[CurlyDave]

It should necessarily also serve as a heat sink with possible cooling usages as well as an electrical source. My question is how efficient is it? Is its efficiency greater than current thermocouples/thermopiles, recognizing the possible advantage of a greatly decreased size for such devices?

Of course you are right, and I even once bought a small Peltier effect ice chest at Costco. It was expensive and did not cool particularly well compared to a bag of ice. But, salable consumer products do exist.

[amorphous]

Peltier

That's the name I was trying to remember. Lol The problem with these devices and all thermoelectric generation is its poor efficiency. If this device is an improvement, it may have great possibilities; even for powering spacecraft.