skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

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

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. Furthermore, 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,more » 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 Lab. (NREL), Golden, CO (United States)
  2. DuPont Company, Wilmington, DE (United States)
  3. Arizona State Univ., Mesa, AZ (United States)
  4. National Institute of Advanced Industrial Science and Technology, Ibaraki (Japan)
  5. Underwriter Lab., San Jose, 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:
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:  
AC36-08GO28308; AC36-08-GO28308
Resource Type:
Journal Article: Published Article
Journal Name:
Energy Science & Engineering
Additional Journal Information:
Journal Volume: 4; Journal Issue: 1; Related Information: Energy Science and Engineering; Journal ID: ISSN 2050-0505
Publisher:
Society of Chemical Industry, Wiley
Country of Publication:
United States
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 Annie, 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 States: 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 Annie, 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 States. 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 Annie, Tamizhmani, Govindasamy, Sakurai, Keiichiro, Inoue, Masanao, Doi, Takuya, Masuda, Atsushi, and Vanderpan, Crystal E.. Fri . "Multi angle laser light scattering evaluation of field exposed thermoplastic photovoltaic encapsulant materials". United States. doi: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 Annie and Tamizhmani, Govindasamy and Sakurai, Keiichiro and Inoue, Masanao and Doi, Takuya and Masuda, Atsushi and Vanderpan, Crystal E.},
abstractNote = {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. Furthermore, 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},
journal = {Energy Science & Engineering},
issn = {2050-0505},
number = 1,
volume = 4,
place = {United States},
year = {2016},
month = {1}
}

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

Save / Share:

Works referenced in this record:

Modeling of rates of moisture ingress into photovoltaic modules
journal, October 2006