Technoeconomic Model and Pathway to <$2/kg Green Hydrogen Using Integrated Halide Perovskite Photoelectrochemical Cells

Abstract

The cost of gray hydrogen produced via fossil fuel-based steam-methane reforming has led the U.S. Department of Energy to specify <$2/kg H2 as a target for commercially competitive green hydrogen generation methods. Integrated photoelectrochemical cells have been proposed as a solar-to-hydrogen conversion technology. Here, we describe a technoeconomically feasible pathway to reaching <$2/kg green H2 using integrated photoelectrochemical cells with halide perovskite photoabsorbers, low-cost conductive barriers, and low precious metal-content catalysts in an aqueous, membrane-separated cell. A base-case solar-to-hydrogen conversion efficiency of 20%, stable lifetime of 10 years, and a combined electrocatalyst-plus-panel cost of $50/m2 enabled a levelized cost of hydrogen of $2.43/kg, which dropped below $2/kg with improved performance metrics including material cost, improvements in process design, or subsidies. We relate these metrics to lab-scale reports to recommend best research practices for scientists and funding agencies working at this intersection of photovoltaics, electrocatalysis, and surface science.

Large-area all-perovskite-based coplanar photoelectrodes for scaled-up solar hydrogen production

“…2,4–11 Yet, the use of PEC devices is not widespread because of their high fabrication cost, low performance and poor stability, along with the absence of large-scale deployment. 12 Recently, the development of lead halide perovskite (LHP)-based integrated photoelectrodes has helped overcome these drawbacks and has facilitated unbiased PEC water splitting, resulting in the achievement of a high solar-to-hydrogen (STH) efficiency exceeding 13% with high stability, encouraged by various encapsulation methods. 13–20 In particular, the solution processability of LHPs renders them suitable for large-scale and low-cost fabrication, as extensively pursued in the field of photovoltaics.…”

Thermally integrated photoelectrochemical devices with perovskite/silicon tandem solar cells: a modular approach for scalable direct water splitting

“…The tunability of the band gap of perovskites explains the growing interest in these materials from the solar fuels community. 23…”

“…The tunability of the band gap of perovskites explains the growing interest in these materials from the solar fuels community. 23 To date, studies on the combination of perovskite/silicon tandem solar cells and electrolysers, or on photoelectrodes based on perovskite/silicon absorbers, have all been carried out on a small scale and under laboratory conditions. The largest active surface area 14 and the longest stability test 20 already reported under controlled indoor conditions are 1.42 cm 2 and 102 h, respectively.…”