How does splitting water to produce hydrogen using solar, wind, wave, nuclear or biomass to generate the electricity to do it use more hydrocarbon energy than the hydrogen can deliver?
It certainly uses more energy than you get out, otherwise the old entropy rules get broken, and you'd get perpetual motion, which would be nice... but the energy doesn't have to be hydrocarbon energy, certainly.
Funny to read the article by Sir Richard Branson. I read something similar recently, may have been an in flight mag, or Fortune or something - in which SRB was saying that he didn't intend to use ethanol in the aircraft, but increasing use of ethanol (in cars, trains, ships, buses etc etc) would eke out remaining supplies of oil so that current aircraft could go on a lot longer.