Patent ID: 8791592

Claim:
A method for providing electric power to a plurality of appliances, the method comprising: determining whether a current power rate is greater than a preset reference power rate; and selectively supplying electric power to the plurality of appliances from either a primary external power supply source or a supplementary power supply source based on operational power requirements of the plurality of appliances in operation after the determination of whether the current power rate is greater than the preset reference power rate is made, wherein selectively supplying electric power comprises: supplying electric power from the primary external power supply source to an air conditioner when the current power rate is less than the preset reference power rate; and supplying electric power from the primary external power supply source to a compressor of the air conditioner, and supplying electric power from the supplementary power supply source to at least one component of the air conditioner having a power requirement that is lower than a power requirement of the compressor when the current power rate is greater than the preset reference power rate.