Hybrid Solar Spectral-Splitting Photovoltaic-Thermal Hydrogen Production Systems.

Utilizing solar energy to produce green hydrogen is sustainable, but achieving high efficiencies remains challenging. In this study, a hybrid solar spectral-splitting photovoltaic-thermal hydrogen (SSPVTH) system is developed. Leveraging emerging membrane-less electrolyzers, this system simultaneously employs photovoltaics and solar thermal energy to maximize solar-to-hydrogen (STH) production efficiency. The SSPVTH system based on gallium arsenide solar cells achieves an STH efficiency of 21.1%, representing a 31.1% relative improvement over a conventional PV-electrolyzer that relies solely on photovoltaic electricity for water electrolysis. When equipped with perovskite photovoltaics, the system attains an STH efficiency of up to 19.0%. Additionally, with the integration of direct current power converters, the system maintains relatively stable performance across varying solar irradiance levels. Overall, this study provides a new design with the potential for achieving high-efficiency hydrogen production through hybrid solar technologies.