抄録
In this study, a method to detect a decrease in output power on photovoltaic systems is proposed. This proposed method is based on using satellite irradiance data. In order to mitigate the error of satellite data, we determine which day has acceptable data to detect a decrease in output power, depending on the climate condition. From the viewpoint of necessary period, the proposed method has shorter the elapsed monitoring time compared to previous study. In addition, cluster analysis to distinguish between permanent decrease and temporary decrease is considered.