Drones that recharge directly on transmission lines

Original Article ↗ Hacker News Discussion ↗

Technical mechanism & feasibility

  • Commenters agree the drones recharge via induction or capacitive coupling from AC transmission lines, similar in principle to transformers and balisors.
  • Contact with the conductor is not required as a traditional closed circuit; coupling can occur via the surrounding electric/magnetic fields.
  • Some ask whether transformers are needed on-board and worry they’d be heavy; others note existing prototypes used ~1 kg transformers on ~4.5 kg drones.

Efficiency, distance, and power limits

  • Multiple replies emphasize coupling strength falls off rapidly with distance (inverse-square or ~inverse-distance depending on geometry).
  • Hover-charging without perching is seen as effectively unworkable: drones consume ~100–200 W/kg to stay aloft, and inductive energy at safe hover distances is too low.
  • Perching on the line (with insulated “feet”) both minimizes flight power consumption and maximizes coupling.
  • A prototype experience shared: works only on AC, needs very high current (hundreds to thousands of amps), and daily load variation makes available power inconsistent. UHVDC lines are incompatible.

Legal status, billing, and “theft”

  • Several comments frame unsanctioned charging as electricity theft, noting explicit illegality in some countries.
  • Others point out unmetered “trust-based” loads (streetlights, pole-mounted gear, irrigation) are already common via contractual estimation.
  • Proposed business models:
    • Utilities as primary customers, where consumed power is negligible or contractually handled.
    • The drone company as intermediary billing party, with DRM-like controls on charging.
    • Utilities owning the charging hardware on drones, treating it like a meter.

Safety, liability, and wildfire risk

  • Liability is widely seen as a major concern: misconnection, arcing, or damage to lines could trigger outages or wildfires, especially in places like California.
  • Some argue that if utilities accept drones perching on energized conductors, they might instead prefer fixed charging platforms on towers, reducing guidance risk.

Autonomous inspection, data volume & analysis

  • Some are uneasy about “removing battery swaps” as the last step to truly autonomous, always-available drones, raising fears of ubiquitous overhead surveillance.
  • Skeptics question whether 20x more inspection coverage just creates unreviewable data and whether this is “solving the problem in the wrong direction.”
  • Others with field experience counter that computer vision for infrastructure inspection (power, wind, oil & gas) already works well:
    • Most imagery is auto-triaged; only suspected anomalies reach humans.
    • This reduces field labor, increases safety, and allows more frequent, granular monitoring.

Military and conflict uses

  • The company’s Air Force/DARPA background and marketing language trigger concern that long-endurance, self-charging drones are dual-use and likely to be weaponized or used for surveillance.
  • Hypothetical wartime use cases (e.g., Ukraine): small drones perching deep in enemy territory to gather data while recharging on power lines.
  • Counterpoints emphasize practical barriers: signal jamming, RF location and destruction, the shift to fiber-tethered drones, and navigation without GPS (inertial systems, vision-based navigation) being nontrivial in current battlefield practice.

Misuse, hobbyists & “stealth” energy tapping

  • Several worry this “normalizes” power siphoning: hobbyists or bad actors might copy the technique to steal small amounts of energy.
  • Others note longstanding low-yield attempts to couple power from HV lines (e.g., loops under 600 kV for a water pump) and suggest the real-world returns are modest.

Deployment model, talent, and alternatives

  • Some see this as a solution in search of a problem, arguing:
    • If utilities accept automated perching on HV lines, they could instead mount conventional chargers on towers.
    • Removing the final humans from operations often has steep diminishing returns; fully-robotic systems can be less economical than human-assisted automation.
  • Questions are raised about maintenance intervals, overall system reliability, and whether a fully in-person, San Francisco–based team is the best way to attract niche inspection/robotics talent.
  • Alternatives mentioned: solar-powered drones that hide on roofs between hops, or other autonomous charging schemes (vehicle-like overhead rods, etc.).

Cultural references and humor

  • Multiple threads riff on the “birds aren’t real” meme, pointing out that birds already “perch and recharge” on power lines.
  • Historical demonstrations and art installations are cited (Tesla’s wireless-lighting photos; fluorescent tubes glowing under HV lines; “Field” and similar works) as precursors illustrating how much ambient energy exists near transmission infrastructure.