3.1 Necessity to Store and Transport Hydrogen
The storage and transport of energy are generally required to compensate differences in time and space between production and demand. In principle, this is true for all energy carriers, but storage and transport are of special importance in the context of green hydrogen. There are two main reasons for this, which are briefly explained in the following.
Challenges in the storage of hydrogen
Due to its special properties hydrogen’s storage and transportation are not trivial. As already described in Chapter 2.1, the challenges result especially from the low volumetric energy density of gaseous hydrogen and the small size of the molecule. The low volumetric energy density leads to the fact that large volumes are required to store and transport gaseous hydrogen. The small size of the molecule in turn makes hydrogen able to diffuse through a lot of material. For example, materials that are used in the natural gas infrastructure are only impermeable to hydrogen to a limited extent. Beside the hydrogen loss, diffusion also causes so-called embrittlement to some pipes, tanks or other devices which get into contact with hydrogen. Affected materials are, e.g., steel and titan.