ITU‐T's Technical Reports and Specifications 321 In general, the detection of the failure of the solar panel module is difficult; hence, it is normally left without maintenance even during the guarantee period. It is also useful for the customer to be informed that the trouble is caused by climate change or a stain/malfunction of the solar panel. The system has to report the result to the cable customer. In case of a home battery, the system has to provide the appropriate exchange date of the defective battery or advise on the economical usage of the battery based on a past operation record. The system must send the information by e‐mail to the assigned address. Presentation items The presentation items are shown below to realize the aforementioned services: 1 Electric power consumption (real time, every hour, past record, regional ranking); 2 Electric power generation (real time, every hour, past record, regional ranking); 3 Electric power fee (time zone, monthly, comparison with previous year); 4 Battery status (real time, charge/discharge record) and exchange date; 5 Usage report by the power company (regional power balance); 6 Malfunction of the solar power panel and/or necessity of cleaning; 7 Setting threshold of power consumption and control. Technical Report of the Focus Group on Smart Cable Television ITU‐T FG Smart Cable Technical Report 5; 8 Alert indication over threshold, usage recommendation, sending e‐mail; 9 Power saving schedule in region; 10 Economical usage information; 11 Contract detail with the power company; 12 Setting of presentation. High‐level system architecture Figure 79 – Shows the high‐level system architecture for home energy management services Pre‐conditions The residential gateway and measurement devices for power consumption should be provided in the customer premises.