> Hydrogen cannot be better than hydrocarbons, because the efficiency of the cycle can reach very close values for both, while storage tanks and associated devices are much smaller and cheaper for hydrocarbons.

So, where do you get the carbon from? Atmospheric capture? That blows the "easier" claim right out of the water. Biomass? Not practical on the very large scale needed.

Efficiency of conversion in combined cycle plants is around 60%.