Hydrogen is considered as the 'holy grail' for our energy community. One of the most promising strategies to produce hydrogen is to split water using renewable energy such as solar radiation. The abundance of water and solar energy enables the potential of scaling-up of this new technology, if suitable electrocatalysts and solar cells are developed. In this work, we investigated a series of materials that are made of earth-abundant elements for hydrogen evolution and oxygen evolution. Among the tested catalysts, MoS 2 and NiFe showed the best activities for proton reduction and water oxidation, respectively. These catalysts were further integrated into an alkaline electrolyzer which delivered a a current density of 10 mA cm -2 at a voltage of 1.9 V for water splitting. Using 2 in series connected perovskite solar cells (PSCs) as a power source we achieved a remarkable solar-to-hydrogen conversion efficiency of 12.67% in an alkaline electrolyzer with a partial current density of 10.3 mA cm -2 for hydrogen production. The usage of earth abundant catalysts in our study, together with the employment of perovskite solar cells, show the potential of scaling up this type of PV-electrolyzer for sustainable hydrogen production.