensitivity study is implemented comprehensively. Net present value is another performance metric investigated in this paper. Besides, a novel multi-objective approach utilizing an artificial neural network combined with a multi-objective grey wolf optimization is performed. Considering four different decision param-eters, optimum objectives include exergy efficiency, hydrogen production rate, and products' unit cost. From the parametric sensitivity study, it is inferred that the outlet pressure of the low-pressure turbine significantly affects performance metrics. Also, from the optimization, the op-timum values of mentioned objectives equal 2587 kg/day, 20.89%, and 17.25 $/GJ, respectively. Moreover, the net present value indicates that the payback period can be reduced up to 8.1 years corresponding to optimum operational conditions.