Spatio-Temporal Modeling of Field Surveyed Backsheet Degradation

Raymond Wieser, Kunal Rath, Stephanie Moffitt, Ruben Zabalza, Evan Boucher, Silvana Ayala, Matthew Brown, Xiaohong Gu, Liang Ji, Colleen O'Brien, Adam Hauser, Greg O'Brien, Roger French, Michael Kempe, Jared Tracy, Kausik Choudhury, William Gambogi, Laura Bruckman, Kenneth Boyce

Research output: Contribution to conferencePaperpeer-review

5 Scopus Citations


Assessing photovoltaic module backsheet durability is critical to increasing module lifetime. Lab based accelerating testing has recently failed to predict large scale failures of widely adopted polymeric materials. Field surveyed data is critical to assess the performance of component lifetime. Using a documented field survey protocol, 13 field surveys where conducted. Each measurement is encoded with it's spatial location in respect to the other modules. By combining field survey data on degradation predictors with real time satellite weather data, data-driven predictive models of backsheet degradation were trained. LOESS models were constructed to investigate the spatial dependence of measurements. It was found that micro-climatic effects like tree-lines, ground surface changes, and elevation changes effected the magnitude and variance of the measurements. A GAM model was created to predict the value of degradation based on measured predictors. The model includes variables on the climate of the system and the location of each measurement in the PV mounting structure. The model performed well with an adj.R2 of 0.95 for yellowness index prediction. The model was cross-validated using k-folds.

Original languageAmerican English
Number of pages6
StatePublished - 20 Jun 2021
Event48th IEEE Photovoltaic Specialists Conference, PVSC 2021 - Fort Lauderdale, United States
Duration: 20 Jun 202125 Jun 2021


Conference48th IEEE Photovoltaic Specialists Conference, PVSC 2021
Country/TerritoryUnited States
CityFort Lauderdale

Bibliographical note

Publisher Copyright:
© 2021 IEEE.

NREL Publication Number

  • NREL/CP-5K00-81320


  • Backsheet
  • Degradation
  • Field Survey
  • Modeling
  • Spatio-temporal


Dive into the research topics of 'Spatio-Temporal Modeling of Field Surveyed Backsheet Degradation'. Together they form a unique fingerprint.

Cite this