6. Energy efficiency of the storage chain

To be sustainable in terms of global warming, the hydrogen storage process in LOHCs must be energy-efficient. Its comparison with other hydrogen storage processes only makes sense in its entirety, i.e. with hydrogen production and utilization systems, with hydrogen storage and release units, and possibly with transportation. Figure 12 shows the overall scheme for hydrogen storage in LOHCs, integrating the production of hydrogen from electricity generated by renewable energies (solar, wind), and integrating processes using the returned hydrogen to produce electrical or mechanical energy, or for transformation in a chemical unit.