The 4 cent/kWh figure is the additional cost it would have to charge, over the life of the plant, to make up for the budget overage, and would go on top of whatever ratepayers would have to pay for its "regular" energy output.
Further pedantry: you'd have to factor in time value, so that kind of understates it, as the entity that built it would have had to borrow that much more to finish, and pay back with interest.
My point is that while 4 cents per kWh for 50 years is a very big number in terms of cost overruns and the taxpayers in Georgia will have to eat it, I as a California resident, somehow pay through the nose despite abundant and cheap solar energy, especially during the daytime.
https://www.energy.gov/ne/articles/whats-lifespan-nuclear-re...
It seems that in Quebec (see the other reply with 6 cents per kWh all included), moving electrons through a copper wire is much-much cheaper. Something is very wrong with the PG&E costs.
For comparison: I live in SF Bay Area and pay 42 cents per kWh.