We have lots of variable production (wind and solar) and those peaks don't line up with peak load (generation peaks in the morning and peak load is noon-8pm). So utility scale batteries to capture the morning excess and discharge in the afternoon makes perfect sense.
Unfortunately it these batteries are unable to multiple gigawatts over many hours of excess wind energy. It will be at least a decade before the battery energy storage systems are close to big enough to absorb the oversupply of wind energy that happens a few times a week.
Don't get me wrong. The BESS helps with frequency, synchronization and voltage issues. They just do very little to flatten the wind spikes without turning off 10-20% of the wind fleet.
