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Renewable Energy for Quads

brym

Junior Member
#1
Hi guys. Recent fan to your show, and I'll be buying my first quad in two weeks; a basic 4 channel, 100 meter range job to get me started. Can't wait! My question/suggestion perhaps for you to test: Would it be feasible to harvest kinetic energy from the propellers to power an on-board laser powered flight system? Maybe even throw some solar cells on top to juice the battery? If I'm way off mark here, it's cool. Just curious.

Thanks!
 

rcspaceflight

creator of virtual planes
#3
I think any kinetic energy produced by the props/motors is actually used by the motor. In a Podcast, Flite Test had a great story about a plane that lost it's battery but was still able to fly in because the motor produced enough electricity to power the Rx and servos. But usually that energy is used to lower the amount of watts actually used by the electric motor. It feeds into it's self.

As far as a solar powered quad, I think it's been done before so it is possible.
 

Tritium

Amateur Extra Class K5TWM
#4
All my aircraft are solar powered. I charge my flight batteries from my household solar panel system.

I am not buying the "Podcast" quip. Don't see how the 3 phase power produced by the motor could translate across the ESC circuitry AND be rectified to DC as well. I would have to see a full schematic of the ESC to be for sure either way but it sounds very fishy! ;)

Thurmond
 
#5
All my aircraft are solar powered. I charge my flight batteries from my household solar panel system.

I am not buying the "Podcast" quip. Don't see how the 3 phase power produced by the motor could translate across the ESC circuitry AND be rectified to DC as well. I would have to see a full schematic of the ESC to be for sure either way but it sounds very fishy! ;)

Thurmond
Nope that ain't happening....perhaps "Magic" brand ESC(s)s. BTW, nothing to do with this thread....wish the best of luck with that laser powered flight thingie.....but its a major pet peeve to hear folk talk about "renewable" energy as if it magically materialized out nowhere. The term "renew" is correct but massively misunderstood. The energy, both potential and kinetic in all its various states and forms in the world....solar system....galaxy....and Al Gore's interweb is the same exact amount of energy present at the "big bang" or creation (whatever you personal belief). There is no NEW source of energy...green or not...simply transitions from one state/form to another by natural or manmade processes. The cow patties out in the pasture next to my place that I can smell wafting in through the window are energy...just in a slightly different form than the one taken in at the other end of the cow.

Think I remember reading in an article the NASA Helios project worked on utilizing windmilling effect of un-powered props to supplement batteries during dark hours. Not sure of the hows or whys but IMHO the drag induced by selectively switching off motors would greatly outweigh any regenerative energy collected. Keep in mind this is a multi-million dollar project involving some pretty "fart smellers".

UAV-Helios-Zephyr.jpg
 

brym

Junior Member
#6
Tritium: NASA, and a company called LaserMotive have both flown aircraft powered by ground based lasers. Not sure of the technicals of it, but LaserMotive managed to keep a quadcopter aloft for over 12 hrs doing this. I was wondering whether or not that could be moved to a platform sitting directly below the quadcopter body, powered by kinetic energy harvesting tools from Arduino or Texas Instruments. I expect not because I don't think it would meet the power requirements for the laser, but curious nonetheless.

See these two videos:
Nasa: http://youtu.be/wto6PEnGWrU
LaserMotive: http://youtu.be/uAic2NC7Qp0

I hadn't seen this older LaserMotive video. But he pretty much answers my question there, at least to say that they're working on mounting the laser system on-board. This quad was tethered. The +12 hour flight test they did was untethered.

Thanks for your feedback guys!
 

rcspaceflight

creator of virtual planes
#7
but its a major pet peeve to hear folk talk about "renewable" energy as if it magically materialized out nowhere. The term "renew" is correct but massively misunderstood. The energy, both potential and kinetic in all its various states and forms in the world....solar system....galaxy....and Al Gore's interweb is the same exact amount of energy present at the "big bang" or creation (whatever you personal belief).
True, very true. But I think the term is a loose expression not a literal definition. Non-renewable energy sources are ones that we can foresee running out of. We can estimate how much oil there is on the planet, we can estimate how much we use, and we can estimate when we'll run out. Although technically we can estimate when the Sun will die, but that's not going to happen for about a billion years? I think the two terms are mostly time related as to when we'd "run out".

