COGENERATION SYSTEM, CONTROL DEVICE AND CONTROL METHOD

Provided is a cogeneration system that includes a plurality of fuel cell devices capable of supplying heat and power to a heat load and a power load and a control device connected to the fuel cell devices. The control device determines an operation mode on the basis of at least one of a heat demand value and a power demand value. The control device controls a power generation efficiency and a heat recovery efficiency by controlling the fuel cell devices on the basis of the operation mode determined.