Balancing energy efficiency and membrane degradation in PEM electrolyzers: A membrane degradation-aware model

The Power-to-X-to-Power (P2X2P) paradigm addresses renewable energy variability by converting surplus electricity into energy-dense molecules, like hydrogen, via water electrolysis. This process splits water into hydrogen and oxygen, allowing the stored hydrogen to be later used for power generation. Among various technologies available, Proton Exchange Membrane (PEM) electrolyzers are gaining interest due to their compactness and flexibility. However, models of such devices rarely include degradation mechanisms, which are crucial for accurately assessing the lifetime. Therefore, a comprehensive model of a PEM electrolyzer combining the modeling of energy consumption, hydrogen production, and membrane degradation is developed. A semi-empirical approach is used, considering only degradation caused by radical attacks resulting from oxygen crossover at the cathode. The membrane degradation submodel shows improved versatility across different operating conditions compared to the previously available models. Ultimately, a case study explores how to run PEM electrolyzers in a pseudo-optimal configuration by finding a balance between high energy efficiency and low membrane degradation.