The energy efficiency of a hydrogen circuit in a smart grid

The paper discusses a hydrogen circuit embedded in an Electric energy network. The circuit is instrumental for electrical energy storage whenever all the batteries (accumulators) within the network are charged, and a constant energy surplus exists in the network. The generated surplus energy is then converted to hydrogen, which is stored in a metal hydride storage case. At times of low energy status in the network, namely when the batteries are discharged and the applied generators (such as photovoltaic, wind, or microhydro power plants) cannot supply energy, a fuel cell is activated. The cell's operation principle is basically the reverse of that for an electrolytic cell (electrolyser), meaning that the cell consumes the hydrogen from the metal hydride storage to produce electric energy; this energy is subsequently stored in batteries (accumulators) connected to the smart grid. In the given context, the article aims to describe the relevant experiment and to present the algorithm to calculate energy efficiency, a most significant parameter of the entire hydrogen circuit.