Utility-Scale Green Hydrogen System’s Operational Flexibility Under Temperature Dynamics

Grid-connected utility-scale hydrogen systems (USHSs) require enhanced operational flexibility to ensure sustainable hydrogen production. Proton exchange membrane (PEM) Hydrogen Electrolysers (HEs) exhibit greater operational flexibility, allowing lower and extended loading ranges to accommodate surplus renewable energy (SRE). However, in a modular setup, temperature variations significantly influence inter and intra-modular HE loadings, affecting their operational flexibility. Most studies either disregard temperature effects or model them simplistically as constants, neglecting variations in HE thermodynamics and ambient temperatures. Furthermore, these USHSs primarily operate near their rated capacities to satisfy downstream hydrogen demands. The need to utilize SRE will force HEs to operate under higher loadings, increasing auxiliary power requirements to regulate temperature, rendering SRE operations economically less attractive. Therefore, to understand the interplay between HE temperature dynamics and SRE utilization, this study proposes a multi-physics HE modelling, addressing the complexities of HE thermodynamics in USHSs. The proposed model considers HE temperature dynamics w.r.t. ambient conditions, lower loadings, extended operations, variable efficiency, modularization, and downstream operations to reflect the exact operational dynamics. Analyzing various HE operations, the results indicate that temperature dynamics modulates HE loadings, limiting its low-load operations to avoid startups and temperature management, providing precise HE operational flexibility in emerging low-carbon grid-connected USHSs.