Dynamic analysis and multi-objective optimization of an integrated solar energy system for Zero-Energy residential complexes

This study introduces and evaluates a novel, integrated solar energy system for achieving sustainable and zero-energy residential buildings. The proposed system integrates photovoltaic-thermal (PVT) solar panels, heat pumps, electrolyzers, fuel cells, reverse osmosis desalination units, and thermal storage tanks to simultaneously supply electricity, heating, cooling, and potable water. A primary challenge in solar energy systems—the intermittency of energy production—is addressed using energy storage solutions, including hydrogen-based electrolysis and fuel cell systems, which stabilize the supply across day-night cycles. The energy system is designed to meet the energy demands of a 160-unit residential complex in San Diego, each unit covering 110 m2. A dynamic simulation over an entire year is performed using TRNSYS software. System optimization is conducted via Response Surface Methodology (RSM), targeting three objective functions: total power capacity, life cycle cost (LCC), and thermal comfort represented by the predicted percentage dissatisfied (PPD) index. Optimization system is based on five key decision variables: solar PVT area, fuel cell capacity, electrolyzer capacity, heat pump capacity, and hydrogen tank size. Results demonstrate that, under optimized configurations, the system achieves an annual electricity output of 29,145.8 kWh/year, an LCC of $894,228, and a PPD index of 6.8 %, fully meeting the residential complex's electricity demand of 200 MWh/year. The results validate the effectiveness of the hybrid system in enhancing efficiency, ensuring system reliability, and mitigating environmental impacts, thus offering a scalable solution for zero-energy building applications.