Title: Impact of environmental variables on the degradation of photovoltaic components and perspectives for the reliability assessment methodology

Abstract

Backsheet cracking has been a major issue observed in the field; however, standardized qualification tests, such as IEC61215, are inadequate to reliably identify such failures of PV modules due to the lack of the critical weathering factors applied sequentially or in combination, such as those found in the service environments. To address this problem, in this work we investigated the effects of various environmental variables on the degradation and failure behaviors of the polyamide-based backsheet in PV modules retrieved from five different locations, encompassing a variety of climates, including humid subtropical, hot-summer Mediterranean, tropical savanna climate and hot arid. The correlations between the degradation indicators and the weathering variables were further demonstrated by principle components analysis (PCA). We found strong relationships between: carbonyl formation and reflected solar radiation; hydroxyl formation and module temperature; yellowness and NO2 concentration, while no simple correlation could be found between a specific weathering factor and cracking. By introducing additional stress factors to the aged polyamide-based backsheet films with the novel 'fragmentation test', we successfully reproduced the field cracking behaviour. This study has demonstrated that different degradation modes of PV components respond differently to the environmental stresses encountered in service. Thereby, any accelerated laboratory test basedmore » on a single set condition or lacking key environmental variables would be inadequate to assess the long-term performance of PV modules and components. A new reliability-based methodology is proposed to quantitatively link laboratory testing with field results for the service life prediction of PV materials.« less

Authors:

Lyu, Yadong  ^[1];

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• Search DOE PAGES for ORCID "0000-0001-6038-7532"

Fairbrother, Andrew  ^[1];

• Search DOE PAGES for author "Fairbrother, Andrew"
• Search DOE PAGES for ORCID "0000-0002-6162-0532"

Gong, Mengyan ^[1]; Kim, Jae Hyun ^[1]; Gu, Xiaohong ^[1]; Kempe, Michael ^[2]; Julien, Scott ^[3]; Wan, Kai-Tak ^[3]; Napoli, Sophie ^[4]; Hauser, Adam ^[4]; O'Brien, Greg ^[4]; Wang, Yu ^[5]; French, Roger ^[5]; Bruckman, Laura ^[5]; Ji, Liang ^[6]; Boyce, Kenneth ^[6]

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+ Show Author Affiliations

1. National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States)
2. National Renewable Energy Lab. (NREL), Golden, CO (United States)
3. Northeastern Univ., Boston, MA (United States)
4. Fluoropolymers R&D, Arkema, King of Prussia, PA (United States)
5. Case Western Reserve Univ., Cleveland, OH (United States)
6. Underwriters Laboratories (UL), Northbrook, IL (United States)

Publication Date:

Wed Feb 19 00:00:00 EST 2020

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; SunShot Initiative

OSTI Identifier:

1603931

Alternate Identifier(s):

OSTI ID: 1600561

Report Number(s):

NREL/JA-5K00-76275
Journal ID: ISSN 0038-092X; MainId:22860;UUID:d9063472-465e-ea11-9c31-ac162d87dfe5;MainAdminID:11336

Grant/Contract Number:  

AC36-08GO28308; EE0007143

Resource Type:

Accepted Manuscript

Journal Name:

Solar Energy

Additional Journal Information:

Journal Volume: 199; Journal ID: ISSN 0038-092X

Publisher:

Elsevier

Country of Publication:

United States

Language:

English

Subject:

14 SOLAR ENERGY; 47 OTHER INSTRUMENTATION; photovoltaic modules; backsheet; polyamide; weathering; reliability; principle components analysis