Electronics > Power/Renewable Energy/EV's

Powering drones with a laser beam, infinite air time?

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charles.ouweland:
According to this article: https://www.scmp.com/news/china/science/article/3205885/chinese-scientists-develop-laser-powered-drone-stay-aloft-forever they have developed a drone that can be powered by a laser beam and can stay in the air forever.

According to the article, no data were released about the efficiency of this application. It aims at military applications, so I guess the energy efficiency is not the first of their concerns.

It reminds me of the solutions for wireless charging of mobile phones at a distance. They have to closely track the position of the drone to be able to direct the beam exactly at the drone. Hmm... interesting

jonpaul:
laser strong enough to power a flying drone will have 100s watts, useful as a weapon.  Power supply and dériver will occupe à truck.

Rain or for or clouds will block it

Efficiency 0.00001%

j

Stray Electron:
   Unless your aircraft is just a very tiny unmanned model aircraft it would require kilowatts, or ten kilowatts, or hundreds kilowatts of laser power at the receiving end to power it. Not only would the laser transmitters require 10x or more power, but there is also no photocells in existence that could convert that much laser power into electricity.  And Lasers of MUCH less power are already a hazard to aircraft and larger lasers would also also be a hazard to satellites and space craft.  And you'd also have to be concerned about lasers reflecting from clouds and aircraft and affecting people back on the ground.

   This whole idea is a non-starter from the git-go.

   In the 1960s they were flouting the same idea but using microwaves instead.  AFIK that idea never went anywhere either.

   Aircraft that have an infinite flight time are already in existence and are already being flown. They use solar cells during the daylight hours to power their engines, and to charge batteries to that they can continue to fly even during darkness.  And let's not forget those old fashioned things called balloons!

Stray Electron:
  Speaking from first hand experience,  lasers of even tens of watts of output power have a very bad tendency to burn up their mirrors, lens and windows. Even the tiniest speck of dust or any imperfection becomes a hot spot in the lens that in turn gathers MORE energy and the cycle grows until the lens is destroyed. That process operated literally at the speed of light so it only takes nanoseconds to occur.  The mirrors, windows and lens used for very high power lasers are effectively one shot items and certainly couldn't be used to continuously supply large amounts of energy to an aircraft for hours on end.

  There is a HUGE difference between being able to transmit very short, megawatt level laser pulses and being able to continuous transmit even tens of watts of power.

AlbertL:

--- Quote from: Stray Electron on January 12, 2023, 03:57:03 pm ---   In the 1960s they were flouting the same idea but using microwaves instead.  AFIK that idea never went anywhere either.

--- End quote ---

See: "History and Status of Beamed Power Technology and Applications at 2.45 Gigahertz"
https://ntrs.nasa.gov/api/citations/19900000834/downloads/19900000834.pdf

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