Usually, just turning down some fossil fuel plant is a better option.

Using the electricity via demand response comes after that.

A long wire to somewhere else that can use it and send you back some of their excess is next.

If you really can't use that power for anything lithium batteries are cost efficient as long as you regularly cycle them (e.g. daily solar peaks).

So you need to get into storing power for long periods of time before they have a niche. Which is on its way, but isn't here yet. So building more renewables makes more sense. (Do enough of that and eventually you'll want some more storage options).