Modelling photovoltaic soiling losses through optical characterization.

Smestad, Greg P.; Germer, Thomas A.; Alrashidi, Hameed; Dey, Sumon; Brahma, Honey; Sarmah, Nabin; Ghosh, Aritra; Sellami, Nazmi; Hassan, Ibrahim A.I.; Desouky, Mai; Kasry, Amal; Pesala, Bala; Sundaram, Senthilarasu; Almonacid, Florencia; Reddy, K.S.; Mallick, Tapas K.; Micheli, Leonardo

doi:10.1038/s41598-019-56868-z

Authors

Greg P. Smestad

Thomas A. Germer

Hameed Alrashidi

Eduardo F.

Sumon Dey

Honey Brahma

Nabin Sarmah

Aritra Ghosh

Nazmi Sellami

Ibrahim A.I. Hassan

Mai Desouky

Amal Kasry

Bala Pesala

Senthilarasu Sundaram

Florencia Almonacid

K.S. Reddy

Tapas K. Mallick

Leonardo Micheli

Abstract

The accumulation of soiling on photovoltaic (PV) modules affects PV systems worldwide. Soiling consists of mineral dust, soot particles, aerosols, pollen, fungi and/or other contaminants that deposit on the surface of PV modules. Soiling absorbs, scatters, and reflects a fraction of the incoming sunlight, reducing the intensity that reaches the active part of the solar cell. Here, we report on the comparison of naturally accumulated soiling on coupons of PV glass soiled at seven locations worldwide. The spectral hemispherical transmittance was measured. It was found that natural soiling disproportionately impacts the blue and ultraviolet (UV) portions of the spectrum compared to the visible and infrared (IR). Also, the general shape of the transmittance spectra was similar at all the studied sites and could adequately be described by a modified form of the Ångström turbidity equation. In addition, the distribution of particles sizes was found to follow the IEST-STD-CC 1246E cleanliness standard. The fractional coverage of the glass surface by particles could be determined directly or indirectly and, as expected, has a linear correlation with the transmittance. It thus becomes feasible to estimate the optical consequences of the soiling of PV modules from the particle size distribution and the cleanliness value.

Citation

SMESTAD G.P., GERMER, T.A., ALRASHIDI, H. FERNÁNDEZ, E.F., DEY, S., BRAHMA, H., SARMAH, N., GHOSH, A., SELLAMI, N., HASSAN, I.A.I., DESOUKY, M. KASRY, A., PESALA, B., SUNDARAM, S., ALMONACID, F., REDDY, K.S., MALLICK, T.K. and MICHELI, L. 2020. Modelling photovoltaic soiling losses through optical characterization. Scientific reports [online], 10, article ID 58. Available from: https://doi.org/10.1038/s41598-019-56868-z

Journal Article Type	Article
Acceptance Date	Oct 30, 2019
Online Publication Date	Jan 9, 2020
Publication Date	Dec 31, 2020
Deposit Date	Jan 23, 2020
Publicly Available Date	Jan 23, 2020
Journal	Scientific Reports
Electronic ISSN	2045-2322
Publisher	Springer
Peer Reviewed	Peer Reviewed
Volume	10
Article Number	58
DOI	https://doi.org/10.1038/s41598-019-56868-z
Keywords	PV; Soiling; Ultraviolet; Infrared; Ångström turbidity equation; Particle; Size; Cleanliness
Public URL	https://rgu-repository.worktribe.com/output/835965