ENERGY STORAGE SYSTEM

An energy storage system includes a cabinet, an air conditioner, a battery energy storage unit, and an air duct. The air conditioner is fastened to the cabinet. The air conditioner includes an air supply vent and an air return vent. The battery energy storage unit is accommodated in the cabinet. A first channel and a second channel that are separated are formed between the battery energy storage unit and an inner wall of the cabinet. The second channel is connected to the air return vent. The battery energy storage unit includes an air intake vent and an air exhaust vent. The air intake vent is connected to the first channel. The air exhaust vent is connected to the second channel. The air duct is accommodated in the second passage.