Green H2 is projected to get cheap enough that a combined cycle plant running as a base load source on green hydrogen would be economically superior to a new construction nuclear power plant. Of course, a 100% RE grid needn't operate any hydrogen plant in base load mode, only to fill in gaps not covered by direct use of solar, wind, and batteries. Very little H2 is actually needed to cover dunkelflauten; somewhat more might be useful for seasonal leveling.