> Hydrogen is not a primary source of energy like oil or coal. It is best thought of as an energy carrier, akin to electricity, and as a means of storage, like a battery. It has to be manufactured. Low-carbon energy sources such as renewables and nuclear power can be used to separate water (H2O) into its constituents of oxygen and hydrogen. This is inefficient and expensive, but costs are falling. Hydrogen can also be made from dirty fossil fuels but this emits a lot of pollution unless it is coupled with technologies that capture carbon and sequester it. Hydrogen is flammable and bulky compared with many fuels. The implacable laws of thermodynamics mean that converting primary energy into hydrogen and then hydrogen into usable power leads to waste.
Does it get any better below the fold?