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Title: Evaluating and predicting molecular mechanisms of adhesive degradation during field and accelerated aging of photovoltaic modules

Abstract

Extending photovoltaic (PV) module lifetimes beyond 30 years is a goal of significant priority. A challenge that must first be addressed, however, is the development of a predictive reliability model that captures the synergy of terrestrial stressors on module degradation, particularly at encapsulant interfaces. Using a metrology designed specifically for PV modules, a comprehensive study of the widely used ethylene vinyl acetate encapsulant was performed in which encapsulant adhesion was evaluated as a function of environmental stressors (UV exposure, temperature, and humidity) for modules aged both under accelerated lab and internationally located field conditions for months to nearly 3 decades. Mechanical and chemical characterization methods are combined with fundamental polymer reaction engineering to unravel the degradation processes active at the molecular scale that lead to encapsulant delamination. An analytical and modular model framework is put forward enabling the prediction of long-term PV module durability, starting from fundamental principles at the molecular level and explicitly accounting for bond rupture events in the bulk encapsulant and at the encapsulant interfaces. Successful parameter tuning to adhesion data indicates a dominant occurrence of deacetylation, β-scission, and hydrolytic depolymerization, respectively. The model contributes to the longstanding challenge of predicting module lifetimes in any geographic locationmore » while minimizing time-consuming and costly aging studies.« less

Authors:
 [1];  [2];  [3];  [4];  [4]
  1. Stanford Univ., CA (United States); Exponent, Menlo Park, CA (United States)
  2. Stanford Univ., CA (United States); Ghent Univ. (Belgium)
  3. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  4. Stanford Univ., CA (United States)
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
OSTI Identifier:
1466665
Alternate Identifier(s):
OSTI ID: 1460125
Report Number(s):
NREL/JA-5K00-72240
Journal ID: ISSN 1062-7995
Grant/Contract Number:  
AC36-08GO28308
Resource Type:
Accepted Manuscript
Journal Name:
Progress in Photovoltaics
Additional Journal Information:
Journal Volume: 26; Journal Issue: 12; Journal ID: ISSN 1062-7995
Publisher:
Wiley
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; adhesion; interface delamination; photovoltaic encapsulation; polymer degradation; predictive model

Citation Formats

Tracy, Jared, D'hooge, Dagmar R., Bosco, Nick, Delgado, Chris, and Dauskardt, Reinhold. Evaluating and predicting molecular mechanisms of adhesive degradation during field and accelerated aging of photovoltaic modules. United States: N. p., 2018. Web. doi:10.1002/pip.3045.
Tracy, Jared, D'hooge, Dagmar R., Bosco, Nick, Delgado, Chris, & Dauskardt, Reinhold. Evaluating and predicting molecular mechanisms of adhesive degradation during field and accelerated aging of photovoltaic modules. United States. doi:10.1002/pip.3045.
Tracy, Jared, D'hooge, Dagmar R., Bosco, Nick, Delgado, Chris, and Dauskardt, Reinhold. Fri . "Evaluating and predicting molecular mechanisms of adhesive degradation during field and accelerated aging of photovoltaic modules". United States. doi:10.1002/pip.3045. https://www.osti.gov/servlets/purl/1466665.
@article{osti_1466665,
title = {Evaluating and predicting molecular mechanisms of adhesive degradation during field and accelerated aging of photovoltaic modules},
author = {Tracy, Jared and D'hooge, Dagmar R. and Bosco, Nick and Delgado, Chris and Dauskardt, Reinhold},
abstractNote = {Extending photovoltaic (PV) module lifetimes beyond 30 years is a goal of significant priority. A challenge that must first be addressed, however, is the development of a predictive reliability model that captures the synergy of terrestrial stressors on module degradation, particularly at encapsulant interfaces. Using a metrology designed specifically for PV modules, a comprehensive study of the widely used ethylene vinyl acetate encapsulant was performed in which encapsulant adhesion was evaluated as a function of environmental stressors (UV exposure, temperature, and humidity) for modules aged both under accelerated lab and internationally located field conditions for months to nearly 3 decades. Mechanical and chemical characterization methods are combined with fundamental polymer reaction engineering to unravel the degradation processes active at the molecular scale that lead to encapsulant delamination. An analytical and modular model framework is put forward enabling the prediction of long-term PV module durability, starting from fundamental principles at the molecular level and explicitly accounting for bond rupture events in the bulk encapsulant and at the encapsulant interfaces. Successful parameter tuning to adhesion data indicates a dominant occurrence of deacetylation, β-scission, and hydrolytic depolymerization, respectively. The model contributes to the longstanding challenge of predicting module lifetimes in any geographic location while minimizing time-consuming and costly aging studies.},
doi = {10.1002/pip.3045},
journal = {Progress in Photovoltaics},
number = 12,
volume = 26,
place = {United States},
year = {2018},
month = {7}
}

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