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.
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.
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.
I do astrophotography as a hobby (taking pictures of galaxies/nebulae/etc). This involves doing long, multi-minute, exposures repeatedly all night long. The heat generated from such long exposures produces what are called "hot pixels" - noise generated by heat disrupting the electronics.
To combat this, dedicated deep sky imaging cameras run a thermoelectric cooler to bring the sensor to sub-zero temperatures. These sensors tend to be about 23.5×15.7mm in size.
Niche, sure. But I saw an opportunity to bring up an aspect of my own life where I sincerely do not think even the smallest compressors would be practical. Plus, the lack of moving parts in thermoelectric is very attractive.
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.
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.
Things I'd never think would exist much less that I would think of actual occasion for utility: my phone was in the sun (windshield), charging and performing wayfinding, resulting in "phone too hot" errors.
On the whole however, can someone explain how efficiency can be over 100%, if 100% represents conversion of inputs into all work and no entropy?
The same is said of those scam "personal" AC devices that blow air over ice. They too are "more than 100% efficient".
That is a little unfair: this is the language of economics rather than physics, so if you are paying for 100w and getting 300w, that is indeed over 100% efficient. SCOP is a more "correct" term but is less clear when communicating with the public and (IMO) is mostly for professionals or people with a technical understanding of heat pumps. Nobody thinks they defy the laws of physics though.
I do some work using TECs for cooling optical sensors. Most of the industry has settled on a very small range of materials, such as BiTe, meaning that we're probably at a plateau until a more efficient material comes along. Some of my applications are battery powered, and cooling consumes a fair portion of the total power budget, so a more efficient cooler would be welcome.
Also, TECs are mechanically delicate. There's a laundry list of needs such as being able to form the material into the desired shapes, and make a good mechanical and electrical connection to it, which is usually done with some kind of low melting solder.
better opex but may not overcome the capex cost.