U.S. Department of Energy - Energy Efficiency and Renewable Energy

Fuel Cell Technologies Office – Hydrogen Production

Photobiological Water Splitting

Photo of system for photobiological algal hydrogen production.

A set of bio-reactors can use light (sunlight or artificial light) and the natural activities of enzymes in green algae to produce hydrogen from water. Photobiological production of hydrogen is a promising renewable option for the long term.

In this process, hydrogen is produced from water using sunlight and specialized microorganisms, such as green algae and cyanobacteria. Just as plants produce oxygen during photosynthesis, these microorganisms consume water and produce hydrogen as a byproduct of their natural metabolic processes. Photobiological water splitting is a long-term technology. Currently, the microbes split water much too slowly to be used for efficient, commercial hydrogen production. But scientists are researching ways to modify the microorganisms and to identify other naturally occurring microbes that can produce hydrogen at higher rates. Photobiological water splitting is in the very early stages of research but offers long-term potential for sustainable hydrogen production with low environmental impact.

Learn more about photobiological water splitting—prospects, challenges, and research to address technical barriers—in the following publications: