I'm sitting here listening to Elon Musk laying out his plans from 2023 onwards, and I must say I am in awe: They have outlined a completely doable route to a fully sustainable future, and leave no stone unturned when it comes to increases of efficiency, by for instance having teams that combine design, manufacturing, software and other areas to produce Tesla's as efficiently as possible. Being so highly integrated and doing everything themselves, they can produce their cars far more efficiently.
Being a Tesla fan is a decidedly different view on reality. As an engineer, I think of it as an awesome dream, even though they are reducing their dependency on the human work force. Still I can see how their path can get us to a society that resembles the Star Trek reality.