As the world now knows air pollution is bad. It’s bad to breathe, it’s bad for the environment and it’s bad for climate change. Turns out it's bad for solar power, too. A new study from Duke University found airborne particles and their accumulation on solar cells can reduce the ability of a solar cell to produce energy by 25 percent in certain parts of the world.
"My colleagues in India were showing off some of their rooftop solar installations, and I was blown away by how dirty the panels were," said Michael Bergin, professor of civil and environmental engineering at Duke University and lead author of the study. "I thought the dirt had to affect their efficiencies, but there weren't any studies out there estimating the losses. So we put together a comprehensive model to do just that."
Bergin and colleagues from the Indian Institute of Technology-Gandhinagar and the University of Wisconsin at Madison measured how the efficiency of solar panels were impacted at the Indian institute after being cleaned. The study found that efficiency of the panels jumped by 50 percent when cleaned after several weeks of collecting grime.
They also analyzed the dust-like substance. They found 92 percent of it was dust while 8 percent of it was carbon and ion pollutants from human activity. "The manmade particles are also small and sticky, making them much more difficult to clean off," Bergin said. "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."
In addition to the scum covering the solar panels, Bergin and Drew Shindell, professor of climate sciences at Duke, also looked into the impact of airborne particles on solar panels. While the there’s little impact of nugatory dust in the US, the study found that in more arid regions like the Arabian Peninsula, Northern India and Eastern China, can see the power production of solar panels fall between 17 and 25 percent between monthly cleanings. If the panels are cleaned once every other month the efficiency is reduced even more from 25 to 35 percent.
"China is already looking at tens of billions of dollars being lost each year, with more than 80 percent of that coming from losses due to pollution," said Bergin. "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. It's yet another reason for policymakers worldwide to adopt emissions controls."
The study was published online on June 23 in Environmental Science & Technology Letters.Tweet