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.
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.
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.
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.
"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?
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.
I have not read the article yet, but I will be doing so after posting this. But from what I understand, concentrated cells via lenses already exist. The problem with them was keeping them cool.
Going to go read the actual article now.
Edit: Well, the article was very sparse on details. From what I understand of the comments, what's really been done here is making cells that can stand the kind of heat that would be focused onto them from the glass.
I want to say I saw a video about this a year ago or so, but it was more solar thermal, where you focus a bunch of mirrors onto a single point high up on a tower, and it's cooled by molten salt. But as I said, that's solar thermal, not solar power electricity.
Yeah the problem has always been that solar panels only really like to operate within a very narrow temperature band. It's why you can't just plate the Sahara desert in solar panels. In theory that would generate loads of power but the heat of the desert is way outside of their operating range.
There's been loads of ideas to heat/cool solar panels, the problem up until now has always been to do that without cutting into the panel's efficiency so much that it isn't worth doing.
But there's been videos on YouTube of people cooling solar panels with plasma cooling and phase change materials for a few years now.
the heat of the desert is way outside of their operating range.
I live in the Phoenix area, there are tons of solar installations here. In fact my house has solar, had it when we bought it 10 years ago, and it cuts the power bill in half.
I think their approach with module is 20-50x concentration instead of 500x, with cooling permitted to be module wide on air gap, as well as usual bottom cooling.
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.
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.
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.
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.
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.
That makes sense. If I understood everyone clearly, it's not the idea to use a fresnel that's new here, it's the fact that we just haven't yet had anything capable of withstanding those temperatures and still allowing for the piezoelectric effect to happen.
Not being any kind of solar energy expert, my initial thought was how the cell’s would hold up under the increased heat, and what technology (if any) they’d be using to monitor/mitigate. The article does briefly mention the cells achieving ~33% @ ~167° F, and does mention (what seems to be tangential) technologies that allow for cells to be nailed down as if they were shingles.
My guess is that it isn’t that they finally using techniques that seem obvious to us, but that they’ve developed supporting tech to mitigate the detrimental effects of using magnification.
i guess a lot of research projects are just there to give the researchers something to do and money, and i'm sure the idea of using lenses has been floated before.
the thing is that it's not really as good an ideas as it originally seems. After all, you need heavy solid lenses that you have to install above all solar panels, and the cost of that is not negligible. On top of that, there's other problems that others have already mentioned.
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. 😄
Grid forming will just mean the keep running the house when the power goes off, it's not safe for them to be pushing power when it's disappeared, that has been set by regulation in many countries.
Small scale installations on regular houses are probably not the best for grid forming. Any pv installation with grid forming capability would be required to give some control to the grid operator because it's their job to keep the grid stable.
What you describe is more like black start, providing power to the grind when it is down. This has to be controlled well, and only a few plants need to be capable of it.
Grid following means something like whatever the grid does, the inverter injects power supporting it. A grid forming generator or inverter also follows the grid somewhat, but tries to get it to an optimal condition. This entails things like voltage control by reactive power, frequency control by operating reserve, fault ride trough capability and so on. Many of those are naturally provided by large conventional power plants using synchronous generators like gas, nuclear or hydro. For inverter based systems, they have to be considered explicitly. For battery storage most are relatively easy to implement, some also in solar inverters. The tech exists, but yes, in some countries the regulations have not kept up with rapid expanse of inverter based power generation in the last years.
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.
I'd like to know what they're going to do about the heating issue. Concentrating solar radiation carries with it an increased heat load. And heat reduces solar PV efficiency. I'm already losing about 30% in summer when the panels heat up.
If I had a penny for every time I heard about new advancements about to revolutionise solar panel technology, I'd have glazed the bloody Sahara with them by now.
I just skimmed the IEEE paper (peer-reviewed, solid journal); The usage of 'slash costs' in the title is entire sensational. The tech gave a SLIGHT increase in efficiency (which is good news - marginal improvements are still very good and can be game-changing if scaled up), but there is no cost/benefit analysis in the paper regarding the additional costs of lenses and whether the increased PV efficiency would offset those costs at scale.
Honestly, we don't need the technology to get any better than it is. It's nice, but not necessary. Labor costs of deployment are the biggest limiting factor.
Wouldn't this be negated by the fact, that the same area of roof now has less actual PV cell on it? Since the light gets concentrated on a smaller area?
I think the idea is that it’s the same amount of light is being used but the actual expensive part of the solar cell is cheaper and designed to take the increased heat. So the same size “solar unit” on the roof collecting the same amount of light and generating the same amount of energy but cheaper overall. At least that was my take. Correct me if I’m wrong.
I think the point is that you can replace one big solar panel with one big lens and a small solar panel. The footprint on the roof is the same, but the implication is a big glass lens is cheaper than a big solar panel.
the glass lens probably is cheaper than a big solar panel
but the cost of setting up a glass lens in 5-10 meters altitude (because that's what's needed to bundle any sunlight) and make it storm-proof is probably more expensive than setting up a big solar panel at hip height.
and considering that labor cost is a significant part (i guess 10% - 50%) of overall solar park cost, i guess it's probably not worth it.