Hydrogen gas (H2) represents nearly 75% of the universes elemental mass and is the most abundant of chemical elements. It is odorless, colorless, tasteless, nonmetallic, and highly flammable. Hydrogen is lighter than air and since it rises into the atmosphere it is not found on earth by itself but rather compounded together with other elements. When combined with oxygen it is water (H2O) and when combined with carbon, it forms other compounds such as methane (CH4), coal, and petroleum. Hydrogen is also found in biomass and is an abundant element in the earths crust.
Since Hydrogen is not an energy source itself it has to be produced by either electrolysis of water or reforming of fossil fuels. Electrolysis of water is a process whereby electricity is used to split water molecules (H2O) to create pure Hydrogen and oxygen. Although this process can be done just about anywhere it is the more expensive of the two processes. In the reforming of fossil fuels, a device called a fuel processor or reformer is used to split Hydrogen off the carbon in hydrocarbons that are found in oil and natural gas (methane) to create pure Hydrogen and carbon, the latter being discarded into the atmosphere as carbon dioxide.
In order to create a true Hydrogen Future pure Hydrogen should be derived from renewable sources and not fossil fuels so that there is no release of carbon into the atmosphere. Today this can be achieved only by generating pure Hydrogen through electrolysis utilizing electricity that is not generated itself by fossil fuels. There are several non fossil fuel options for generating the electricity needed for electrolysis which include wind turbines, solar cells, hydroelectric dams, nuclear power, geothermal power, wave and tidal power and co-generation.
The Hydrogen Future will be driven in large part by the non fossil fuel option that becomes not only the safest, most feasible and most efficient source of electricty needed to produce pure Hydrogen but also the most affordable.