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Title: Multi angle laser light scattering evaluation of field exposed thermoplastic photovoltaic encapsulant materials

Abstract

Abstract As creep of polymeric materials is potentially a safety concern for photovoltaic modules, the potential for module creep has become a significant topic of discussion in the development of IEC 61730 and IEC 61215. To investigate the possibility of creep, modules were constructed, using several thermoplastic encapsulant materials, into thin‐film mock modules and deployed in Mesa, Arizona. The materials examined included poly(ethylene)‐co‐vinyl acetate (EVA, including formulations both cross‐linked and with no curing agent), polyethylene/polyoctene copolymer (PO), poly(dimethylsiloxane) (PDMS), polyvinyl butyral (PVB), and thermoplastic polyurethane (TPU). The absence of creep in this experiment is attributable to several factors of which the most notable one was the unexpected cross‐linking of an EVA formulation without a cross‐linking agent. It was also found that some materials experienced both chain scission and cross‐linking reactions, sometimes with a significant dependence on location within a module. The TPU and EVA samples were found to degrade with cross‐linking reactions dominating over chain scission. In contrast, the PO materials degraded with chain scission dominating over cross‐linking reactions. Although we found no significant indications that viscous creep is likely to occur in fielded modules capable of passing the qualification tests, we note that one should consider how a polymermore » degrades, chain scission or cross‐linking, in assessing the suitability of a thermoplastic polymer in terrestrial photovoltaic applications.« less

Authors:
 [1];  [1];  [1];  [1];  [1];  [1];  [2];  [2];  [2];  [3];  [3];  [4];  [4];  [4];  [4];  [5]
  1. National Renewable Energy Laboratory 1617 Cole Boulevard Golden Colorado 80401
  2. DuPont Company 200 Powder Mill Road Wilmington Delaware 19803
  3. Polytechnic Campus Arizona State University 7349 East Unity Avenue Mesa Arizona
  4. National Institute of Advanced Industrial Science and Technology 1‐1‐1 Umezono Tsukuba Ibaraki 305‐8568 Japan
  5. Underwriters Laboratories 455 East Trimble Road San Jose California
Publication Date:
Research Org.:
National Renewable Energy Laboratory (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
OSTI Identifier:
1234272
Alternate Identifier(s):
OSTI ID: 1234273; OSTI ID: 1237033
Report Number(s):
NREL/JA-5J00-64515
Journal ID: ISSN 2050-0505
Grant/Contract Number:  
DE‐AC36‐08‐GO28308; AC36-08GO28308
Resource Type:
Journal Article: Published Article
Journal Name:
Energy Science & Engineering
Additional Journal Information:
Journal Name: Energy Science & Engineering Journal Volume: 4 Journal Issue: 1; Journal ID: ISSN 2050-0505
Publisher:
Wiley Blackwell (John Wiley & Sons)
Country of Publication:
United Kingdom
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; adhesives; creep; EVA encapsulant; polymer; qualification standards; thermoplastic

Citation Formats

Kempe, Michael D., Miller, David C., Wohlgemuth, John H., Kurtz, Sarah R., Moseley, John M., Nobles, Dylan L., Stika, Katherine M., Brun, Yefim, Samuels, Sam L., Shah, Qurat, Tamizhmani, Govindasamy, Sakurai, Keiichiro, Inoue, Masanao, Doi, Takuya, Masuda, Atsushi, and Vanderpan, Crystal E. Multi angle laser light scattering evaluation of field exposed thermoplastic photovoltaic encapsulant materials. United Kingdom: N. p., 2016. Web. doi:10.1002/ese3.106.
Kempe, Michael D., Miller, David C., Wohlgemuth, John H., Kurtz, Sarah R., Moseley, John M., Nobles, Dylan L., Stika, Katherine M., Brun, Yefim, Samuels, Sam L., Shah, Qurat, Tamizhmani, Govindasamy, Sakurai, Keiichiro, Inoue, Masanao, Doi, Takuya, Masuda, Atsushi, & Vanderpan, Crystal E. Multi angle laser light scattering evaluation of field exposed thermoplastic photovoltaic encapsulant materials. United Kingdom. https://doi.org/10.1002/ese3.106
Kempe, Michael D., Miller, David C., Wohlgemuth, John H., Kurtz, Sarah R., Moseley, John M., Nobles, Dylan L., Stika, Katherine M., Brun, Yefim, Samuels, Sam L., Shah, Qurat, Tamizhmani, Govindasamy, Sakurai, Keiichiro, Inoue, Masanao, Doi, Takuya, Masuda, Atsushi, and Vanderpan, Crystal E. 2016. "Multi angle laser light scattering evaluation of field exposed thermoplastic photovoltaic encapsulant materials". United Kingdom. https://doi.org/10.1002/ese3.106.
@article{osti_1234272,
title = {Multi angle laser light scattering evaluation of field exposed thermoplastic photovoltaic encapsulant materials},
author = {Kempe, Michael D. and Miller, David C. and Wohlgemuth, John H. and Kurtz, Sarah R. and Moseley, John M. and Nobles, Dylan L. and Stika, Katherine M. and Brun, Yefim and Samuels, Sam L. and Shah, Qurat and Tamizhmani, Govindasamy and Sakurai, Keiichiro and Inoue, Masanao and Doi, Takuya and Masuda, Atsushi and Vanderpan, Crystal E.},
abstractNote = {Abstract As creep of polymeric materials is potentially a safety concern for photovoltaic modules, the potential for module creep has become a significant topic of discussion in the development of IEC 61730 and IEC 61215. To investigate the possibility of creep, modules were constructed, using several thermoplastic encapsulant materials, into thin‐film mock modules and deployed in Mesa, Arizona. The materials examined included poly(ethylene)‐co‐vinyl acetate (EVA, including formulations both cross‐linked and with no curing agent), polyethylene/polyoctene copolymer (PO), poly(dimethylsiloxane) (PDMS), polyvinyl butyral (PVB), and thermoplastic polyurethane (TPU). The absence of creep in this experiment is attributable to several factors of which the most notable one was the unexpected cross‐linking of an EVA formulation without a cross‐linking agent. It was also found that some materials experienced both chain scission and cross‐linking reactions, sometimes with a significant dependence on location within a module. The TPU and EVA samples were found to degrade with cross‐linking reactions dominating over chain scission. In contrast, the PO materials degraded with chain scission dominating over cross‐linking reactions. Although we found no significant indications that viscous creep is likely to occur in fielded modules capable of passing the qualification tests, we note that one should consider how a polymer degrades, chain scission or cross‐linking, in assessing the suitability of a thermoplastic polymer in terrestrial photovoltaic applications.},
doi = {10.1002/ese3.106},
url = {https://www.osti.gov/biblio/1234272}, journal = {Energy Science & Engineering},
issn = {2050-0505},
number = 1,
volume = 4,
place = {United Kingdom},
year = {Fri Jan 08 00:00:00 EST 2016},
month = {Fri Jan 08 00:00:00 EST 2016}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at https://doi.org/10.1002/ese3.106

Citation Metrics:
Cited by: 11 works
Citation information provided by
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Works referenced in this record:

Field testing of thermoplastic encapsulants in high-temperature installations
journal, November 2015


Measuring temperature-dependent water vapor and gas permeation through high barrier films
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Silver nanoparticles cause snail trails in photovoltaic modules
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