Totally agree that it's easier to plan a centralized system over a decentralized one, provided that you adequately fund people to maintain all the components. (

Totally agree that it's easier to plan a centralized system over a decentralized one, provided that you adequately fund people to maintain all the components. (And trim trees!) But have you ever been in a power outage, used your cell phone as a flashlight, and thought, "man, I wish my entire house ran off of a battery like my cell phone?" A home builder already plans for 95% generation adequacy of hot water -- they literally find space in the floor plan for a hot water heater, and decide how big the tank should be. If you run out, either you ration usage or you buy a bigger water tank. If home batteries had the right safety-energy density ratio (admittedly -- hard problem; see the RFS for Energy), you could just include one in the floor plan based on 80%ile usage, like the batteries in laptops, and cell phones, and electric cars. They're just too big and expensive now.