But, do you think we could just burn the fuel source from which the hydrogen came. OH NO! Can’t do thet, that would create evil carbon dioxide.
That's the case with any energy storage and transportation medium (which is what hydrogen, gasoline, electricity, etc., are). It's all about moving energy from its source (solar, primarily, through lifting of water, creation of fossil fuels, wind generation...) to the place where it can be put to work. Efficiency will never be 100 percent.