Harvesting electricity from high-voltage transmission lines using fences
High‑voltage transmission lines can induce enough energy in nearby metal structures, such as fences or coils, to power small devices, prompting interest in “wireless” power harvesting from the grid. Commenters debate whether intentionally capturing this energy constitutes electricity theft or harmless use of waste fields, noting that even tiny loads measurably increase transmission losses and have led to prosecutions in some countries. Safety and health concerns are also raised, from fire risks due to improvised collectors to long‑standing questions about living near strong electromagnetic fields.
Legality and “theft”
- Many argue this is legally “abstracting electricity” (a form of theft in several jurisdictions), even without physical contact, because power is drawn from the grid via induction/capacitance.
- Examples are cited of people being prosecuted or sued (e.g., a Finnish cottage, a French employee near a line, a Canadian case), though details are second‑hand.
- Others note ambiguous or narrow statutes (e.g., requiring a conductor), suggesting induction may or may not be covered depending on jurisdiction.
- Several distinguish legality from enforcement: it can be technically illegal yet too trivial to prosecute, unless public bragging or precedent forces a utility to act.
- Some frame it as a contract issue between landowner and utility (easement/right‑of‑way terms), not necessarily a criminal matter.
Physics and energy impact
- Strong emphasis that this is not “free overspill”: the fence or antenna modifies the near field, increases load, and forces extra generation.
- Near‑field coupling is contrasted with far‑field radio reception; the former clearly affects the source.
- Some push back that the harvested power is minuscule compared to line losses and environmental coupling (ground, trees), but others respond that any deliberate load increases losses.
Safety concerns
- Multiple posts stress fire and damage risks: a current‑transformer‑like collector can create very high voltages on open circuit or huge currents during faults, potentially starting fires or destroying connected electronics.
- This safety argument is seen as a major reason utilities strongly discourage such setups.
Health and environmental effects
- Power‑line EM fields are compared to Earth’s magnetic field and sunlight; consensus in the thread leans toward fields being relatively small and likely safe, though old leukaemia correlations are mentioned as unresolved.
- A brief question is raised about effects on implants, but no concrete answer is given.
Scale and practicality
- Calculations from the video suggest tens of joules and sub‑watt power levels; this is far from being able to power a house.
- Some mention exam‑style problems and old stories of farmers powering barns, but these are treated skeptically unless coils are very close to the lines.
Analogies, ethics, and enforcement
- Analogies used: grapes in a supermarket, rain‑barrel water collection, sprinklers, overhead shafts in factories, data copying.
- Common view: it can be theft in principle, but in this specific DIY example the amount is extremely small; debate centers on proportionality of punishment and the danger of over‑zealous rule enforcement.
Related side topics
- Discussion touches on:
- Art installations lighting fluorescent tubes under lines.
- Using EM fields for “electrofarming.”
- Grid monitoring and network‑frequency fingerprints used in forensic timing of recordings.