Hydrogen Production By Solar Beam

Various methods of water-splitting with use of solar energy are reviewed and compared to each other. Direct thermal method has the highest efficiency, but the difficulty is the heat-resisting materials. Thermochemical method is promising if the corrosion-resisting materials are found. Electrolytic method is traditional, but the hybrid system combined with thermochemical and/or photochemical reactions are valuable and believed to be actualizing in the earist stage. Photolysis and biochemical methods are most environmental, but they are of low efficiency at present stage. Actually working system of so-called Yokohama Mark5 is introduced, too.