The mass energy density of hydrogen is 33 KWh/Kg, which is far higher than that of gasoline or diesel 12 KWh/Kg. Moreover, under typical temperature and pressure circumstances, it has a very low energy volume density of 3 KWh/Nm3. On the contrary side, due to its extremely low molar mass and very low liquefaction temperature, storing hydrogen to make it accessible anywhere in the world is difficult and expensive. where, by lowering its temperature to -253 °C, hydrogen becomes liquefiable.
Mobile hydrogen storage in hydrogen vehicles uses hydrogen tanks compressed to between 350 bar and 700 bar. For instance, the technical goals are to create a 5 kilogram hydrogen tank, which equates to storage of around 90 kg and 125 L, for a car with a range of about 500 km.
Tank for liquid H2, produced by Dynetek Industries LTD Museum Autovision, Altlußheim, Germany
Based on type IV carbon-composite technology, compressed hydrogen in hydrogen tanks is utilized in cars for hydrogen tank systems at 350 bar and 700 bar.
It is critical that hydrogen storage devices be of strong and safe construction, due to the purposes that hydrogen is designed for as well as its intrinsic qualities, particularly its flammability and explosiveness. Three different states in which hydrogen can be kept in storage are solid, gaseous under pressure, or liquid at -253 degrees Celsius in enclosed tanks with improved thermal insulation. This storage solutions loses technological and financial competitiveness with more volumes or quantities.
Available storage technologies, their capacity and discharge time
Regarding the outcomes, demands, and markets in the short- and medium-term, compressed hydrogen storage is the most promising, but for the moment, from a scientific and industrial perspective, gas storage is the most developed method; experience has proven that compressed gas cylinders are reliable and secure.