Electronics > Power/Renewable Energy/EV's

Powering drones with a laser beam, infinite air time?

<< < (3/3)


--- Quote from: Siwastaja on January 30, 2023, 03:47:21 pm ---
--- Quote from: mikerj on January 30, 2023, 03:09:33 pm ---
--- Quote from: Siwastaja on January 21, 2023, 03:55:04 pm ---
--- Quote from: jonpaul on January 12, 2023, 10:15:01 am ---Efficiency 0.00001%

--- End quote ---

Quite pessimistic. Given that consumer grade laser diodes are ~30% efficient and solar cells ~20% efficient, and specialized products (like solar cells working at narrow wavelength) are much better than this.

--- End quote ---

And the losses though absorption and scattering caused by gas molecules and aerosols, atmospheric turbulence, thermal blooming etc?

--- End quote ---

We all know that during good weather, loss of light in typical drone distances is some single-digit percents, maybe just barely double-digit. Otherwise we could not see the drone properly, it would appear darker or fuzzy. If you can see it, you totally can power it.

I don't know enough to say what happens when you significantly exceed the power density of sunlight (1000W/m^2), i.e., thermal blooming. Does it become non-negligible at 10kW/m^2? 100kW/m^2? 1MW/m^2?

During colossally bad weather, the problem with absorption and scattering in water droplets is obvious. On the other hand, it is not set in stone that a drone that can only fly during good weather is useless.

--- End quote ---

The effects of thermal blooming vary greatly with wind speed, aerosols and distance; the cleaner the air, the faster the wind and the closer the target the less the effect.  Above a few km it's less of a problem, but for a ground based power source it could be pretty significant.

As an example of the kind of efficiencies you could get have a look at this paper: https://jwcn-eurasipjournals.springeropen.com/articles/10.1186/s13638-020-01874-3


[0] Message Index

[*] Previous page

There was an error while thanking
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod