this post was submitted on 14 Jul 2025
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cross-posted from: https://slrpnk.net/post/24690127

Solar energy experts in Germany are putting sun-catching cells under the magnifying glass with astounding results, according to multiple reports.

The Fraunhofer Institute for Solar Energy Systems team is perfecting the use of lenses to concentrate sunlight onto solar panels, reducing size and costs while increasing performance, Interesting Engineering and PV Magazine reported.

The "technology has the potential to contribute to the energy transition, facilitating the shift toward more sustainable and renewable energy sources by combining minimal carbon footprint and energy demand with low levelized cost of electricity," the researchers wrote in a study published by the IEEE Journal of Photovoltaics.

The sun-catcher is called a micro-concentrating photovoltaic, or CPV, cell. The lens makes it different from standard solar panels that convert sunlight to energy with average efficiency rates around 20%, per MarketWatch. Fraunhofer's improved CPV cell has an astounding 36% rate in ideal conditions and is made with lower-cost parts. It cuts semiconductor materials "by a factor of 1,300 and reduces module areas by 30% compared to current state-of-the-art CPV systems," per IE.

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[–] humanspiral@lemmy.ca 25 points 6 days ago (2 children)

https://ieeexplore.ieee.org/document/10938951

This is 36% MODULE efficiency with expensive cooling. 30% actual year long efficiency without it. Requires dual axis tracking. Seems heavy as its very tall/deep.

Headline of cost reduction is very unlikely. Especially on a per acre/fairly large area basis. Dual axis tracking requires more spacing than fixed orientation rows, and loses benefits under cloudy conditions. While power at 7am and 5pm is more valuable when competing against high penetration solar, batteries are now more competitive than tracking, and can serve edge of day and night power needs. Tracking solar tends not to be built anymore, due to low cost of panels. The cooling infrastructure is also not as useful as it is on rooftops because the heat capture has useful benefits for homes.

It is also unclear how this has advantage over parabolic mirror.

Agri PV is a real use case, where more free land means more land use, even if most of it gets more shade, except around noon.

[–] Knock_Knock_Lemmy_In@lemmy.world 4 points 6 days ago (3 children)

Solar panels as fences is what is needed.

[–] Bytemeister@lemmy.world 7 points 6 days ago (1 children)

Kinda works if you use bifacial panels.

[–] Knock_Knock_Lemmy_In@lemmy.world 2 points 6 days ago* (last edited 6 days ago) (1 children)

Bifacial panels as a fence provides 3% extra yield but 30% extra revenue

https://www.gridcog.com/blog/solar-fence-vs-ground-mount-solar

[–] Bytemeister@lemmy.world 1 points 6 days ago* (last edited 6 days ago) (1 children)

Sure, but if you wanted solar panels to work on both sides of your East/West facing fence, you'd have to buy 100% more panels, so bifacial saves you 70% there. Seems like a good deal. I'm sure you read the "Model Overview" of that article and caught that the monofacial panels were facing the equator, and the bifacial panels were facing East/West...

Edit: bad read on my part, I didn't not understad the full content of the previous message.

[–] Knock_Knock_Lemmy_In@lemmy.world 3 points 6 days ago (1 children)

I don't think we are arguing. I was just giving you more details.

[–] Bytemeister@lemmy.world 1 points 6 days ago (1 children)

My interpretation of your comment was that bifacial solar panels are a useless gimmick which allows companies to charge more for a cheaper product.

Is that correct?

[–] Knock_Knock_Lemmy_In@lemmy.world 3 points 6 days ago (1 children)

No, the opposite. They are superior. Bifacial panels have a 3% additional yield over standard panels. The +10-20% cost premium is covered by the +30% revenue

Even with traditional mountings, Bifacial panels pick up extra light reflected from the ground.

[–] Bytemeister@lemmy.world 2 points 6 days ago (1 children)

Bad read on my part, sorry for the snark. Carry on.

No problem. Take a closer look a the link, particularly the graphs.

[–] humanspiral@lemmy.ca 2 points 6 days ago

It's viable as edge of day high power boost in east/west direction, and simply any extra power that is cheap and easy to install, that adds privacy or keeps the controlled beings inside.

[–] Shanedino@lemmy.world 1 points 6 days ago (1 children)

You are at least completely and utterly wrong about tracking solar not typically being built anymore. Any major solar site uses tracking if you have a couple acres on a corner maybe not but I think you are being a bit too general. Panels are only one of many costs per solar panel installation, its still cost effective overall to increase efficiency.

