Technological Pathways to Produce Compressed and Highly Pure Hydrogen from Solar Power

Hydrogen (H2) produced from renewables has a growing impact on the global energy dynamics towards sustainable and carbon-neutral economy. The share of green H2 is still too low to meet the net-zero target, while the demand for high-quality hydrogen continues to rise. These factors amplify the need for economically viable H2 generation technologies. This presentation gives an overview of the existing technologies for high-quality H2 production based on solar energy. Technologies such as water electrolysis (PV coupled to electrolyzers), photo-electrochemical and solar thermochemical water splitting, liquid metal reactors and plasma conversion utilize solar power directly or indirectly (as carbon-neutral electrons) and are reviewed from the perspective of their current development level, technical limitations and future potential for the generation of highly pure and compressed H2 [Angew. Chem. Int. Ed., e202218850, 2023]; Acknowledgement: The Helmholtz Association of German Research Centers (HGF) and the German Federal Ministry of Education and Research (BMBF) are acknowledged for supporting the Innovation Pool Project “Solar H2: Highly Pure and Compressed“ under the Research Program “Materials and Technologies for the Energy Transition” (MTET) - Topic 3: Chemical Energy Carriers. The review paper in Angew. Chem. Int. Ed., e202218850 (2023) is a joint contribution of the HGF Centers FZJ GmbH, KIT, DLR, HZDR, HZB and MPI-IPP