Roughly speaking, 7-8 million new cars are bought every year in the US. Likely even more as people dump giant gas guzzlers, new and used alike, en masse for Electric Vehicles (EV) or plug-in hybrid-electric vehicles (PHEV) which will draw their power from the residential grid, typically around 10kWh for an average 30-mile round-trip commute.

10kWh isn't a whole lot. A car with a simple 15A 120V plug would recharge in 6 hours. 240V 30A would recharge that in less than 90 minutes, and could recharge a 300-mile battery overnight. I don't see this being a terrible strain for most houses.

The problem is that within 10 years, there is a potential for 50-100 million EV/PHEV on the street, each adding 10kWh of load to the grid every day. Now, proponents have said "that's OK, look at all the excess capacity we have a night, we'll just use that!" but the truth is that time of day (TOD) metering is only in a very small number of areas, and everybody else is just going to plug in their car simultanously as soon as they get home, which will double the demand on residential electrical distribution in the early afternoon when AC demand is still near peak, and power generation and distribution are all about maxed out...

Thoughts?