Decay of Electrostatic Force of Dust Particles on Photovoltaic Modules

Chun Sheng Jiang, Helio Moutinho, Bobby To, Chuanxiao Xiao, Lin Simpson, Mowafak Al-Jassim

Research output: Contribution to conferencePaperpeer-review

1 Scopus Citations


Photovoltaic (PV) energy yield loss due to solar module soiling has become increasingly important as solar module deployment is now at the hundreds of gigawatts scale and continues to grow rapidly. We have reported on direct measurements - using atomic force microscopy (AFM) - of strong electric-field-induced attraction and adhesion force (Fes) of dust particles onto solar panel that are 1 to 2 orders of magnitude stronger than the van der Waals and water capillary forces, corroborated by observing the increase in system voltage-induced soiling rate. Here, we report another characteristic of Fes on soiling - long lasting or slow decay after turning off the high voltage applied to solar panels. The Fes decay time varies in a wide time range of 1 to 10 hours, depending on two factors: 1) either/both the cell or/and particle were charged with high voltage before the voltages were turned off; and 2) how the cell was connected to the ground after the voltage was turned off - either connected through the power supply electronics, directly connected to the ground, or electrically floated. The Fes decay is understood in terms of 1) net electrical charge dissipations in both particle and cell, 2) thermal disordering of dipole polarization in the module glass dielectrics, and 3) charge redistribution by the electrostatic interaction of particle and module glass. This long-lasting Fes for hours can significantly affect the solar panel soiling after sunset, especially combined with water condensation.

Original languageAmerican English
Number of pages5
StatePublished - Jun 2019
Event46th IEEE Photovoltaic Specialists Conference, PVSC 2019 - Chicago, United States
Duration: 16 Jun 201921 Jun 2019


Conference46th IEEE Photovoltaic Specialists Conference, PVSC 2019
Country/TerritoryUnited States

Bibliographical note

Publisher Copyright:
© 2019 IEEE.

NREL Publication Number

  • NREL/CP-5K00-76314


  • adhesion force
  • atomic force microscopy
  • attraction force
  • dust particles
  • electrostatic force
  • module reliability
  • soiling loss


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