Hydrogen as a carbon-free fuel is amenable to utilization in all heat engines, including gas turbines and reciprocating internal combustion engines, which are the most efficient technologies for electric power generation from fossil fuels. Alas, H2 is not an energy resource. It is an energy carrier. Prior to its use as a fuel, it must be produced, stored and/or transported. There are significant problems associated with all three phases of the hydrogen fuel chain. Those aspects will be discussed qualitatively and quantitatively in the remainder of the present chapter.