Included are: a raw material component storage unit that stores the raw material component supplied to the ammonia synthesis unit; a high-pressure raw material component storage unit that stores the raw material component at a pressure higher than a pressure at which the raw material component is stored in the raw material component storage unit; and a surplus electric power processing unit including a high-pressure raw material component transfer unit that boosts and transfers the raw material component from the raw material component storage unit to the high-pressure raw material component storage unit, and an expander that converts pressure energy of the raw material component supplied from the high-pressure raw material component storage unit into motive power to generate power.