On Earth, hydrogen is generally found in compounds with other elements. The most common are carbon, with which it forms methane (CH4), and oxygen, with which it forms water (H2O). To get pure hydrogen for industrial applications, it must be separated from the chemical elements to which it is bound. Today, 95% of hydrogen is extracted either from wood or from fossil fuels, such as natural gas and oil.
Hydrogen can also be produced using electricity, through electrolysis of water. An electric current is used to split water (H2O) into oxygen (O2) and hydrogen (H2). The great advantage of this method is that the energy can come from renewable sources! This is currently the most sustainable method of producing hydrogen.
In fact, hydrogen production represents an ideal way to convert electricity into a chemical fuel when production from renewable sources exceeds demand over a long period of time. For example, excess solar energy produced during summer would be fully utilised, and would be dispatchable – available whenever needed.