OK, I think I see why we're seeing this differently. The only way this actually saves energy (instead of merely money) is if, later in the future, you would've

OK, I think I see why we're seeing this differently. The only way this actually saves energy (instead of merely money) is if, later in the future, you would've actually wasted the heat that would've be produced if your initial goal had been computation. In that case, yes, it's true that doing the computation now and using it for heat is better. My assumption was that you would be already using any heat you generate from computation for heating regardless, so it didn't make sense to me that, in other situations where your goal is only heating, adding computation to the problem would save any energy. (Sorry this is complicated to explain, I hope it makes sense. Regardless, I get your point.)