Series Episode Three: Understanding PVsyst Reports

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In the third episode of the PVsyst series, Daniel Tarico and Frances Wilberg-Plourd from E3 discuss the interpretation of PVsyst reports and how they relate to PV system energy estimation, specifically focusing on how PVsyst calculates energy production using statistical probabilities.

Key points:

1. PVsyst Report Overview: The report begins with system inputs such as equipment, location, orientation, and shading factors, and then presents energy estimates, including monthly generation based on climate data. The final report includes an energy waterfall diagram showing energy production and losses on both the DC and AC sides of the system.
2. P50 and Probabilistic Estimates: The P50 value represents the long-term average expected energy production. It's based on probabilistic modeling, considering weather variability. The system's actual performance will, in some years, exceed or fall short of the P50 estimate, with a 50/50 chance of being above or below the predicted value.
3. Other Probabilistic Levels (P75, P99): Other probabilities, like P75 and P99, indicate more conservative estimates. The P99 represents energy production that the system is expected to exceed in 99% of years. These are useful for ensuring energy and revenue guarantees.
4. Degradation and Performance Tracking: Module degradation typically leads to a half-percent annual decrease in energy production, impacting long-term projections. If system production drops faster than expected, it might indicate issues requiring attention.

The episode emphasizes the importance of accurate and up-to-date data in PVsyst reports to ensure reliable energy and financial forecasts.