A network system is provided. The network system includes: at least one component selected from an energy receiving unit receiving energy and an energy management unit managing the energy receiving unit. The energy receiving unit or the energy management unit receives energy rate related information; an energy usage amount or a usage rate of when the component is controlled on the basis of at least the energy rate related information is less than that of when the component is controlled without the basis of at least energy rate related information; if the energy rate related information is high cost information, a function of one component constituting the energy receiving unit is limited; and an operating time or an output of the energy receiving unit is adjusted in correspondence to the limited function of one component.