What is ESS means, Well, many people ask for this.  ESS is Energy storage system for short. and from Wikipage,as the capture of energy produced at one time for use at a later time. While there are a number of approaches to storing energy including mechanical (eg – flywheels), chemical (eg – hydrogen) and thermal (eg – ice systems), it is the electro-chemical approach using different types of batteries where the vast majority of industry activity is focused today.

Early activity in stationary energy storage systems for the grid focused on only two components – the battery modules which store the electricity and the power conversion systems (PCSs) that convert the electricity from the direct current form stored in the battery to the alternating current form that is used on the electric grid.   But as the industry has moved from simply deploying pilot ESSs and demonstrating that they can charge and discharge to integrating these systems as standard parts of the production grid, it has become clear that control software is a vital third component. This control software serves as the “brains behind the battery,” providing remote visibility of the asset in grid control systems such as SCADA and enabling second by second optimization of the battery across a wide range of valuable roles that it can play for the utility owner managing the power system.