Electrical Energy Storage is a process of converting electrical energy into a form that can be stored for converting back to electrical energy when needed (McLarnon and Cairns, 1989; Ibrahim et al., 2008). In this section, a technical comparison between the different types of energy storage systems is carried out.
Energy comes in multiple forms including radiation, chemical, gravitational potential, electrical potential, electricity, elevated temperature, latent heat and kinetic. Energy storage involves converting energy from forms that are difficult to store to more conveniently or economically storable forms.
In the electricity market, global and continuing goals are CO 2 reduction and more effi cient and reliable electricity supply and use. The IEC is convinced that electrical energy storage will be indispensable to reaching these public policy goals.
Electrical energy storage systems (EESS) for electrical installations are becoming more prevalent. EESS provide storage of electrical energy so that it can be used later. The approach is not new: EESS in the form of battery-backed uninterruptible power supplies (UPS) have been used for many years. EESS are starting to be used for other purposes.
All energy is difficult to store, not just eletrical. Indeed, electrical energy is quite easy to store once you consider the big picture. If you look at a tank of gasoline, you can see "wow, what a great storage for energy!".
Energy storage solutions for electricity generation include pumped-hydro storage, batteries, flywheels, compressed-air energy storage, hydrogen storage and thermal energy storage components. The ability to store energy can facilitate the integration of clean energy and renewable energy into power grids and real-world, everyday use.