HA! I know we're not supposed to do "me too" posts, but literally the second I saw the headline I was thinking of the Technology Connections videos I've seen comparing thermoelectric to <anything else> and how inefficient it is in comparison. My memory is more than 2x, but I figure it's worth checking the videos to be sure before making an ass of myself.
But before that I figure it's worth it to check the comments already to see what people are thinking. And of course, your comment is at the top of the list.
Someone should code an "HN TC poster-bot" that scans headlines for topic matches and just immediately posts the relevant TC video. All of which to say, TC is awesome and everyone should check it out.
Well, the thing is, heat pumps/compressors can be more than 100% efficient by using phase change, they can be "200-300% efficient". It's not clear that TEC will be able to do that, and they're currently around 5-10% efficiency.
They're good for active cooling phone holders, maybe a chilling cupholder or stuff like that. Novelty items where you have USB power and want to cool something maybe 10-20 degrees below ambient and can have a heatsink/fan on the hot side. You can stack them for a bigger delta T, but the efficiency drops even more, and you end up needing to use increasingly smaller modules on the cold side, so only good if you need to get something small and well-insulted down to very cold temps, not active cooling.
Efficiency is pretty lousy. But sometimes you don't want to lug around a compressor, like inside a portable device (such as a food cooler, portable computer, or even a prosthetic limb). In that case inefficient is often better than nothing.
But also if this is an indication that more research effort is going into this because of breakthroughs, that’s a good thing. Double the efficiency a few more times and pretty soon it could be competitive in many uses.
Solar panels used to be horrible at efficiency. Now they’re pretty amazing and extremely competitive in the power generation market. It, similarly, took a few decades of these kinds of efficiency improvements to get there.
> Solar panels used to be horrible at efficiency. Now they’re pretty amazing and extremely competitive in the power generation market.
To be fair, in my understanding economies of scale kicked in _hard_ for solar, making it much cheaper to produce single panels, moreso than making each individual panel more efficient.
While Peltier devices are less efficient than a compressor/heat pump, they are a lot quieter due to being completely solid state. Comparing the two technologies is tempting but the applications can be very different.
Since these devices can also produce power given a heat differential, they are used in spaces where you need just a little power and heat is readily available.
By far their most useful application is precision thermal control. Need that LED or laser to be within 0.05C to maintain its wavelength? Literally nothing else can do it.
Also camera sensors. AFAIK most (all?) high speed sensors are actively cooled with TEC. All high sensitivity cameras are, most telescopes and satellite cameras also i think
Also sensors with long exposure times, which are cooled to reduce the dark current. Amateur telescope camera chips are often actively cooled for long exposures.
interesting to know that there are actual critical applications for this technology though it does have limitations as I think the JWST is cooled with some sort of exotic compressor useing liquid helium, though perhaps a solid state device is part of the stack as they are after a very low, very stable temperature
Scaling up (eh, out?) MEMS compressors in matrixes seems a more likely path to success to me. Some research is ongoing there. I’m not expert, but I find it interesting.
One of the greatest need for energy in the next few years is going to be for air conditioning if this really works it is going to be put another nail in the coffin of Oil and gas industry.
The press release doesn't give any concrete numbers, but if it doubles efficiency of Peltier coolers, it's still 3-5× less efficient than heat pumps.
Thermoelectric cooling is notable for not having any moving parts and ability to scale down to small sizes, so it might end up having many specialized applications, but for A/C heat pumps are already very effective.
And what about service life? I had a mini-fridge that used this technology, and it stopped working after about 2 years. Was that just bad luck or poor quality, or some inherent lifetime of the components?
In principle peltier elements should be very robust over time, as a solid state system where the only moving parts are fans (versus traditional refrigeration which includes a high pressure pump...).
In practice I strongly suspect most peltier based systems are built very cheaply... because their inefficiency means the majority of the market is bordering on a scam. Sophisticated consumers aren't going to be buying very many fridges built with them (of course you might have a niche use case where they actually make sense and you're willing to pay for a quality product, but do most purchasers?).
Thermal cycles is murder on rigid electronic connections; the mechanical connection between the heatsink on each side of the peltier cell being a prime example.
Air conditioning is mostly needed while the sun is shining, and so electricity of A/C can come mostly from photovoltaics (plus batteries). So I think this technology is not quite as important. Sure, its nice to reduce electricity usage! But cheaper heat storage, for winter, seems more important.
Yes you can! Not with peltier elements, but with elastocaloric (phase changes in solid metal induced by stress) and maybe magnetocaloric (phase change induced by magnetic fields) heat pumps.
There's engineering challenges here, but I believe the science is pretty clear that in principle these beat gas phase change systems.
