The wear and tear on lithium-ion batteries can be significant. It's a big capital cost and every time you cycle it you take a little of its life away. Eventua

The wear and tear on lithium-ion batteries can be significant. It's a big capital cost and every time you cycle it you take a little of its life away. Eventually you have to replace it. And you really need to be using it, because a lithium-ion will still degrade even if its sitting unused on a shelf in a perfect climate-controlled room. Demand shifting seems a much bigger payoff: using your AC to superchill parts of your building overnight (or build up ice packs) when electricity is cheap.