Hydrogen has been discussed as an option for energy storage for decades, but research and development efforts have accelerated within the last few years. The main drawback of energy storage using hydrogen is the low volumetric storage density. A broad spectrum of technologies has been developed to make storage and transport of energy using hydrogen feasible. Many of these approaches shift the challenge from volumetric to gravimetric storage density. Furthermore the electricity-to-electricity efficiency is a demanding topic in the field of hydrogen energy. This review gives an overview of the different approaches suggested so far, from the storage of elemental hydrogen to the reversible and irreversible conversion of hydrogen.