[ben_w]

I'm less optimistic about the current state of affairs than the person you're conversing with, but I think more than you.

The LCOE values I've seen place batteries+PV at ~ nuclear… but nuclear is more expensive than almost anything else.

I anticipate further reductions in the price of batteries from the learning curve and demand driven by electric cars where they're already cheap enough to replace ICEs, such that the cost of batteries for electricity time-shifting will be OK fairly soon (as in: 5-10 years)but that's a forecast and not a guarantee.

There's also the possibility of a global power grid — the maths works out just fine, few hundred billion USD and a year or two of global aluminium production, we have to spend more than that on upgrading the last (hundred) miles even if we never build the global interconnects — but basically only China has both the interest and the capabilities to attempt something like that as part of a future belt-and-road initiative, everyone else will definitely not get past the "talking about it" stage.

[XorNot]

I mean that to me seems like the obvious answer if we're doing solar: don't really do storage, just wrap the generating capacity around the Earth and have it follow the sun.

Nation-states would likely still retain strategic reserves of thermal powerplants, but they wouldn't be run, and the budgeting for them would be under national defense and interpreted through that lens (i.e. you can buy it down with strategic alliances and diplomacy).

[svnt]

Why wouldn’t the right answer just be don’t grid-tie and switch back to DC for everything. Almost everything gets simpler and cheaper.

[ben_w]

Switching everyone to DC is expensive; for one, we'd have to replace all the AC transformers on the existing grids.