**2. Importance of energy storage**

Energy storage is important for developing electricity, since storage technology allows us to 'reserve' electricity, which is of tremendous advantage not only in terms of technical growth but also in economic terms. As energy storage is being used more often than ever before, diversification and protection of supply have improved, which means that the energy market will be balanced. Another energy storage aspect is the use of green energy sources. Ancillary networks for grid convergence are probable options for the advantage of clean energy sources. Asset utilization is supported as well as voltage control and device stability due to the likelihood of a long-term reserve, which is not necessarily feasible for any form of storage technology [2].

The second application is transport and mobility, but this form of application is not as large as for the usage of electricity, but even energy storage in this area provides the possibility of minimizing fuel consumption by providing a kinetic force against a gasoline-fueled internal combustion engine. A particular interest can be defined by the lengths of the charge/discharge, which will be deemed to be the most relevant features that have contributed to a great deal of concern on the end-user side.

*Energy Storage Efficiency DOI: http://dx.doi.org/10.5772/intechopen.109851*

Energy storage in transport and mobility has benefits on a broader scale, as increasing system reliability and reducing greenhouse gas emissions and technology related to this form of storage are flywheels or supercapacitors [2].

Prioritizing the use of energy from the on-site renewable energy source over the utility grid (based on fossil fuel) also aims to minimize the consumption of fossil fuels and, as a result, to advance the priorities of the clean environment [3]. In 2015, the European Commission released two Communications: "*Providing a New Deal for Energy Consumers"* and *"On a New Energy Market Layout*" [4]. Their message was that there are three columns of future customer energy plan, which include:

a.Consumer empowerment,

b.Clever houses, work environment,

c.Information monitoring and security.

The importance of this was clearly emphasized from the beginning: minimizing energy expenses with self-generation and consumption [4] as well as increasing the customer's role via intermediation and cumulative engagement systems [5].

To fulfill the environmental and energy policy goals of the European Union, the energy market will have to experience systemic improvements in the coming decades, where electricity will play a key role in the transition phase and increase its share of final energy use.
