STUDY - Dust, pollution buildup can cut PV output by up to 35%

Dust and other pollutants can lead to solar power generation losses of 17% to 25% or more in arid regions such as Eastern China, Northern India and the Arabian Peninsula, a new study reveals.

These estimates are for installations where the photovoltaic (PV) panels are cleaned monthly. The decrease in power generation can be of up to 35% if cleanings are done every two months.

Duke University engineering professor Michael Bergin worked with colleagues at the Indian Institute of Technology-Gandhinagar (IITGN) and the University of Wisconsin to study the effects of dirt and the composition of the grime on panels. Samples taken at a solar system at IITGN showed that 92% was dust while the rest came from carbon and ion pollutants from human activity. The smaller man-made particles block more light than natural dust, the scientists say.

According to the study, solar power plants on the Arabian Peninsula have to deal mainly with dust. In contrast, certain regions of China face decreased generation due to the accumulation of man-made pollutants on the solar panels. These could also be an issue for solar generation in regions of India.

"You might think you could just clean the solar panels more often, but the more you clean them, the higher your risk of damaging them," Bergin said. His previous work includes analysis of pollutants discoloring India's Taj Mahal, which actually helped create the equation to estimate the amount of sunlight blocked by dust and pollution buildup on PV panels.

In the study, Bergin used NASA’s GISS Global Climate Model, which estimates the amount of particulate matter deposited on surfaces worldwide, and also helps determine the amount of sunlight blocked by different types of airborne particles in the air. Ambient particles in the air can also affect solar power generation.

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