One proton and one electron are all that an element of hydrogen consists of – it is the simplest and most abundant element on earth. Hydrogen is an energy storage and delivery component, but it does not occur in nature naturally and must be obtained from compounds containing it.

It is possible to produce hydrogen from diverse domestic sources. At present, the majority of hydrogen is produced from fossil fuels, specifically natural gas. Hydrogen can also be produced using electricity derived from renewable sources such as biomass, geothermal heat, solar power, or wind. With new technologies, solar energy and biomass can be used to generate hydrogen more directly in the long term.

Most hydrogen can also be produced through steam methane reforming, a high-temperature process in which steam reacts with a hydrocarbon fuel to produce hydrogen. Electrolysis can also be used to generate hydrogen from water by splitting the molecule H2O into oxygen and hydrogen. During electrolysis, water molecules are converted into hydrogen by an electrolyzer that functions like a fuel cell in reverse. Instead of using the energy of a hydrogen molecule, like a fuel cell, an electrolyzer produces hydrogen from water molecules.