More Durable UV Coating For Solar Panels Made From Red Onion Skins (zmescience.com) 39
Long-time Slashdot reader fahrbot-bot shared this report from ZME Science
Researchers from the University of Turku, in collaboration with Aalto University and Wageningen University, have developed a bio-based UV protection film for solar cells that not only blocks nearly all harmful ultraviolet light but also outperforms commercial plastic films. The key ingredient is a water extract made from red onion skins...
[T]he same sunlight that powers [solar cells] can also degrade their delicate components — particularly the electrolyte inside dye-sensitized solar cells (DSSCs), a type known for their flexibility and low-light performance. To mitigate this, manufacturers typically wrap cells in UV-protective films made from petroleum-based plastics like polyethylene terephthalate (PET). But these plastics degrade over time and are difficult to recycle... Nanocellulose can be processed into thin, transparent films that serve as the perfect substrate for UV-blocking compounds.
Their breakthrough came when they dyed these films using an extract from red onion skins, a common kitchen waste. The result was a filter that blocked 99.9% of UV radiation up to 400 nanometers, a feat that outstripped even the PET-based commercial filters chosen for comparison... [T]he onion-treated filter excelled: it let through over 80% of light in the 650-1,100 nm range — an ideal sweet spot for energy absorption... Even predictive modeling based on early degradation trends suggested the CNF-ROE filter could extend a solar cell's lifetime to roughly 8,500 hours. The PET-based filter? Just 1,500 hours... [T]he red onion extract offered a rare combination of longevity, transparency, and sustainability...
The team envisions biodegradable solar cells for smart packaging, remote sensors, or wearable devices — especially in applications where recovery and recycling are not feasible. Their work is part of the BioEST project, funded by the Research Council of Finland, which supports sustainable innovation across electronics and materials science. This achievement taps into a broader movement to decarbonize every step of solar energy production. Plastic packaging is one of the overlooked sources of emissions in clean technology. Swapping out fossil-based plastics for biodegradable alternatives helps close that loop...
The findings appeared in the journal Applied Optical Materials.
[T]he same sunlight that powers [solar cells] can also degrade their delicate components — particularly the electrolyte inside dye-sensitized solar cells (DSSCs), a type known for their flexibility and low-light performance. To mitigate this, manufacturers typically wrap cells in UV-protective films made from petroleum-based plastics like polyethylene terephthalate (PET). But these plastics degrade over time and are difficult to recycle... Nanocellulose can be processed into thin, transparent films that serve as the perfect substrate for UV-blocking compounds.
Their breakthrough came when they dyed these films using an extract from red onion skins, a common kitchen waste. The result was a filter that blocked 99.9% of UV radiation up to 400 nanometers, a feat that outstripped even the PET-based commercial filters chosen for comparison... [T]he onion-treated filter excelled: it let through over 80% of light in the 650-1,100 nm range — an ideal sweet spot for energy absorption... Even predictive modeling based on early degradation trends suggested the CNF-ROE filter could extend a solar cell's lifetime to roughly 8,500 hours. The PET-based filter? Just 1,500 hours... [T]he red onion extract offered a rare combination of longevity, transparency, and sustainability...
The team envisions biodegradable solar cells for smart packaging, remote sensors, or wearable devices — especially in applications where recovery and recycling are not feasible. Their work is part of the BioEST project, funded by the Research Council of Finland, which supports sustainable innovation across electronics and materials science. This achievement taps into a broader movement to decarbonize every step of solar energy production. Plastic packaging is one of the overlooked sources of emissions in clean technology. Swapping out fossil-based plastics for biodegradable alternatives helps close that loop...
The findings appeared in the journal Applied Optical Materials.
I know I'll cry (Score:4, Funny)
when my panel breaks.
onions are too sexy for your body (Score:3)
Some. But a few other religions don't eat onions and garlic. My understanding are these hot and tasty foods arouse carnal desires in those that eat them. But for some practitioners the are not supposed to fulfil their material desires.
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Sure, Jains have an entirely different reason. But the other religion I was referring to was some schools of Buddhism
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My understanding are these hot and tasty foods arouse carnal desires in those that eat them.
