BATTERY RACK, ENERGY STORAGE SYSTEM, AND POWER GENERATION SYSTEM

A battery rack includes a plurality of battery modules; and a rack case configured to accommodate the plurality of battery modules and mount another rack case above, wherein the rack case includes a fixing unit provided on a lower end portion of the rack case, wherein the fixing unit includes a main body part of a plate shape. The main body part includes a fixing groove formed to be recessed from an edge of the main body part, and wherein the rack case includes at least one bolt provided on an upper end portion of the rack case and configured to be inserted into the fixing groove included in a lower end of the other rack case.