Yes I definitely agree to this fact. I also suspect it could even be something more than electric cars. By the way the world is going now, there is a high possibility that there can be inventions that can produce enormous amount of energy with less efforts.
For example, NASA has been working on a concept called Mercury Vortox Engine to take space travel to the next level. If they end up successful, the propulsion system will have a great breakthrough. Similar breakthroughs can even happen in our regular transportation syustem as well.