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...

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