Tandem solar cell achieves 32.5 percent efficiency
helmholtz-berlin.de
helmholtz-berlin.de
The main obstacle to commercialization is keeping the perovskite material stable over long periods of operation. This family of materials is more sensitive to water/oxygen/light than silicon itself, but they need to last nearly as long as silicon for cells used in solar farms and rooftop panels.
This certainly may not be the case if you follow PV industry news and are aware of how many PV panel manufacturers have formed as startups and gone bankrupt in the last 8 to 14 years.
edit: the other reply here in the thread asks:
> but can be replaced as a layer every, say, 5 years or so? It's not trivial maintenance, but you have to do some maintenance on the panels anyway
Typical mass market PV panels are cells permanently encapsulated behind glass sandwiched with a back sheet, it is not practical or possible to replace a layer or modify the cells once they're assembled into a panel. The only maintenance done on a series of ground or roof mounted typical PV panels is to wash them.
I just bought 26 AEG panels for exactly that reason. They were a bit more expensive but my estimate is that AEG will outlive me so that should be fine. Contrast with many other solar panel producers who seem to go out of business ever five years or so.
https://www.zonnepanelen-store.nl/aeg-as-m1202z-bhm6-365hv-g...
https://en.wikipedia.org/wiki/AEG
These panels are produced by AEG Industries:
https://www.aeg-industrialsolar.de/about-us/
A licensee of the AEG brand from Electrolux aka The Solar Solutions Group.
In that sense 'Volvo' is also 'just a Brand', as is 'Audi' and many others. Still, that's what people will refer to.
High altitude drones or EVs are much easier to service than satellites: https://spectrum.ieee.org/new-type-of-unmanned-aircraft-aims...
Even a minor boost to efficiency could push this concept from "doable in ideal scenarios as a tech demo" to "useful in the real world as a way to multiply the range of electric fixed-wing aircraft"
So you're now pulling two trailers but using the watts/km for one. Also your panels will be fixed to the roof and not tracking the sun. you aren't going to get near 30% for them.
Second, you aren’t limited to the top of a vehicle, covering the sides is viable and makes up for the sun not being directly overhead.
Methinks a better strategy would be trying to make them keep >17% efficiency even if the perovskite fails and just treating it as a temporary bonus for the early movers. Still sounds hard to manage the voltages as it fails though and would require a different strategy for the busbars even if it were viable.
There could be a solid secondary market 20 years from now for panels that have dropped to say 20% efficiency where the surface area to yield ratio isn’t a factor (rural areas I would guess).
Current drop down to 70% output is roughly 30 years. These panels won't go anywhere for a long time.
There are a large number of research-lab-only PV cells made in the last 10-12 years which greatly exceed 23% but are economically unfeasible or impossible to purchase for ordinary use. Some of this tech does trickle down eventually, however.
Of more practical real world interest is $ per STC watt for a panel you can buy in a 20-panel pallet load from an ordinary PV wholesaler. Like a figure of $0.28 USD/W for nominally 380W rated 72-cell monocrystalline Si panels for rooftop or ground mount applications. Meaning that a pallet of 20 panels would be somewhere around $2100 to $2200 USD to purchase plus freight.
In approximately the last 12 years we've seen things go from if you buy a pallet of "cheap" mass market 72-cell panels, you'd get 320W rated per panel (STC rating of about 4.44W per cell), to now being able to buy something that is 380W rated as mentioned above, approximately 5.27W per cell. All under STC measurement conditions which are only a rough approximation of real world sunlight of course. The same panels typically measure 1.99 x 0.99 meters so you can do the math on the improvement in STC W per square meter if mounting space is a limiting factor.
I won't make a profit for decades, unless the price of grid power shoots up. It would make more sense in a place with higher power costs. But I can keep the lights on if there's a power outage, without the maintenance costs (and noise) of a hydrocarbon-fueled generator.
If you're installing solar for monetary gain, don't put it on your roof, buy/lease cheap land and build a solar farm. My electricity provider even lets you buy in on syndicated solar farm deals, if you don't want to manage the process yourself; you get the generated kWh credited back on your power bill!
Saving money with the setup beats getting the last percent out of the install. Although probably only some rural home-owners are going to be able/allowed to just put the panels flat on the ground.
Might be ok in some areas, but not at northern latitudes, and definitely not their winters.
So now I'm in the process of putting together a 1.8kW solar system for the roof of a cargo trailer. Not the biggest solar setup, but I'm also not a huge consumer of power - this should offset a significant portion of my consumption in summer, and it's also expandable to ~2.7kWh (though I should've bought a 6th panel for that).
I've paired the panels up with a 3kW hybrid inverter and a 5.1kWh LFE rackmount battery. Should do pretty well together, and like you said... I'll be able to keep the lights (+fridge/furnace) on if there's a power outage - a huge plus.
Total cost for the main components and most of the necessary wire/hardware? ~$4000, before any tax credit.
Recommendations for wholesaler or even just examples? (West coast preferred)
minimum quantity will be one pallet typically
[0] https://en.wikipedia.org/wiki/Sunlight#/media/File:Solar_spe...
On the other hand, the terrestrial space is dominated by the green plants because here the problem is not absorbing more of the abundant light, but avoiding overheating from absorbing too much light (because the efficiency of photosynthesis is low, so most of the absorbed energy becomes heat, and not only there is much more light in air, but also the cooling is more difficult than in water).
On the cool side, it's theoretically possible to make them translucent (without the silicon substrate ofc) which could make for cool power generating windows in the future.
