Low-Cost High-Throughput Photoelectrochemical Hydrogen Production

Hydrogen production via photoelectrochemical (PEC) water splitting has promise for storage of solar energy in a clean fuel for vehicular and grid applications. However, PEC technologies with high solar-to-hydrogen (STH) efficiency have high materials and processing costs, and less expensive alternatives have not achieved high efficiencies. Here we discuss a systems-level approach to improving utilization of high-efficiency III-V PEC cells using optical concentration factors much higher than have been previously considered. Full system and cost analyses are presented, indicating the potential of this approach to reduce the cost per kilogram of hydrogen produced to significantly lower than that of a photovoltaic-plus-electrolyzer solution.