There is provided a consumption energy calculating device which simulates power consumption of a heating and cooling appliance operated by a customer living in a house. A first receiver and a second receiver receive a demand response signal and an external environmental factor parameter. A pain level model shows a relationship between an indoor air temperature and a pain level. A first calculator calculates, when the appliance is not in operation, the indoor air temperature of a next sample time. A second calculator calculates, when the appliance is in operation, determines the indoor air temperature of the next sample time. A working sequence generator determines whether the appliance is or not to be operated during the next sample time. The power consumption determination unit determines power consumption consumed by the appliance before the next sample time and outputs data showing the power consumption.