General Information
    • ISSN: 1793-821X (Print)
    • Abbreviated Title: J. Clean Energy Technol.
    • Frequency: Quarterly
    • DOI: 10.18178/JOCET
    • Editor-in-Chief: Prof. Haider F. Abdul Amir
    • Executive Editor: Ms. Jennifer Zeng
    • Abstracting/ Indexing: CNKIElectronic Journals Library, Chemical Abstracts Services (CAS), Ulrich's Periodicals Directory, Google Scholar, ProQuest.
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Universiti Malaysia Sabah, Malaysia.
I would like to express my appreciation to all the reviewers and editors, who have been working
very hard to ensure the quality of the journal. It's my honor to work with such a wonderful team.

JOCET 2019 Vol.7(3): 25-31 ISSN: 1793-821X
DOI: 10.18178/JOCET.2019.7.3.505

Soiling of Photovoltaic Modules: Size Characterization of the Accumulated Dust

Dirk Goossens
Abstract—Soiling significantly reduces the energy production of photovoltaic (PV) modules. The reduction is not only determined by the amount and composition, but also by the size distribution of the particles. This study investigates the particle-size characteristics of dust accumulated on horizontal and inclined glass surfaces used in PV modules. The accumulated dust is compared to the ambient airborne dust. Effects of tilt angle and wind speed are investigated. Variations in particle size over the glass surface are also studied. Dust accumulating on a photovoltaic module is finer than ambient airborne dust, except for a combination of forward tilt AND low wind velocity. For wind velocities large enough to initiate wind erosion the accumulated dust is finer than the airborne dust even in the case of forward tilt. For backward tilt the accumulated dust is always finer than the airborne dust. Reasons for the finer dust are the preferential accumulation of the finer particles in the wake of the module due to their lower response time compared to coarse particles and the preferential removal of the coarsest fractions by the wind. At forward tilt accumulated dust is finest near the leading and trailing edges of a module whereas at backward tilt the particle size distribution over a PV module is more uniform. Energy prediction models should incorporate these internal variations and the differences with airborne dust.

Index Terms—Dust, glass, particle size distribution, PV module, soiling.

Dirk Goossens is with the Department of Electrical Engineering and the Department of Earth and Environmental Sciences at KU Leuven, Belgium (e-mail:


Cite:Dirk Goossens, "Soiling of Photovoltaic Modules: Size Characterization of the Accumulated Dust," Journal of Clean Energy Technologies vol. 7, no. 3, pp. 25-31, 2019.

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