I would just add that most people don't understand the concept of source of energy and the medium (energy storage) to transport it.
Our problem is the source. Hydrogen isn't the source it is the medium.
Natural gas or oil or coal isn't the source. It is stored sun energy from millions years ago. Super-capacitor or battery is not the source. It is the medium.
No matter how you look at it most of the energy we use today came at some point from the Sun. Wind or wave energy is transformed sun energy etc.
In long term we, as humans, will depend on the Sun and perhaps nuclear energy. Our problem is overpopulation. I just read somewhere that by 2010 two thirds of people ever born on this planet will be alive. If you want to see what overpopulation does to a country go to India or some countries in Africa. Been there.