It’s explicitly part of Chinese science and technology strategy to think outside the box and it’s what’s pushing them forward on areas like semiconductors as well.Given the massive advantage in talent they’ve built up while the Us reverts to Drill Baby Drill we know how this ends.Eventually the Us with push for atmospheric dimming to “fix” the negative externalities of their approach which had the nice side effect of degrading solar ….FMl

I did data collection for a paper looking at the Seebeck effect in magnetic insulators about ~10-15 years ago, and it seemed like everyone in the whole physics department considered spintronics pretty dead. It feels great to see some big promising applications coming out of the field.

Yeah, I&#x27;d expect anything solar thermal to scale worse than current standard n-topcon glass glass PV panels.

What doesn’t work is concentrated PV, due to the scattering.

PV panels work in shaded or cloudy settings (at reduced power of course).

But do they actually out-perform solar panels in any situation yet?

Photovoltaic efficiency drops as the panels overheat. Some have demonstrated active cooling methods that are net energy gain. I wonder if it would be cost effective to use these between the panels and cooling system?

Would it be possible to do both on a single panel? In other words, put photovoltaic cells on the sunny side and thermoelectric generators on the shady side.

Two materials (often n-type and p-type semiconductors) are joined at two junctions, one junction is heated and the other cooled. The temperature difference makes charge diffuse from the hot side toward the cold side, and this charge is what turns into the seebeck voltage they describe. It was just very hard to get anything meaningful out of this because you can&#x27;t easily get such a temperature difference. If you&#x27;ve read of the peltier effect, it&#x27;s the same thing as this, just in reverse.

They both use heat. But stirling converts mechanically, whereas STEM converts energy to electricity «directly».

so they are basically using a similar idea to that of a stirling engine in thermoelectric generator or they use a different mechanism to produce energy?

Some of the cooling tricks could likely be used on standard PV, since overheating affects efficiency.

This new solar thermoelectric generator (STEG) traps heat on one side and cools the other, making electricity from the hot-cold gap via the Seebeck effect. Unlike solar panels, which need direct sunlight, STEGs can use ambient heat and scattered light. That’s why they still work in shaded or cloudy areas—any temperature difference can generate power. Today they’re only ~1% efficient (vs. ~20% for solar), but the new design is 15× better than earlier STEGs. They won’t beat solar panels yet, but could be useful in spots where panels underperform.

The authors carefully avoid giving any actual efficiency figures (or figures from which the efficiency could be easily calculated). Since they barely managed to power an LED under concentrated sunlight, it is probably safe to assume that the efficiency is extremely low. The reference point for the &quot;15-fold&quot; improvement is literally putting a Peltier element out in the sun. Looks like they really don&#x27;t want their device to be compared to a photovoltaic cell.

RTGs aren&#x27;t quite the same, in that they use simple radioactive decay, no? And cooling in space is really hard.

Would this increase in performance they discovered make deep space satellites more powerful?

Sort of, They are called Radioisotope Thermoelectric Generator (RTG) used where you need a small amount of super reliable power. Mainly used on deep space missions where there is not enough sunlight. The soviets also used them in unmanned deep north lighthouses.<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Radioisotope_thermoelectric_generator" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Radioisotope_thermoelectric_ge...</a>Neat tech, but very inefficient, to make it efficient fluids start needing to be moved around which hurts reliability. The next step up are pebble bed reactors, I don&#x27;t think any have been built but the idea is to have self contained fuel &quot;pebbles&quot; enriched enough to get hot but with enough built in moderation so they can never melt down. Then a traditional heat engine is bolted on.<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Pebble-bed_reactor" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Pebble-bed_reactor</a>

I don&#x27;t entirely follow. A lot of existing nuclear plants use ambient temperature for cooling, via cooling towers, no? They use pumped coolant to get the heat out of the reactor, sure, but the cold end is just air.Also, I guess you could have the hot end very hot too..? This improving efficiency. Especially if, by virtue of cooling being safer, you could run it at a higher temperature (less safety margin needed).

