I'm not like a drone-i-ologist or nothin, but from what I gather, both sides have gotten really good at detecting and jamming drone communication in the Ukraine/Russia conflict, which would probably make that a tough use case. I've read that the newer attack drones are controlled by a reaaallly long, reaaalllyy thin fiber optic line!

as soon as it sends RF it'll be located and destroyed.

There has been lots of work to make fibre connected drones, so that they can't be located as easily (also the pilot)

The problem is signal jamming which forced using fiber.

So the limit isnt batteries, its fiber spools.

The radio links and navigation are the hard parts.

Discussed april/may 2024

"'Vampire drone' can leech electricity from power lines to live forever" https://news.ycombinator.com/item?id=40317484

"Autonomous Overhead Powerline Recharging for Uninterrupted Drone Operations" https://news.ycombinator.com/item?id=39945733

The prototype in the linked video was first tested back in 2023, and since then a few startups have set their sights on the technology (e.g. Nomadic Drones and Voltair). When working on the linked prototype we ran into some fundamental issues. Firstly, the recharging will only work with AC lines, and there's currently a lot of hype around UHVDC lines which are not compatible. Secondly, the AC lines must carry substantial current (ideally thousands of amps) for the recharging to not take forever. You can of course carry a much larger transformer on the drone to compensate, but this will in turn severely limit your flight time (ours was 1kg on a drone of 4.5kg and we could charge with 50W from 300A line current). You also have to account for significant daily fluctuations in the line current. It'll be interesting to see how the tech evolves, and I'll definitely be following these startups closely.

I'd assume otherwise you have to have a way for the drones to meter their usage and pay the power company. It will likely make power theft easier, but it seems entirely viable to have an account with the power company where you report "I drew X joules from line Y" and for them to bill appropriately.

Presumably they'd be doing inspections for the power company, who probably don't care if some minuscule amounts of power are consumed directly during operations.

Liability is probably the biggest issue, rather than using the energy. If it causes damage because it fails to connect properly, or if it has a trailing wire to pick up other phases (not actually connect to it but to pick up induction)

There is a not so subtle hint in the description that they were mainly inspired by military applications (Air Force, DARPA). Legality doesn’t matter when you’re in enemy territory.

The drones heavier than 250g already must transmit remote id

You can install electric fencing beneath high voltage transmission lines and it will be energized for ‘free’.

Coupling falls off rapidly with distance. It's why a thick enough phone case will interfere with magnetic charging, and that's only on the scale of a few millimeters.

Drones consume a lot of power while in flight. You can get a little bit of power out of powerlines standing underneath them with some tricks, but it's not enough to keep a drone in flight. At least not without something prohibitively large to couple to the line.

It's also risky to hover near a stationary object because the longer you hover, the more you're exposed to the risk of a wind gust knocking you into the nearby obstacle.

iirc efficiency loss in wireless energy transmission is exponential? someone correct me. But basically after just a few mm the losses are so great that the amount of electricity needed becomes ridiculously wasteful.

to power a running drone at more than a few inches would be just...a lot.

That was my thought as well...I suppose there may be something I am not thinking of. Perhaps they get more total energy if they "perch" on the tower.

When I was a kid, we had a neighbor who had somehow wrapped some wire around the power lines enough times to siphon off an interesting amount of power. I never saw the wire myself, so it might not have actually happened. But people certainly talked about doing it way back when.

The proposed initial use case is use as inspection drones for the power company themselves.

We have done automated utility inspections for the past few years. Computer vision is not a problem any more. When we were starting we had to annotate thousands of images. Today some use cases require less than a 100. More interesting problems are pre-field planning, sagging, or BLOS compliance

We do semi-automated analysis of imagery of things like utility right-of-ways and it's pretty scalable. We triage the vast majority of images automatically and then surface a small subset to human experts to review, but it's much, much faster than having the experts be in the field, while having high coverage. (Most images are really boring.)

And in most cases of inspection, you need to look at the stuff anyway, so any cost reduction is very welcome. And if you do increase the total coverage volume while reducing human time, you get a double benefit of being able to provide more granular information, either in time or in space, which can often be useful.

(And as a commenter below notes - this all works pretty well with several year old CNNs. We use a limited amount of image-LLM stuff to surface things zero-shot, but a lot of what we end up doing is a very conventional classifier with a lot of engineering work to make it very fast for the experts to see only the important things.)

> And we have 20x the manpower to review this footage?

I was involved with a startup that did inspections of power generation windmills. The computer vision anomaly detection was really good and that was about five years ago. The goal was to have the automated visual inspections route images with suspected anomalies to humans for review and it was working well the last time I heard.

Compared to having a human who needs to rappel down to the blades for a manual inspection, this is a huge productivity and safety boost.

Why would humans be reviewing footage?

I've worked on similar systems for oil & gas that combined hyperspectral imaging and LIDAR. The analysis of data collected by drones was fully automated. It was at least as effective as humans at detecting anomalies (something which was thoroughly verified prior to adoption).

The more thorough coverage, potential issues being detected much earlier, and increased automation greatly reduced the total manpower required. Humans only came into the picture when the drones found a problem that needed mitigation. Humans have long been the bottleneck for finding operational risks and issues before they turn into a headline. The more humans you can remove from that loop the bigger the win.

This was years ago, the tech has only improved.

Gosh I hope my house isn't inspection coverage

Maybe it'll lead the US burying their power lines

This is built especially with the military thought as the primary client.

I mean, they'd also fix fire detection as well.

It’s just a technology that can be used for both civilian and military applications, not only by private entities.

That might be why the first customers are utilities themselves.

> Power utilities are the perfect first customer.

Sounds like having contracts with the power companies is their #1 goal.

Lol, yes. I came here to say, "This technology has been around for years in birds. /s"

Balisor[1] usually uses capacitive coupling, but it require a long parallel cable.

Some lamps do use induction, like this one[2].

I guess it uses induction looking at the drone, it also works with an open coil.

[1]: https://en.wikipedia.org/wiki/Balisor

[2]: https://www.delta-box.com/en/marking/bht-marking-light-for-h...

I would guess that its just a coil thats near the cable. however I can't imagine its actually that much power, as the field isn't that strong.

_but_ at 33kv, you start to get corona discharge, which gives you a potential difference, so that might be the mechanism they get power.

(thats a wild guess. )

Edit I did some more digging, induction appears to be magnetic induction, long cables do produce a magnetic field, but not that much (unless you put it in a coil)

Capacitive coupling is much more effective at high voltage.

It can be a closed circuit when using AC instead of DC.

Remember that the primary and secondary side of transformers never touch.

Induction

Goes back a long way:

https://commons.wikimedia.org/wiki/File:Nikola_Tesla_holding...

> The bulb is a prototype "fluorescent" light he invented consisting of a partially evacuated glass bulb with a single metal electrode. Nearby, probably behind the curtain, there is one of his Tesla coil high voltage oscillators which produces a radio frequency electric field. The electric field ionizes the gas in the bulb, causing it to glow similar to a neon light. This photo is a 2 second time exposure taken by the light of the bulb

https://collidecolludecollaborate.wordpress.com/2016/01/12/f...

https://www.bbc.co.uk/programmes/p00l1slw < although its not available at the moment

Yes. That should be done along hiking and biking trails under power lines. There's one in Silicon Valley along the bay shore line. The fluorescent tubes don't wear out; the filaments at the end are not in use. Just slip them inside polycarbonate tubes.