Prospects for hydrogen production by water electrolysis to be competitive with conventional methods

Abstract With the impending unavailability of oil and natural gas, hydrogen will be produced on a large scale in the United States (1) from coal, or (2) by water electrolysis using electricity derived from nuclear or solar energy. In many parts of the world which lack fossil fuels, the latter will be the only possible method. The cost of purification of hydrogen produced from fossil fuels will increase its cost to about the same level as that of electrolytic hydrogen. When hydrogen is required in relatively small quantities too, the electrolytic method is advantageous. To minimize the cost of hydrogen produced by water electrolysis, it is necessary to reduce capital costs and approach 100% energy efficiencies. Areas of research, which will be necessary to achieve these goals are: (1) maximization of surface areas of electrodes; (2) use of thin electrolyte layers; (3) increase of operating temperature in alkaline water electrolysis cells to about 120–150°C; (4) selection and evaluation of separator materials; (5) electrocatalysis of the hydrogen and oxygen electrode reaction; (6) mixed oxides as oxygen electrodes; and (7) photoelectrochemical effects. The progress made to date and proposed studies on these topics are briefly dealt with in this paper. The General Electric Solid Polymer Water Electrolyzer and Teledyne Alkaline Water Electrolysis Cells, operating at about 120–150°C, look most promising in achieving the goals of low capital cost and high energy efficiency.