First, if you haven't seen "Who Killed the Electric Car" yet, go watch it. Even if they don't agree with the assertions made by either side, it's a good educational flick about what electric cars are (and aren't), and how they're part of automotive history.
The current energy solution to our dependence on oil is Hydrogen -- or so they say. Just look at the Hydrogen Fuel Cell Vehicle that the current administration is promoting. Its only byproduct: pure water.
Ironically, the whole "Hydrogen Fuel Cell" (HFC) Vehicle concept is bunk.
A Hydrogen Fuel Cell is VERY inefficient until it's "heated up" (much like a traditional gas ICE). Not only that, it's VERY inefficient outside a relatively narrow "RPM window" (for lack of a better phrase).
The ideal solution for HFC is to have an HFC that runs at a consistent output level and charges a battery pack. The battery pack then powers an electric engine and turns the wheels -- THAT would be more efficient (even taking in the inefficiencies of power conversion and storage).
Don't even ask about how much energy is WASTED producing Hydrogen to begin with. Trust me, you don't wanna know. (More important may be that you aren't being told that aspect, so we'll save that for another article.)
So, with hydrogen being so inefficient to produce, HFCs being so inefficient to use, and the complete lack of a hydrogen "filling station" infrastructure, why even consider hydrogen as a solution at all?
Wouldn't a better solution be to have a PURE electric vehicle with a large enough electric motor/generator to drive the car at "highway speeds," and a large enough battery pack to accommodate the average daily commute, AND allow you to plug it in to the grid to recharge, BUT offer an e85/gasoline or diesel/bio-diesel engine which runs at an optimal RPM to supply charge to the batteries (and be completely disconnected from the drive train)?
You'd have the ICE there "just in case" or for long hauls, but typically you'd just be running of the charge obtained from the grid.