In this chapter considers the use of hydrogen as an energy storage medium. Hydrogen can be prepared from electricity produced by renewable means using electrolysis. Stored energy can be recovered from the hydrogen either by combustion, to produce heat, or by use of a fuel cell to produce electricity. The present chapter reviews the properties of hydrogen and the methods by which it can be produced and efficiently stored. The properties of fuel cells that can be used to produce electricity from hydrogen are reviewed. Finally, the use of energy stored in hydrogen either by combustion or fuel cells is considered, with specific reference to back-up and remote power sources and transportation.