The real effort should be directed towards using the our hydro carbon resources more efficiently. We're not going to stop using them anytime soon, but in N. America, for example, we could be more than self sufficient if we did it efficiently, and think of the security bonus.
I've heard that the reciprocating engine that we all use is about 30% efficient. In other words, about 70% of the stored energy in a volume of fuel goes out the tail pipe. If we used the oil and coal to make and store fuel more efficiently and developed the infrastructure accordingly, we'd have something. Make hydrogen, or electricity, or whatever, and then use a more efficient method to change it to noise and motion.