@inproceedings{6c9276bf9bba44b7aab1347b6086d91c,
title = "Temperature coefficient of power (Pmax) of field aged PV modules: Impact on performance ratio and degradation rate determinations",
abstract = "The determinations of performance ratio (per IEC 61724 standard) and degradation rate (using slope of performance ratio over time) of photovoltaic (PV) modules in a power plant are computed based on the power (Pmax) temperature coefficient (TC) data of the unexposed modules or the exposed modules during the commissioning time of the plant. The temperature coefficient of Pmax is typically assumed to not change over the lifetime of the module in the field. Therefore, this study was carried out in an attempt to investigate the validity of this assumption and current practice. Several 18-19 years old field aged modules from four different manufacturers were tested for the baseline light I-V measurements and dark I-V measurements to determine the power temperature coefficient and series resistance for each module. Using the dark I-V and light I-V data, the series resistances (Rs) and shunt resistances (Rsh) were calculated in order to determine their impact on fill factor (FF) and hence on Pmax. The result of this work indicates a measurable drop in fill factor (FF) as the series resistance (Rs) increased which in turn increases the temperature coefficient of Pmax. This determination goes against the typical assumption that the temperature coefficient of (Pmax) for aged modules does not change over time. The outcome of this work has a significant implication on the performance ratio and degradation rate determinations based on the temperature coefficient of Pmax of new modules which is not an accurate practice for analyzing field aged modules.",
author = "Farrukh Mahmood and Hatif Majeed and Haider Agha and Saddam Ali and Sai Tatapudi and Telia Curtis and Govindasamy Tamizhmani",
note = "Funding Information: This project was funded by USPCAS-E (U.S.-Pakistan Centers for Advanced Studies in Energy). The USAID-funded USPCAS-E program is a partnership between Arizona State University and two leading Pakistani universities: the National University of Sciences and Technology (NUST) and the University of Engineering and Technology (UET) Peshawar, to focus on applied research relevant to Pakistan{\textquoteright}s energy needs and help produce skilled graduates in the energy field. Funding Information: National University of Sciences and Technology (NUST) Publisher Copyright: {\textcopyright} COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.; Reliability of Photovoltaic Cells, Modules, Components, and Systems X 2017 ; Conference date: 06-08-2017 Through 07-08-2017",
year = "2017",
doi = "10.1117/12.2281840",
language = "English (US)",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Kempe, {Michael D.} and Dhere, {Neelkanth G.} and Keiichiro Sakurai",
booktitle = "Reliability of Photovoltaic Cells, Modules, Components, and Systems X",
}