Yep. Tesla energy storage has proven to beat the cost of intra-day peaker plants in some cases. As Tesla grows in scale and battery costs come down, their addressable market will grow in a virtuous cycle. Hard to predict where the limit is.There are 1,264 operating peaker plants in the US according to this report:
Peaker Plant Map - Clean Energy Group
In areas that have more power from variable sources, typically wind and solar, the need for some typwe of buffer is even more important than it otherwise is. The normal distribution of peaker plants is highest where power peaks are most correlated with time of day or coupled with seasonal differences too. basically that means everywhere. At the present time some form of energy storage is increasingly popular to compensate for variable sources, but now is becoming more popular to supplement peakers.
There are three major motivations for. using storage to offset peakers.
First, time and expense to build a peaker are both much higher than they are for storage;
Second, battery storage is instantly available, thus eliminating the time lag of minutes or hours to activate a peaker.
Third, battery storage operation is essentially free to operate and cheap to maintain while all other peaker from are expensive to run and maintain.
An ancillary reason is that battery storage allows crowing about being a 'Green' utility.
I don’t expect battery storage to be the best solution for seasonal timescale energy storage. But who knows. We’re just getting started.