TY - JOUR
T1 - Prediction of Climate-Specific Degradation Rate for Photovoltaic Encapsulant Discoloration
AU - Sinha, Archana
AU - Gopalakrishna, Hamsini
AU - Bala Subramaniyan, Arun
AU - Jain, Deepak
AU - Oh, Jaewon
AU - Jordan, Dirk
AU - Tamizhmani, Govinda Samy
N1 - Funding Information:
Manuscript received February 28, 2020; revised April 12, 2020; accepted April 14, 2020. Date of publication May 14, 2020; date of current version June 19, 2020. This work was supported in part by the U.S. Department of Energy under Grant DE-EE0007138, the SunShot program, PREDICTS II. (Corresponding author: Archana Sinha.) Archana Sinha, Hamsini Gopalakrishna, Arun Bala Subramaniyan, Deepak Jain, and GovindaSamy TamizhMani are with the Photovoltaic Reliability Laboratory, Arizona State University, Mesa, AZ 85212 USA (e-mail: archana.sinha@asu.edu; hgopalak@asu.edu; abalas18@asu.edu; dveerend@asu.edu; manit@asu.edu).
Publisher Copyright:
© 2011-2012 IEEE.
PY - 2020/7
Y1 - 2020/7
N2 - Encapsulant discoloration is a well-known field degradation mode of crystalline-silicon photovoltaic modules, particularly in the hot climate zones. The discoloration rate is influenced by several weathering factors, such as UV light, module temperature, and humidity, as well as the permeability of oxygen into the module. In this article, a rate dependence model employing the modified Arrhenius equations to predict the degradation rate for encapsulant discoloration in different climates is presented. Two modeling approaches are introduced, which utilize the field and accelerated UV testing degradation data in conjunction with the field meteorological data to determine the acceleration factor for encapsulant browning. A novel method of accelerated UV stress testing at three simultaneous module temperatures in a single environmental chamber test run is implemented to estimate the activation energy for browning. The test was performed on three field-retrieved modules to capture the wear-out failure mechanism. The degradation in short-circuit current Isc rather than maximum power is used as a decisive parameter for the discoloration analysis. Furthermore, the developed model has been used to predict the Isc degradation rate for the Arizona field characterized by a hot and dry climate and is validated against the field-measured value. It has also been applied to other climate types, e.g., the cold and dry climate of New York.
AB - Encapsulant discoloration is a well-known field degradation mode of crystalline-silicon photovoltaic modules, particularly in the hot climate zones. The discoloration rate is influenced by several weathering factors, such as UV light, module temperature, and humidity, as well as the permeability of oxygen into the module. In this article, a rate dependence model employing the modified Arrhenius equations to predict the degradation rate for encapsulant discoloration in different climates is presented. Two modeling approaches are introduced, which utilize the field and accelerated UV testing degradation data in conjunction with the field meteorological data to determine the acceleration factor for encapsulant browning. A novel method of accelerated UV stress testing at three simultaneous module temperatures in a single environmental chamber test run is implemented to estimate the activation energy for browning. The test was performed on three field-retrieved modules to capture the wear-out failure mechanism. The degradation in short-circuit current Isc rather than maximum power is used as a decisive parameter for the discoloration analysis. Furthermore, the developed model has been used to predict the Isc degradation rate for the Arizona field characterized by a hot and dry climate and is validated against the field-measured value. It has also been applied to other climate types, e.g., the cold and dry climate of New York.
KW - Acceleration factor (AF)
KW - Arrhenius model
KW - activation energy
KW - degradation rate
KW - discoloration
KW - encapsulant
KW - photovoltaic (PV) module
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U2 - 10.1109/JPHOTOV.2020.2989182
DO - 10.1109/JPHOTOV.2020.2989182
M3 - Article
AN - SCOPUS:85088042483
SN - 2156-3381
VL - 10
SP - 1093
EP - 1101
JO - IEEE Journal of Photovoltaics
JF - IEEE Journal of Photovoltaics
IS - 4
M1 - 9093139
ER -