Performance and analysis of variance for alkaline water electrolyzer PV-powered system for green hydrogen production

The increasing global demand for clean, sustainable energy has driven a surge in interest in hydrogen production using renewable energy sources. Solar-powered water electrolysis, particularly via Alkaline Water Electrolyzers (AWE), offers a promising solution due to its scalability and environmental compatibility. However, optimizing the performance of such systems requires a comprehensive understanding of how the operational parameters affect the system efficiency and productivity. This research examined the performance of a PV-powered AWE system for hydrogen production using TRNSYS simulation and Analysis of Variance (ANOVA) in Minitab. The interplay between AWE operational parameters and varying solar radiation levels is assessed to determine their impact on the system performance. Then, an ANOVA is used to quantify the significance of the factors and identify the optimal operating parameters for best performance. The study includes investigating the effects of operating temperature (40–85 °C) and pressure (1–45 bar) on the performance of an AWE, with a specific focus on voltage and energy efficiencies, as well as specific energy consumption. Additionally, the effects of photovoltaic (PV) module surface temperature (20–60 °C) and solar radiation intensity (100–1000 W/m²) on PV output power, conversion efficiency, AWE performance, hydrogen production rate, and overall system efficiency are examined. Validation of the outcomes derived from the PV module and AWE against experimental data from the literature yields good agreement. The results indicate that increasing the operating temperature of the AWE improves its energy efficiency and reduces its specific energy consumption. Conversely, increasing the operating pressure has the opposite effect. Alkaline Water Electrolyzer operating at 85 °C and 1 bar achieves a theoretical optimal performance with 94.4% efficiency and an energy consumption of 3.75 kWh/Nm³ at a low current density of 78 mA/cm². A significant increase in the hydrogen production up to 5.6 Nm³/h was achieved at solar radiation intensity of 1000 W/m². Elevated PV module temperatures were observed to reduce electrical output and system efficiency, despite the corresponding slight improvements in AWE efficiency. Analysis of Variance confirmed that the PV module surface temperature primarily affects its efficiency, while AWE efficiency is mainly influenced by the electrolyzer temperature. Solar irradiance was recognized as a key factor driving hydrogen production. Ultimately, the overall system efficiency is principally influenced by the PV module surface temperature.