What (if any) effect does temperature have on electrolysis of water?

If you mean: do you get more gas per Amp, the answer is yes.

If you mean: do you get more gas per Joule, the answer is generally no.

Efficiency? No.

Rate? Yes.

Does that mean:

If temp higher current flows faster through cell for fixed voltage?

Meaning, does the eletrolyte's resistance change with temp?

Yes, on both questions.

Erm, I just found this:

http://en.wikipedia.org/wiki/High-temperature_electrolysis

Any comments?

Thanks

Yes. Read the WIKI article very carefully. It sounds for all the world like a press release for sales of that process.

The key is that the high efficiency (they actually quote greater than 100% !!) comes as a result of being able to pick up free thermal energy from the mysteriously available surroundings. Heck, if I could magically find pennies scattered about, I could afford a "free" milling machine.

For those who think I'm an curmudgeonly OF for not liking WIKI, this is why.

This general thread, however, does point out that there is a huge reservoir of wasted heat energy out there that might be available to increase efficiencies of existing processes. That seems a promising path, but is very poorly funded at the moment.

Mmmm... I see what you mean - 135% efficiency. Not a promising sign I agree!

The other link to a US Dept of Env. pdf looks a bit more solid:

http://www1.eere.energy.gov/solar/pdfs/doctor.pdf

Page 4 shows a graph illustrating lower energies with high temps.

From this I conclude there is reasonable savings in overall energy needs if high temps are used.

Initially, when I first started this thread, I was wondered about was: Could waste heat from an IC engine be used in conjection with a high temp cell to generate H2?