&gt; Use nuclear magic to make the hot side, cool with ambient temperature.If you use ambient temperature for cooling, you are severely limited in your total power output. Like, we&#x27;re talking about less than a megawatt output (depending on how big the ambient heat dispensers are) compared to the ~1GW of a regular old nuclear plant.You might say: that&#x27;s fine, let&#x27;s just build many small ones. But you still need to track your radioactive material, make sure it&#x27;s not stolen etc., which is a lot of overhead per installation.

Yes I wonder if with the current trend, solar might become the real alternative, less expensive, less risky.But to be fair, you have to consider your « aside », because nuclear has the tremendous advantage of working when it’s cloudy, dark and you need the energy the most in the winter.I do not think that we can just compare the prices, or maybe we should also add the cost of storage (that is going down too) for solar.But currently a mix is probably the pragmatic approach.

&gt; (setting aside overall strategy for base load and stuff).You can&#x27;t really set aside the reality of the electric grid, you have to do with it.

Especially at their price point, the new british one is bound to cost like 40 billion pounds in total, that&#x27;s far off from solar+batteries.I&#x27;d love to have more modern nuclear, but I don&#x27;t see it happening anymore, no expertise in building them anymore, cost and time overruns all over...

&gt; setting aside overall strategy for base load and stuffEnergy got increasingly expensive in Germany the further the Energiewende agenda advanced, to the point that we’re now rapidly deindustrialising.Turns out base load kinda matters.

Nuclear plants sometimes aren’t even worthwhile at their current efficiency. Even if TEGs simplified things mechanically, you’d still face the problem that nuclear often can’t compete (with renewables) in direct a comparison (setting aside overall strategy for base load and stuff).

Could you run a plant with less-refined fuel if it doesn’t need to temp up to boil water?

Nuclear power plants aren&#x27;t inherently any more unsafe than the nuclear material itself before having been mined.What makes them potentially unsafe is nuclear technology having an incredible energy density, which can be misused and the radioactive material being active even without prior activation. The latter makes many radioactive isotopes a very effective poison.And misuse or bad practices are a general problem. One can build awful buildings, toys or government structures, too.And if you have a look at what the worst reasonable non-political consequences from a nuclear powerplant meltdown can be, they&#x27;re surprisingly harmless.We have to Soviets to thank for their absolutely incompetent response to the Chernobyl meltdown, that we have a good idea of the long term effects. The powerplant never stopped operating, people kept working there every day for decades. Hundreds of people were never evacuated and hundreds more returned within weeks.Just to put this into perspective: Chernobyl was effectively a dirty super-bomb dispersing 50t of highly active radioactive materials and yet the death count among anyone who didn&#x27;t approach into rock throwing distance remains 0.

Any nuclear reactor capable of generating power via TEGs can be made to have an identical safety profile, but run turbines.Outside of RTGs.

Almost the entirety of safety issues with existing reactors is around cooling them. Bad things happen when you can&#x27;t cool them.There&#x27;s many ways in which this can happen in existing reactors. You may have a catastrophic leak and lose the coolant - and you can&#x27;t just send some welders in, what with radiation, superheated steam etc. The pumps that push the coolant around might fail. Etc. etc.Even when you &quot;switch off&quot; the chain reaction, the fuel rods keep emitting heat from the decay of transient radioactive elements, enough to need active cooling for days or weeks.So a lot of new reactor designs revolve around eliminating such failure modes. NuScale for example, IIRC, don&#x27;t use pumps to circulate the coolant, and that&#x27;s one thing less that can break.What I&#x27;m daydreaming about simply cannot stop working, in terms of cooling. You have something hot in the middle, you let all the heat get our naturally, and you harvest some of it along the way.

You can build fixed power reactors where they don&#x27;t go critical if cooling is lost. It&#x27;s just the cost more and they have a capped output. Pebble bed reactors are like this.

