Visualization of the DBSCAN filtering process on the 2014 dataset. Left: The unfiltered relationship between array yield and reference yield, visualized with high point transparency. The overlapping data points reveal a dense, linear trend corresponding to the system's primary operational mode, but it is surrounded by significant noise. Middle: The anomalous data points identified as noise by the DBSCAN algorithm. These outliers, which constitute only around 12% of the total data, are removed from the analysis. Right: The clean, high-density cluster retained after filtering. This cluster, comprising approximately 87% of the original data. Given the consistency, we present the results for a single representative inverter (Inverter 2001). The filtering results for the other two inverters, which show nearly identical patterns, are provided in Appendix A (Figs. A1–A3).