[pjc50]

Look, bare hydrogen from electrolysis is not magic and not that useful. Hydrogen is a pain to store.

What it is useful for is as input to the Sabatier reaction, where it can be combined with CO2 (if you can extract it from the atmosphere without expending too much energy) to produce methane. Which can be stored or turned futher into gasoline, jet fuel, etc.

Or you could just use free Canadian propane: http://www.argusmedia.com/pages/NewsBody.aspx?id=1041736&men... or any of the natural gas being flared at the moment because it's too cheap.