Another unrelated rant: it's a pet peeve of mine when people talk about "saving trees" when we can properly utilize the source and "never run out". (by that I mean that we can keep using trees for about a million years.) Like I was watching a "home improvement" show that was explaining how it's better to replace your wood burning fire place with propane. :confused:
 
#8
True, very true. But I think the term is a loose expression not a literal definition. Non-renewable energy sources are ones that we can foresee running out of. We can estimate how much oil there is on the planet, we can estimate how much we use, and we can estimate when we'll run out. Although technically we can estimate when the Sun will die, but that's not going to happen for about a billion years? I think the two terms are mostly time related as to when we'd "run out".

Another unrelated rant: it's a pet peeve of mine when people talk about "saving trees" when we can properly utilize the source and "never run out". (by that I mean that we can keep using trees for about a million years.) Like I was watching a "home improvement" show that was explaining how it's better to replace your wood burning fire place with propane. :confused:
Propane for wood???? HUH?! I can plant two trees for every one I take....but little harder to put fossil fuel back in the ground.
 
#10
Tritium: NASA, and a company called LaserMotive have both flown aircraft powered by ground based lasers. Not sure of the technicals of it, but LaserMotive managed to keep a quadcopter aloft for over 12 hrs doing this. I was wondering whether or not that could be moved to a platform sitting directly below the quadcopter body, powered by kinetic energy harvesting tools from Arduino or Texas Instruments. I expect not because I don't think it would meet the power requirements for the laser, but curious nonetheless.

See these two videos:
Nasa: http://youtu.be/wto6PEnGWrU
LaserMotive: http://youtu.be/uAic2NC7Qp0

I hadn't seen this older LaserMotive video. But he pretty much answers my question there, at least to say that they're working on mounting the laser system on-board. This quad was tethered. The +12 hour flight test they did was untethered.

Thanks for your feedback guys!
I am amazed by the NASA approach....no sensor tracking on the laser?? Manually tracked=Pain in the A$$
 

Tritium

Amateur Extra Class K5TWM
#13
You can bet that the Flight Test crew is NOT going to be able to accomplish this feat by ripping a laser tube from the laser cutter and making it happen. NOPE not even DAVID could do this one! :p

One of my quads uses about 30A at 11.5V or 345watts for hovering. Sure it would be less power required for no battery on board BUT a photovoltaic system capable of the power needed WILL weigh a bit. MORE than a battery I am guessing so that reduces the gain of such a system to unlimited flight time (and possibly control/telemetry via the same beam) IF you can keep the laser on target and if the atmospheric conditions don't eat too much of your laser power before the craft is able to consume it.

Thurmond
 

rcspaceflight

creator of virtual planes
#14
I don't think the solar cells would weigh as much as a battery. If you had a really good system to lock the laser onto the solar panel, it would only need to be as big as the laser point. You don't actually need more solar panels for more power, just more lasers onto that one panel. Plus you could use the computer board that the panel is on as the airframe. So the hard part would be to make a system so the laser can lock onto the quad. Even then the quad would have to stick to slow, basic maneuvers so it really wouldn't be that fun to fly.

A glider with the ability to climb by shooting a laser at it would be awesome, though.
 

Tritium

Amateur Extra Class K5TWM
#15
Concentrated power on a solar cell causes a MUST be cooled or FAIL situation. 345 watts at regular sun intensity power levels requires about 30 sq FEET of cells.;)

Microwave could be workable though I would not want to be nearby. :p

Thurmond
 
#16
There is a practical limit to the amount of power a solar cell can produce. The limit is higher than what one produces when you just lay it in the sun, but it's not infinite.
 

vk2dxn

Senior Member
#18
Chaos he did.
He used it to power the lighting for the opening of the Sydney opera house from Colorado Springs

Edit: it was called the magnifying transmitter commonly called "tesla coil"
 
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chaos23

Senior Member
#19
true but as we all know nothing actually works without money, and like the first astronauts said "no Bucks, no Buck Rodgers". and if our overlord masters say "NO" then it obviously doesn't work lol. but wouldn't that be nice, unlimited range and flying time (drools in the corner)