Experimental and numerical investigation of a PVT-PEM system: impact of flow channel configurations on hydrogen production

We investigate the potential benefits of coupling photovoltaic-thermal (PVT) modules with proton exchange membrane (PEM) electrolysis systems for hydrogen production, specifically focusing on optimized PVT backplate flow channel configurations, and aiming to promote the thermal-electrical synergies of the coupled solar-hydrogen production system. Both experimental and computational methods are applied to evaluate the thermal, electrical, and fluid flow characteristics and performance of the proposed PVT-PEM system. A novel temperature uniformity evaluation (TUE) index is developed based on the circuit theory and statistical analysis. Results indicate that PVT components with serpentine tube flow channels exhibit the highest electrical efficiency, while parallel tube structures demonstrate superior thermal performance. Bidirectional flow configurations show better TUE values than unidirectional ones. When the mass flow rate is 0.02 kg/s, the bidirectional parallel tube exhibits the TUE, which is 0.14. The proposed PVT-PEM system outperforms a conventional PV-PEM system by 3.3% in producing hydrogen and has a 23% higher exergy efficiency. When the electrolysis temperature exceeds 50 °C, the hydrogen production efficiency improves by 3.8%. This study presents critical insights into the optimization of PVT-PEM systems for sustainable energy applications, emphasizing the potential of bidirectional parallel tube configurations in improving energy efficiency and hydrogen generation.