Cosmic Thinker, I like your name, but no, this cannot be. FIrst, large black holes (solar mass or bigger) have a very low (black hole thermodynamic) temperature and they emit less energy than a firefly on the Fourth. Also, if they did somehow, we'd observe such a huge amount of energy. But most diabolical is this. Bear in mind that energy is conserved, so the radiation gained is at the cost of the mass lost. It turns out your insights are good, the radiation pressure pushes a little more (cosmologically speaking) than inert black holes, but you still lose. Remember, you need some new kind of energy or field (or theory of gravity), and radiation jusy won't do :(