(Invited) Shunt-currents in Alkaline Water-Electrolyzers and Renewable Energy

Shunt-currents are inevitably an integrated part of a bipolar electrolyzer with a common manifold system for distribution of the electrolyte in and out of the different cell compartments. Shunt-currents represent some extra challenges when operating alkaline water-electrolyzers (AWE) with renewable energy, both with respect to energy efficiency and reduced lifetime of electrodes. These challenges multiply for increasing length of the electrolyzer-stack and limits the number of cells in the stack. This paper will explain the challenges in more detail, how it limits the operation with renewables and what are the important design criteria to mitigate the impact of shunt-currents.