Why is it safe to have no coolants around when things run out of control?

I sometimes wonder if you could make a much safer nuclear plants with TEGs. There would be next to no active processes and moving parts, no pumps and coolant and circulation. Use nuclear magic to make the hot side, cool with ambient temperature.No doubt this would be less energy efficient, but perhaps you reap so much savings by not having to worry about water circulation that it&#x27;s worth it.

Cars are an obvious application.Some parts get very hot, and any electricity produced without engine or fuel add to range &#x2F; efficiency.

I caught that as well. Further reading it looks like they had a ~2x improvement over a flat aluminium sheet (Which itself performed worse then the bare TEG). And of that improvement about half came from radiative cooling.So my very hot take is that a conventional forced air finned radiator treated with this laser process would show an improvement, it is unlikely to be economically viable versus just using a bigger radiator (at desktop&#x2F;server CPU&#x2F;GPU scales). At laptop scales it might be more viable given space constraints.

I wonder if the improvements for the aluminum heatsink might be applicable to other situations like cpu&#x2F;gpu heatsinks or other places where cooling is needed. It seems like it might be economical.

your cell phone display was probably cut with a fs laser, is a less exotic process than you think.

Femto second laser processing is probably not a scaleable process.

I agree, it has quite broad application!

2x the radiative + convective heat dissipation for a passive aluminum heat sink seems like as big a deal as its use in this particular application.

Only skimmed the paper but this looks more like an advance in absorbing solar energy through laser patterning a metal than in more efficient thermoelectric effects.Laser patterning is a lot easier than improving thermoelectric device efficiency.

That&#x27;s low-grade heat. E = (T2 - T1) &#x2F; T2, remember.

AI data centres can perhaps harvest some of the waste heat back as electricity.

It&#x27;s not a good solar power source, but could the technology be adapted to heat sinks? Maybe they could license the technology to CoolerMaster.

&gt; Over the lifetime of an air conditioner, the cost of the energy used to run the equipment will be larger than the cost of the equipment itselfMy point is this is rapidly becoming not true.Thanks for the info on the efficiency though. I’m still hoping we can figure something out. If not , we should switch to propane for the coolant. Way cheaper than whatever they keep making manufacture switch to.

I’m not sure what you mean by solid state AC, peltier cooling? That will never be used for air conditioning, the theoretical max COP is 1 (1w of heat removed for 1w of input power) and a decent heat pump will have a COP of 4 (4w of heat removed for each 1w of input power). Most peltier coolers have a COP of .1, which makes a heat pump 40 times more efficient.It is impossible to make a solid state peltier cooler that is even 25% as efficient as a vapor-compression cycle heat pump at removing heat, therefore it will never gain traction in applications where a heat pump can be used.Over the lifetime of an air conditioner, the cost of the energy used to run the equipment will be larger than the cost of the equipment itself, so efficiency is important if you want to reduce your total cost of ownership. SEER ratings eventually have diminishing returns per dollar spent, but finding the most efficient unit per dollar is time well spent.

I’m really excited for this technology to be used for solid state AC. I think we’ll get there one day.I’m even willing to accept a lot of inefficiency because new AC’s in the US can cost 10-20k now and you can need them as frequently as every 7-10 years.The whole industry is really getting absurd.

I presume this would be useful for thermal camouflage, since you could store the heat energy in a battery instead of diverting or diffusing it. I hope bleeding edge research sees the potential for aiding the climate crisis as ethically imperative over a military&#x27;s niche technological advantage&#x2F;cash.

No <a href="https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;Fold_change" rel="nofollow">https:&#x2F;&#x2F;en.m.wikipedia.org&#x2F;wiki&#x2F;Fold_change</a>

I imagine folding too. But then we couldn’t ever achieve more than maybe a twelve-fold increase.

