It’s really, really weird to comment on the efficiency of these devices on an article like this, without actually checking the paper being referenced. Like, we know traditional thermoelectric are inefficient. But that’s the whole point of this research. To improve it.

It seems like they achieve a CoP of 1.3-6.8 (depending on heat transfer load) versus e.g. - CoP of 2-4 which is common for a household refrigerator. So we are already in similar territory.

The article also references a Samsung refrigerator already in the market using a hybrid system with thermoelectric to achieve higher efficiency. So clearly commercial thermoelectics are already efficient enough to have a role in efficient cooling.

https://news.samsung.com/global/samsung-unveils-new-refriger...

I think the role of the peltier is to allow them to design the compressor to be more efficient in a temperature maintenance mode.. so their peltier is probably not more efficient than the compressor in low heat transfer mode. That’s exactly the mode where the CHESS device is making massive improvements, so clearly it unlocks the potential for a thermoelectric-only refrigerator that’s more efficient than one using a compressor

The article has the CoP numbers for the thermoelectric element used in that Samsung refrigerator as well, if you’re interested.

The abstract of the paper mentions temperature differential of 1.3°C and 2°C - not really inspiring for use in a refrigerator.

Neither the article nor the abstract go out of their way to compare the efficiency of the new system to traditional heat pumps. Makes it kinda hard for a lay person to really assess the situation.