The problem with hydrogen-fuled cars

[space toker]

I heard that water could be used to manufacture hydrogen.
So let me get this straight. You can derive the hydrogen from water, then it also makes water as the waste product? So couldn't you collect that water and maybe even have something built into the car that converts the waste water back to hydrogen?
I am no physicist so I don't know if this is possible or not. Maybe in the near term you could just collect the water exhaust if it can't be converted back to hydrogen onboard.

[Coelho]

I heard that water could be used to manufacture hydrogen.
So let me get this straight. You can derive the hydrogen from water, then it also makes water as the waste product?

Yes, its exactly this.

So couldn't you collect that water and maybe even have something built into the car that converts the waste water back to hydrogen?

Well... its possible, but its not useful. This cars burn hydrogen to get the energy that makes it move, like the usual cars get their energy from burning gasoline.
This process of burning generates water, that can indeed be used to make hydrogen again. But it needs energy to be done. The energy that the hydrogen generates when burnt comes from the energy you must give to the water to turn it into hydrogen.
So, we can say that hydrogen is just a thing that stores the energy given to water during its decomposition (to transform it in hydrogen), and releases it when its burnt.

[MadSativa]

The very first cars were fueld on Alcohol and bio fuels. The only reason the big switch happend was cause of alcohol prohibition. Bunch of Smart people came up with that fix??

[kieffster]

there have been a few ppl that have made an engine that converts water to hho gas than burns it than just pipes the exhost back into the gastank thats filled with water. its really not all tht hard as long as u can get the water to condense quickly and i dnt think tht would be very hard on a cold day