Dust-induced shading on photovoltaic modules

Authors

  • Hassan Qasem,

    Corresponding author
    1. Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and System Engineering, Loughborough University, Leicestershire, UK
    • Correspondence: Hassan Qasem, Centre for Renewable Energy Systems Technology (CREST), Loughborough University, Leicestershire, LE11 3TU, UK.

      E-mail: h.qasem@lboro.ac.uk

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  • Thomas R. Betts,

    1. Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and System Engineering, Loughborough University, Leicestershire, UK
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  • Harald Müllejans,

    1. European Commission, Joint Research Centre, Institute for Energy and Transport, Renewable Energy Unit, Ispra, VA, Italy
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  • Hassan AlBusairi,

    1. Kuwait Institute for Scientific Research (KISR), Building and Energy Technologies Department, Safat, Kuwait
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  • Ralph Gottschalg

    1. Centre for Renewable Energy Systems Technology (CREST), School of Electronic, Electrical and System Engineering, Loughborough University, Leicestershire, UK
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ABSTRACT

The effect of dust on photovoltaic modules is investigated with respect to concentration and spectral transmittance. Samples were collected in the form of raw dust as well as accumulated dust on exposed sheets of glass at different tilt angles. Spectral transmittance of the samples was determined. Transmittance variation between top, middle and bottom was identified for samples collected at different inclinations, where the worst case was seen at a tilt angle of 30o with a non-uniformity of 4.4% in comparison with 0.2% for the 90° tilt. The measured data showed a decrease in transmittance at wavelengths <570 nm. Integrating this with measured spectral responses of different technologies demonstrates that wide band-gap thin-film technologies are affected more than, for example crystalline silicon technologies. The worst case is amorphous silicon, where a 33% reduction in photocurrent is predicted for a dust concentration of 4.25 mg/cm2. Similarly, crystalline silicon and CIGS technologies are predicted to be less affected, with 28.6% and 28.5% reductions in photocurrent, respectively. The same procedure was repeated with varying Air Mass (AM), tilt angle and dust concentration values to produce a soiling ratio table for different technologies under different AM, tilt angle and dust concentration values. Copyright © 2012 John Wiley & Sons, Ltd.

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