Which would be a problem when everyone gets an electric car and every night the owners will request 20 kW for up to 8 hours (hence sustained, not peak). For a condo that could easily be half a megawatt.
That is an unreasonable number. That is 160 kwh of power which is double the largest model 3 battery. This would require everyone to drive nearly 600 miles a day at highway speed. Roughly nine hours of driving a day at 75miles an hour.
The expectation is that people drive 30ish miles a day. This is about 11kwh. Over 8 hours a night, well within reasonable limits.
I was thinking of 10 kW * 2 cars, but actually even for a single car you need 120 kWh to charge 85 kWh. You're right that it won't happen every night for 8 hours, I was wrong about that.
Problem is that you have to size for the worst case, which may happen only once a year, but it will happen. Everyone coming back after Thanksgiving. Everyone reaching a vacation place on a Sunday evening in the summer. Bam, 20 kW sustained for a few hours.
It takes only a few big condos before you need to bring 400 kV lines downtown...
Although your power requirements are somewhat overblown, this is one reason that companies like EMotorWerks are developing grid-connected EVSE’s (“Chargers”) that can be centrally controlled to manage load. Ultimately, EV’s will be plugged in for the 20+ hours a day that they aren’t being driven, and the grid will use them as a giant variable load to soak up excess solar and wind power and shed load when everyone turns on the A/C on a hot day.
Lots of plugged EV’s are also the perfect pairing to rooftop solar — in Hawaii, they’ve had to stop people from installing panels on their homes because the neighborhood feeder circuits can’t handle the power being generated by all of the homes. Just redirect that power to the EV in the driveway (or your neighbor’s driveway), problem solved!
The expectation is that people drive 30ish miles a day. This is about 11kwh. Over 8 hours a night, well within reasonable limits.