Good point about the local temperature delta… I kind of lost sight of that in the discussion. But my understanding of that equation is it would be the maximum theoretical efficiency of any thermal generator as it represents an idealized heat engine.
If you plug the numbers into the Carnot equation, it looks like the maximum theoretical efficiency of a thermoelectric generator or heat engine operating at that temperature gradient is about 0.75%. And, I could be wrong, but my assumption would be any attempt to reclaim that energy would slow its exchange and potentially bottleneck a cooling system to some extent.
I mean the cow probably doesn’t care if you needlessly killed it to throw away the meat or to eat it… both are unnecessary and both result in the same outcome for the cow. Both are also destroying the planet. “Predator/prey” is a great appeal to nature that I am sure many people use to justify themselves lazily shuffling through Walmart to throw frozen burgers into their cart.