Hanging from a power line could recharge a
batteries, using the “standing waves” generated by power flowing through the lines.
One of the first “robots” was designed to motor down a hallway and look for electric outlets. When it found one, it would plug in and recharge. That was all it did, but in its day it was pretty cool. It used a lot of energy, so it had to journey from outlet to outlet as it were.
This idea seems like a natural, and likely will become an app that is useful in a lot of drone designs.