I believe "pumped water" is the currently available battery technology that has the capacities required, but I'm under the impression that it can't scale further (new dams / loss of green space)
Moreover, you need an absolute MASSIVE amount of storage to make intermittent sources like solar and wind equivalent to baseload power.
In winter months, solar in New York will produce less than 5% what the same facility will produce in the summer. Shorter days, lower sun, snow, leaves, clouds... all contribute to this.
One cloudy winter and the entire state would be without power - for weeks. It would be catastrophic.
The size of the water reservoir needed to replace plants like Indian Point plant don't exist on the East coast. You would need to flood absolutely massive areas of land.
Nuclear isn't an option. It's a necessity.
From the numbers I’ve seen, on rooftop systems, output is 2x in the 6 best months versus the 6 worst months:
https://www.lighthousesolarny.com/blog/2017/february/the-sea...
But some of this summer production increase is by design: summer power is worth more on the grid, so you over-design to capture more sun in summer (steeper angles, ignorance of winter shadowing, reduced focus on winter cleaning/maintenance) at the cost of winter production.
If you were building an off-grid system, the summer/winter discrepancy would be smaller. You might even overbuild for winter production at the cost of summer production.
I've generally seen pumped-hydro quoted as 80% efficient.
Such projects could scale to a large enough size to solve the intermittency problem.