Netherlands Researchers Break the 30 Percent Barrier In Solar Cells (interestingengineering.com) 65
An anonymous reader quotes a report from Interesting Engineering: A collaboration of researchers from various institutes in the Netherlands broke the 30 percent barrier associated with solar cells. The achievement will help uptakeworldwide solar energy and reduce our dependence on fossil fuels, an organizational press release said. [...] To do so, researchers in the Netherlands came together to create a four-terminal perovskite/silicon tandem device. A tandem device can better use solar spectrum since it uses a mix of silicon-based solar cells with perovskite-based solar cells. While the former works well with light in the visible and infrared spectrum, perovskites can use wavelength in the ultraviolet and visible light while being transparent to infrared light. In a four-terminal tandem device, the top and bottom cells can operate independently, allowing bifacial tandems to be used, further boosting the power output of the architecture.
The press release said that the researchers improved the efficiency of a semi-transparent perovskite cell with an area of 3x3 sq. mm up to 19.7 percent. Below this, a silicon solar cell, which was 20X 20 sq. mm wide, was placed. The tandem device also had a highly transparent back contact that allowed 93 percent of the near-infrared light to reach the bottom of the device. The silicon device was optimized using a host of features, and its efficiency improved to 10.4 percent. Together with the perovskite solar cell, the device delivered a combined energy conversion efficiency of 30.1 percent, making it the best efficiency achieved so far.
The press release said that the researchers improved the efficiency of a semi-transparent perovskite cell with an area of 3x3 sq. mm up to 19.7 percent. Below this, a silicon solar cell, which was 20X 20 sq. mm wide, was placed. The tandem device also had a highly transparent back contact that allowed 93 percent of the near-infrared light to reach the bottom of the device. The silicon device was optimized using a host of features, and its efficiency improved to 10.4 percent. Together with the perovskite solar cell, the device delivered a combined energy conversion efficiency of 30.1 percent, making it the best efficiency achieved so far.
Misleading headline. (Score:5, Informative)
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Not sure why that makes the headline wrong? They broke the 30%, it's about the materials they use.
Misleading, not wrong (Score:1)
Not sure why that makes the headline wrong?
The OP did not say wrong, just misleading. Since "breaking the barrier", especially when referring to an arbitrary line in the sand like 30% efficiency, generally means that you are the first one to achieve it, it is extremely misleading to say this when you are not the first.
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30% is a record for Perscovite/Si cells... per the very graph you linked to. Sure, the headline could be more clear... but it is still a huge win. The cost of the most efficient experimental cells is... a lot higher.
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(Also, I'll kvetch about 4-terminal devices. 4 terminals aren't actually impossible to interconnect, but they sure do make it complicated.
Re: Misleading headline. (Score:2)
That sounds pretty annoying, but not devastating. At a guess you'd string them independently and have two dc/dc converters rather than one to handle maximum power point tracking.
The III-V current-matched junctions are pretty slick. Too bad nobody has gotten thin films of those cells to be economical yet.
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That sounds pretty annoying, but not devastating. At a guess you'd string them independently and have two dc/dc converters rather than one to handle maximum power point tracking.
Doable as long as the interface between the subcells can take the full module voltage.
Re: Misleading headline. (Score:2)
It really only needs to stand off the difference in voltage between the cells in normal operation. You could build in a protection diode to shunt current if the voltage gets excessive.
Re: Misleading headline. (Score:1)
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Yes... but the headline doesn't say "Netherlands Researchers Break the 30 Percent Barrier In Perovskite/Silicon Tandem Solar Cells."
Thank god it doesn't. It would overrun the edge of the screen and break a lot of rules of headline writing you should have been taught in highschool. Such as to only use the minimum amount of information, and not use technical words which require explaining.
The appropriate place for more information and technical details is ... the article. As it is the headline is too long.
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Yes... but the headline doesn't say "Netherlands Researchers Break the 30 Percent Barrier In Perovskite/Silicon Tandem Solar Cells."
Thank god it doesn't. It would overrun the edge of the screen and break a lot of rules of headline writing you should have been taught in highschool. Such as to only use the minimum amount of information, and not use technical words which require explaining. The appropriate place for more information and technical details is ... the article. As it is the headline is too long.
But nothing in the article notes that 30% efficiency has been achieved in other materials, either.
The headline and the article are claiming credit for breaking a "barrier" that has been broken years ago.
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Not sure what your complaint is. That the article talks about something that it isn't about? The entire article is written about "most commercially available" solar cells. It even includes the abstract itself which also says its about "conventional single-junction cells".
