Please tell me this was a joke. That 13 GW figure is for covering
all of California's 4,000 mile canal system.. Based on the cost of this pilot system, that would cost 2,500X as much: (see:
https://www.tid.org/wp-content/uploads/2022/03/Fact-Sheet_final_updated.pdf)
Furthermore, your calculation takes advantage of the ignorance of the average taxpayer, who doesn't realize that a nuclear plant produces power at a 90-95% capacity factor, whereas solar cells are lucky to reach a 30% CF. Put simply, if a nuclear plant has a 1GW output, it will reliably produce 90% of that figure over a year. A 1 GW solar farm won't produce even a third of that -- except at noon, on a cloudless day. That triples again the solar cost of a direct apples-apples comparison.
But these cost comparisons ignore the real problem with wind and solar, which any power engineer will tell you. Generating the power is only half the problem. Matching the supply to the demand in real time is an equally thorny problem ... and it explains why no nation in the world has come anywhere near generating even half its electricity from these sources. Wind and solar always produce either too little, or too much. Nations like Germany which managed to break a 30% figure only manage to do so by massively increasing their reliance on natural gas turbines, and by selling excess power to neighboring nations less bound to these "green" sources.