Likely from the magnetic field from the conductor. They even have street lights that are powered this way. https://livrepository.liverpool.ac.uk/3005516/1/TPEL

Likely from the magnetic field from the conductor. They even have street lights that are powered this way. https://livrepository.liverpool.ac.uk/3005516/1/TPEL2436702%20Sheng.pdf https://livrepository.liverpool.ac.uk/3005516/1/TPEL2436702%... https://www.youtube.com/watch?v=KqbIhZO7SJc https://www.youtube.com/watch?v=KqbIhZO7SJc