Are Hydrogen cars the future of motoring?

Also, while hydrogen has great energy per weight numbers, its energy per volume numbers are mediocre at best, even if you pressurize the crap out of it or liquify it (liquid hydrogen has about 30% the energy per volume of gasoline, and that's as high as it goes). The fact that producing useful work from said stored hydrogen in combustion engines or fuel cells has further inefficiencies just makes it worse. Gasoline mainly gets around the inherent inefficiencies in chemical energy storage by having insanely high energy density in the first place.

(Note that electricity has to be produced somewhere, which will have inefficiencies due to those pesky laws of thermodynamics- electric cars running on fossil fuel or renewable electricity have that inefficiency "baked in" at the source of electricity, and aren't forced to lose much more to store it or convert it into mechanical work with an electric motor).

If you really wanted to be silly with chemical energy storage, you could run a chain of CO 2 + H 2 O + energy -> gasoline + oxygen like such:

• Split water into hydrogen and oxygen using your favorite method. Store the oxygen somewhere, you might want it later.
• Use carbon dioxide and hydrogen to produce synthesis gas (a mixture of hydrogen and carbon monoxide) using the water gas shift reaction and then use the Fischer-Tropsch process to turn that into liquid hydrocarbons.

The energy for doing this can come from any renewable source of energy that you like, but I suspect it won't be very efficient as an energy storage method.

Might work as a portable one. Or one where we need actual combustion as opposed to simple energy generation.