So it is impossible until it is possible? Gotta prove it physically instead of engineering a system that is known to work. > Also the world is about 82% fossil

So it is impossible until it is possible? Gotta prove it physically instead of engineering a system that is known to work. > Also the world is about 82% fossil and biofuel. Primary energy usage, so an utterly irrelevant metric. With a completely electrified society, the primary energy use decreases heavily. As we all know, heat engines throw away 65-80% of the incoming energy as heat leading to that number.