Renewable hydrogen production

TLDR

The U.S. Department of Energy and NREL are advancing renewable hydrogen technologies, targeting a cost of $2–$3 kg⁻¹ to compete with gasoline, with electrolysis as the standard method and emerging biomass and other processes still in development. Renewable hydrogen is produced by using wind and solar electricity for electrolysis, and by employing solar‑driven conversion pathways—including thermochemical reactions at high temperatures, photoelectrochemical splitting, and photobiology—to split water and process biomass.

Abstract

The U.S. Department of Energy and the National Renewable Energy Laboratory are developing technologies to produce hydrogen from renewable, sustainable sources. A cost goal of $2.00–$3.00 kg−1 of hydrogen has been identified as the range at which delivered hydrogen becomes cost competitive with gasoline for passenger vehicles. Electrolysis of water is a standard commercial technology for producing hydrogen. Using wind and solar resources to produce the electricity for the process creates a renewable system. Biomass-to-hydrogen processes, including gasification, pyrolysis, and fermentation, are less well-developed technologies. These processes offer the possibility of producing hydrogen from energy crops and from biomass materials such as forest residue and municipal sewage. Solar energy can be used to produce hydrogen from water and biomass by several conversion pathways. Concentrated solar energy can generate high temperatures at which thermochemical reactions can be used to split water. Photoelectrochemical water splitting and photobiology are long-term options for producing hydrogen from water using solar energy. All these technologies are in the development stage. Copyright © 2007 John Wiley & Sons, Ltd.