There is so much misinformation in here, so densely packed.

Ivanpah is is not the largest solar power plant in California. It's an experimental solar-thermal plant. Talking about megawatts per year is not a meaningful term (megawatt-years would be). Ivanpah despite its much talked about failures delivers between 350 and 850GWh per year.

The largest solar plant in California is Edwards Sandborn, producing somewhere around 2500GWh per year (it's newer so numbers are less published).

Diablo Canyon produces around 18000GWh/year, which is huge.

But with all costs combined, Diablo's price per MWh is close to ONE HUNDRED AND TWENTY DOLLARS off of a massive initial capex. Modern solar battery installs trend towards $30-60 for the same output.

So I'm sure your tour guide had some neat numbers but you should be careful not to repeat them verbatim (or unremembered).