The impracticability of large-scale generation of hydrogen from water photolysis by utilization of solar radiation

Abstract

The possibility of using solar radiation for the generation of hydrogen by the photolysis of water is discussed in relation to requirements of large-scale generation which would be needed in a hydrogen economy or in coal gasification. Although the point is conceded that solar energy is, for all practical purposes, an infinite source, the conclusion is that solar radiation is not available on the surface of the plant in energy densities which would allow large-scale hydrogen generation without overwhelming technical and economic difficulties. The particular restriction lies in the large ground areas required for generation of reasonably large quantities of hydrogen, since the volume of hydrogen at atmospheric pressure which can be generated per square metre of surface is only of the order of 0.2–0.4 m 3/day.