Re: What is the most efficient means of electrolysis to produce hydrogen as a useable fuel?

There is an old saying that "There is no such thing as a free lunch." It applies here.

When hydrogen and oxygen combine to form water, they release about 230 kilojoules of energy per mole of hydrogen gas at 298K. To break the water back down into hydrogen and oxygen, it takes the same amount of energy being put back into the water as an electrical current to release one mole of hydrogen gas. There is no way around it.

The efficiency of running the current through the water is high as long as you add a little acid or salt to make the water electrically conductive (truly pure water has a resistance of about 18 megaohm*centimeters versus 1.68 microohm*cm for pure copper). Some control of current density is required at the anode and cathode to prevent excessive bubble formation, but again any reasonably sized electrodes will have approximately the same efficiency.

So, unless and until there is a breakthrough, there are no significantly more efficient ways to perform the electrolysis.