Scientists in China have demonstrated a wireless power transmission system that uses a ground-based microwave emitter to beam energy to an antenna array mounted on the aircraft’s underside. Importantly, they were able to do this while both the drone and charging system were in motion.
In tests, the car-mounted system kept fixed-wing drones in the air for up to 3.1 hours at an altitude of 15 metres (49 feet). The key challenge that the team overcame was maintaining alignment between the emitter and the drone during flight, wrote Song Liwei, the project’s leader.
Neat but 3 hours of loitering is nothing for a fixed wing drone. We have drones that stay in flight for a month or more.
The difference is likely size and expense.
Now you don’t need a 100 million dollar Boeing 737 sized drone to loiter for 3 hours.
Previously small and cheap drones could loiter for 40 mins on an internal battery. Now they can stay up for 3 hours. That can be useful.
Of course these mobile wireless recharging stations will become military targets for the opposition. So the overall combat math isn’t obvious to me, but it’s not a tech I see as obviously useless.
This could be much more straightforwardly a win for civilian applications.
I have a 6 year old electric car that takes 40ish minutes to charge, now BYD has batteries that will go from 10% to 70% in 5-10 mins.
In a few years time these drones will be getting charged from a microwave stream of power from a solar array floating in the upper atmosphere.
Yes but you are charging through a conductive cable. It’s not even remotely the same as charging something with microwaves.
The power delivered decreases exponentially with distance. I’m sure you’ve heard the phrase “inverse square law”.
Because you divide the effect and gain by 4pi(r^2) meaning your output is decreased by 75% every time you double the distance.
You’re going to need ridiculously powerful hardware and an enormous amount of electricity to run it on any meaningful distance.
A concentrated, collimated beam doesn’t act like a point source. There’s of course some amount of scattering and absorption loss due to atmospheric particles, but other than that a fully collimated wireless energy transmission doesn’t lose intensity over distance. Kind of obvious, really, because “where would the energy go?”.
The decreased chargng time comes with a massive increase in charging power. The equivalent in ths scenario is to massvely increase the microwave power - which would likely cook the drone.
I prefer my drones cooked in an old fashioned oven, microwaves leave the middle too cold and the outside too hot.
Exactly, proof of concept was all the scientists needed to see.
Solar power is still more practical
not nearly enough surface area to power a drone.
Has already been done
https://www.geeky-gadgets.com/solar-powered-drone-design-2025/
try that with the drone in the article. ain’t gonna work buddy.
That thing is just a dollar panel with the bare minimum amount of motors to hold up the solar panel. That not practical at all for someone that also needs to move quickly and fire munitions
You can have solar panels and batteries on the ground, and use them to charge the microwave emitter, which can then charge the aircraft, which now does not need to carry solar panels and as much batteries, and thus has increased payload / range.
The microwave receiver will not be small or efficient
Oh, ok.
Even though this entire post is… about how it is small enough to fit on a drone, and efficient enough to power it for 3 hours.
Ok.
Gotcha.
I’m not sure if you’re aware of this, but densely packed explosive bombs and missiles and warheads tend to be pretty heavy.
… the entire problem with purely onboard solar powered vehicles of any kind is that they have to be absurdly lightweight, flimsy.
That isn’t practical.
It might be purely efficient, in a sense, but it isn’t very useful.
Being able to actually move stuff, that is practical.
Most transportation modes involve the ability to haul stuff.
You know, do work, aka the capacity to make stuff move.
You picking a fight that makes no sense to pick.
You can have solar and batteries be more stationary, and use microwaves to power things that are more mobile, this post is literally the proof of that concept… you can charge a battery with a any kind of power source.
Look heres another massive potential application of this, if you science fiction extend the accuracy/capability of this:
Plop a bunch of solar panels/batteries in the L1 point between the Earth and the sun.
Now, via a set of satellites in something like concentric orbits, you can get absurd amounts of power, beam it back along chains of satellites, snd then beam it to recieving stations on Earth. Or the Moon. Or orbital infrastructure.
Microwave transmission power loss will be waaaay less in space, because there’s no atmosphere.
Same with solar panel efficiency!
Solar Power + Microwave Transmission = Very Good, Actually.
The only two metrics that matter here are W/m^2 and weight.
You can’t make a reasonable microwave receiver lighter than solar film and efficiency peaks around 50% in FIXED installations and you can easily assume less than a quarter (under 10%) when the target isn’t just moving, but is also changing angles and distance (you’d have to put the receiver on a gimbal like for cameras) and now it’s also interfering with flight (propeller airflow, unless you do weird propeller geometries or tilted body flight
Tldr DUMB
Microwave power transfer only make sense between distant fixed line of sight locations with minimal infrastructure available. On earth that’s literally just island mountain tops. Even then it’s easier and cheaper to still just install solar
On the moon, it would basically just mean you have one big generator and everything gets powered by the sun when in sunlight and switch to microwave from the generator when in shadow, which is pretty much the only configuration that even make sense
https://www.sciencedirect.com/topics/engineering/microwave-power-transmission
That was 8 years ago.
What I’m describing are… currently extremely active areas of research.
You should maybe look into the level of precision that things like Phalanx CIWS systems have at tracking a moving target, with the ability to throw bullets at it, and hit it.
Or basically any SPAAG type platform that throws rounds down range.
Or I dunno, MASERs used in deep space transmission.
Or all the research that has gone into developing tracking gimbal systems that do intentionally use lasers or some kind of DEW to shoot down small drones, or damage aircraft in flight, or burn out incoming missiles.
Hell of a lot easier to track a friendly aircraft.
Genuinely no clue what you are talking about.
Are you assuming only like, quadcopters here?
We’ve had RQ 4 drone aircraft the size of WW2 medium bomber planes, with jet engines, for 20 years now.
I’m fairly sure that a jet engine produces a considerable amount of consistent heat.
Do… you think aircraft engineers… do not know… how to handle… heat?
Shall I describe a ramjet to you?
Or maybe we could go with something like the Space Shuttle’s reentry tiles?
In conclusion, you are vastly uniformed as to the state of… not even state of the art technology, that would be incredibly relevant to this discussion.