The power System is in transition from fossil fuel to renewables for environmental and economic reasons. This Transition results in many challenges to power system design and operation. Frequency regulation, Voltage regulation, Generator ramp up / down requirements, Fault withstand capability, Rigidness of the grid, Protection are a few key impacts. There are many Renew alone projects are aimed across the world and in such cases the intensity challenges is extremely high. Energy Storage is the best possible option to resolve the issues and selecting the right type of energy storage is the key. Though they are many energy storage options available Battery energy storage system looks technically feasible and commercially viable at this stage. The session address the key challenges along with solution by from Battery Energy Storage. Session also brings out a few real-time case study outcomes and highlight the simulation requirements at the early stage of the projects to choose the optimal sizing and configuration of BESS.