Yeah, but some religious dietary suggestions came from the time where the practitioners ate goat meat and drank fermented goat's milk from goatskin wine bags. In the KJB, Leviticus 19 says sacrificed offerings should be eaten the same day and anything left on the third day should be thrown out. This might not be necessary anymore because of refrigeration, but some religious practices perpetuate for more than 2000 years without questions.
The Bible is a collection of stories and parables from 2000+ years ag
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I assume by "The Bible" that you mean some version of the Christian Bible that can be traced to the compilation defined as the Canon of Scripture at the Council of Rome in 382.
Texts recorded over a span of a few thousand years, but traced back to oral history much further. From a large library of what was available at the time, scholars discussed and compiled various sets in order to represent their own view of Christianity. With the Old Testament living heavily from Hebrew Bible (Tanakh) and Greek translat
A life of 8500 hours? (Score:3, Informative)
For those keeping score at home, 8500 hours is just over 354 days.
Re:A life of 8500 hours? (Score:5, Informative)
According to the paper the hours measured was for an accelerated light soaking stress test. Still not 100% on the timeframes here, still seems a little short...
DSSCs along with UV filter films were subjected to an intensive light soaking protocol using an Atlas XLS+ solar simulation system. The xenon lamp of the system (model NXE 1700), which simulates the AM1.5G solar spectrum, (34) facilitated a 1000-h exposure to artificial sunlight. The spectral irradiance within the UV 300–400 nm range was quantified at approximately 240 MJ/m2. The simulator maintained internal conditions of approximately 35 C, a black standard temperature (BST) of 60 C, and a relative humidity level of 20%. Thermal imaging, conducted with a Fluke TiS75 camera, indicated the average temperature of the filters and DSSC to be 45 C. This 1000-h duration was chosen since it aligns with standard light soaking protocols in photovoltaic research, corresponding to roughly one year of outdoor exposure in a central European climate under the AM 1.5G solar spectrum. (54)
The 1000-h light soaking test demonstrated that the CNF-ROE filter film effectively minimized electrolyte color bleaching and preserved JSC of the DSSC, outperforming other films, including the commercial SFC-10l filter. Predictive modeling based on the accelerated aging test projected that CNF-ROE could retain the lifetime of DSSCs for approximately 8500 h, significantly longer than the 1500 h for typical, commercially available, conventional, fossil-fuel-based UV filter.
Re:A life of 8500 hours? (Score:5, Interesting)
The important part is that they are talking about dye-sensitized solar cells (DSSC), not the typical solar panels you put on your house.
DSSCs are attractive because they are very easy and cheap to manufacture, and flexible. But they degrade fast with UV light, and the expected gains in protecting them have not been made. If their life could be extended to a usable amount they would offer an even lower cost option than already extremely cheap conventional solar cells, and open up some new applications.
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For those keeping score at home, 8500 hours is just over 354 days.
(a) The Sun doesn't shine 24 hours/day. (On on spot on the Earth /pedantic :-) )
(b) It's still projected to last 5.6x longer than the current petroleum-based coating.
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For those keeping score at home, 8500 hours is just over 354 days.
(a) The Sun doesn't shine 24 hours/day. (On on spot on the Earth /pedantic :-) )
(b) It's still projected to last 5.6x longer than the current petroleum-based coating.
Just a guess here, and I could easily be wrong. But maybe that's 8500 hours of direct and strong sunlight?
I mention that because solar panels also produce low-but-still-useful levels of power when it's cloudy, as well as during early morning and late afternoon. In those cases of lower levels of sunlight, I suspect that that the UV levels are disproportionately lower; witness the reduced incidence and severity of sunburn on cloudy days and in the early morning and late afternoon.
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Just a guess here, and I could easily be wrong. But maybe that's 8500 hours of direct and strong sunlight?
