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Title: Evaluation and modeling of the potential effects of a module manufacturing anomaly

Photovoltaic lifetime predictions are in great demand, but are exceedingly difficult to achieve with uncertainties small enough to be useful. During the construction of photovoltaic modules, small unplanned variability in materials or processes can have profound effects on module durability. Thus, continual monitoring of production quality is needed. In the subject production run, module quality, as monitored by damp heat testing, revealed a subset of modules that were prone to higher degradation rates. An assessment of the potential long-term power loss and mitigation strategies was needed. To do this, modules were exposed to variable levels of humidity and temperature with periodic monitoring. The analysis takes into account the kinetics of the degradation and the spatially and temporally varying humidity content within the module during accelerated stress testing. This is an important aspect for extrapolating laboratory results to field exposure because moisture ingress is diffusion limited in most laboratory module tests but not limited in these fielded modules. This analysis predicted that although a solder flux induce degradation mechanism is significant in accelerated stress test, this is probably an artifact of a process with a very large acceleration factor that is not likely to be significant for deployed modules. The degradationmore » mechanism affected a limited area around the tabbing helping to minimize the effect. Furthermore, three years after the system was commissioned, the fielded modules indeed show no significant power loss.« less
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  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
Publication Date:
Report Number(s):
Journal ID: ISSN 1062-7995
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Progress in Photovoltaics
Additional Journal Information:
Journal Volume: 25; Journal Issue: 12; Journal ID: ISSN 1062-7995
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)
Country of Publication:
United States
14 SOLAR ENERGY; damp heat; durability; kinetics; manufacturing quality; reliability
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1401558