Impact of environmental variables on the degradation of photovoltaic components and perspectives for the reliability assessment methodology
[1];
[1];
- National Inst. of Standards and Technology (NIST), Gaithersburg, MD (United States)
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Northeastern Univ., Boston, MA (United States)
- Fluoropolymers R&D, Arkema, King of Prussia, PA (United States)
- Case Western Reserve Univ., Cleveland, OH (United States)
- Underwriters Laboratories (UL), Northbrook, IL (United States)
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 based 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.
- Research Organization:
- National Renewable Energy Laboratory (NREL), Golden, CO (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office; SunShot Initiative
- Grant/Contract Number:
- AC36-08GO28308; EE0007143
- OSTI ID:
- 1603931
- Alternate ID(s):
- OSTI ID: 1600561
- Report Number(s):
- NREL/JA-5K00-76275; MainId:22860; UUID:d9063472-465e-ea11-9c31-ac162d87dfe5; MainAdminID:11336
- Journal Information:
- Solar Energy, Vol. 199; ISSN 0038-092X
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Degradation Analysis of Field-Exposed Photovoltaic Modules with Non-Fluoropolymer-Based Backsheets
Material characterization of seven photovoltaic backsheets using seven accelerated test conditions