[arghwhat]

> Even if I only get a combined total of 100W

Quoting Wikipedia:

> The typical efficiency of TEGs is around 5–8%

To get 100W out at 5% efficiency, you'd need to put 2kW in, 1.9kW of which has to be moved away to keep the cold side cold with perfect cooling.

Realistically speaking, the cooling will not be that efficient, and will probably cost you a bit more energy. I'd ballpark that to 2.5kW lost total for 100W of charging.

That's pretty significant.