PV Gap

Joe Said:

Fuel cells Hydrogen consumption rate.?

We Answered:

The amount of energy generated during formation of water from H2 and separation of water into H2 would be the same provided the reaction is reversible.
Also, the efficiency for the two reactions may be different (due to technological problems) because of which the actual available energy as work may be different. Probably because of this consideration it is more economical to run the car using a fuel cell instead of directly running it on the electricity.

As for the 2nd question: a fuel cell producing its own fuel would not be possible. The theoretical maximum efficiency of the system cannot be 100% (2nd Law of Thermodynamics). Thus, after each cycle there would be a loss of energy which would eventually lead to zero available energy in the system.

Wade Said:

Hydrogen Fuel Cell...?

We Answered:

I'm going to focus on "If I am converting the water into energy, wouldn't I be able to extract more electricity then the stand alone solar array?"

In order to split water to gain H2 gas, we need electric to split Hs with O. So, if you are speaking of making electricity out of H2O, I don't think it's efficient. However, I know that electricity from solar panels can be stored in H2 form by splitting water.

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Theoretically speaking, yes, you can use the stored solar energy to generate hydrogen gas but as for any chemical reaction, there are always loss of energy by heat or imperfect reactions. So, it won't be as efficient. Also, running an alternator also involves friction and more heat. Might be better to conserve while lasting cloudy days are expected.

Storing energy in H2 form is not much different than making H2 gas for energy. Same electrolysis is required from H2O. The electricity from solar is going to split the water to O2 and H2. H2 can be stored in pressured gas tank. Chemically speaking...

H2O + energy (from solar electric) ? H2 + O2

So, the stored H2 and O2 from air can combine again to form H2O, which is reverse action of the above. When H2O forms, it also generates energy. But it won't be electric but more of heat energy. Heat energy can be collected to chamber and heat up water. Heated water generates pressure that could turn a turbine that could generate electricity. Or houses can use fuel cell to generate power.