IIRC from reading up on these in the past, you need a pretty large input energy in order to make them work. The elastocaloric ones are also super loud IIRC.
Gas phase change systems in practice are up to about 60% efficiency (relative to an idealized carnot cycle), magnetocaloric systems in labs have been something like 70%, and elastocaloric 80%.
You can double the speed of a slug and not have it do anything meaningful as a useful domestic animal.
Thermoelectric cooling is extremely inefficient, to the point that we have very little practical use for it right now. Heat pumps a hundred times more effective predominate.
> This is the same sort of person that MAGA and tech workers want to discourage coming to the United States.
Tangential, but let's not forget that there are also Indian MAGAs like the current FBI director.
There are also influential and wealthy Indians who are more than willing to partner with MAGA to pay whatever tribute is necessary to curry favor, and throw working Indian immigrants under the bus to line their own pockets and accomplish their own personal and political objectives.
In the end, it has little to do with being Indian and more to do with scapegoating and dividing tech workers among themselves, to distract them from the squeeze that big corporations are putting on them.
> Abstract: Refrigeration needs are increasing worldwide with a demand for alternates to bulky poorly scalable vapor compression systems. Here, we demonstrate the first proof of practical solid-state refrigeration, using nano-engineered controlled hierarchically engineered superlattice thin-film thermoelectric materials. [...] The improved efficiency and ultra-low thermoelectric materials usage herald a new beginning in solid-state refrigeration.
Previous discussion: https://news.ycombinator.com/item?id=44424087
Doubles efficiency? From what I understand, the efficiency was pretty lousy to start with: https://www.youtube.com/watch?v=CnMRePtHMZY
Aren't there theoretical limits to this sort of cooling too?
But, if this innovation causes Technology Connections to make yet another heat pumps video, I'm all for it.
There are current applications for solid state cooling. Why wouldn't you welcome those applications being more efficient?
HA! I know we're not supposed to do "me too" posts, but literally the second I saw the headline I was thinking of the Technology Connections videos I've seen comparing thermoelectric to <anything else> and how inefficient it is in comparison. My memory is more than 2x, but I figure it's worth checking the videos to be sure before making an ass of myself.
But before that I figure it's worth it to check the comments already to see what people are thinking. And of course, your comment is at the top of the list.
Someone should code an "HN TC poster-bot" that scans headlines for topic matches and just immediately posts the relevant TC video. All of which to say, TC is awesome and everyone should check it out.
Well, the thing is, heat pumps/compressors can be more than 100% efficient by using phase change, they can be "200-300% efficient". It's not clear that TEC will be able to do that, and they're currently around 5-10% efficiency.
They're good for active cooling phone holders, maybe a chilling cupholder or stuff like that. Novelty items where you have USB power and want to cool something maybe 10-20 degrees below ambient and can have a heatsink/fan on the hot side. You can stack them for a bigger delta T, but the efficiency drops even more, and you end up needing to use increasingly smaller modules on the cold side, so only good if you need to get something small and well-insulted down to very cold temps, not active cooling.
Efficiency is pretty lousy. But sometimes you don't want to lug around a compressor, like inside a portable device (such as a food cooler, portable computer, or even a prosthetic limb). In that case inefficient is often better than nothing.
But also if this is an indication that more research effort is going into this because of breakthroughs, that’s a good thing. Double the efficiency a few more times and pretty soon it could be competitive in many uses.
Solar panels used to be horrible at efficiency. Now they’re pretty amazing and extremely competitive in the power generation market. It, similarly, took a few decades of these kinds of efficiency improvements to get there.
> Solar panels used to be horrible at efficiency. Now they’re pretty amazing and extremely competitive in the power generation market.
To be fair, in my understanding economies of scale kicked in _hard_ for solar, making it much cheaper to produce single panels, moreso than making each individual panel more efficient.
While Peltier devices are less efficient than a compressor/heat pump, they are a lot quieter due to being completely solid state. Comparing the two technologies is tempting but the applications can be very different.
Since these devices can also produce power given a heat differential, they are used in spaces where you need just a little power and heat is readily available.
By far their most useful application is precision thermal control. Need that LED or laser to be within 0.05C to maintain its wavelength? Literally nothing else can do it.
Also camera sensors. AFAIK most (all?) high speed sensors are actively cooled with TEC. All high sensitivity cameras are, most telescopes and satellite cameras also i think
Also sensors with long exposure times, which are cooled to reduce the dark current. Amateur telescope camera chips are often actively cooled for long exposures.
interesting to know that there are actual critical applications for this technology though it does have limitations as I think the JWST is cooled with some sort of exotic compressor useing liquid helium, though perhaps a solid state device is part of the stack as they are after a very low, very stable temperature
Scaling up (eh, out?) MEMS compressors in matrixes seems a more likely path to success to me. Some research is ongoing there. I’m not expert, but I find it interesting.
