PV plant monitoring needs both – data analysis and on-site inspection

Photovoltaic systems can be controlled with several approaches. By means of monitoring or with sample measurements on site. On a 9-year-old photovoltaic system with 970 kWp in the south of Austria, both approaches were pursued to investigate whether a cost-effective monitoring analysis alone is sufficient. The identification and partial repair of several superimposed failure cases such as shading, dirt, glass breakage and backsheet cracks ultimately showed that a data analysis with a determined performance ratio alone is not sufficient to draw complete conclusions about PV system and energy yield.