GRA
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Study finds anthropogenic PM and dust undercutting global solar energy production

Tue Jun 27, 2017 7:27 pm

http://www.greencarcongress.com/2017/06 ... -duke.html

According to a new study led by a team at Duke University, airborne particulate matter and dust are cutting solar photovoltaic energy output by more than 25% in certain parts of the world, with roughly equal contributions from ambient PM and PM deposited on photovoltaic surfaces. The regions hardest hit are also those investing the most in solar energy installations: China, India and the Arabian Peninsula. An open-access paper on the study appears in the ACS journal Environmental Science & Technology Letters.

With colleagues at the Indian Institute of Technology-Gandhinagar (IITGN) and the University of Wisconsin at Madison, Michael Bergin, professor of civil and environmental engineering at Duke University and lead author of the study, measured the decrease in solar energy gathered by the IITGN’s solar panels as they became dirtier over time. The data showed a 50% jump in efficiency each time the panels were cleaned after being left alone for several weeks.

The researchers also sampled the grime to analyze its composition, revealing that 92% was dust while the remaining fraction was composed of carbon and ion pollutants from human activity. While this may sound like a small amount, light is blocked more efficiently by smaller man-made particles than by natural dust. As a result, the human contributions to energy loss are much greater than those from dust, making the two sources roughly equal antagonists in this case. . . .

The resulting calculations estimate 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 manmade pollutants, Bergin said. But the reverse is true for regions of China, and regions of India are not far behind. . . .
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

GetOffYourGas
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Re: Study finds anthropogenic PM and dust undercutting global solar energy production

Wed Jun 28, 2017 5:52 am

It seems that as countries like China and India install more renewables and maybe eventually decommission coal plants, that this problem would lessen. Of course, we know that as part of the Paris Accords, both countries promised to install MORE coal plants, albeit not as many more as originally planned.
~Brian

EV Fleet:
2011 Torqeedo Travel 1003 electric outboard on a 22' sailboat
2012 Leaf SV (traded for Bolt)
2015 C-Max Energi (302A package)
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Reddy
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Re: Study finds anthropogenic PM and dust undercutting global solar energy production

Wed Jun 28, 2017 8:55 am

With all that dust, they may benefit from investing in one of these robotic cleaners:
https://www.revolvesolar.com/5-robots-that-are-revolutionizing-how-we-clean-solar-panels/
E4 cleaning robot uses a water-free cleaning process that combines a controlled airflow with a soft, microfiber cleaning system. The result is the removal of 99% of the daily desert dust. E4 even comes with its own solar panel for self-charging and self-cleaning and makes use of Eco-Hybrid technology to recover energy whenever the robot descends the incline of a solar panel.
Reddy
2011 SL; 9 bar, 46.44 AHr; 40,067 mi; rcv'd Aug 18, 2011
Long: http://www.mynissanleaf.com/viewtopic.p ... al#p226115"
Cold: http://www.mynissanleaf.com/viewtopic.p ... 60#p243033"

GRA
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Re: Study finds anthropogenic PM and dust undercutting global solar energy production

Wed Jun 28, 2017 5:15 pm

Reddy wrote:With all that dust, they may benefit from investing in one of these robotic cleaners:
https://www.revolvesolar.com/5-robots-that-are-revolutionizing-how-we-clean-solar-panels/
E4 cleaning robot uses a water-free cleaning process that combines a controlled airflow with a soft, microfiber cleaning system. The result is the removal of 99% of the daily desert dust. E4 even comes with its own solar panel for self-charging and self-cleaning and makes use of Eco-Hybrid technology to recover energy whenever the robot descends the incline of a solar panel.

Very interesting, and highly necessary, although I think the drone's a bit over the top, and likely to cause more damage to panels in gusty winds than it saves in increased power. The waterless approach is a critical deal, although where AG PM is the major issue there may be problems with that approach; the article I quoted mentioned that AG PM is sticky, and harder to clean than environmental dust.
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

DarthPuppy
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Re: Study finds anthropogenic PM and dust undercutting global solar energy production

Wed Jun 28, 2017 8:49 pm

Hmm... Guess I should adopt a regimen of cleaning my solar panels periodically.

GetOffYourGas
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Re: Study finds anthropogenic PM and dust undercutting global solar energy production

Thu Jun 29, 2017 4:11 am

DarthPuppy wrote:Hmm... Guess I should adopt a regimen of cleaning my solar panels periodically.


Depends on where you live. Where I am, it rains so often that I haven't even considered cleaning the panels in the >5 years I've had them. I know rain doesn't clean everything, but it certainly washes away dust.
~Brian

EV Fleet:
2011 Torqeedo Travel 1003 electric outboard on a 22' sailboat
2012 Leaf SV (traded for Bolt)
2015 C-Max Energi (302A package)
2017 Bolt Premier

GRA
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Joined: Mon Sep 19, 2011 1:49 pm
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Re: Study finds anthropogenic PM and dust undercutting global solar energy production

Thu Jun 29, 2017 1:41 pm

GetOffYourGas wrote:
DarthPuppy wrote:Hmm... Guess I should adopt a regimen of cleaning my solar panels periodically.


Depends on where you live. Where I am, it rains so often that I haven't even considered cleaning the panels in the >5 years I've had them. I know rain doesn't clean everything, but it certainly washes away dust.

Bird droppings will cause a major drop in output, so if there's any of that on them, a cleaning is definitely in order. Long handled soft brushes and squeegees are available, if walking/crawling around on the roof isn't something you want to do. Here's a somewhat pricy one,but I'm sure you could find others: https://www.amazon.com/Mr-LongArm-1008-Cleaning-System/dp/B002YNRQGM

Whatever you do, be sure to wash the panels when they're cool (assuming you use cold water), i.e. earlyish morning or after sunset on a hot day, otherwise the thermal stress can cause problems. If you've ever put cold water into an empty hot glass coffeepot, you know what I'm talking about :(
Guy [I have lots of experience designing/selling off-grid AE systems, some using EVs but don't own one. Local trips are by foot, bike and/or rapid transit].

The 'best' is the enemy of 'good enough'. Copper shot, not Silver bullets.

DarthPuppy
Posts: 476
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Re: Study finds anthropogenic PM and dust undercutting global solar energy production

Thu Jun 29, 2017 7:25 pm

Thanks for the tip regarding when to do the cleaning so as not to cause temperature stress.

In So. Cal., we don't get enough rain to keep them clean. Plus bird droppings etc. So I'm probably quite overdue. I think the last time I cleaned them was about 2 years ago.

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