One of the greatest need for energy in the next few years is going to be for air conditioning if this really works it is going to be put another nail in the coffin of Oil and gas industry.
The press release doesn't give any concrete numbers, but if it doubles efficiency of Peltier coolers, it's still 3-5× less efficient than heat pumps.
Thermoelectric cooling is notable for not having any moving parts and ability to scale down to small sizes, so it might end up having many specialized applications, but for A/C heat pumps are already very effective.
And what about service life? I had a mini-fridge that used this technology, and it stopped working after about 2 years. Was that just bad luck or poor quality, or some inherent lifetime of the components?
In principle peltier elements should be very robust over time, as a solid state system where the only moving parts are fans (versus traditional refrigeration which includes a high pressure pump...).
In practice I strongly suspect most peltier based systems are built very cheaply... because their inefficiency means the majority of the market is bordering on a scam. Sophisticated consumers aren't going to be buying very many fridges built with them (of course you might have a niche use case where they actually make sense and you're willing to pay for a quality product, but do most purchasers?).
Thermal cycles is murder on rigid electronic connections; the mechanical connection between the heatsink on each side of the peltier cell being a prime example.
This has nothing to do with that application.
Air conditioning is mostly needed while the sun is shining, and so electricity of A/C can come mostly from photovoltaics (plus batteries). So I think this technology is not quite as important. Sure, its nice to reduce electricity usage! But cheaper heat storage, for winter, seems more important.
If you're heating with non-fossil-fuels you're doing it with heat pumps, just like AC, just with the hot side inside and the cool side outside.
You can't beat gas phase change for moving heat around. But there are a lot of applications for small coolers where a compressor is too bulky.
Yes you can! Not with peltier elements, but with elastocaloric (phase changes in solid metal induced by stress) and maybe magnetocaloric (phase change induced by magnetic fields) heat pumps.
There's engineering challenges here, but I believe the science is pretty clear that in principle these beat gas phase change systems.
IIRC from reading up on these in the past, you need a pretty large input energy in order to make them work. The elastocaloric ones are also super loud IIRC.
> I believe the science is pretty clear that in principle these beat gas phase change systems.
Do you know by how much?
Gas phase change systems in practice are up to about 60% efficiency (relative to an idealized carnot cycle), magnetocaloric systems in labs have been something like 70%, and elastocaloric 80%.
Probably very applicable, this video from Ben
https://www.youtube.com/watch?v=lfmrvxB154w
I mean USA is now subsidizing coal and wants to double toxic fracking
"better" "cheaper" "cleaner" is buried by political spite agendas
Is this similar to Peltier coolers?
Yes, "thermoelectric" and "Peltier" are the same thing.
You can double the speed of a slug and not have it do anything meaningful as a useful domestic animal.
Thermoelectric cooling is extremely inefficient, to the point that we have very little practical use for it right now. Heat pumps a hundred times more effective predominate.
TEC are used everywhere, actually.
To note, the lead investigator on this is Rama Venkatasubramanian, an Indian:
https://www.jhuapl.edu/about/people/rama-venkatasubramanian
This is the same sort of person that MAGA and tech workers want to discourage coming to the United States.
> This is the same sort of person that MAGA and tech workers want to discourage coming to the United States.
Tangential, but let's not forget that there are also Indian MAGAs like the current FBI director.
There are also influential and wealthy Indians who are more than willing to partner with MAGA to pay whatever tribute is necessary to curry favor, and throw working Indian immigrants under the bus to line their own pockets and accomplish their own personal and political objectives.
In the end, it has little to do with being Indian and more to do with scapegoating and dividing tech workers among themselves, to distract them from the squeeze that big corporations are putting on them.
You know who used to love thermoelectric cooling? Jimmy Kimmel.
ScholarlyArticle: "Nano-engineered thin-film thermoelectric materials enable practical solid-state refrigeration" (2025) https://www.nature.com/articles/s41467-025-59698-y :
> Abstract: Refrigeration needs are increasing worldwide with a demand for alternates to bulky poorly scalable vapor compression systems. Here, we demonstrate the first proof of practical solid-state refrigeration, using nano-engineered controlled hierarchically engineered superlattice thin-film thermoelectric materials. [...] The improved efficiency and ultra-low thermoelectric materials usage herald a new beginning in solid-state refrigeration.
Holy ads Batman - https://imgur.com/a/6vwJBkT