[–] humanspiral@lemmy.ca 1 points 6 days ago

You're right about US. seems half uses tracking. No numbers on China which is 30x larger market. Economics still only make sense at consumer level of $1/watt panel prices, to me, but I guess there are reasons I don't understand.

[–] SocialMediaRefugee@lemmy.world 18 points 6 days ago (2 children)

They need changes in laws too. Instead of chewing up open space and farmland I'd rather see more urban areas used like parking lots and industrial sites.

[–] A_Random_Idiot@lemmy.world 17 points 6 days ago

Yeah, Don't put the solar farms in meadows, or on mountains. put them on warehouse roofs, over highways, over parking lots, on government buildings, etc etc.

[–] taguebbe@feddit.org 11 points 6 days ago* (last edited 6 days ago) (1 children)

Roughly 50% of germany is used as farmland. On 60% of the farmland crops to feed livestock are grown. On 20% of it crops for energyproduction (biofuel, biogas). If you take for example rapeseeds, used for biodiesel, you would harvest around 50 times as much energy with a pv-plant on the same area. You would need to install pv on 5-6% of the farmland to produce enough electric energy for all of germany for a year. Granted you also can provide the grid for it and enoguh storage.

[–] Jason2357@lemmy.ca 8 points 6 days ago (1 children)

Not only that, but livestock can still graze under panels, on grass that often grows just as well with a little shade.

[–] sqgl@sh.itjust.works 1 points 6 days ago (1 children)

Surely the grass would grow better with more son(?)

[–] Jason2357@lemmy.ca 4 points 6 days ago (1 children)

Not always. Wide open fields get baked dry mid summer in a lot of local climates.

Yup, my grass does best under my trampoline.

[–] sqgl@sh.itjust.works 7 points 6 days ago

That is Fraunhofer who are the people most responsible for developing MP3

[–] Prior_Industry@lemmy.world 6 points 6 days ago

US Government - not on my watch....

[–] Vinstaal0 3 points 6 days ago

The issue here in NL is with the power grid, not the price of the panels. The installing of them is already one of the most expensive parts of getting panels since you need to build scafolding for most houses.

[–] Alloi@lemmy.world -2 points 6 days ago

at this point it doesnt matter. theres no saving us from extinction due to climate change. this serves only for the intermediate period where we can "save" some money on energy day to day, before the inevitable collapse that makes money and savings worthless.

dont get me wrong, if i could afford a house, let alone additional panels and the additional fees that come with installation, maintenance, regulations, licensing, etc. then id be all in, even if it was just to contribute to the dying ideal that there was some semblence of hope for a better future. this is up to the landlords and the upperclass to give a shit about, and most of it is for grandstanding and keeping up with the joneses.

i used to install these for a living during covid. only people in my area who could afford them were multigenerational farmers and eco concious suburbanites. even for the suburbanites living in million+ dollar homes it was a stretch financially, and a hastle due to regulations.

good idea. but a bit late. we are at the point that if someone waved a magic wand tomorrow, and everyone stopped driving cars and pulled a full 180 on coal, oil, and gas, it would still be far too late.

if you can afford the inevitable markup that comes with proffessional installation. be my guest. if you are a poor person wanting to slap some panels on a tiny home, go nuts. just dont expect to save the world by doing so. its fucked. live how you want to while you can. drink, fuck, fight, eat good food, play video games, bed rot and consume to your hearts content.

nothing can save us. not even the "indomitable will of the human spirit" not a god damned thing.

sorry to shit in your salad. but thems the breaks.

[–] anamethatisnt@sopuli.xyz 61 points 1 week ago (1 children)

What are concentrating photovoltaics? One of the ways to increase the output from the photovoltaic systems is to supply concentrated light onto the PV cells. This can be done by using optical light collectors, such as lenses or mirrors. The PV systems that use concentrated light are called concentrating photovoltaics (CPV). The CPV collect light from a larger area and concentrate it to a smaller area solar cell. This is illustrated in Figure 5.1.

Also, from the article - 33.6% efficiency in real-world conditions:

A 60 cell-lens prototype was studied for a year. In "real-world" conditions, CPVs achieved up to 33.6% efficiency. The 36% mark was posted at 167 degrees Fahrenheit. The prototype showed no signs of degradation, according to IE.

[–] BombOmOm@lemmy.world 46 points 1 week ago* (last edited 1 week ago) (11 children)

A lighthouse uses the same lens, just with the light coming from the inside. Since this is old knowledge, what is the drawback? Why isn't this widespread?

My completely uninformed guess:

  • The lens and assembly costs too much compared to just more solar panels

  • The lens/panel combo is so bulky/prone to failure it becomes unreasonable to actually install/use.

