PAN file

A PAN file is the module parameter file that PVsyst or a similar energy model uses to describe how a PV module behaves. It holds the module's electrical behavior, temperature response, low-light performance, incidence angle (IAM) assumptions and other parameters that turn weather data into expected power. If those parameters are optimistic, incomplete or do not match the modules actually delivered, the modeled energy can be too high. The expected yield is then off before any physical fault exists at the plant. Files made by the manufacturer and files made independently can differ, and the difference can affect procurement comparisons, financing assumptions and post-construction variance analysis. In the field, a flawed PAN file looks like a persistent gap between expected and measured performance that remains after weather, availability, clipping, curtailment, soiling, degradation and instrumentation have been checked, even though the plant may be running normally. To diagnose it, find the exact PAN file used, including its source, version and any manual edits. Compare it with data sheets, independent lab data, third-party files and site behavior, then run sensitivity cases. Treat PAN source and version as a controlled, documented model input, and keep model-baseline problems separate from real operational losses so that no one tries to repair a field defect that does not exist.