So how do you come up with a fair price to capture the carbon externality?

And do you add the externalities to green power like solar? More people have died installing solar equipment than all nuclear accidents. Or what about environmental damage during PV manufacturing? Do we add those to the price of solar at the time of sale?

Indeed, it's difficult to exactly price externalities. There are published estimates of the carbon externality. You do you best; it's far better than the "estimate" we currently use ($0).

When comparing, you add in the externalities to everything. To be specific:

- you don't count the deaths in PV installation as its not an externality. The installers are an involved party; they can (for example) ask for higher wages due to risk. (Also, if you wanted to compare this to nuclear, you need to include deaths building those nuclear plants as well. And possibly mining the uranium.)

- you do count the environmental damage during PV manufacturing (and turbine manufacturing, and coal mining, and oil drilling, etc.)

Perhaps a nice benefit of these plants, presumably, is that your operating costs don't change much due to changes in fuel costs (your fuel is free) and these plants ought to be somewhat easier to site / approve than a nuclear plant.

The other benefit to these plants over nuclear is that the time it takes to get them operational is much shorter. This allows for faster iteration time, and therefore more opportunities to improve the technology and reduce costs.