ENERGY STORAGE SYSTEM

An energy storage system according to the present disclosure includes at least one battery rack, each battery rack including at least two battery modules, a container in which the at least one battery rack is received, an air conditioner including an outside heat exchanger configured to cool a heat exchanger medium having a temperature rise in the container, and a circulation path configured to allow the heat exchanger medium to circulate between the container and the outside heat exchanger, a fire extinguishing unit including a fire extinguishing agent tank in which a fire extinguishing agent is stored inside, and configured to detect a temperature of the at least one battery module that is equal to or higher than a predetermined temperature or smoke that is generated in the at least one battery module and feed the fire extinguishing agent to the battery module, and an air conditioner management unit configured to spray the fire extinguishing agent in the fire extinguishing agent tank onto an outer surface of the outside heat exchanger.