It is common knowledge that small compressors are much less efficienct than large ones, leaving thermoelectric coolers as the technology of choice for small-scale applications. Then again, maybe not.
Compressors are a moving target and we are seeing more and more small compressors, like the ones described in the attached report from Fabricio C Possamai, an R&D engineer at Embraco, one of the world’s major compressor manufacturers.
This particular Embraco compressor is small, delivers 60 W of cooling and is not much less efficient than large compressors. Might be worth keeping an eye on this technology, even if it isn’t exactly thermoelectric.