A benefit of some of the smaller battery / storage options is they can be placed closer to the source of consumption, reducing losses in a way that massive builds can't always do. 

"This new technology proposal might sound odd in the beginning, but it is brilliant. By stacking colossal cement blocks on top of each other to form a circle around the lifting tower, energy can be used when available and released when needed."

Markus, I first read of a proposal for storing energy by hoisting concrete blocks into the air at least 30 years ago. It generated a flurry of excitement, then disappeared. Like a brood of cicadas it re-emerged from the ground every thirteen years or so, until recently. Now it's more or less an annual event.

It sounds promising until you do the math. Example: a 55-gallon oil drum, when filled with concrete, will weigh roughly .655 metric tonnes. If you hoist it atop another such drum, and do it with perfect efficiency, you will have stored 5,708 joules of potential energy - less than one-third of the energy storage capacity of your cellphone. Not so brilliant, after all.

The last thing we need at this stage of the game is another desperate attempt to justify the intermittency of solar and wind energy - they're losers. For their proponents to take their ball and go home is long overdue.

Markus, A very interesting and timely topic. The GRID has not have good storage options for 100 years but as you show the need is very big to balance the changing loads and demand. You mention QUOTE= long-term storage options. Yet from what I have seen the biggest needs are for fast acting energy exactly when needed. It is usually not long therm.

    So for good Return on Investment and power that matches the needs in nano seconds are Lithium batteries. They can be deployed anyplace, they react in nano seconds and don't take up a lot of room. Today in 2021 they have 10 year warranties and that is getting better with each new version.