Who on earth told you that? Hafnium doesn't work - DOE and DOD moved mountains in the nineties trying to get it to work and a number of people lost their careers and sanity in the process. But you go ahead and tell yourself that it's the "fossil-fuel hegemony"

https://en.wikipedia.org/wiki/Hafnium_controversy

(I'm sure you think muon-catalyzed fusion is right around the corner too)