Patent ID: 8364324

Claim:
An energy management system comprising: a home appliance located in a home; and a terminal device connected to said home appliance, wherein said home appliance comprises a main current measurement unit, a main electrical energy calculation unit, a branch current measurement unit, a branch electrical energy calculation unit, and a processing unit, said main current measurement unit being configured to measure a current flowing through a main breaker, said main electrical energy calculation unit being configured to calculate electricity usage at said main breaker on the basis of a measurement of said main current measurement unit, said branch current measurement unit being configured to measure a current flowing through each branch breaker connected to an output terminal of said main breaker, said branch electrical energy calculation unit being configured to calculate electricity usage at each of said branch breakers on the basis of a measurement of said branch current measurement unit, and said processing unit being configured to generate information of electricity usage at the home on the basis of the electricity usage calculated by said main electrical energy calculation unit together with the electricity usage calculated by said branch electrical energy calculation unit, wherein said terminal device comprises a display unit configured to display the information of the electricity usage generated by said processing unit, wherein said energy management system comprises a server connected to said home appliance via an outside network, and wherein said server comprises a history registration unit, an analysis unit, and an result transmission unit, said history registration unit being configured to store history information of the electricity usage at said main breaker and the electricity usage at said branch breaker of each of the homes, said analysis unit being configured to make a ranking of the homes in terms of the electricity usage according to the history information of each of the homes stored in said history registration unit, and said result transmission unit being configured to transmit the ranking made by said analysis unit to said terminal device of each of the homes.