Does anyone know how to get hydrogen from water?

Question

couldn't you run your house with it?could you hook the feul cell up to the generator and get electricity to heat your home and power your lights?

Answer 1

You can separate hydrogen out of water using electrolysis.  

Yes, you could do all of that stuff with it, but you would be defeating the purpose -- It takes more energy to use electolysis to separate the Hydrogen out of water, than you get back out of the Hydrogen when you use it.  That is why hydrogen fuel cell technology is not currently used for practically everything.  Until we find a pracitcal source of Hydrogen, this whole technology is just a pipe dream.

EDIT: Leo is incorrect; centralizing hydrogen production will not make the problem go away.  When elemental hydrogen is used for energy, it is combined with oxygen to produce water, which releases energy.  Electrolysis is the current best way for us to isolate elemental hydrogen, and it is exactly the reverse process... energy is applied to water to isolate the hydrogen.  They are exact opposite processes - if there was an infinitely large centralized electrolysis plant that operated at perfect efficiency, we would use exactly the same amount of energy to isolate the hydrogen as we could get back out of the hydrogen when we use it in a perfectly efficient engine.  Of course that ideal state could never happen, in real life there are always going to be losses on both ends:  no electrolysis plant can work at 100% efficiency, and no hydrogen fuel cell or engine can capture 100% of the energy from the hydrogen.

Answer 2

hydrogen is an excellent fuel and the other answers are correct that making hydrogen is the issue because of the energy required.  But what everybody misses is that large scale centralized production is always more efficient.  the same is true for battery operated vehicles.  although we have to burn coal to make the electricity to charge the batteries there could well be a reduction in the net carbon emissions.    

Answer 3

If we could split it, it would be widely implemented right now, unless the method for splitting it was ridiculously expensive like Hydrogen Fuel Cars.