Online Community of Zenith Builders and Flyers
Perhaps I missed it, but haven't seen any discussion about electric power plants in Zeniths or perhaps kit planes in general? With the new siemens motors 100 hp and 250 hp soon becoming available and a number of battery suppliers is that another option to the list of combustion engines? At somepoint I will bedoing more than just looking at 750 kits and the electric power plant has always intrigued me.
I haven't heard of anyone doing it yet. I think you should pave the way forward.
Hi Mark, I have been a brushless motor engineer for 25 years. The motor and controller technology is here, but even the best lithium batterys lag far behind. First applications will be electrically launched sailplanes, followed by small electric vertical takeoff and landing (EVTOL) air taxis with replaceable battery packs for short hops. My Zenith Zodiac with Viking Honda 110 HP will give the range and power that I need. It is truly amazing how much energy is in 1 gal. of gasoline compared to battery power! Best Regards, Larry Zepp
I think we might be a bit further along than that, the Eflyer and Pipistrel for example. But you're right, at this time gasoline is still ahead of batteries but that gap is closing. The examples above can stay aloft for 3+ hours and are promoted as training aircraft, a 4 seater Eflyer is currently in the works. If the technology can get an LSA to100hp and say 5 hours run time, I think that would change everything. I was just thinking out loud that kit planes with all the customizing you can do would be particularly suited to a non traditional power unit.
I think we are considerably further along. Below is a link that talks about six companies to watch. Highlights include "Alice" (maiden flight planned late this year) 650 mile range, 276 mph, 9 seats, $165 per hour operating cost.
The Siemens 100 HP SP70D motor weighs only 57 lbs vs. about triple that for the equivalent Rotax 912. Take out 24 gallons of gas in STOl 750, another 144 lbs, you're getting close to 250 lbs of weight to play with before looking at anything else. I haven't been able to find a cost for the SP70D or what appropriate batteries would sell for but when the link above says "According to the company’s CEO, compared to the $50 per hour it typically costs to fuel a traditional training aircraft, it costs $3 per hour to power Bye Aerospace’s electric eFlyers" it's probably worth checking out.
Link about batteries:
Great thread and discussion! Electric power is very intriguing....Are there any estimates of when electric engines may be available for homebuilders?
The Eflyer people are working towards FAA certification now (see link), I would guess another year. Once that happens presumably Siemens and the battery vendors will be able to sell to anyone who wants them.
The Zenith Mission is not a great match for electric motors. The STOL/701/801 is too draggy, even the Cruzer is still too draggy and the wing profile takes too much power. The 650 does not have the gross weight. The composite planes are really better built for this because they can go reasonably fast on "Cruise" power. At slower speeds they can make the battery last, but still fly fast enough to be useful and make efficient use of the wing. It takes too much power on our "Dirty" planes to be good platforms for electric right now. A battery capacity revolution might changes this, but Zeniths are meant for a different mission then pure energy efficiency.
That's a good point, you're saying it would take more battery power to fly a 750 for 4 hours at say 100 kts than a composite doing the same? That's too bad, an electric STOL would be a blast especially if you could carry your own solar/wind chargers and be truly independent. Hopefully that day is coming!
It also takes more fossil fuel to fly a high drag airplane at the same speed. Any mission has a set fuel requirement. In electric, the fuel must be substituted with batteries, so fuel intensive missions are not appropriate for battery powered airplanes. The problem is the mission, not the airplane. Fly more slowly and don't fly as far. Don't let this stop you. I want to see an electric Zenith.
Cool to see, is there a blog or project webpage?
What is the Max Gross weight on this?
Does empty weight mean with the Batteries?
1320-950 gives 370lbs of useful load which is two 185lbs folks with no baggage, or two sub-faa weight folks with bags.
Can't be used for commercial training, so what it the mission?
How long to charge the batteries?
Is this flying already?