In examining the potential role of hydrogen in the energy economy of the future, we take an optimistic view. All the technology required for implementation is feasible but a great deal of development and refinement is necessary. A pessimistic approach would obviously discourage further thinking about an important and perhaps the most reasonable alternative for the future. We have considered a limited number of alternative energy systems involving hydrogen and have shown that hydrogen could be a viable secondary source of energy derived from nuclear power; for the immediate future, hydrogen could be derived from coal. A hydrogen supply system could have greater flexibility and be competitive with a more conventional all-electric delivery system. Technological improvements could make hydrogen as an energy source an economic reality. The systems examined in this article show how hydrogen can serve as a general-purpose fuel for residential and automotive applications. Aside from being a source of heat and motive power, hydrogen could also supply the electrical needs of the household via fuel cells (19), turbines, or conventional "total energy systems." The total cost of energy to a residence supplied with hydrogen fuel depends on the ratio of the requirements for direct fuel use to the requirements for electrical use. A greater direct use of hydrogen as a fuel without conversion to electricity reduces the overall cost of energy supplied to the household because of the greater expense of electrical transmission and distribution. Hydrogen fuel is especially attractive for use in domestic residential applications where the bulk of the energy requirement is for thermal energy. Although a considerable amount of research is required before any hydrogen energy delivery system can be implemented, the necessary developments are within the capability of present-day technology and the system could be made attractive economically .Techniques for producing hydrogen from water by electrolysis, from coal, and directly from thermal energy could be found that are less expensive than those now available; inexpensive fuel cells could be developed, and high-temperature turbines could be used for the efficient conversion of hydrogen (and oxygen) to electricity. The use of hydrogen as an automotive fuel would be a key factor in the development of a hydrogen energy economy, and safe storage techniques for carrying sufficient quantities of hydrogen in automotive systems can certainly be developed. The use of hydrogen in automobiles would significantly reduce urban pollution because the dispersed fossil fuel emissions would be replaced by radioactive wastes generated at large central stations. The conversion of internal or external combustion engines for combustion of hydrogen fuel would probably have less economic impact on the automotive industry than the mass introduction of electric automobiles. However, this is a subject that requires more detailed study. All of the safety aspects of hydrogen utilization will have to be examined, especially the problems of safety in the domestic use and the long distance transport of hydrogen in pipelines at high pressures. It is our opinion that the various energy planning agencies should now begin to outline the mode of implementing hydrogen energy delivery systems in the energy economy. The initial transition to hydrogen energy derived from available fossil fuels such as coal should be considered together with the long range view of all the hydrogen being derived eventually from nuclear energy. By the year 1985 when petroleum imports may be in excess of the domestic supply, these plans could set the stage for the transition period from fossil to a predominantly nuclear energy economy able to supply abundant synthetic fuels such as hydrogen. Synthetic fuels will obviously be more expensive than fuels now derived from petroleum; however, there may be no other viable choice. Thus, it is essential that the analysis and technological feasibility of a hydrogen energy system be considered now. It is of vital importance to the nation to develop some general-purpose fuel that can be Produced from a variety of domestic energy sources and reduce our dependence on imported oil.
