There's some sort of mis-assumption that 20 years from now we'll all still
be driving/cruising around as usual in H2 or whatever powered vehicles ...
my opinion, most of us peasants will be walking.

And this I find interesting ... about 99% of the energy that goes into your
gas tank is used to move the frikken vehicle ... and about 1% is used to
move the driver. How's that for modern day dinosaur ... complete with the
brain to weight ratio :-)

A light weight vehicle would not require "the same horsepower".

A significant paradigm shift is required before even beginning to think
constructively about replacing combustion and carbon energy.


Ergo, it takes lots of gas to create the same horsepower. Where are you
gonna put all that gas in a vehicle? You have to compress it and put it
into some kind of storage tank. Compressing anything takes more energy.
How are you going to create the hydrogen or other gas? You don't just
gather it up. It has to be manufactured, which takes more energy. Some
methods allow you to use passive energy such as solar, but take a long
time
to generate the quantities required to be useful. Other methods require
energy input from... petroleum fuels... to create the "clean" gas. Ack.