"The overall energy efficiency of this process is pretty low, the amount of new electrical capacity needed would be huge.

14 Megawatt/hr per ton of AlO2 converted to Al metal.

US gasoline consumption is about 1 billion tons/year

So you need 2.5 Gton Al/yr, which works out to 3.5 billion Mwh. One big nuclear plant produces 8 million Mwh/year, so you need to build 500 full-size nuclear plants."

Well, the US has about 100 nuclear plants and hasn't built new one in decades, so build more nuclear power plants.
The US electrical demand is about 20% supplied by Nuclear energy, whereas the with the French, about 80% of their electrical power is provided by nuclear. If we provided 80% of our electrical power from Nuclear power plants we would close to providing the total amount of energy needed- just from nuclear energy. If instead we just had about 50% of our electrical power provided by nuclear energy and reduced our gasoline consumption by 50% within the next couple of decades, we would not need to import oil- except perhaps from Canada and/or Mexico.