Coal is properly dried and the efficiency of a boiler is increased while suppressing any reduction in efficiency of the boiler and the generation of hydrocarbon gas components. Employed are a coal dryer that dries coal, a boiler in which the coal that is dried in the coal dryer is mixed with air for combustion and burned, an air heater that heats the air for combustion that is supplied to the boiler using combustion exhaust gas discharged from the boiler, a precipitator that collects dust included in the combustion exhaust gas, a desulfurization plant that performs a desulfurization process on the combustion exhaust gas, and heat recovery equipment that heats a heating medium using the combustion exhaust gas. The coal dryer dries the coal using the heat energy of the heating medium that has been heated in the heat recovery equipment.