There are limits to battery production, especially on short time frames. If your expecting every nation to try and deal with storing days of electricity production to cover for a rainy week your going to run out of easily accessed raw materials such as lithium.

You need either reliable generation, absurd quantities of undersea cables, or scalable storage. The only practical storage tech we’ve seen is hydro, and there are limited places to flood in order to construct built massive resivors, and it has far worse timelines and costs than nuclear, so that means on demand generation.

In this category we have nuclear, and location dependent options like hydro and geothermal. All of these are about as expensive, but output constant or at will power.

If you let the market decide, it’s going to do what its already decided to do, which is cheap solar plus cheap gas and coal. If you ban gas and coal, then it will be cheap solar and batteries for nations that can afford them and all gas and coal for the poorer nations that can’t afford the batteries.

Leave the batteries for applications like transport and smaller grids that need them instead of brute forcing them into places where they don’t fit like long term grid storage.

Finally, though this is the most minor, nuclear is by far the winner in local environmental impact, as it lacks the land use and habitat distruction requirements of solar, wind, and hydro. It’s also location agnostic, and unlike batteries gets cheaper and faster as it scales.