So apparently this is the “small device eliminates need for AC” that I see advertised everywhere! </s>

But in all seriousness, it seems this converts ambient heat (not a heat differential) directly into electricity. Therefore it must necessarily cool its surroundings by the equivalent energy extracted?

So it’s a kind of air conditioner which doesn’t use electricity to move heat but rather converts heat directly to electricity? I thought we “knew” this was impossible...