Recent Development in Direct Generation of Hydrogen Using Multi-Junction Solar Cells

Hydrogen produced from solar energy has a high potential as a storage medium to buffer the fluctuations of renewable energy sources. The direct combination of concentrator photovoltaics with an electrolyzer has the capability to produce Hydrogen from sunlight at high efficiency. For this, the individual components have to be adjusted carefully and optimized with the final system in mind. This paper focuses on the solar cell development and shows first results of the combined module of a solar cell and an electrolyzer. The solar cell used for hydrogen production is a metamorphic GaInP/GaInAs dual-junction solar cell. This tandem cell reaches a maximum efficiency of 34.2% under concentration. The performance of the combined module shows a strong influence of temperature and DNI.