Yeah, but what is really needed is to get utilities to do the storage, but on smaller scales. Ideally, they utilities would do storage AND GRID SEPARATION. The small grids should be around 100 MW, with the storage able to do say, 15-120 minutes. Now to many, the separation sounds foolish, however, with this, it enables a utility to make faster changes to the super grids, while the storage allows for utilities to not only deal with AE, but also to better handle the variables demand. Interestingly, you mentioned a number of these that have been going on for a LONG TIME.
BUT, one that is new and really gaining traction are the flow batteries. These are built to a certain size (i.e. a maximum amps that it can deliver) combined with a reserve of liquid (which is the total kWHs). One that I like is the EOS Energy which uses zinc (dirt cheap and plentiful). They are charging less than what a nat gas plant costs and have around 75% efficiency. As such, they are around .12-.17 / kWh, and is dropping quickly. Right now, the national average is .13 / kWh, so, this will only get better.