<P> Electrolysis of water is the decomposition of water into oxygen and hydrogen gas due to an electric current being passed through the water . The reaction has a standard potential of − 1.23 V, meaning it ideally requires a potential difference of 1.23 volts to split water . </P> <P> This technique can be used to make hydrogen fuel (hydrogen gas) and breathable oxygen; though currently most industrial methods make hydrogen fuel from natural gas instead . </P> <P> Jan Rudolph Deiman and Adriaan Paets van Troostwijk used, in 1789, an electrostatic machine to make electricity which was discharged on gold electrodes in a Leyden jar with water . In 1800 Alessandro Volta invented the voltaic pile, and a few weeks later William Nicholson and Anthony Carlisle used it for the electrolysis of water . When Zénobe Gramme invented the Gramme machine in 1869 electrolysis of water became a cheap method for the production of hydrogen . A method of industrial synthesis of hydrogen and oxygen through electrolysis was developed by Dmitry Lachinov in 1888 . </P>

Where does the energy to hydrolyze water come from