You definitely need HV. At 100kV and 10A, the lost power if you send 1MW is around 60kW: a fairly serviceable 6% or 20W/km. However, your losses at a fixed voltage scale quadratically with your power draw: you'd lose 24% of 2MW.
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.
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.