Hydrogen as a fuel

Hydrogen, used as fuel, has a number of attractive features that make it a leading candidate in the search for an alternative to the dwindling and progressively less reliable supply of fluid hydrocarbon fuels. Hydrogen produced by electrolysis using hydro- or nuclear-generated electricity will be available in Canada at prices competitive with other portable forms of energy before the end of the century. This paper examines the use of carbon-free electrolytic hydrogen as a motor vehicle fuel and as a fuel for fuel cells. A review of onboard hydrogen storage systems indicates that the propulsion power unit of hydrogen-fueled vehicles must be considerably more efficient than present gasoline-fueled internal combustion engines in order to compensate for the larger size and greater weight of hydrogen storage systems. Hydrogen-fueled internal combustion engines are more efficient than similar gasoline-fueled engines, but the improvement is not sufficient to offset the storage system limitation. Fuel cells operate with much higher efficiency than internal combustion engines, especially at partial loads. A comparison between H₃PO₄ and KOH fuel cells show that where carbon-free hydrogen is available from the onboard storage system, the KOH fuel cell offers the higher level of performance.