I’ve not heard the term used that way—I’ve always understood it to indicate a multiple. But now that you’ve said it, the idea of -fold as “folding something in half” is interesting to think about!

I don&#x27;t know if the engineering field has the same conventions, but in biology we use &quot;fold&quot; as it was used in the paper. 
When comparing the signal of two things, the fold change is how many times one is bigger than the other (basically A&#x2F;B). If A is 15-fold higher than B then it&#x27;s 15x B.What you described is the Log2 Fold Change (log2(A&#x2F;B)), meaning that if A has a log2FC of 15 over B, its signal is 2^15 times higher, hence ≈32,000x.

I think its getting downvoted because they suggested that the article&#x27;s copyeditor should have caught it, despite the article being right. I doubt they would have been downvoted if they just asked, but suggesting that someone failed at their job despite them actually doing it correctly tends to get people a bit uppity.Words are arbitrary, but there really isn&#x27;t any dispute what -fold means as a suffix. See the dictionary entry for it <a href="https:&#x2F;&#x2F;www.merriam-webster.com&#x2F;dictionary&#x2F;-fold" rel="nofollow">https:&#x2F;&#x2F;www.merriam-webster.com&#x2F;dictionary&#x2F;-fold</a>Also as far as i know, this isn&#x27;t just an english being weird thing, most germanic languages use &quot;fold&quot; the same way.

&gt; folding naturally implies a doubling.Why is that? I can imagine doing two folds on a sheet of paper and ending up with three layers of paper. Imo one fold adds one layer.

I&#x27;m bummed that you&#x27;re getting downvoted for what&#x27;s IMO a very natural question, especially given that &quot;times&quot; is unambiguous and that folding naturally implies a doubling. But this is English, it&#x27;s deliberately designed to not make sense (see also the modern definition of &quot;literally&quot;).mumbles something else about 2^15

Doesn’t 15-fold mean multiplied by two 15 times, or 32,000x not 15x?I feel like someone should have caught that before publication.

Well yes, but this is not a competing technology but a complementary one.You can use this to improve the efficiency of a regular solar panel and as a way to still produce electricity when there is less direct light but enough temperature difference.

It&#x27;s hard to come close to solar cells&#x27; Carnot... I don&#x27;t think they improved &quot;efficiency&quot; by much. That&#x27;s why by performance they actually mean something like raw power output. TEG is notorious for having like microwatts per sq cm of output near room temp. Now they are a 100th to a 10th of PV &quot;performance&quot;.. mildly disingenuous titling imho.

I don’t fully get it, thermoelectric is relying on a surface temperature differential compared to the radiation temperature differential for solar panels. Wouldn’t the carnot efficiency of these panels significantly pale solar panels?

We have passive thermal heat tubes on our roof to heat our pool. It works amazingly well. I want to put PV on our roof, but that’d mean having to pull up those tubes first and replacing our pool heater with something electric.Turns out there’s companies that do hybrid systems! Water is used to cool the PV, increasing the efficiency of the panels in the process, and then the heated water is used wherever you need it.Unfortunately it seems there’s only a couple of providers, it’s rare to find installers that do it, and it’s ssuuuppppeeerrr expensive relative to the normal options. Such a shame. I wish there were more options here. It seems like a great approach.

&gt; until you factor in the cost of doing so and realize you would get 10x the return on adding a few more panels.You&#x27;re looking what the cost would be now and I don&#x27;t think they were suggesting that, but rather as a direction of development for panels.Luckily this is exactly how things work and why we have continues progress in the area, including with the batteries. Because 10 years ago you wouldn&#x27;t even bother with super expensive Lithium batteries for home energy storage and go with NiCd, right?

Sure, solar panels get wicked hot and are more efficient when cold, so attaching something to scavenge heat from them, bonus hot water and a little electricity are all wins until you factor in the cost of doing so and realize you would get 10x the return on adding a few more panels.

Could you combine them with solar panels?

15-Fold increase in solar thermoelectric generator performance