Hydrogen is not a power source - it has to be generated by cracking water...with extremely large amounts of heat, or with electricity. So we need the high-capacity power plants either way (nuclear to generate the extreme heat for that method, or just any significant power output for the electrolysis method).
Just to be clear (and I'm not saying that you erred), hydrogen
is the power source for fusion. The question involved is whether the power required for isolating the correct isotopes, generating and maintaining ignition temps/pressures plus conversion losses are less than the rate at which can be energy obtained from fusion of whatever amount of hydrogen we can fuse at a time (on average).
Unless of course we uncover some cheap source of ready to burn or nearly ready to burn hydrogen.
Edited by NoNukes, : No reason given.
Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846)
I have never met a man so ignorant that I couldn't learn something from him. Galileo Galilei
If there is no struggle, there is no progress. Those who profess to favor freedom, and deprecate agitation, are men who want crops without plowing up the ground, they want rain without thunder and lightning. Frederick Douglass
™ Version 4.2