Hydrogen is the most abundant element in the universe; it fuels the sun and is the third most common element on Earth. But it is so reactive that it is seldom found in its elemental state – it combines strongly with other elements such as oxygen to form water or with carbon to form methane. It is an essential component in all acids, alkalis, hydro-carbons and organic materials.
To extract hydrogen from natural compounds such as water, methane or coal requires very large inputs of energy. Most commonly hydrogen is produced from methane gas using heat and steam, or by electrolysis of water using large quantities of electricity.
Hydrogen can be used to power rockets, cars and engines of all types. However the energy used to produce the hydrogen can never be fully recovered from the energy in the hydrogen. It is thus NOT a source of energy – it is merely a storehouse for energy – a battery.
It is possible to produce hydrogen from water using electricity from nuclear or hydro-carbon fuels, or even intermittent green energy. The hydrogen gas could then be transported to cities as a clean energy source for cars, thus reducing pollution from petrol/diesel vehicles.
But hydrogen is a very dangerous gas. It has tiny lightweight molecules which have low energy density and are difficult to compress, contain and store. It also forms a very explosive mixture with air. To provide a network of hydrogen car-fuelling stations, or to suggest hydrogen as a domestic gas, is inviting explosive disasters in the suburbs – (imagine the Health and Safety regulations!)
Even the impractical electric cars have benefits compared to the hydrogen car. Electricity is safer and the supply network is easier and essentially in place. Moreover, electric cars do not reduce the oxygen content of city air – every tonne of hydrogen fuel consumes eight tonnes of oxygen to produce nine tonnes of water vapour. So instead of urban smog, we may get urban fog.
And to suggest that hydrogen can provide base-load power tops all green energy idiocy.
Hydrogen is a Net-Negative Energy Option.