Ah, good point. I hadn't considered that. It looks like you are correct! You might sandwich two Seebeck-Peltier devices and switch between them, though. https:

Ah, good point. I hadn't considered that. It looks like you are correct! You might sandwich two Seebeck-Peltier devices and switch between them, though. https://en.wikipedia.org/wiki/Thermoelectric_effect https://en.wikipedia.org/wiki/Thermoelectric_effect