Dynamic multicriteria optimization of household heating and cooling system for reusing fuel-cell waste heat at optimal thermodynamic conditions while considering climatic effects

Abstract

Energy system structures are evolving toward increasing cost benefits, efficiency, and environmental sustainability. Achieving these goals is contingent upon the utilization of renewables. Energy storage is the primary challenge associated with renewable energy. Hydrogen and fuel cells are key in addressing these issues. Iran demonstrates significant renewable-energy potential; however, only a small fraction of this potential is currently utilized. Furthermore, the country’s energy system is inefficient. Thus, a feasible plan for creating a sustainable energy system that reliably includes renewables must be developed. The household heating and cooling system is a good starting point. The required model must be dynamic and consider climatic effects, which have not been sufficiently addressed in previous studies conducted in Iran. In this study, the optimal thermodynamic variables, output power, and waste heat for different fuel-cell capacities are first determined by solving a nonlinear model. Subsequently, through a dynamic multicriteria optimization of household heating–cooling systems, the optimal system configurations for 10 years across five different case studies in various climates in Iran are determined. The objective function is to minimize the total costs, which include technology, energy, raw material, and social costs. This study demonstrates the feasibility of developing a fuel-cell technology to satisfy the energy demands of household heating and cooling systems based on case studies. However, reusing waste heat is only practical in hot and humid climates because of the low heating demand.