While extracting hydrogen out of petrochemical is quite stupid (there is no benefit for the enviroment),
That's not entirely true, Fuel cells have at least the potential to be more efficient than internal combustion engines because the reaction that takes place is controlled. Combustion implies a large amount of inefficiency. Also, the hydrocarbons would be processed at one facility rather than being burned all over our cities in the cars, so there'd be opportunity to apply more involved pollution reduction measures to the process (they still don't have a clue what to do with the carbon dioxide though).
I believe that you have ommited the easiest way to obtain Hydrogen, water hydrolisis, just apply electricity to water and start collecting hydrogen from one pole.
That's not at all reasonable. Think about it, you start with water, you divide it into its component parts, hydrogen and oxygen, then you take the hydrogen and oxidize it, releasing energy, and you're back to water! Did something magic happen? No. Here's what the equations look like:
Electrolysis:
2 H2O + Energy => 2 H2 + O2
Oxidation:
2 H2 + O2 => 2 H2O + Energy
The energy in the electrolysis was came from the electricity applied to the water, and because of the law of conservation of energy, you will never get more energy out than you put in. In fact, because no reaction is 100% efficient (chemists call it the difference between theoretical and experimental yields) you'll always get *less* energy out than what you started with! So in reality, if you're using electrolysis, the hydrogen is a battery, you can use it to store energy, but it's not an energy source itself.
That's not the case with hydrocarbons because the bonds in the hydrocarbons take less energy to break than the bonds in water, so you break those bonds to get hydrogen, then oxidize the hydrogen to get water, you'll end up with more energy than you started with. It may be a little hard to see why that is true. Think of it this way, in high school physics you learned that a rock on a hill has potential energy, that energy can be realized by rolling it down the hill. With electrolysis, the rock is at the bottom of the hill, you have to roll the rock all the way up the hill before you can roll it down. With hydrocarbons, the rock starts off part-way up the hill, so you only have to roll it up the rest of the way, but then you get the energy from the rock rolling all the way down.
Ultimately, fuel cells may result in a marginal increase in fuel efficiency. I really thing Bush and others are playing them up to try to sell the public on the fantasy that technology will save us from our energy problems. It won't. If we are to get ourselves out of this mess, we need to change the way we live. Which is where planners come in.
