It may be calculable, but is it economical? That 8 cents isn't free. If the power company pays, that means customers pay. If customers don't pay, society has to pay. There are other power storage solutions like pumped hydro that don't have to deal with battery chemistry degradation, for example, but they have higher investment costs.

This study is great but a energy storage comparison study that calculates total cost would tell us much more. Wouldn't be surprised if the Department of Energy already has or is [1]

[1] They do a lot of these studies already. i.e. https://iea.blob.core.windows.net/assets/ae17da3d-e8a5-4163-...