[–] brendansimms@lemmy.world 34 points 1 week ago (1 children)

Adding to what Eldest_Malk said: They aren't just putting a new type of lens over standard solar cells, they are also designing/fabricating custom cells to work with the lenses. [I'm not a PV expert, but the fact that the IEEE paper focuses so much on the cells and not just the lenses leads me to believe that the lenses can't just be used with whatever standardized solar cells are on the market]

[–] humanspiral@lemmy.ca 2 points 6 days ago

The cells are super expensive but super small. They need cooling for efficiency, but if the heat moving is useful, can ignore the energy cost.

[–] rem26_art@fedia.io 19 points 1 week ago (1 children)

id guess a lot went into designing a solar cell that could take being heated to 167F without losing efficiency or breaking. I think most common house solar panels have a temperature coefficient listed on their datasheet that measures how much its ability to generate power decreases per every degree above 77F

[–] anomnom@sh.itjust.works 2 points 6 days ago

Tech ingredients did a test with active cooling on standard solar panels and found the energy to cool it was about what was gained by having a cooler panel.

The upshot should be longer life if the panel though, so the conclusion was still a net gain.

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[–] callouscomic@lemmy.zip 48 points 1 week ago (3 children)

Wait for something fucking idiotic like:

"U.S. government to implement 5,000% tax on new solar technology...."

[–] match@pawb.social 25 points 1 week ago

"also, revenue from new tax will be used to build new coal mines staffed by concentration camp inmates 1"

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[–] stringere@sh.itjust.works 44 points 1 week ago

The only thing slowing down the transition from fossil fuels to renewables is the same impediment it has always been: oil money protecting itself.

[–] msprout@lemmy.world 34 points 1 week ago (5 children)

I am not a scientist so please correct me if I am off base, but did it really take them this long to attempt to focus light onto PV cells using a fresnel lens?

My hobby as a 15 year old was buying broken projectors to harvest the fresnel lenses in the lamp on top. They could focus sunlight so powerfully that you could burn shit. I didn't do that, surprisingly. I was like Marge Simpson, I just thought they were neat.

[–] brendansimms@lemmy.world 35 points 1 week ago (2 children)

Adding to what the others wrote, solar cells become less efficient at power conversion (light -> electricity) as the temp of the solar cell materials (semiconductors) increases. So the issues is how to get more photons to the semiconductor without heating it up.

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[–] dogslayeggs@lemmy.world 20 points 1 week ago (1 children)

OK, take that Fresnel lens that you were using to melt pennies and then focus it on a PV cell that is also made of metal. What might be the expected response? The science in this case is making PV cells that can handle the intense heat.

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[–] cmnybo@discuss.tchncs.de 28 points 1 week ago (4 children)

Solar panels are already quite cheap. What we need is much cheaper grid forming inverters so we can stop destabilizing the grid with solar.

[–] avidamoeba@lemmy.ca 19 points 1 week ago* (last edited 1 week ago)

If the cost of panels drops significantly, there would be more capital available to spend on inverters, even if they stay at the current prices, still decreasing the cost of deployment. But yes. 😄

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[–] gandalf_der_12te@discuss.tchncs.de 28 points 1 week ago* (last edited 1 week ago) (10 children)

I'm not sure what to think about the Fraunhofer institute in general. They have made some nice discoveries/inventions in the past, such as audio compression algorithms and such. That is why i hyped them for a bit.

But they really disappointed me with their writings on solar panels in the past few years.

They said that the efficiency of solar panels today is too low to deploy them widely in practice, which is simply not true. They tried pushing Perovskite solar cells for no reason.

I'm not sure what to think about this article's idea. On one hand, adding lenses to solar parks makes them significantly more complicated and therefore expensive to build. Also, if the parks have complicated physical forms, they're more susceptible to wind, and that could damage them.

On the other hand, yes, adding lenses means you need fewer actual solar panels for the same amount of energy harvested.

I'll therefore put it in the category of inconclusive inventions, together with the idea of adding a motor to the solar panels so they can track the sun. That would also make the solar panels more efficient, but also more complicated and more prone to mechanical failure.

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[–] tobiah@lemmy.world 21 points 1 week ago (3 children)

"The lens makes it different from standard solar panels that convert sunlight to energy with average efficiency rates around 20%, per MarketWatch. Fraunhofer's improved CPV cell has an astounding 36% rate in ideal conditions"

Why would I want to compare one panel's average efficiency to another panels efficiency in ideal conditions?

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