I’ve been SUPER happy with my plug-in hybrid car. (Volva XC90)
It gets me just enough all electric range while having a gas powered generator onboard for extended trips of 500+ miles on a tank+charge.
What size gas motor could you get away with if you only needed ‘bursts’ of high energy for takeoff, climb, supplied by a battery/super-capacitor? The fact that the gas motor could run at constant throttle is a huge bonus for efficiency. In fact, a small jet turbine would possibly be even more ideal! (except the noise!)
It would take a 50-60cc engine 2 stroke engine to maintain level flight, and you would have to add the electric motor and battery for launch and climbs, I think you will end up being pretty heavy to justify the combo. By increasing the engine to 80cc, not a huge weight increase, you can do it all. Not saying that a special ICE engine with built in electric motor is possible, it would be pretty expensive to develop, and sales would be too low to justify the costs. As for small turbines, they suck huge amounts of fuel and are very inefficient.
Seems like the average ‘cruise’ power is something around 4kw. So, you’d need a generator rated for at least that for continuous operation.
It was kinda fun working through a theoretical design with Gemini:
3.9lb, 60cc Twin 2-Stroke Engine (e.g., DLE-60) as the gas power generator
2.98lb 3-Phase BLDC Alternator / Generator
11.11lb battery pack consisting of 72x Molicel INR21700-P45B Cells
And then, it kinda pointed out that the entire effort is kinda pointless. The main reason for going electric was simplicity. If I wanted a lighter setup that could fly longer than 1 hr, I should just put less gas in my Kangook HE125NG paramotor.
Do ya really need 4kw for level flight ; that’s a bunch compared to my Atos glider that only needs 22Lb of thrust to keep from going down-hill. The Gas/Electric hybrid would work really well on my machine; but 19:1 L/D is somewhat clean by foot-launched standards , and not that great compared to sailplane standards. Bummer I missed out on that $1800 deal for the SP 140 that aerovations had for sale ; it woulda worked perfect for my application.
I believe we have about half the glide rate as your Atos, on average (EDIT: From the following posts, looks like it’s more like >3x higher on the Atos!). I’m presuming a lot more wind resistance from the lines and wing, and the piloting position itself.
I averaged ~5.5-6kw level flight on my 23m Charger, and about 4.5kw on the 26m Mojo. I don’t see many folks reporting less than 4kw for level cruising, so I think that is the lower average for modern highly efficient PPG gear.
My 19:1 should go up to near 25 or 26:1 when i put my fat A$$ in a clean pod , and get rid of the control bar & wires ; but that glide ratio will go from the now 32-mph to a bit over 40-mph , and that is where the real efficiency will come into play.
The last free-flight PG flight I did , was on a Delta -2 , but my favorite PG is the slower Skywalk Cumeo ; my go-fast machines are the Atos VRX . This is the one I wanna put the Hybrid on:
Yeah, that’s gonna be a pretty efficient setup. Typically for my flights and looking at the logs, I see a glide ratio of 7:1, and my cruise power’s typically sitting around 3.3 to 3.6 kilowatt for level flight.
About what speed are you getting at cruise Paul ? That info will help me determine what pitch prop I need for the Atos. Once I get a ballpark figure ; a variable pitch prop would be easy to build. VP is legal for ultralights in the USA.
Here, I grabbed a typical flight for you. For me, this is with the large battery, and I was doing a little bit of prop testing in it.
You can click through the charts and see the different speeds and look at various details. There are a bunch of different sensors that can be viewed and charted.
Looking at my average speed, I think it was around 24 miles per hour, which is what I would say is pretty much what the average paramotor cruises at.
Note this is our experimental dashboard domain and will be moved over soon to a proper openppg.com setup. ^
Super excited to share more around flight logging/sharing
Thanks for taking the time to give me that Flight Data !!!
In your opinion sir : Would I be better off saving up and getting the newer SP140 , instead of a used older version ; since after climb , I will be at a much lower throttle setting than the PPG guys for cruise ?
The new system’s pretty sweet; all the data, updatability, and efficiency make it quite nice. It has a lot more flexibility, especially for the future.
So it definitely is more flexible about setting RPM thresholds and things like that. There’s just a lot more that can be done with it, so I would recommend that. If you can find an old system, motor, ESC, and hand controller under a thousand bucks might be worth it. Otherwise, the new system is just going to be a much better option. I would definitely look at the V2.5
Thanks for the Info ; I will do as you suggest and just save the money for the better one .
This is kinda cool — but I ran the numbers based on the SP140 V2.0 motor , and with the light battery along with a 1700 Running watt capable generator ; I am quite certain that a World record could be had with the glider pictured above , (for most miles flown on One gallon of gas). If a guy tried the same with a typical ultralight or performance sailplane, it wouldn’t work ; that’s because my glider has a 15m ,(49,2-ft) span and the wing loading along with L/D are perfect for such a record ! Another cool thing is the German factory who built it told me I have the only one like it in the entire USA ; only a few were ever made world-wide. As for My flying capabilities : In the early 80’s I was #4 in the world at ACRO on a Rigid-Wing glider ; so I don’t suck too bad at avaiation.LOL
Look at the picture above and ya might notice that I fly with (2) below the knee Fake legs.
