Keep in mind that 600TWh/year is likely a capacity of at least double that. But the peak rate is only under worst case scenarios like a sustained heat waves.

Keep in mind that 600TWh/year is likely a capacity of at least double that. But the peak rate is only under worst case scenarios like a sustained heat waves. Unfortunately that high peak capacity is very expensive and goes unused for the majority of the year. Electric cars consume quite a bit of power, but the longer range cars like the Audi, Jaguar, Tesla, top of the line leaf, and bolt all have a 200 mile or so range. So under normal use (somewhere around 12,000 miles a year) they don't need charged every day. So generally cars can charge off peak, but in times of dire need I can see only allowing cars to charge when there's a surplus of power... strangely enough these surpluses are becoming common because of solar. Sometimes utilities even have to pay to get rid of the power.