If you want to write an article about something else, go do it.
Misleading headline, summary, and article [Re: (Score:2)
My complaint was that the headline was misleading. The headline says nothing about "these cells are better than most commercially available cells." It says the efficiency "broke a barrier". To the extent that such a "barrier" even exists, it was broken years ago.
The article summary also says nothing about "most commercially available cells".
When you had told me that the headline couldn't actually be accurate because accuracy would be too long to explain, I pointed out
But nothing in the article notes that 30% efficiency has been achieved in other materials, either. The headline and the article are claiming credit for breaking a "barrier" that has been broken years ago.
This statement is also accurate. The art
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Drilling down [Re:Misleading headline.] (Score:2)
Actually, per that chart, perovskite/silicon tandem have hit 31.3%. It's the red triangle with blue fill. So it's not even a record there.
If you keep clicking down to get to the original source (which was a press release [www.tue.nl] announcing the result), what it said was "For the first time, four-terminal perovskite/silicon tandem devices with certified top cell pass the barrier of 30%."
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I wish people would stop using the word "barrier" when "threshold" would be more appropriate.
"Barrier", to me, means there was some qualitative difference being below and above the barrier, or there was some fundamental physical principle which keeps you on one side or the other.
The speed of sound is a barrier. Flying supersonic is qualitatively different from subsonic. 500 MPH is not: there's no difference between flying at 499 and 501 MPH.
There's no abrupt difference between a cell working at 29% and 31%
Gettin' there (Score:5, Funny)
A few more percent and we can even use them at night! :-)
Re:Gettin' there (Score:5, Interesting)
They're making good progress.
Re: Gettin' there (Score:4, Funny)
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You'll have to buy special lunar panels for that
You joke about lunar, but the actual research into night time solar panel use is focused not on the moon, but on capturing emitted energy radiated from the earth itself.
We've discussed multiple such developments on Slashdot before.
What about the lifespan? (Score:2, Interesting)
+2% the efficieny, +700% the cost (Score:4, Insightful)
Nobody can compete with the existing panels when it comes down to cost-performance.
Getting 2 percent extra efficiency at 7 times the cost makes such inventions irrelevant.
Re:+2% the efficieny, +700% the cost (Score:5, Insightful)
Nobody can compete with the existing panels when it comes down to cost-performance. Getting 2 percent extra efficiency at 7 times the cost makes such inventions irrelevant.
Not necessarily. For consumer home systems yes, for a satellite or other niche applications that’s not true.
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Not necessarily. For consumer home systems yes, for a satellite or other niche applications thatâ(TM)s not true.
What niche applications? Nobody uses silicon on satellites anymore where 30% efficiency is a huge leap backward. Perovskites still have longevity issues to be worked out.
Re:+2% the efficieny, +700% the cost (Score:4, Interesting)
You're making up numbers. The reality is +36% efficiency (the best conventional cells are 22% efficient, this produces 30/22 = 1.36x more energy) at maybe +2% cost. Perovskites are thin films made from cheap ingredients. Adding the second layer is easy and makes little difference to the manufacturing cost, and of course it adds nothing to the installation cost. That's why people are interested in adding perovskites on top of silicon.
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On top of this, >30% efficiency seems to be nothing new [wikimedia.org] so indeed the question is all about price and feasibility.
When I see an article starting with "The achievement will [...] reduce our dependence on fossil fuels" I know I'm not going to learn a lot and it has a high chance of being some PR by a random organization trying to get some funding, surfing on the climate wave.
If that's real though, great.
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Those >30% efficiencies are other, much more expensive technologies.
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Depends on the application. Same reason why we still have monocrystalline, polycrystalline, and bendable panels, all of which have different cost, estimated lifetimes, and efficiency gained.
For a campervan, you want as much efficiency as you can get, as every square centimeter of roof space is precious. This is why you want bifacial panels, a MPPT charge controller, and maybe even 24 or 48 volt panels to lower voltage drop losses. However, for a large surface like a south facing roof, it may be better to
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No it doesn't make the inventions irrelevant. That's like saying inventing the telephone was irrelevant because it was so much more expensive than the telegraph.
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Getting 2 percent extra efficiency at 7 times the cost makes such inventions irrelevant.
You've just declared every efficiency improvement in every product we've ever researched irrelevant. Congrats. Now remember the cost of a product is never the same as what it cost to produce in a lab during the R&D phase, and go facepalm yourself for your silly post.
