Infrastructure that's used how often per year? A dozen times? Rail lines that get a dozen trains per day tend to not get electrified...
As I've stated elsewhere, I expect a future with drone swarms that carry a power line while feeding from it. Certainly not cheap (high performance cables are never cheap, think hundreds of meters of supercharger cable?), but it would be a near-universal base technology for many application fields so it would have all the possibility a technology might need to start in some an niche and grow from there.
So many problems with cable-fed drones over farm-sized distances: (1) Cables rapidly exceed the vehicle weight; (2) keeping cables off the ground requires extreme tension beyond the forces capable by the drone; and (3) aerial drones are very sensitive to thrust-to-weight. You'd effectively need a swarm of drones just to lift the cable...
A swarm of drones to lift the cable is exactly what I meant: basically a cable with a set of thrust motors spliced in every n length units that can be coordinated to make the cable levitate. The total length of the cable is kind of irrelevant, it all boils down to how much cable (length and transmission capacity) you can levitate per dollar, and per watt.
I dunno - it's a thought I hadn't seen put out there and you're 100% against it within minutes. The field ain't going anywhere - why not have permanent solar-powered infrastructure to recharge robotic agricultural enthusiasts?
The commenter who stated he works for John Deere put out the same thought here, but like the parent expressed that diesel would have to become a lot more expensive for the infrastructure costs to pencil out.
