I said several time in this discussion that waste heat sources are typically ~600C with flow rates of ~80-100kg/s. Do the math and that's about 100MW of energy in a stack. Off the shelf Organic Rankine Cycle engines can convert heat energy at that temperature at about 20% efficiency.

Of course that varies by ambient temperature and pressure, but not significantly for the purposes of this discussion. A good rule of thumb is that for a given delta-T, current OTC tech can get you about half of Carnot efficiency at the optimal spot on the cost-efficiency curve.

I wouldn't know how to fix a laptop if you offered me a yacht to do it. What I asked about was not waste heat to power tech, but fusion power economics, which I know nothing about.

You don't seem nice.