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BUT, perovskite solar cells are considered cheaper to produce.
The only reason that perovskite is not being done is stability. They do not last as long. Yet.
Once their efficiencies are up AND they have a long life time, it will make sense to combine with silicon.
Cost per watt (Score:2)
For solar cells, cost per watt is far more important than efficiency. If the panels were cheap but inefficient we could blanket the deserts and have enough power. Efficiency only matters for satellites.
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Perovskite is cheap. It's what we'd spray paint the deserts with, if it were robust enough. Here they're considering what happens when you paint existing panels with it.
The catch (Score:2)
I just bought solar (Score:2)
I'm sure this has some non-residential use but for home use (I did a ton of research on this), the better techs are a few % better but the costs are also -much- higher. And the duration they last before they wear down below the point they make sense to install varies per tech too.
I was originally looking at 500w panels but oh wait those are just the same as 250w panels but twice as big and cost more per watt..... sigh.
So, for residential we need something that can last a long time (95% production at 25 yea
This efficiency is amazing (Score:1)
When you stop to think about it for a moment the efficiency of solar cells is breathtaking...
Putting aside nuclear, geothermal and tidal, most of our other electrical energy comes from the sun - directly (solar) or indirectly (fossil fuels, wind energy etc).
30% conversion of all energy striking the panel from the sun is bonkers efficient (even 20% is). By comparison - fossil fuels is more like 2%, breaking down as 4% efficiency on conversion of sunshine to biomass, assume lossless conversion of biomass to f
Some clarifications (Score:5, Informative)
The article is a bit confusing. Passing 30% on its own isn't a milestone. There are cells now on the market that are above 40%. But those are very expensive three layer structures that mostly only get used in special applications, like on satellites.
The news here is the type of solar cells they're working on: a perovskite layer on top of a silicon layer. Silicon is the standard kind of solar cell you see on rooftops. They have pretty good efficiency (up to about 22%), but they're kind of expensive. Perovskites are thin films. That makes them very cheap. You can put them on any kind of backing you want, even glass. They used to have much lower efficiency than silicon, but that has mostly been fixed. They still have shorter lifetimes, but that has improved in recent years and is likely to improve further.
The idea here is to combine them: a perovskite layer on top of a silicon layer. They absorb different wavelengths, giving better efficiency than either one alone. The perovskite layer adds hardly anything to the cost of making the silicon solar cell. You get higher efficiency at almost no extra cost.
People have been working on that for a while. This paper is the best total efficiency yet reported, the first to get above 30%. Again, that's at almost no extra cost compared to a standard silicon solar cell. That's why it's a big deal.
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Mass production of such panels would greatly benefit the world.
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Current space solar cells are three-junction cells. Four and five junction are working in the lab, but not yet commercalized.
Each junction, of course, is several layers-- p, n, front window, rear minority carrier reflector, tunnel junctions to connect to the other junctions above and/or below, often some other layers for bandgap grading.
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47% efficiency in the lab. Damn. I thought we had topped out in the 20. I need to read up on this. Thaks for the link.
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Hopefully, in time, that can be solved.
you can do better than 30% - (Score:2)
- and you can do it right now without a team of scientists. Use the waste heat that accumulates with solar panels. Most solar panels have an air gap underneath to dissipate waste heat. That heat just drifts away with the breeze when it could be put to good use.
You've already seen roof panels that circulate water for heating swimming pools, etc. And if you are here, you have probably seen liquid cooling systems that draw waste heat from GPUs. Similarly, liquid circulating behind (or in front of) a solar pan
Sunshine is not scarce (Score:2)
Nor is roofspace scarce. Improved PV efficiency will do very little to reduce cost.
The efficiency of combustion engines, batteries, electric motors, and transmission lines all matter very much, but for PV panels? No.
We just want them cheaper, and a means to store the power.
These panels will not make the Netherlands any less dark and gloomy in winter.
Just in time (Score:1)
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Or recovering from a hurricane that went from a cat 1 to a cat 4 and walloped a good part of Florida because the Gulf waters were much too warm. Gee, how did they get that warm?
Give me solutions (Re:Just in time) (Score:1)
Hurricanes are a heat engine, they dump the heat in the water into the air, and the air dumps that heat into space. When the conditions are right something of a "short circuit" happens and the water gets moving to dump that heat directly into space. So, yes, the heat of the water is a factor but so is also the coolness of the air. If the air is also warm then this "short circuit" doesn't develop.