On the not so cool side you really don't want the materials anywhere near you or your water table in the event of a panel being damaged. Lead halide perovskites, methylammonium lead iodide, are insanely toxic and a race to the bottom on price if they become widespread could be an environmental disaster waiting to happen.
Not to take from the achievements described here, but there isn't any mention of it. There is some hope in taking the lead out (tin based perovskites) but that tends to result in a drop in efficiency.
If you just want high returns I'd look elsewhere.
Also you can’t lay massive solar farms withou native manufacturing. What you’ll just buy them from China for hundreds of billions of dollars cough Europe cough but also the US??
Buy a shed? Comes with a panel and a battery and a socket inside. As standard.
What's not to like?
Edit: I mean widespread usage. One lone 10kw plant using 30% panels was not my intention.
Single junction caps out around 28% at the module level so surpassing this at scale requires commercialising a new technology like these perovskite tandem cells.
The other benefit is it reduces consumption of the main limiting critical mineral of silver down to insignificant levels by increasing the voltage on the metal layer.
But I have a question to the more knowledgeable here: The chart in the story shows other technologies which achieve significantly higher efficiency figures:
https://www.helmholtz-berlin.de/pubbin/news_datei?did=15092
specifically, multi-junction cells. Why are they faded-out? Are they not practicable to mass produce and deploy? Only usable in limited scenarios?
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Partial self-answer: According to Wikipedia,
https://en.wikipedia.org/wiki/Multi-junction_solar_cell
> As of 2014 multi-junction cells were expensive to produce, using techniques similar to semiconductor device fabrication, usually metalorganic vapour phase epitaxy but on "chip" sizes on the order of centimeters.
The fading is to de-emphasize cells of different technologies.
https://www.google.com/search?client=firefox-b-d&q=boeing+sp...
https://en.wikipedia.org/wiki/Solar-cell_efficiency
(The top is 47.1%)
Interactive version: https://www.nrel.gov/pv/interactive-cell-efficiency.html
NREL's website has a lot of good stuff if you're interested in renewable energy.
The main limiter for solar cells from silicon is the overlap of the bandgap with the spectrum of the sunlight and also the loss in efficiency when cells get hot. So what people do is they use multiple materials (often in different layers) that cover different parts of the spectrum to absorp most of the sunlight. Researchers tend to have a good idea which these are (although there is research in creating new organic ones), but the challenge is to combine this in fabrication with the silicon and in a cheap easy to fabricate way and with materials that don't degrade over time. So short answer researchers have a general idea what needs to be done, but as usual the devil is in the details.
Again not an expert in the exact area, so anyone who is please correct if something isn't right.
It's about preventing reflections at various surface boundaries (or more generally, controlling reflections everywhere) and structuring things so that different wavelengths go to the right layers, and preventing recombination, and a zillion other details. Material quality and process control to get the right surface properties are very important.
The cells that make it out of the lab are those where the cells are robust and processes can be adapted and scaled to mamufacturing quantities, competitively with current products.
edit: the chart from the article is great at showing the progress
https://www.nrel.gov/pv/assets/pdfs/best-research-cell-effic...
(Base webpage for the chart: https://www.nrel.gov/pv/cell-efficiency.html)
canibuyoneforunderfiftyusd.com
Personally I’d buy most of the products I upvote on HN, but it’s a gamble whether they even have a retail product at all.
Probably build a small solar-powered light, or see how much usage I could get out of a solar-powered microcontroller, or even just see how small of a thing I could make that still collects power.
The technological advances we (society) make are endlessly fascinating to me. I just want to have more of them in my hands.
The efficiency doesn’t matter much, it’s just the cost. Most people don’t pack as much solar on their roof as they can possibly fit on anyway, so higher efficiency would just mean less of the roof is taken up.
The problem right now isn't so much panel efficiency as the lump cost of doing a project like this and the affordability / justifiability of that.. Especially when solar companies take advantage of people receiving tax credits & gouge on labor pricing.
Not sure what benchmark to be excited about here aside from progress for the sake of progress
> in other forms of progress the goal post is pretty clear
I'm not sure that's true. Incremental progress is fairly common. A 7nm feature size microchip is generally better than a 10nm one (from the same manufacturer, at least; annoyingly, people are increasingly fudging the numbers there), which in turn was better than a 13nm one and so on, as an example.
For a long time, solar cell efficiency was around ~10-20%. There's actually a theoretical upper limit, the Shockley–Queisser limit, of a bit less than 34% for a single p-n junction photocell. [1] This is a tandem cell – for which higher efficiencies are possible but costs go up. The thermodynamic limit is reached if you have an infinite number of layers.
Obligatory plot of progress vs time: https://upload.wikimedia.org/wikipedia/commons/2/25/Best-res...
[1] https://en.wikipedia.org/wiki/Shockley%E2%80%93Queisser_limi...
[1]: 20% is already quite a good efficiency for a car in mixed traffic. That doesn't even account for all the energy used to provide the fuel.
Single layer silicon is in the 22-25% range now with the 22% modules being the optimal cost in most areas.
The modules also only make up a small fraction of the cost of a PV install (around 25-30%), so increasing efficiency from 22% to 32% reduces BOS costs by almost as much as the entire module currently costs
Perovskites are also dirt cheap, so are a good candidate for increasing efficiencies. The difficulty is in making them last. Accelerated aging tests are promising but they haven't hit market yet.
BOS: balance of system, i. e., everything else besides the panels (mountings, wiring and connectors, labor and land costs being the main parts of BOS affected by panel efficiency.)
Note the PDF link above to best research cell efficiencies, which means somebody made a very small number of PV cells in a lab environment. Not something that's produced for sale to end-users in any real quantity.