Centralized power storage is appropriate for some scenarios, DEcentralized storage for another.
Consider this: You have a 50MW power plant with 30MW avg demand and 45MW peak demand but the growth is where your grid isn't up to demand. Depending on how much backhaul is involved, it could be cheaper to put several MWhr of batteries out in the grid. Charge them when demand is low and feed the local sub-grids during peak hours.
Alternately, you could have a 50MW power plant with 30MW avg demand but 55MW peak demand on a grid that can handle it. You can either add more generation or centralized batteries.
In both cases, it's a cost effectiveness decision.
Having said that, $13k for 10kWhr is pretty pricy. If you're willing to go with AGM batteries, you can get 10kWhr kit for $7k (google "full house backup battery"). This is only price effective if they're actually providing ~17KW batteries so you only discharge them 60% to give them several decades of total life.