Experimental and theoretical development of a PEM electrolyzer model applied to energy storage systems

Electrolyzers have been pointed out as a promising technology for use in energy storage applications. Basically, electrolyzers convert electrical energy to electrochemical energy, which stays encapsulated in diatomic hydrogen molecule for posterior use in fuel cells, which convert the electrochemical energy back to electrical energy. The main advantages of the electrolysis process are the zero-emission of greenhouse gases, the use of water as the source of hydrogen, and the high efficiency in energy conversion. Electrolyzers can be fed by the grid or by renewable sources such as solar and wind. In both cases a power converter is necessary to conditioning the electrical energy in order to deliver a clean DC current to the electrolyzer. In this context, this work shows a modeling of a PEM (proton exchange membrane) electrolyzer intending its use in conjunction with power converters. The main losses in such electrolyzer are modeled and it is shown the influence of the current ripple in the electrolyzer behavior and efficiency.