DoE study says US could switch 73% of cars to electric without another plant

This assumes all the cars are charged at night. The grid is heavily taxed during the day.

Check out http://www.caiso.com/outlook/SystemStatus.html on a hot day (A/C load has a huge impact on system demand), and this article might look a little optimistic.

Ironically, SCE is in the CAISO, not NEPOOL (i.e. Maine, where the reporter lives.), control area.