ABSTRACT
This chapter describes the possibility of storing energy through transformation into hydrogen. The high weight energy density of hydrogen makes it a candidate for seasonal storage, combined with techniques of compression, liquefaction, or other transformations for volume reduction as metal hydrides.
First, a power-to-power storage system such as an ESS (electrical storage system) is defined with its main components, namely, the electrolyzer, the hydrogen conditioning device, and the fuel cell used to produce electrical power in the back transformation.
Three main electrolyzers are described: the alkaline electrolyzer, the PEM (polymer electrolyte membrane) electrolyzer, and the high-temperature steam electrolysis.
Then the storage of hydrogen itself is described with the liquefaction, the compression, and the storage by adsorption.
The chapter includes also efficiency considerations, and is completed by a dedicated exercise.
