The storage of the exsessive electric energy is a very expensive stand-by equipment endeavour.
A stand-by unit is a stand-by unit, no matter the way it operates.

Let’s explain:
Assuming we have Renewables which are supported with
stand-by conventional units.
And assuming we have Renewables which are supported with
stand-by storage units.

When there is not wind and solar, the conventional units will produce electricity.
But when there is not wind and solar, the storage units will not produce electricity, because they would be empty.

And, when there is a lot of wind and solar, the storage units will not produce electricity, because they would stand-by.
And they will not storage more exsessive electricity, when they are already charged.

If we built more storage units – for all the exsessive green electricity to accumulate – there will be enourmous large stand-by reservoirs.
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