Air Pollution, Dusts Could Decrease Efficiency of Solar Energy Production

A new study from Duke University, in collaboration with University of Wisconsin and Indian Institute of Technology-Gandhinagar revealed that dusts accumulating in solar panels and airborne particles could reduce the efficiency of solar energy production.

The study, published in the journal Environmental Science and Technology Letters, showed that the ability of the solar cells to gather solar energy could be reduced by more than 25 percent due to airborne particles and accumulated dusts.

"We always knew these pollutants were bad for human health and climate change, but now we've shown how bad they are for solar energy as well," Michael Bergin, professor of civil and environmental engineering at Duke University and lead author of the study, in a press release. "It's yet another reason for policymakers worldwide to adopt emissions controls."

Bergin first thought of the possibility that dirt could reduced the efficiency of solar energy production when his colleagues from India showed some of their rooftop solar installations that were covered by dusts. To determine how much energy is loss, the researchers developed an equation capable of accurately estimating the amount of sunlight being blocked by different composition of solar panel dust and pollution build up.

The researchers found that some parts of the world may suffer significant loss in their solar energy production due to dusts and airborne particles, especially in arid regions such as the Arabian Peninsula, Northern India and Eastern China. Solar energy production in these regions could be reduced by 17 to 25 percent if the solar cells are cleaned once a month. These losses could reach 25 to 35 percent if the cleanings were done once every two months.

Samples taken from the accumulated dirt showed that it is composed of 92 percent dust while the remaining fraction was composed of carbon and ion pollutants from humans. Interestingly, the researchers noted that the efficiency of solar energy production was increased by 50 percent every time the solar panels were cleaned after being left alone for several weeks.