Outdoor soiling microscope for measuring particle deposition and resuspension

Benjamin Figgis, Ahmed Ennaoui, Bing Guo, Wasim Javed, Eugene Chen

Research output: Contribution to journalArticle

30 Citations (Scopus)


The rate of soiling of photovoltaic modules depends on environmental parameters such as aerosol concentration, humidity and wind speed. Previously we found low correlations between daily averages of these values and the daily soiling rate of a PV system. In this study we aimed to achieve stronger correlations by increasing the measurement frequency, with a simple device able to quantify soiling in outdoor conditions in real time. The so-called outdoor soiling microscope developed could measure the deposit and removal of individual dust particles larger than 10 μm2 every few seconds, and could detect the onset and disappearance of condensation. In an initial trial the device revealed qualitative relations between the parameters not seen with 24-h data. However most linear correlation coefficients remained low, suggesting the need for a more sophisticated model of outdoor soiling.

Original languageEnglish
Pages (from-to)158-164
Number of pages7
JournalSolar Energy
Publication statusPublished - 1 Nov 2016



  • Condensation
  • Microscope
  • Particle deposition
  • Photovoltaic
  • Resuspension
  • Soiling

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • Materials Science(all)

Cite this