Reliable Off-grid Power Supply Utilizing Green Hydrogen

Green hydrogen produced from wind, solar or hydro power is a suitable electricity storage medium. Hydrogen is typically employed as mid- to long-term energy storage, whereas batteries cover short-term energy storage. Green hydrogen can be produced by any available electrolyser technology [alkaline electrolysis cell (AEC), polymer electrolyte membrane (PEM), anion exchange membrane (AEM), solid oxide electrolysis cell (SOEC)] if the electrolysis is fed by renewable electricity. If the electrolysis operates under elevated pressure, the simplest way to store the gaseous hydrogen is to feed it directly into an ordinary pressure vessel without any external compression. The most efficient way to generate electricity from hydrogen is by utilizing a fuel cell. PEM fuel cells seem to be the most favourable way to do so. To increase the capacity factor of fuel cells and electrolysers, both functionalities can be integrated into one device by using the same stack. Within this article, different reversible technologies as well as their advantages and readiness levels are presented, and their potential limitations are also discussed.