Tokyo University and Mitsubishi Chemical jointly developed a new artificial photosynthesis technology that generates energy using light. This technology makes it possible to generate hydrogen without emitting carbon dioxide by irradiating light on water containing a special chemical compound. If this chemical compound can respond to light of various wavelengths, it is possible to build a plant to produce hydrogen using sunlight as a plant generates high energy hydrogen using sunlight. The chemical compound developed by the two organizations incorporates tungsten oxide and tantalum oxynitride and resolves water into hydrogen and oxygen if it is put in water and light is irradiated. The newly-developed compound generates hydrogen using 6.3% of the visible light with a wavelength of 420 nanometers when it is irradiated on the compound. It is estimated that if 10% of sunlight is used and this compound is put in a water reservoir of 5 km by 5 km, 570 tons of hydrogen can be obtained daily. If this kind of water reservoir is built near a thermal plant, raw materials of the chemical industry like methanol can be produced by reacting hydrogen with carbon dioxide generated by the thermal plant. The two organizations plan to put this technology into practical use in five years.