Electrolysis – Proton-exchange membrane electrolyzer | Small- and large-scale units

Electrolyzers offer a good alternative to conventional steam reformation for producing hydrogen if they are powered by electricity from renewable sources. Polymer electrolyte membrane technology offers advantages over other electrolysis technologies, particularly in the case of dynamic load changes. For the industrial use of electrolyzers, not only the stack but also other components are required. This chapter describes which components belong to the balance-of-plant and the functions they fulfill. In smaller systems (<100 kW), the electrolyzers are scaled by increasing the active cell area or the number of cells. For larger systems, electrolyzer manufacturers are switching to modular designs in which they connect identical stacks in parallel to increase capacity. The modular design simplifies the replacement of defective modules and enables easier partial load operation by switching off individual modules.