Robust PV Degradation Methodology and Application
Robust PV Degradation Methodology and Application Published in: IEEE Journal of Photovoltaics ( Volume: 8 , Issue: 2 , March 2018 ) Dirk C. Jordan National Renewable Energy Laboratory, Golden, CO, USA; Chris Deline ; Sarah R. Kurtz ; Gregory M. Kimball ; Mike Anderson Abstract: The degradation rate plays an important role in predicting and assessing the long-term energy generation of photovoltaics (PV) systems. Many methods have been proposed for extracting the degradation rate from operational data of PV systems, but most of the published approaches are susceptible to bias due to inverter clipping, module soiling, temporary outages, seasonality, and sensor degradation. In this paper, we propose a methodology for determining PV degradation leveraging available modeled clear-sky irradiance data rather than site sensor data, and a robust year-over-year rate calculation. We show the method to provide reliable degradation rate estimates even in the case of sensor drift, data shifts, an