Electric cars need less energy than you might think.<p>Using Tesla numbers, 230 miles on 60kwh.  Average person drives 13,000 miles per year which averages out to 9.3kwh per day.  Split that over 12 hours and your looking at ~780watts.<p>Further, if it cost less we would charge cars during the day.<p>PS: Average household uses 31kwh per day.  But, offices are really daytime biased.