250 MW of constantly available power from a reactor may be more valuable than 600 MW during sunshine that goes to 0 MW during night time.

Solar will become vastly more valuable once enough electrical storage capacity goes online.

And after electrical storage capacity is solved, let's work on heat storage capacity. Do I really have to spend ten grand digging up my yard ?

I think it's more than that actually, but still a great idea if you don't have subway or something under you. I finally met someone in real life that has that set up and it's a bit capital intensive even after the diffing. In about half of US you need a backup heating system for real cold spells.

Like, well, home insulation and heat-exchanging ventilation?

In Scandinavia the summers provide loooong days. When it's sunny, there is SUCH a surplus of heat that could (in principle) be captured for wintertime use.

I wish we would build out nuclear here in CA.

Thankfully we were able to save Diablo. I can't believe how close we came to shutting it down.