Publications

Predicting Photovoltaic Module Series Resistance based on Indoor-Aging Tests and Thermal Cycling Cumulative Exposure Estimates

Jones, C.B.; Hobbs, William B.; Libby, Cara; Gunda, Thushara G.; Hamzavy, Babak

The IEC 61215 and Qualification Plus indoor aging tests are recognized as valuable assessment procedures for identifying photovoltaic (PV) modules that are prone to early-life failures or excessive degradation. However, it is unclear how well the tests match with reality, and if they can predict in-field performance. Therefore, the present work performed indoor-aging thermal cycling tests on pristine-condition modules and evaluated, using in-field current and voltage (I-V) curve scans, modules of the same make and model exposed to the actual environment within a production field. The experiment included the estimate of the overall exposure to thermal cycling in both indoor and outdoor environments, the extraction of the series resistance from the I-V curves, the development of a model based on the indoor results, and finally the testing of the model on outdoor exposure amounts to predict actual changes in resistance. Index Terms - photovoltaic, accelerated aging, series resistance.