[tliltocatl]

Based on what I could find:

They generate the RF on the surface and transmit it down the borehole thru a waveguide, so it's only limited by arching in the waveguide. Since we only need power transfer and don't care about multimode propagation, the waveguide diameter isn't limited, and probably on the larger side to reduce copper losses. And the heat management is provided by blowing argon which also carries abalated rock particulate to the surface.

See the schematics here: the schematic here: https://www.thinkgeoenergy.com/wp-content/uploads/2021/03/mi...