A PV-driven multifunctional dehumidification/hydrogen-production system based on PEM: Experimental investigation and performance analysis

A PV-driven multifunctional dehumidification/hydrogen production system was developed, and proved that it has good all-day operation stability. With the increase of operating voltage, the system had a maximum dehumidification rate (0.21 × 10−4 g/s at 9.3 V), and the cathode hydrogen concentration was in the range of ca. 400–800 ppm. [Display omitted] •PV-driven multifunctional electrolytic dehumidification/hydrogen-production system was proposed.•The influences of solar irradiance, PV operating voltage and shading ratio on all-day operating performance were tested.•The multifunctional dehumidifier had a good stability though the solar irradiance fluctuates greatly.•Hydrogen production was very sensitive to changes in operating voltage and shading ratio.•Exergy analysis showed that the losses of PV modules and the dehumidifier were 85.5% and 4.1%, respectively. The combination of polymer electrolyte membrane (PEM) electrolysis and solar energy can offer many advantages. This paper developed a photovoltaic (PV)-driven multifunctional air dehumidification/hydrogen-production system. Its all-day operating performance under different solar irradiance was experimentally studied. The influence of PV operating voltage, area, and shading ratio on system performance was also investigated. The results demonstrated that the multifunctional system had good operational stability, despite the considerable fluctuation in solar irradiance throughout the day. When the system was driven by a 6 V PV module on sunny days (average solar irradiance during 12:00–14:00: 186–753 W/m2), it operated at a stable moisture removal rate (0.13–0.16 × 10−4 g/s). As the operating voltage increased, the dehumidification rate first increased and then decreased, displaying a maximum value of 0.21 × 10−4 g/s at 9.3 V. However, the hydrogen concentration of the cathode air (767 ppm at 3 V) showed a decrease trend in applied voltage. The solar utilization efficiency also exhibited a maximum value (2.8% at 75.9 cm2) as the PV module area was increased. When PV was partially shaded (shading ratio 1/12), the dehumidification deteriorated, while the hydrogen concentration increased by 33.3%. Exergy analysis showed that during operation, PV module (85.5%) and shunt current (6.2%) caused great losses, while the exergy consumed by the electrode polarization and electrolytic reaction of PEM module was only 3.0% and 1.1%, respectively. Thus, possible optimizations are provided.