Alkaline water electrolysis for hydrogen production is a technique well established with electrolysers in a wide power range being commercially available. Hydrogen production by electrolysis is increasingly studied as a way to smoothen the fluctuating power output of renewable energy sources not correlating with the electrical energy demand. However for this purpose present electrolysers have to be improved for fluctuating power operation and the system costs have to be decreased to reach a low cost energy conversion.
To address these challenges in the project RESelyser a new separator membrane with internal electrolyte circulation and an adapted design of the cell to improve mass transfer, especially gas evacuation, is investigated and demonstrated. Intermittent and varying load operation with RES will be addressed by improved electrode stability and a cell concept for increasing the gas purity of hydrogen and oxygen especially at low power operation as well as for very high pressure. Also the system architecture will be optimized for intermittent operation of the electrolyser.