But there are so many more fundamental problems with the high altitude Venusian colony idea that you would never get to the "temperature gradients > power" pipeline implementation in any case.
I mean right off the bat, imagine building or navigating anything in hurricane Katrina. Then, since we're talking 50km, imagine winds that would make the forces you're dealing with an order of magnitude more problematic.
Yeah, in terms of knowledge and technology, mankind is just not there yet to be perfectly frank.