The "Water Fueled Car"

[Nystul]

But the benefit of this technology, is that you could use electricity to seperate water into Hydrogen and Oxygen. Electricity can (Key word being 'Can') potentially be produced in more environmentally friendly ways then burning fossil fuels. (See - geothermal, solar, hydroelectric (despite all of its flaws), tidal, nuclear).

This isn't a magical energy pancea, but if more of our electricity is produced from non-polluting processes, then this will produce less pollution in the long run. Oh, and it'll reduce our reliance on oil.

That's a big if though. For it to reduce our consumption of fossil fuels in a given location, all of the non-peak power in that location would have to come from something other than burning fossil fuels. Otherwise, you might actually be burning more instead of less, to make up for the lost efficiency. In most heavily populated areas that don't have some giant dam, I don't think this can be a reality unless there is a nuclear power plant involved.

Otherwise, the environmental benefit is a matter of emissions control. It's not that you are actually burning less fuels, but that you hope to contain the emissions at a power plant much more effectively than you could on thousands of individual automobiles which have very limited cost, weight, and size contraints.