As of 2020, the majority of hydrogen (∼95%) is produced from fossil fuels by steam reforming of natural gas and other light hydrocarbons, partial oxidation of heavier hydrocarbons, and coal gasification.[1][2] Other methods of hydrogen production include biomass gasification, zero-CO2-emission methane pyrolysis, and electrolysis of water. The latter processes, methane pyrolysis as well as water electrolysis can be done directly with any source of electricity, such as solar power.

The production of hydrogen plays a key role in any industrialized society, since hydrogen is required for many essential chemical processes.[3] In 2020, roughly 87 million tons of hydrogen was produced[4] worldwide for various uses, such as oil refining, in the production of ammonia through the Haber process, and in the production of methanol through reduction of carbon monoxide. The global hydrogen generation market was valued at US$135.94 billion in 2021, and expected to grow to US$219.2 billion by 2030, with a compound annual growth rate (CAGR) of 5.4% from 2021 to 2030.[5]