Kilowatt-scale solar hydrogen production system using a concentrated integrated photoelectrochemical device

Abstract

The production of synthetic fuels and chemicals from solar energy and abundant reagents offers a promising pathway to a sustainable fuel economy and chemical industry. For the production of hydrogen, photoelectrochemical or integrated photovoltaic and electrolysis devices have demonstrated outstanding performance at the lab scale, but there remains a lack of larger-scale on-sun demonstrations (>100 W). Here we present the successful scaling of a thermally integrated photoelectrochemical device—utilizing concentrated solar irradiation—to a kW-scale pilot plant capable of co-generation of hydrogen and heat. A solar-to-hydrogen device-level efficiency of greater than 20% at an H₂ production rate of >2.0 kW (>0.8 g min⁻¹) is achieved. A validated model-based optimization highlights the dominant energetic losses and predicts straightforward strategies to improve the system-level efficiency of >5.5% towards the device-level efficiency. We identify solutions to the key technological challenges, control and operation strategies and discuss the future outlook of this emerging technology.

Solar hydrogen production devices have demonstrated promising performance at the lab scale, but there are few large-scale on-sun demonstrations. Here the authors present a thermally integrated kilowatt-scale pilot plant, tested under real-world conditions, for the co-generation of hydrogen and heat.