Energy management for modular proton exchange membrane water electrolyzers under fluctuating solar inputs: a constrained nonlinear optimization approach

This study introduces an advanced nonlinear optimization-based energy management system (EMS) specifically designed for modular Proton Exchange Membrane Water Electrolyzers (PEMWE) under fluctuating solar energy conditions. To optimize system efficiency, reduce degradation, and maintain balanced stack operation, the Rotary Power Allocation Strategy (RPAS) employs a dynamic power distribution method that allocates power among multiple stacks based on current demand. A validated electrochemical model calibrated through laboratory experiments and genetic algorithm optimization serves as the foundation for the analysis. Benchmarking in this study has demonstrated the superiority of the proposed strategy to established EMS methods, such as rule-based, fuzzy logic, composite optimization, and decentralized multi-agent scheduling. In terms of system efficiency, it has been demonstrated that there is an increase of 63 % in system efficiency, a greater hydrogen yield exceeding 4200 kg per year, and a considerable reduction in stack voltage degradation. The strategy effectively addresses key limitations associated with conventional EMS approaches, ensuring consistent and equitable stack usage, thus providing a robust, scalable solution for renewable energy-driven hydrogen production. • Novel nonlinear EMS enhances PEM electrolyzer efficiency under solar variability. • Rotary allocation strategy reduces degradation and ensures balanced stack use. • Validated electrochemical model optimized using genetic algorithms. • EMS achieves highest annual hydrogen yield and efficiency among benchmarks.