Integrated Heat Transfer Management and Policy-Oriented Design of Photovoltaic Systems in Hot Climates Using PCM and Hybrid PV/T Strategies

Efficient heat transfer management is a critical challenge for photovoltaic (PV) systems operating in hot climates due to the accumulation of heat, which accelerates material degradation and reduces electrical conversion efficiency. This study presents an integrated thermal design approach that combines rear ventilation, phase change material (PCM), and hybrid photovoltaic–thermal (PV/T) systems to enhance performance under the extreme summer conditions of Baghdad, Iraq. Four system configurations were experimentally tested: standard flat PV, tilted ventilated (25°), PCM-enhanced tilted (35°), and hybrid PV/T with PCM and ventilation. Results revealed a strong inverse relationship between surface temperature and efficiency, with an average penalty of 0.5% per °C rise. The baseline system recorded 15.2% efficiency at 62°C and 410 W/m² heat loss, whereas the hybrid PV/T configuration achieved 20.1% efficiency at 36°C and the lowest heat loss of 190 W/m². Numerical methods for predicting efficiency and classification configurations have been built with an error margin of less than 5%. The results showed that combining photovoltaic and hybrid technologies may reduce efficiency losses by up to 30%, enhance energy production, and make the system last longer. This study provides a coherent technical and policy framework for enhancing the performance of photovoltaic systems in hot temperature zones.