Now, you could lay both conductors in parallel and only need to build the power line half-way around the moon, probably save some dough on prospecting for and constructing pylon sites that way. Alternatively, you could run a single conductor all the way around. Doing that, you could establish a lunar scale magnetic field, though it'd probably be pretty wimpy unless you ran serious kA (MA?) of current, which would mean much bigger conductors etc, but it's fun to think about. Heck, with a loop that big, you'd probably get significant induction from the solar magnetic field .. which might be something to harness, or might just be a headache for your line operators.
Or a stator in orbit? But hrm… for Mars the same idea needs only 1T to 1.5T stator but has to place xt at lagrange between Mars and Sun. So, I naively guess for the stator to be far enough away that the deflected solar wind merges after the moon could /reall/ mean that the stator would be at lagrange between Earth and Sun, which could have perhaps interesting effects on Earth.
Would heat pumps work on the moon?
Where can I book a Starship flight for $1M?
But even at $100m/launch, a big fat copper wire (IIRC aluminium is better per unit mass) would still make more sense than shipping up a nuclear reactor or a huge pile of batteries, and that part of this hypothetical mission would still be about 80% cheaper than the JWST.
Starship is supposed to be cheaper, the moon is definitely more expensive.
I wonder, how hard is it to make aluminium from the oxide if you're bootstrapping and in a vacuum? I know the normal process is "melt it with added cryolites and apply current for electrolysis", but if the goal is low mass rather than good energy efficiency, can you do it a different way? Like, what happens if you focus sunlight and just melt it, does the oxygen bubble out in a vacuum, or is this just going to do vapor deposition of sapphire on all nearby surfaces?
That would bump that number up to ~$10m/$20m or so. Still ridiculously cheap and not likely to be anywhere close to the price charged as it would absolutely sink the rest of the market, which SpaceX is not interested in doing.
One can see pretty quickly that any larger constructions far from earth would really benefit from maximum use of local materials.
If you sent it at 1000V, the I²R losses to send 1000A over that cable outweigh the transmitted power by 600 to 1 and your cable is burning 200kW per kilometre. Which in a vacuum would probably just melt it in fairly short order.
Which is why the bigger HVDC links get, the higher the voltage: there's a 1MV+ system in China that sends 12GW over 3000km.
Also I'm not sure how lunar regolith will work with regards to the "earth" return path so you might well actually need two wires.