A photovoltaic (PV) system has been widely deployed in residential areas to reduce energy cost. However, it is not monitored in detail or managed in a user-friendly manner in many cases. Therefore, a PV monitoring system needs to provide both detailed monitoring of each PV module and a user-friendly way of access to the monitored data. In addition, the PV monitoring system needs to be low-cost to be widely deployed. To achieve these needs, this paper proposes a user-friendly PV monitoring system based on a low-cost power line communication (PLC).
For cost reduction, the PLC module is developed without a communication modem. For detailed monitoring, the PLC modules are installed at each PV module; the data logger aggregates the monitored data of each PV module and the PV inverter. For userfriendly access, a smart app is used to show the aggregated data graphically. In the field test, the developed PV monitoring system is installed at a real PV system composed of sixteen 400 W PV module; users can figure out the status of the whole PV system through a smart device. This scheme is expected to reduce energy cost in residential areas by maintaining a PV system performance.