story
Nonetheless, storage is ready, and even in profit driven grids like Texas' ERCOT:
> Citing lower costs and increased renewables, momentum continued in the growth of battery energy storage systems in 2021, roughly doubling with 1,262 MW online, compared to 640 MW in 2020. ... with the next two largest systems in Texas, namely the 102-MW Gambit Battery Energy Storage Park and the 100-MW North Fork Battery Storage Project.
https://www.spglobal.com/marketintelligence/en/news-insights...
If you want week long batteries, you'll first have to show the need for that, but something like that won't be built until it is needed: enough cheap solar and wind on the grid.
With how slow utilities are to adopt cheap new technologies, that will be a while. But cost-optimization strategies for carbon free grids tend to select a lot of excess solar and wind capacity, and almost no nuclear at all. Though I would say that those models are flawed in that they assume that nuclear can be built, when the last decades have shown that it can not really be built.