The other advantage of using hydrogen is (in an emergency fuel situation) being able to slowly 'rob' the ballast ballon for fuel for use in either the motive en

The other advantage of using hydrogen is (in an emergency fuel situation) being able to slowly 'rob' the ballast ballon for fuel for use in either the motive engines or an ICE genny if the solar setup failed for some reason or you needed 'hyper-drive tubo-boost' levels of power