Electric cars will take ~30 years to transition (~10 years before almost all new cars are electric, and then another 20 years before the old cars are off the road). They will increase electrical demand by 20% over 30 years, or under 1% a year increase to demand.

The US increases its generating capacity by about 4% per year. (50GW added per year, 1.3TW total).

EV's are a very small part of demand increase.