In some embodiments, an electric energy information provision method includes measuring electric energy, analyzing the measured electric energy to generate electric energy information, and displaying the generated electric energy information in response to a request of a user. The electric energy information may include a variation status, a standard deviation analysis result, a dispersion deviation analysis result, trend line information, past accumulative electric energy variation information, anticipated future accumulative electric energy variation information, an electric energy usage status diagnosis, and electric energy reduction plan information.

Methods, systems, and computer readable media are disclosed for monitoring photovoltaic solar systems. In some examples, the system includes a solar power measurement input for coupling to a solar panel system, a measurement circuit configured to measure power produced by the solar panel system using the solar power measurement input, and a data transmission system. The measurement circuit is configured, by virtue of the measurement circuit including electrical components rated to at least a certain tolerance level, to take revenue-grade power measurements from the solar power measurement input with a level of accuracy that meets a national or international metering standard. The data transmission system is configured to transmit the revenue-grade power measurements from the measurement circuit to a remote system.

Methods, systems, and computer readable media are disclosed for monitoring photovoltaic solar systems. In some examples, the system includes a solar power measurement input for coupling to a solar panel system, a measurement circuit configured to measure power produced by the solar panel system using the solar power measurement input, and a data transmission system. The measurement circuit is configured, by virtue of the measurement circuit including electrical components rated to at least a certain tolerance level, to take revenue-grade power measurements from the solar power measurement input with a level of accuracy that meets a national or international metering standard. The data transmission system is configured to transmit the revenue-grade power measurements from the measurement circuit to a remote system.

An operation control device for an electronic apparatus is provided. An operation control device for an electronic apparatus according to an embodiment of the present disclosure, which is connected to an electronic apparatus and can transmit and receive signals to and from the electronic apparatus and a control device for remotely controlling use of power in the electronic apparatus, comprises: a measuring unit for calculating the amount of power supplied to the electronic apparatus; and a communicating unit for receiving identification information of the electronic apparatus and state information of the electronic apparatus from the electronic apparatus, transmitting information regarding the amount of power, the identification information of the electronic apparatus, and the state information of the electronic apparatus to the control device, and receiving a first control signal for controlling operation of the electronic apparatus from the control device and then transmitting the first control signal to the electronic apparatus, thereby switching the electronic apparatus to an off mode or a sleep mode.