It doesn't matter if powerplants are more efficient, they aren't the weak link. The weak link is the electric cars, which are not effecient. Batteries lose too much energy from heat, especially for the cars and trucks that will be operated in cold climates. The waste is in the storage and transmission of the electricity, even within households. All of this waste must be made up with more coal and oil being burned, which means more oil and coal being transported. People have done the math on this, and it doesn't work out well at all. Unless we build more nuclear plants, and figure out a good plan for handling that waste, we will eventually hit a wall.