Energy storage doesn’t just have to be chemical reservoirs like that. Since most residential loads are thermal (heating and cooling of air and water), there’s quite a potential to make improvements there. Other loads are often “deferrable” or advancable.

When electricity is cheap, run the fridge/freezer extra hard, make ice or ultra-heat the water tank. Or “pre-charge” the building extra hot or cool but within level of comfort.

When it’s expensive, maybe slow down the dryer/dish|clothes washing or defer it for some hours. Same for any charging. At the end of the day, I don’t care if my stuff is washed+dry in 50 or 500 minutes most of the time.