@TomScott<br>You say there's no battery that can do this on a national scale, but we don't need to have one. That's like saying there's no Circuit Breaker that can monitor every line in every house on every street in the US... you're right.... there's not, but we don't need one. Simple home-batteries. Rechargeable battery banks in every home to power every home in the event the wind decides to take a break for a couple of minutes, much like your suggesting with the Cars but less like a movable appliance and more like, well, Water Heaters.<br>Or even better, thinking about how British Appliances are sold with fuses in the appliance plug; a battery for every electrical appliance.