We need every approach that's viable. Batteries are part of the solution, and will be in future. But I don't see why we we should assume they're better in every way than this approach

We need anything that scales quickly, safely, and cheap. Just getting us through the duck curve would be a tremendous win for energy. https://en.wikipedia.org/wiki/Duck_curve

> What we need is a storage technology with a duration of months

Actually, having expandable, highly re-usable tech like this is much better when the capacities are in terms of hours.

This storage, combined with say 2.5x solar panel installation, could essentially provide power at 1x day and night.

A few hours are sometimes enough to start generators when renewable energy supply decreases. Obviously, the more capacity the better, but costs will increase linearly with capacity in most cases.

Pumped-storage hydroelectricity - where it is feasible - is the only kind of energy storage close to "months".

Had heard a lot about flow batteries few years back. I am guessing they are slowly taking off as well, the trial and error that explains their feasibility , need and ability to pay for themselves in a market like ERCOT is the key.

This is one place where I think by 2030 a clear no of options will be established.

I don't understand. Why is a duration of months preferable? What is the benefit above storing energy beyond say peak-to-peak? I suppose you can flatten out seasonal variation, but that's not nearly as big of a problem.