It is another 20 percent power consumption, mostly coming from residential areas at night. - the average nighttime draw from any given residence will go up by 20kwh/8h/220v: 11/22 amps. (one or two cars) The maximum draw (full recharge in 8 hours) from the same residence goes up by 110 amps. This assumes people dont buy speedcharging gear for their homes, which I think is a safe assumption. I certainly do not wish to have electrical equipment able to recharge a 100kwh battery in 30 minutes in my garage. I think the existing grid infrastructure will suffice for this with only minor upgrades, but a lot of residencies are going to need their fuseboxes and bits of their wireing beefed up. Lot of work for electricians.