UCL Department of Chemical Engineering


Hydrogen Storage

Storage is a vital factor in the commercialisation of fuel cells as a safe, efficient and energy dense way of storing hydrogen will greatly improve the viability of fuel cell technology, particularly for automotive applications. Hydrogen can be stored in any state; as a solid, a liquid or a gas.

More information about hydrogen storage can be found at the International Energy Agency website.

StateStorage Mechanism and Supply MechanismAdvantagesDisadvantages
GasPressurised Carbon Fibre composite gas tank up to 700 bar.Commercially available.

Energy required for compression.

Energy from fossil fuels usually used to produce hydrogen.

Tanks are bulky and must be cylindrical.

Safety concerns.

Costly tanks.


LiquidCryogenic tank at -253 degrees centigrade.

Commercially available.

Excellent gravimetric and volumetric hydrogen capacity at low pressures.


30-40% energy loss to cool to cryogenic temperatures.

1%/day losses from boil-off.

Safety concerns.

Costly tanks.

SolidChemical hydrides heated to <100 degrees centigrade to decompose and release hydrogen.

Excellent gravimetric and volumetric hydrogen capacity.

Safe, easy to handle.

In the early development stages.

Energy required for off-board regeneration.

Harmful by-products must be removed from the impure hydrogen gas stream.