A European research team investigated theimpact of sand and dust pollution on Oman's photovoltaic modules. Theycollected 60 samples from different seasons, months, and tilt angles.

The study points out that "the loss ofsand and dust pollution largely depends on the particle size, shape, andrelated spectra, which will have a significant impact on the performance ofphotovoltaic panels."

In this recent paper published in thejournal Renewable Energy, titled "Characterization of Glass SurfaceFouling and Its Impact on Optical and Solar Photovoltaic Performance,"Markides and colleagues explained that the test samples were made from low ironglass specimens. In the solar energy industry, these test pieces are often usedto encapsulate the top layer of photovoltaic modules. They collected glasssamples at the end of each month in 2021, distinguishing between the rainy anddry seasons. In each collection period, researchers collected four samples withtilt angles of 0, 23, 45, and 90 degrees.

Subsequently, they sent these samples toLondon for transmittance testing. Analysis shows that the relative transmittanceof horizontal samples decreases by 65% during the rainy season, 68% during thedry season, and 64% throughout the year.

The research team added, "In contrast,the relative transmittance of vertical specimens decreased by 34%, 19%, and31%, respectively. The average relative transmittance of wet specimens, dryspecimens, and one-year specimens with three different tilt angles decreased by44%, 49%, and 42%, respectively."

Based on these results, researcherscalculated the expected power loss of single crystal photovoltaic modules understandard test conditions (i.e. radiation intensity of 1000 watts/square meterand temperature of 25 degrees Celsius).

They added, "The relativetransmittance decrease measured using samples from the rainy season, dryseason, and annual levels corresponds to a relative decrease in predicted powergeneration of 67%, 70%, and 66%, respectively. Based on a local tilt angle of23 degrees, the monthly relative transmittance loss is estimated to be about30%, resulting in a decrease of about 30% in the equivalent relativephotovoltaic power at the research site each month."

Then, scientists analyzed thecharacteristics of soil particles using X-ray and electron microscopy. Due toall glass samples being taken from the same location, scientists assume thattheir dirt has identical material characteristics. Therefore, they onlyanalyzed horizontal glass specimens during the rainy and dry seasons, as wellas throughout the year.

They emphasized, "The X-raydiffraction (XRD) results indicate that the annual level of sand and dustpollution test pieces contain various minerals, such as silicon dioxide,calcium carbonate, calcium magnesium carbonate, titanium dioxide, iron carbide,and aluminum silicate. The element distribution map focuses on the compoundsreported by XRD analysis. The most important element is silicon (Si), while theremaining elements include carbon (C), oxygen (O), sodium (Na), magnesium (Mg),aluminum (Al), calcium (Ca), and iron (Fe)."

Researchers also found that the amount ofPM10 particles in dry season samples is higher than that in rainy seasonsamples. PM10 is inhalable particulate matter with a diameter less than 10microns. They explained in the paper, "Research has also shown thatperiodic rainfall can naturally clean up accumulated large particles, butcannot remove small particles."

Therefore, relying solely on rainfall toachieve self-cleaning of solar panels is unreliable and requires the use ofcleaning equipment for cleaning. Multifit Solar has been dedicated toresearching photovoltaic cleaning for six years, and has developed variousequipment such as handheld semi-automatic cleaning brushes and fully automaticcleaning machines to meet your cleaning needs in different scenarios.