Dust in the air blocks incoming solar energy too.
Researchers in India who cleaned their solar panels every few weeks discovered an immediate 50% jump in efficiency after each cleaning.
92% of the dust on each panel was natural, but the 8% human made particles are smaller and stickier.
But the 8% human-emitted-dust blocked as much solar energy as the 92% natural dust.
Pollution and natural dust will slow the clean-green-energy future in India and China unless we get auto-cleaning panels.
Solar panels work best when clean, near the equator, not under many clouds, and when electricity demand peaks at 12 noon ... which no modern country does.
Global solar energy production is taking a big hit due to air pollution and dust.
According to a new study, airborne particles and their accumulation on solar cells are cutting energy output by more than 25% in certain parts of the world.
The regions bit hardest are also those
investing the most in solar energy installations:
China, India and the Arabian Peninsula.
The study appears online June 23 in Environmental Science & Technology Letters.
“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.”
With colleagues at the Indian Institute of Technology-Gandhinagar and the University of Wisconsin at Madison, Bergin measured the decrease in solar energy gathered by the solar panels as they became dirty over time.
The data showed a 50% jump in efficiency each time the panels were cleaned after being left alone for several weeks.
8% of the grime was carbon and ion pollutants from human activity.
“The human made particles are also small and sticky, making them much more difficult to clean off,” said Bergin.
“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.”
Grimy buildup on solar panels isn’t the only thing blocking sunlight — ambient particles in the air also have a screening effect.
The NASA GISS Global Climate Model already accounts for the amount of the sun’s energy blocked by different types of airborne particles and estimates the amount of particulate matter deposited on surfaces worldwide.
The resulting calculations estimated the total loss of solar energy production in every part of the world.
While the United States has relatively little migratory dust, more arid regions such as the Arabian Peninsula, Northern India and Eastern China are looking at heavy losses — 17% to 25% or more, assuming monthly cleanings.
If cleanings take place every two months, those numbers jump to 25% or 35%.
The Arabian Peninsula loses much more solar power to dust than it does human made pollutants, Bergin said.
The reverse is true for regions of China and India.
This work was supported by the US Agency for International Development and the Office of the Vice Provost for Research at Duke University.
REFERENCE
Bergin, M.H., Ghoroi, C., Dixit, D., James Jay Schauer, Drew Shindell. (2017) Large reductions in solar energy production due to dust and particulate air pollution. Environmental Science & Technology Letters, 2017; DOI: 10.1021/acs.estlett.7b00197
PS: Let me add the following problems that
would also reduce solar panel efficiency:
(1) Moss growth in humid areas,
(2) Bird doo doo,
(3) Hail storms, and possibly
(4) Juvenile delinquents
or hostile neighbors with rocks!