Before you build a thing, it has not been built yet. To have that thing, you have to build it first. Having built it, you then have it. No breakthroughs of any

Before you build a thing, it has not been built yet. To have that thing, you have to build it first. Having built it, you then have it. No breakthroughs of any kind are needed for grid-scale storage. It is just civil engineering. It won't be batteries. Nukes have never, at any time or place, anywhere in the world, operated without massive public subsidy. There is no reason to expect that ever to change.