Earlier quoted context omitted.
I've come across a few in the past, these 18 inch giant-ass "desktop replacement" / gamer things that had insanely large power bricks. Been a few years but I think they all had desktop GPU chips from NV. But I think it's not possible to do any more, not with any high-power card that is... the RTX 5090 has a TDP of 600-ish watts, you can neither get in that kind of power into a laptop, even at 24 volt that's still 25…
That's not the case. A 5060 has a 145W TDP, which is borderline feasible. A 5090 is 575W, which is approaching furnace territory.
Resistive heat is really crappy, a 7-8kW heat pump could replace the hypothetical 24kW furnace.
1Wh = 3.412141633 BTU/hr