The only way hydrogen is a viable fuel source for a vehicle, IMO, is via the fuel cell. The only way to generate enough hydrogen is by consuming a *lot* of electricity, stripping the hydrogen, storing it, then transporting it to fuel stations across the nation.
How to do this? Well, I came up with a plan but no one likes to listen to it. It involves nuclear energy....
We can build much better plants today. Believe it or not, technology has advanced a lot since the last nuclear plant was built in the US. We can build them such that they are safer, easier to manage, and less wasteful.
Besides just generating electricity, there are other benefits to nuclear energy. One is that we can put a hydrogen plant right beside the nuclear plant and while generating electricity, strip off hydrogen to power our cars.
We can also desalinate sea water so everyone has plenty of drinking water, just like us Alaskans do!
"What about all that icky nuclear waste??"
'Less wasteful' in the above statement means we generate a lot less of that icky byproduct called nuclear waste. Let me clarify this. We can 're-burn' the nuclear waste from one plant in a different and special nuclear power plant. It takes nuclear waste that would have to be stored for about 10,000 years and makes it so that it only has to be stored for about 300 years.
http://en.wikipedia.org/wiki/Nuclear_powerMy proposal? Each state in the United States picks areas where they build the following: 1 large nuclear power plant, 1 plant with "fast spectrum reactors" (to burn the reprocessed fuel), a hydrogen generation plant, and for those states bordering an ocean, a desalination plant. Each state should have enough of these "areas" to sustain their own population. If this idea is unpopular, then the US should pick a few very large areas, move people out of them, and build many of these plants in those areas. If you really want, I can show you how this would pay for itself in the long run but mainly, it all boils down (forgive the pun) to cleaning up our act.
We have plenty of energy available that would have very little negative impact on our planet. Hydrogen generated in the method talked about in this thread and used as a fuel additive is not one of those energies. Neither is ethanol but that's another whole topic.
Oh, and burning wood in the right way is less pollutive than running your oil burning boiler.