Cal ISO this month announced it would begin to integrate energy storage devices like batteries and flywheels into the grid. Grist
Living on a farm, I am well acquainted with the value of running a laptop computer on batteries instead of a desktop machine off the grid. The battery does a nice job of preserving my work when the power goes out.
I am not very confident that positive experience with battery energy storage scales the overall grid. I wonder if the concept would work better if the state encouraged people to run their entertainment devices off a battery that is charged from a solar panel instead of attempting to incorporate solar energy into the power grid.