Power loss due to soiling on photovoltaic module with and without anti-soiling coating at different angle of incidence

ABSTRACT

This paper evaluates the electrical performance of photovoltaic (PV) modules with and without anti-soiling coating at different incidence angles and layers of soiling. Two test coupons were evaluated, one of which was uncoated and the other was coated with an anti-soiling coating. Preliminary examinations for the presence of inherent defects were carried out using Ultraviolet Fluorescence and Electroluminescence imaging techniques. The coupons were then exposed to different layers of soil, accumulated naturally, using an outdoor soiling setup. The short-circuit current (I_SC) was measured at different angle of incidence (AOI) before and after the deposition of soil. The maximum drop in the I_SC was recorded to be 8.79% and 5.47% at 60° AOI for clean uncoated and coated coupons respectively. The I_SC of soiled modules also depicted a similar downward trend in the I_SC. Further, it was found under soiled conditions, the critical AOI for the coated coupon was found to be enhanced by 5–15 degrees in comparison to the uncoated one. Henceforth, the significant reduction in soiling loss would ultimately result in the improved efficiency of the module.

KEYWORDS:

• Photovoltaic
• anti-soiling coating
• angle of incidence

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgments

This work was supported by the United States Agency for International Development (USAID) through Higher Education Commission (HEC) of Pakistan [Grant No: AID-391-A-14-000007, 2018].

Nomenclature

AOI	=	Angle of Incidence
ASU	=	Arizona State University
CAD	=	Computed Aided Design
DC	=	Direct Current
EL	=	Electroluminescence
EVA	=	Ethyl Vinyl Acetate
I-V	=	Current-Voltage
Isc `	=	Short Circuit Current
MPP	=	Maximum Power Point
Pmp	=	Maximum Output Power
PRL	=	Photovoltaics Reliability Lab
PV	=	Photovoltaic
UV	=	Ultraviolet
UV-F	=	Ultra Violet Fluorescence
VOC	=	Open-circuit voltage