Hydrogen Storage

Hydrogen storage technologies are a key enabler for the advancement of hydrogen and fuel cells in applications including stationary power, portable power, and transportation.

Hydrogen has the highest energy per mass of any fuel. However, because it has low density at ambient temperatures and pressures, it has very low energy density (i.e., low energy per unit volume). Advanced storage methods that provide higher energy density can have significant benefits for commercial use of hydrogen.

Hydrogen can be stored physically as either a gas or a liquid. Storing hydrogen as a gas typically requires high-pressure tanks (at tank pressures of 350–700 bar [5,000–10,000 psi]). Storing hydrogen as a liquid requires cryogenic temperatures because the boiling point of hydrogen at ambient pressure is −252.8°C. 

Hydrogen can also be stored in materials, using reversible or non-reversible processes. Reversible processes include storing hydrogen on the surfaces of solids (by adsorption) or within solids (by absorption); both types of processes allow the hydrogen to be stored and released without changing the chemistry of the storage material. Non-reversible processes involve a chemical reaction that combines hydrogen with other elements or compounds to create a new material, thereby fundamentally altering the underlying chemistry. These processes require another chemical reaction to release the hydrogen when it is needed.

Download the Hydrogen Infrastructure section of the Multi-Year Program Plan for full details about technical targets.