In my Mechanical Engineering design course in the 1980s we considered water pumps and hydroelectric generators. Inefficiencies get you though as well as having available incline and volume in the necessary locations.

The US and Canadian power plants at Niagara Falls both use huge reservoirs to buffer demand; they even feature reversible generators.

Other viable storage schemes (at various scales and levels of maturity):

Compressed/insulated air bladders deep underwater

Liquid-electrode batteries (no solid electrodes to wear out; scalable to enormous size using storage tanks)

Flywheels

Molten salts

Hydrogen that can be stored and burned to run electrical generators.

Just did a google search and there is a wind to hydrogen project.

https://www.nrel.gov/hydrogen/wind-to-hydrogen.html

So that's why this is so concerning. Cheap electricity is great; electricity that's negatively priced too long means the utilities don't have the cash to maintain vital grid infrastructure or enough employees to repair downed lines.

Why do we need to keep rates artificially high just so shareholders can get a dividend? The public can own their utilities just as it owns the military. Okay — not every municipality or region. But a good many.

It’s a new world. The need for corporate growth via stockholders seems so antiquated and counter- productive now.

We've let far too many vitally important segments of society be dictated by the free market and it's constant quest for greater profits.

With utilities charging a provider fee...

Cheaper solar panels and Power Walls would erode the customer base and force the utilities to jack up prices on the remaining customers, driving more people to go off-grid, etc, etc.

Just like how people cutting the cord for Netflix and streaming services today is eroding cable's profit margins.