Solar UAV
Hi Everyone,
I am planning to begin making a solar powered UAV and have spent some time researching Solar Panels , MPPT’s, Airframes and Autopilots. I think the best way to go is to run the Motor / speed controller directly from the Solar panels / MMPT, but also have a small battery to “back up” the electronics just incase the UAV tips upside down etc.. so it has power to recover.
I have tested the Powerfilm solar panels but don’t think they will be efficient enough for what I want to do. I think I will use the A-300 panels instead.
This is the airframe I am thinking of using.
My question is.. Is anyone else out there trying this, thinking about trying this or done this yet??
I am interested to see some different approaches to the same problems.
I am planning to begin making a solar powered UAV and have spent some time researching Solar Panels , MPPT’s, Airframes and Autopilots. I think the best way to go is to run the Motor / speed controller directly from the Solar panels / MMPT, but also have a small battery to “back up” the electronics just incase the UAV tips upside down etc.. so it has power to recover.
I have tested the Powerfilm solar panels but don’t think they will be efficient enough for what I want to do. I think I will use the A-300 panels instead.
This is the airframe I am thinking of using.
My question is.. Is anyone else out there trying this, thinking about trying this or done this yet??
I am interested to see some different approaches to the same problems.
Replies to This Discussion
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Permalink Reply by NorthSweden on -
Sounds interesting, i have think about it to,
but the efficient are not so good, and expensive,
I have tested and experimenting with solarpanels to run an Wifi accespoint, and i can only say that you must carefully measure and calculate how much current your solarpanels/cells can produce in a mount of time, plus you must have a battery to store the energy for cloudy days and night,
BTW the AP running 24/7 right now.
But on UAV i think it is a good way to expand the battery duration, or just power the reciver/autopilot,
The motor take so much current so you must have a very big solar panel to run it directly.
I have one 10watt solar panel and that one weights about 1.5kg and produce around 550mah in sun,
But experiment whit smal solarpanels and hock them in parralell and series to make your desired voltage and current.
I will test whit some smal solarpanels soon.
Take care.
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Permalink Reply by Rory Paul on -
You are going to have a hard time packing your autopilot batteries etc into that fuselage. I would think a flying wing may offer better surface area to for solar panels and allow you space to load electronics etc.
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Permalink Reply by Scott James on -
Hi Condor,
I have been thinking of a flying wing also, but I am yet to find one that will suit (still looking though.)
Here are some pics of the Graupner that I found. There seems to be a fair bit of space in there. I know that efficiency (Watts per kilo to sustain level flight) is everything when it comes to this design. And from what I have read the sailplane airframe will be the most efficient. (with the right motor, prop and esc of course.)
There is defiantly a lot to consider.
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ModeratorPermalink Reply by Varga András on -
I've just found something interesting for you (a solar mini-UAV from Switzerland):
http://sky-sailor.epfl.ch
Some flexible solar cells which are said to be good for an RC aircraft:
http://solarworld.com/PowerFilm.htm
Solar gliders from Chris Good:
http://www.chrisgood.com/rcplanes/solar/index.htm
Well, my diploma work was the concept of a solar UAV, but this would be too expensive to be built by a hobbyist. It was based on the SoLong of AC Propulsion. Note that if you want a hybride system (accumulator and solar cells at once) you need to use DC/DC converters for connecting them in parallel (to make a power line with constant voltage) and these converters are usually heavy. That is why this concept had a large wing area and 4,8 metres of wingspan:
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Permalink Reply by Scott James on
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That design look great!
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Permalink Reply by dincer hepguler on -
take look at my project... i am using Powerfilm solar panels that perfectly fit on my plane. they weigh 120grams and producing 1.25amps at full sun... i am using them to power all my equipment (including the brushless motor) together with a bank of batteries...
http://borsaci06.com/robotics.html
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Permalink Reply by Scott James on
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What is the climb rate like? Has it got lots of power or just enough to keep it in there air?
Can you please post some video of it flying? Thanks
I think I will have to select the solar panels last. I have got some of the power film panels here but I'm worried they will not be efficient enough. I was thinking I would get the plane and deck it out with a (just big enough) motor / ESC and then install an eagle tree (or similar) data logger. Then I will know how much power I need to sustain level flight.
Then I can get an idea of how many power film panels I need or if they will all fit on the wing. If they don’t fit I will need to use a more efficient solar cell. (A-300).
Here is a list that I think will end up being part of the project…….
-Motor / gearbox (Maybe something like this if the stock motor is too power hungry)
-ESC
-MPPT (Maximum power point tracker) Good description here. See pdf.
-Dean Goedde’s Atto pilot 1.7. (Very small, light and awesome. Just have to wait for the release)
-Solar panels (yet to be determinaded)
-Spectrum AR-7000 receiver
-Small battery (To back up electronics only)
-Maxtream 9xTend Data modem
-A small light digital camera
-Hours and hours of nightmares
-And an angry wife :)
My goal is to make a UAV that can stay in the air for up to 8 hours (in summer). I have looked at trying to incorporate batteries to keep it up longer but the added weight and electronics would turn it into something way out side my skill level!
You only have to look at the people that have done it to see that they had almost unlimited budgets and teams of scientists behind the project.
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Permalink Reply by Scott James on
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I have looked at the MPPT that these guys built but also the guy from this website said he can custom make one.
I’m still looking into it myself. I’m going to start with a small plane just to test all the electronics to get a feel for it and then I am thinking of building something bigger. (Large wingspan to hold all the cells, still deciding what to use there as well??)
The formulas here (2nd post) are interesting also.
Good luck! (I know I need it!)
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Permalink Reply by bGatti on -
You don't need an MPPT - because you have most of it already.
The ESC is capable of pulling more current or less current - that is the heavy-lifting of an MPPT. You don't want to do this twice because you'll just make more transistors hot and waste energy doing it.
If you have more power, then you should be climbing up to your ceiling, if you have less power, then your esc will slow down automatically; the plane will either level off or descend.
Moving the effective voltage around will, I believe, only waste the heat and weight of the converters, since the esc is probably doing a fairly good job of optimally pumping the available power into the prop, and if not, the better solution may well be to change the prop pitch rather than the voltage.
IF Batteries are in your future, than an MPPT charging strategy might be helpful. The MPPT will only manage the charging current, not the full current.
Generally one should use all solar power to climb until one is close to ceiling, then increase the charging cycle to the point that altitude is stable - until the batteries are full. Only that extra current needs to be handled by the MPPT, so an MPPT much smaller than the solar panel power rating can be used.
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ModeratorPermalink Reply by Giles Barton-Owen on -
From what I have gathered from the odd picture of them they have to be huge (at least 3m wingspan) to actually have enough area to power them, they also should fly high and be a wing. The US did a project like this and it was something in the region of 10m across!
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Permalink Reply by Scott James on
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It's not always the case, it depends on the efficiency of the cells. Have a look at this.
The Spectrolab cell look impressive at almost 30% efficiency!
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