I'd agree that utilities ought to handle most of the energy storage problem, if only to realize economies of scale. But, two points: 1. Battery backup for home

I'd agree that utilities ought to handle most of the energy storage problem, if only to realize economies of scale. But, two points: 1. Battery backup for homes could actually be a huge market. If you're looking at two homes, one is $500,000 and the other is $503,500 and outage-proof, which one would you buy? It's a nice feature at a relatively small price. 2. At the launch event Musk stressed the benefits of grid independence for the 3rd world. He drew an analogy with cell phones, where cell phone proliferation basically leapfrogged and obsoleted landline deployment. So in places where there is poor or no electrical grid they might jump straight to solar and batteries. (I don't know if he actually expects the 3rd world to be a significant customer base, but that's what he said.)