So, how did the air get so cool?
The claim has been that global warming would result in more powerful storms.
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What would be evidence against global warming? Be specific or it's still not helpful in showing global warming as true.
The global average temperature over a 30 year period being the same or lower than the global average temperature over the 30 years that immediately preceded it.
It's as falsifiable as it gets.
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Here's a big problem with your suggestion, if it takes 30 years to disprove the theory then that's not very useful to us today, now is it? You've been sufficiently specific on how to prove the theory, still not helpful.
It appears I needed to demand specificity in asking the question, not just demand specificity in the answer.
Proving the temperature rising isn't sufficient. We would still need to show this is something we can do something about, if this isn't from human activity then we may be unable to st
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Global warming has been going on for a lot more than 60 years. We already have the data.
We can't even agree that there is global warming
It is certainly true that there is no evidence that I can present that you cannot arbitrarily deny.
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Global warming has been going on for a lot more than 60 years. We already have the data.
And nothing has been done? Pretty sure plenty has been done. How can we know we've been successful and done enough?
It is certainly true that there is no evidence that I can present that you cannot arbitrarily deny.
Don't kill the messenger. I'm not denying anything, I'm just pointing out the arguments on both sides. I want people to stop arguing about global warming because not everyone is going to be convinced there is a problem if only because all the solutions involve costing them money or restrictions on their freedom. We have solutions that don't require costing more money, and don't require res
Please use proper English. (Score:2)
Researchers from The Netherlands, i.e. Dutch researchers.....
(it may be the only exception to the rule, but there is just one exception where the adjective and name of the country do not line up).
Perovskite is lead (Score:2)
I'm just going to have to go ahead and be a wet blanket here, because perovskite is a lead compound. No, it is not safe for the environment. So keep that particular design in the lab please.
Re: Perovskite is lead (Score:1)
We better go take all the lead out of the environment then, and put put it somewhere safe like a solar cell.
Still doesn't solve very big issues with solar PV. (Score:1)
Even if we get to 100% conversion of sunlight to useful energy, and useful energy doesn't have to be electricity but that is very useful, then we still have problems with solar power taking a lot of land, raw materials, labor, and perhaps other valued commodities like freshwater. These things cost money. These things also tend to produce CO2.
How does solar PV use up freshwater? The panels will be exposed to wind, birds, and other things that can cause dirt to collect on the panels. In places where it is
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How does solar PV use up freshwater? The panels will be exposed to wind, birds, and other things that can cause dirt to collect on the panels. In places where it is especially warm (and those tend to be places with the most sun) the panels may need cooling or efficiency will suffer. Water run over the panels to clean and cool them will evaporate and be lost. The water needs to be fresh or it will deposit salt and/or other substances on the panels as it evaporates.
I'm told I really only need to wash them like once year. I'll probably wash mine every few months just because I can; assuming the rain doesn't do a good enough job. I'll probably use less than a gallon of water each time so I'm not too concerned about "wasting freshwater". Also, no water cooling required, so I don't know where you got that idea --
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...Look at the chart from the US Department of Energy as Figure 2 here: http://cmo-ripu.blogspot.com/2... [blogspot.com] (If for some reason anyone has a disagreement with the chart from the US DOE then feel free to offer an alternative source to discuss.)
But the link you give is not to the US Department of Energy. It is a link to a pro-nuclear blog. The blog copies a figure from a textbook titled Nuclear Power. The textbook figure graphs data from table 10.4 of a report "DOE Quadrennial Review." Doesn't say which DOE quadrennial report, but it turns out to be this one: https://www.energy.gov/sites/p... [energy.gov]
The table of data
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I have a "quibble" of my own. You didn't give what the correct data should be for a comparison. The conclusion solar power is a bad idea could still hold, and likely does given the wide margins for error shown on the chart. For some reason I can't load your link right now so I'm at a disadvantage. I doubt there's anything wrong with the link, the file just is not loading for some reason.
You say not to get my information from blogs but everything is a blog now. The US DOE report is posted on the US DOE b
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I have a "quibble" of my own. You didn't give what the correct data should be for a comparison.
Turns out that it is better to have no data than wrong or misleading data.
The conclusion solar power is a bad idea could still hold,
It could. The data you gave, however, did not support that conclusion.
30% in CHEAP solar cells (Score:2)
The advance here is that they broke the 30% mark in cheaper solar cells, rather than the very expensive version.
It's the equivalent of making a Toyata that can hit 180 mph rather than a Ferrari.