PV Gap

Tracey Said:

Suggest how you would use the electricity from solar cells to produce a clean, nonpoluting fuel.?

We Answered:

Use the electricity to separate the hydrogen and oxygen ,from water, by electrolysis, and then burn the hydrogen to produce only H2O

Phyllis Said:

What will be greatest source of energy in the next few hundred years? Solar energy? Hydrogen fuel cells?

We Answered:

If you mean greatest source as in overall production then solar shall be your answer hands down. If you mean, greatest in the sense of coming from one place as a power plant, then one should answer fusion. And we should not discount used vegetable oil diesel vehicles. The smell of cooking french fries on the highway is one generations to come shall savior..he..he.

Ruben Said:

besides batteries or solar cells or fuel cells, or generators what else is there that can produce high voltage

We Answered:

You CAN produce electricity directly from a nuclear fission source, see:
http://en.wikipedia.org/wiki/Atomic_batt…

Jorge Said:

fuel cells and solar cells?

We Answered:

Primary and secondary cells, by definition, are electrochemical cells.

And solar cells are photovoltaic, while fuel cells are, um well, fuel cells. A solar cell get it's source of energy from the sun, an unlimited resource, while a fuel cell gets energy from fuel intake.

So both should not be classified under either of the two categories above.

But then if you want to know if fuel cells have reversible electrochemical reactions, then most have not (hence the need for intake of more fuel) so they can be considered primary. Although, some fuel cells are "reversible fuel cells" so they might be considered secondary, but according to this:
http://en.wikipedia.org/wiki/Reversible_…
they are inefficient as such.

Marcia Said:

Difference between solar cells and fuel cells?

We Answered:

Solar cells convert light into electricity.
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Fuel cells convert hydrogen into electricity. Except there's another step; there is no source of free hydrogen for fuel cells, so hydrogen must be 'made' by using electricity to separate hydrogen from water.
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This means that fuel cells are not a source of energy - rather they are a means of reclaiming stored energy, much like a battery.
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This is a principal difference. The solar cell provides essentially free energy. The fuel cell does not.