The chemistry of carbon nanomaterials and hydrogen materials science will play an important role in hastening the conversion to the Hydrogen Energy System. In this connection the research and application of materials capable of interacting actively with hydrogen, its accumulation and storage will be of the utmost significance. This is particularly relevant for creating mobile energy sources both for mobile telephones and for hybrid electric cars that are developed by all large car manufacturers of the world. In this connection the hydrogen capacity of carbon nanostructural materials, such as fullerenes, nanotubes, nanofibers and other nanostructures, has aroused special interest. Hydriding metals, alloys, nanocarbon and composite materials can store hydrogen safely at relatively low pressures and temperatures. Many other applications are also possible such as heating and cooling, waste heat storage, pumping, pressurizing, heat-pumping, hydrogen purifying, deuterium separation, electricity production, etc. As a source of clean energy, hydrogen will also be the permanent answer to other global problems caused by utilizing fossil fuels, such as the greenhouse effect, climate change, acid rains, ozone layer depletion, pollution and oil spills.