Electrical energy storage aims to support the implementation of the smart grid and maximize the integration of renewable energies. In this sense, it is used as backup of power generation and distribution systems. The main reasons for the deployment of electrical storage facilities in the context of smart grids are the intermittent character of decentralised renewable sources, and the need to meet demand with unpredictable daily and seasonal variations. When there is a peak on renewable production, energy is stored as electricity to be released during peaks of demand.
There is a wide list of options for electrical energy storage. The increasing deployment of electrical vehicles in cities, for example, is recognized as an underpinning technology with great potential in storing large quantities of electrical energy to support demand support strategies.