Wow, this got long. TL;DR summary: Our sun isn't massive enough to go supernova, it's silly to think anything could make the earth "go nova", and hydrogen is not terribly useful as a power source unless we can figure out how to control and sustain fusion.
OK, here goes. Memories from my Astronomy class, all too long ago:
Our sun is not large enough to go supernova, where by "large" I mean "massive". The physical size of a star is a matter of fluid equilibrium, and is largely irrelevant to its eventual ability to go supernova. As a star ages and consumes its hydrogen, it will begin to fuse heavier and heavier elements. Stars of our size get up to around carbon before dying. More massive stars get up into the metals: iron and beyond.
An aging star will eventually exhaust all available fuel (where by "exhaust" I mean "convert into elements so heavy that they won't fuse at the energies produced by a star of a given mass"). When this happens, the star will collapse. If the star was sufficiently massive in life, its core will compress down to a neutron star, which the outer gaseous layers rebound off of. Fueled by this rebound (and super-heated by their rapid collapse), these layers explode violently outward. That's a supernova.
A yellow star like our sun will never go nova. Rather than collapsing inward and then violently exploding, our star will expand and cool until it's roughly the size of the orbit of Mars. The expanding star will eventually reach a point where the outward force of radiation and other pressures is greater than the force of gravity. When this happens, the star will gently (well, gently compared to a supernova) give off its outer layers into an ever-expanding cloud, leaving behind a white-hot carbon core that cannot sustain fusion of any sort; this is a white dwarf. White dwarfs are doomed either to slowly cool or accrete enough matter from other sources to go nova themselves.
The idea that anything at all could make the Earth "go nova" is ludicrous. Sorry, but there's no other way to say it. It just doesn't make any sense. The largest thermonuclear explosion ever created on the surface of the Earth (the 50 megaton Russian Tsar Bomba) did some crazy stuff like blow out windows hundreds of miles away (atmospheric focusing of pressure waves), and it registered on seismic instruments around the world. But destroy the entire world? Not a chance.
Lastly, the idea that we should burn hydrogen in power plants is misguided at best. You can't mine hydrogen, nor can you find a way to produce it that uses less energy than you put in (that would be a violation of the laws of thermodynamics). The only potential use for hydrogen in a power plant context is fusion, which is, by all reports, 30-50 years away if it ever happens at all.
Somewhat ironically, the best way to produce hydrogen for transportation fuel (also not the best idea, for efficiency, energy density, and infrastructure reasons) is lots of nuclear power.