how much power do you need to crack water for extracting hydrogen?

Question

Is it posible to use photovoltaic cells to generate enough power to extract hydrogen? how much power is used in terms of wattage does it take and how do you capture and store the element after you have got it to bubble out???

Can you use AC Voltage?

Answer 1

You got to be a little careful here. When it bubbles out the hydrogen is bubbling out at the negative electrode and the positive electrode is bubbling out oxygen. So, you can capture the hydrogen in an inverted test tube. This is not a problem if you are only doing a little bit. But if you did a larger amount, watch out for an explosion! The hydrogen is flammable, and the oxygen makes it very flammable.

One thing you might think about is that it take as much (well, it takes more actually) electricity going in to the water to make it split than you are going to get back when you burn the hydrogen as fuel. So this only works as a way to produce fuel if you are getting the electricity for free!

Another thing is, that it is not so much the voltage of the electricity that you need to split the water, as the amount of electricity - that is, how many electrons - you need. Since Hydrogen atoms are very light, you need a LOT of electrons to produce a small mass of Hydrogen.

Answer 2

Matt's comments are right and his safety notice is to be taken seriously. (Nearly blew up my bathroom as a kid). The techonology works. You want to keep the voltages within safe levels and want to safely handle the gas. The amount of electricity required to create the gas is more than the energy you get out of burning the gas. This is why we are not up to our armpits in H2 cars. We would burn more oil making the electricity to make the hydrogen then we would use just making the oil into gasoline and putting it in our tank.

Answer 3

very little at STP from the standard emf is 1.23V

a solar cell will work , try it with a 1.5V D battery

Answer 4

I would like to know too....!!