Hydrogen can be produced using 4 broad process groups. Within each group, multiple forms of
technology have been developed. For the map, we have divided the dataset into these groups. The
and map are intended to be evergreen. As the hydrogen sector develops, the PE Media Network data
maps team will be adding more projects. Most of the current projects indicated on the map fall
Thermal and Electrolytic process groups.
Thermal processes for hydrogen production typically involve steam reforming, a high-temperature
process in which steam reacts with a hydrocarbon fuel to produce hydrogen. Many hydrocarbon
fuels can be
reformed to produce hydrogen, including natural gas, diesel, renewable liquid fuels, gasified
coal, or gasified biomass. Today, about 95% of all hydrogen is produced from steam reforming
Water can be separated into oxygen and hydrogen through a process called electrolysis.
Electrolytic processes take place in an electrolyser, which functions much like a fuel cell in
Instead of using the energy of a hydrogen molecule, like a fuel cell, an electrolyser creates
Biological processes use microbes, such as bacteria and microalgae, to produce hydrogen. In
microbial biomass conversion, the microbes break down organic matter like biomass or wastewater
hydrogen, while in photobiological processes the microbes use sunlight as their energy source.
Solar-driven processes use light as the agent for hydrogen production. Solar-driven processes
include photobiology, photoelectrochemical reactions and solar thermochemical reactions.
processes use the natural photosynthetic activity of bacteria and green algae to produce
hydrogen. Photoelectrochemical processes use specialised semiconductors to separate water into
and oxygen. Solar thermochemical hydrogen production uses concentrated solar power to drive
splitting reactions, often along with other species such as metal oxides.