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

Hydrogen (H2) produced from renewables will have a growing impact on the global energy dynamics towards sustainable and carbon‐neutral standards. 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. The present article aims at evaluating the existing technologies for high‐quality H2 production based on solar energy. Technologies such as water electrolysis, photoelectrochemical 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. This Review gives an overview of the technological pathways for direct and indirect production of H2 from solar power within the frame of the Innovation Pool project “ Solar H2: Highly Pure and Compressed ”. Technologies such as water electrolysis, photoelectrochemical and thermochemical water splitting, liquid metal and plasma reactors are described in terms of their principle of operation and specifics regarding to the quality (purity, pressure) of produced H2.