The Applied Optical Materials.journal article referenced in TFA/S describes the stability testing setup:
2.6. Stability Testing and Color Alteration Characterization
DSSCs along with UV filter films were subjected to an intensive light soaking protocol using an Atlas XLS+ solar simulation system. The xenon lamp of the system (model NXE 1700), which simulates the AM1.5G solar spectrum, (34) facilitated a 1000-h exposure to artificial sunlight. The spectral irradiance within the UV 300–400 nm range was quantified at approximately 240 MJ/m2. The simulator maintained internal conditions of approximately 35 C, a black standard temperature (BST) of 60 C, and a relative humidity level of 20%. Thermal imaging, conducted with a Fluke TiS75 camera, indicated the average temperature of the filters and DSSC to be 45 C. This 1000-h duration was chosen since it aligns with standard light soaking protocols in photovoltaic research, corresponding to roughly one year of outdoor exposure in a central European climate under the AM 1.5G solar spectrum. (54)
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Thanks - guess that teaches me to RTFA.
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TFS didn't claim it was 8500 hours of direct sunlight.
As someone else pointed out, this was an accelerated life test where 1000 hours of light is thought to model a year of real exposure, bit going from 1.5 to 8.5 years of life still means it's a pretty short lifetime.
And that's 5.6 times as long, not 5.6 times longer.
Re: A life of 8500 hours? (Score:2)
Silly question ... (Score:2)
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... is stuff gonna eat that solar panel covering now?
It's the red coloring in the onion skins, which is extracted and bound with cellulose from wood pulp. From TFA:
The CNF-ROE film—short for cellulose nanofiber with red onion extract ...
I'm guessing it'll be too meager a meal for termites... :-)
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I'm guessing it'll be too meager a meal for termites... :-)
Well in that case, count me in :)
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Toyota started using non polymer cable wraps/sheathing based on a soy compound years ago. Rodents love to eat that stuff.
Interesting.. (Score:5, Interesting)
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This UV blocking ability is yet another notch for onions being the GOAT of vegetables.
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I mean for sure garlic is top contender but onions are just too versatile.
Fried, caramelized, sautéed, grilled all work great. Mirepoix, soups, pizza, salads could go on and one, there's just so much they can go with.
Now as a seasong or a flavor or such as garlic is usually used, for sure, the greatest. Oh whats that recipe? 2 cloves of garlic? That means mince the entire head and throw it in.
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Did you even read his post?
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Do I control your post button? I wasn't aware I carried that type of responsibility.
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I won't knock a good onion, but their close cousin garlic has the edge in my book. In addition to the wonderful flavor, it is also well known for it's anti-vampiric properties. Perhaps garlic, unlike these onions which block UV, instead emits it, which may explain why it repels vampires. I'm currently working on an NSF grant proposal to study this now that my previous proposal (aimed at studying how much fun alvinrod could have with a $300,000 Ferrari) fell through.
Vampires like garlic on their pizza. This "garlic is anti-vampiric" propaganda is something they've pushed for centuries to throw people off from taking real action against vampires and needs to be stopped. It's almost as anti-truth as the idea that vampires can't eat human food just because they aren't sustained by it without a healthy blood supply to go along with it. Too many people believe the propaganda, to the point some of it has become common tropes in vampiric fictions. Real vampires are simply amp
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It shouldn't be really all that surprising. They're root vegetables, and that nice meaty bulb grows in the dark, where it's constantly under attack by bacte
"a common kitchen waste" (Score:2)
that explanation felt uncommonly unnecessary
Would be better if the UV light was converted (Score:2)
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You can use the UV light. You need different material with a different bandgap. Basically a whole other panel, stacked on the first. But before you go after that 5% UV you're going to want to go after the blue, and probably the red and some of the near IR.
They're called multijunction solar cells and they're used in places where you need maximum efficiency, like in space. For regular use, single junction cells are much more popular because a single bandgap panel absorbing at the maximum solar emission is goi
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Multi-junction cells can do this. They're expensive though.
IS it sour when you lick it? (Score:2)
Just asking for a friend.
I hate to be optimistic, but (Score:2)
Nobody uses dye-sensitized solar cells (Score:4, Informative)
Nobody uses dye-sensitized solar cells. They were an interesting idea for a technology, but the improvements in silicon cell performance along with reductions in cost just made their mediocre performance obsolete.
Also, nobody uses plastic coatings for solar cells. Plastics simply deteriorate too fast. Everybody uses glass.
We need a Slashdot breakthrough list... (Score:2)