Fitting regression model and experimental validation for a high-pressure PEM electrolyzer

Advanced materials and improved design allow to obtain hydrogen from electrolysis directly at medium-high pressure (70 bar) with no need of mechanical compression stages. This single-step process is more efficient than the two-step electrolysis þ mechanical compression process. In this paper the authors display the experimental results obtained with a prototype of high-pressure PEM electrolyzer manufactured by Giner Electrochemical Systems LLC, including the description of the test bench for the experimental characterization. The experimental design, based on Design of Experiments techniques, studied the effect of the main operation factors (temperature, pressure, water flow) at different levels of power load, presenting a regression model of the electrolyzer voltage as a function of the operating factors, at different values of the electric load.