Err, not necessarily... at that point, it's decoupled, and can come from any source, which can be changed at any time. And your whole argument was about conveni

Err, not necessarily... at that point, it's decoupled, and can come from any source, which can be changed at any time. And your whole argument was about convenience, but now you seem to be darting to a tangential argument. Once the car fleet is fuel-agnostic, it becomes much easier to shift into whatever clean power source ends up working well, or whatever mix of clean and dirty works well. In terms of dirtiness, it's not hard to make the average impact of a car on the environment better... I think even pure coal might be cleaner with these things due to efficiency gains. In any case, I don't particularly care if their solar proposal ends up panning out overall - it's more or less irrelevant to the feasibility of the plan, other than for PR and making the people who implement them look good.