Most hydrogen today is made from natural gas. Electrolysis can make hydrogen from water using electricity. Once produced, hydrogen can be stored, piped, or converted in fuel cells and turbines. Round-trip efficiency is often lower than batteries for many electricity-storage jobs, so hydrogen is most interesting where chemistry, high-temperature heat, or long-duration storage matter.
An energy carrier, not a well
How it works
Electrolysers split water when powered. Steam methane reforming splits hydrocarbons, typically emitting carbon dioxide unless captured. Fuel cells reverse the chemistry of electrolysis in a controlled electrochemical cell.
Key facts
Hydrogen must be manufactured; it is a carrier.
Production pathway determines emissions.
Fuel cells combine hydrogen and oxygen to make electricity and water.
Storage and leakage (including as an indirect greenhouse influence) need careful engineering.
Environment
Climate benefit exists only if production is low-carbon and leaks are controlled. Water use for electrolysis and land use for dedicated renewable supply must be counted at system level.