Results of the NASA 1975 Hydrogen Energy Systems Technology Y 9Y Y 9Y (HEST)Study are reported. The Study projected national needs for hydrogen, evaluated technologies of production, handling, and utilization, and determined the critical research and technology activities required to meet the needs. It adopted an approach of seeking the broadest available spectrum of information and insights from NASA and other government agencies, ' from universities and from industry, and of assessing, validating, and integrating the results of other hydrogen-related studies in order to form ; specific conclusions.The HEST Study found current U.S. hydrogen utilization to be dominated 1 by chemical-industry and petroleum-processing applications, and to represent 3% of total energy consumption. The Study's projections of hydrogen use show growth in the remainder of this century by at least a factor of five, and perhaps a factor of twenty. New applications in the manufacture of synthetic fuels from coal and directly as an energy storage medium and fuel are expected to emerge later this century. Of these new uses, electric utility energy storage for peak-shaving, supplements to the natural gas supply, and special purpose transportation fuel such as aircraft, show promise.The Study concludes that the development and implementation of new means of supplying hydrogen, replacing the use of natural gas and petroleum feedstocks, are imperative. New production technology is essential to support even the lowest growth estimate. Methods based on alternative fossil feedstocks, such as coal and heavy oils, which are less expensive and nearer to technical maturity than non-fossil production systems, should be made operational while these feedstocks are abundant. Concurrently, the longterm tasks of advancing electrolysis technology, researching other water splitting techniques, and integrating these with developing nuclear and emerging solar primary-energy systems, must be carried on, together with work on hydrogen combustion systems and research in materials and safety engineering. Systems studies and assessments of the economic, social, and environmental impacts of hydrogen technology are also called for.
ACKNOWLEDGMENTSThe HEST Study was initiated and carried out under the direction of the NASA Office of Energy Programs. Supportive efforts were provided by the