<p>This handbook serves as a guide to deploying battery energy storage technologies specifically for distributed energy resources and flexibility resources.</p><p>Battery energy storage technology is the most promising rapidly developed technology as it provides higher efficiency and ease of control. With energy transition through decarbonization and decentralization energy storage plays a significant role to enhance grid efficiency by alleviating volatility from demand and supply. Energy storage also contributes to the grid integration of renewable energy and promotion of microgrid.</p>