If there's a blackout, and your car is flat, how do you get to work?
I'm not talking about hybrid cars that still contain a petrol or diesel engine - I'm talking about cars that purely run on battery.
At present, we have energy diversity - power at home from electricity (generated from multiple sources), hot water from gas and transport from diesel, petrol or LPG. But if we move to electric cars, we put most of our eggs in one basket.
I'm thinking of putting an inverter in my car so that when we have our next power failure, I can use the car as a generator and keep things like the fridge and freezer running. Whilst we have a very, very reliable power grid, it does not have 100% uptime. 99.99% still means a reasonable amount of downtime per year.