There is, but storage isn't cheap enough yet. Tesla powerwalls are still pretty expensive, at around $8k each, from what I hear. If they can get the cost down

There is, but storage isn't cheap enough yet. Tesla powerwalls are still pretty expensive, at around $8k each, from what I hear. If they can get the cost down by another factor of 5-10, I think you'll see a huge acceleration in adoption and possible arbitrage.