The extensive application of Sodium–Nickel Chloride (Na–NiCl2) secondary batteries in electric and hybrid vehicles, in which the safety requirements are more restrictive than these of stationary storage applications, depicts the Na–NiCl2 technology as perfectly suitable for the stationary storage applications. The risk of fire is negligible because of the intrinsic safety of the cell chemical reactions, related to the sodium-tetrachloroaluminate (NaAlCl4) content into the cell, which acts as a secondary electrolyte (the primary one being the ceramic β″-alumina as common for Na-Beta batteries). The 3 h rate discharge time makes this technology very attractive for load levelling, voltage regulation, time shifting and the power fluctuation mitigation of the renewable energy sources in both HV and EHV networks.