Someone smarter than me can probably answer this hypothetical: If scaled up, would this device become a heat pump? Extracting energy from the electromagnetic field via the Casimir effect would seem to transform random field fluctuations (i.e. "heat") in the environment into the movement of electrons down a conductor. If those electrons are sent away to do work elsewhere, to my mind that's a transfer of heat from one place to another. Moving 0.5W of heat isn't very interesting, but I wonder if there's a scaling up that would let you move meaningful amounts of heat around in this manner while generating electricity as a "bonus".

The market for moving heat around is pretty enormous.