Through the discussion on climate change and the security of energy supply, hydrogen has obtained global attention and gained political, industrial and social importance. The advantages of an increasing use of hydrogen in the future include the ability to store it and to convert it into electricity without producing any CO2. Applications in the field of decentralised hydrogen generation using electrolysers with low electric power for petrol stations, energy buffers and systems for autonomous energy supply, which have come into consideration as a result of these properties, require new conceptual approaches adapted to the system.
This paper summarises the results of an investigation into advanced electrolysis concepts. The characteristic differences and potentials of electrolysis operation are discussed as a function of the temperature level, pressure and the electrolytes used. Moreover, we report on technical concepts for bifunctional operation as electrolyser and fuel cell. The results of a process and systems analysis provide information on the specific challenges and opportunities associated with small electrolysers in a systems and process engineering context. In conclusion, the pressing need for R&D in order to verify advanced electrolysis for decentralised hydrogen generation is defined and Research Centre Jülich's contribution to this is presented.