Towards highly efficient solar photovoltaic thermal cooling by waste heat utilization: A review

Photovoltaic (PV) systems are popular for their reliability and zero fuel costs. However, only around 20 % of solar energy is converted into electricity, while the remainder is dissipated as waste heat. Excessive waste heat affects the lifespan of PV systems, leading to abnormal operating temperatures. In this notion, Photovoltaic-thermal (PV/T) systems are introduced to extract waste heat through various cooling techniques to harness electrical and thermal energies, demonstrating their capabilities through experimental and modeling techniques. Researchers have sought to develop optimized modeling techniques based on empirical, semi-empirical, and AI-based modeling for efficient execution of PV/T systems. This study reviews the current optimization developments in the PV/T systems, focusing on multiple numerical and experimental designs. Various cooling methods, including air, water, and phase change materials (PCM) with nanofluids, are examined for their promising contributions to electrical and thermal efficiency enhancement. Additionally, optimization methods have been investigated by incorporating automated processes into PV/T systems employing self-automation techniques. These processes aim to reduce the overall cost and establish a self-sustaining performance. Finally, the challenges and recommendations for future research for PV/T enhancement are highlighted.