There are several approaches to classifying energy storage systems. The most common approach is classification according to physical form of energy and basic operating principle: electric (electromagnetic), electrochemical/chemical, mechanical, thermal.
Energy storage systems (ESS) can be widely classified into five main categories: chemical, electrochemical, electrical, mechanical, and thermal energy storage. Chemical energy storage systems are one of these categories.
Chemical energy storage systems are sometimes classified according to the energy they consume, e.g., as electrochemical energy storage when they consume electrical energy, and as thermochemical energy storage when they consume thermal energy.
Energy storage technologies could be classified using different aspects, such as the technical approach they take for storing energy; the types of energy they receive, store, and produce; the timescales they are best suitable for; and the capacity of storage. 1.
An energy storage system (ESS) can be classified based on its methods and applications. Some energy storage methods may be suitable for specific applications, while others can be applied in a wider range of frames. The inclusion of energy storage methods and technologies in various sectors is expected to increase in the future.
For example, mechanical-energy storage systems include the subgroup of potential energy storage systems such as pump-storage plants (PSP), as well as the subgroup of kinetic energy storage systems such as flywheels.