Electric / hybrid aircraft propulsion (NOT cars)

I agree with the basic ideas but this one is a mystery:

Confusing scuba diving with flying?

Which bit: the oxygen being carried already or the oxygen being released on recharging? The first point seems a bit of a red herring as if you needed pure oxygen for a lithium air battery then you’d need lots of it. The second part makes more sense: pure O2 will be given off during recharging and this could be compressed and recycled.

Sunflyer 2 seater seems very heavy at 1900 lbs AUW but only 440lbs crew.

That Wired article is useless (nobody who has paid a bit of attention to the area can learn anything new from it) … predicting what the state of technology will be in 30 years based on current state … “aircraft design takes decades”.

Progress (and evolution!) goes in big leaps followed by relative stagnation periods (of only incremental changes) during which it is impossible to predict the next big leap.

In 5-10 year’s time the picture will be much clearer – whether anything that comes out due to auto-push can be meaningfully used for aviation.

The best case scenario:
a) cheap, simple & reliable (but a bit short-legged and not very fast) pure electric motor-gliderish flying for fun (& teaching), breaking the stranglehold of the few
producers of expensive aircraft engines
b) not so cheap & simple hybrid with great takeoff & climb performance and efficient cruise (even if this arrives, it will be quite a bit later than a) ).

More realistic scenario:
- cost competitive (but not seriously cheaper), eventually reliable pure electic motor-gliderish flying with incrementally longer (but still short) legs for those who want to just turn at the airport, turn on the airplane and go flying, without all the hassle & magic formulas caring for a capricious gas burner

I went to a presentation about the Sun Flyer a few days ago. It was conducted by George Bye, the founder and CEO. While of course wildly optimistic (they expect certification this year….) I found it very interesting. The Santa Monica Airport Association who organized the event promised to email the presentation slides out in PDF format to everyone who registered. If they do indeed turn up in my inbox, I’ll post them here.

For the time being, the web site is here: http://sunflyer.com

As to hybrids:
Just recently in an US car rental I got a Ford hybrid. The instrument panel was like a video game, flashing, saying how much does the car consume, how much does it recuperate, and how much is the gas mileage. I was getting a steady 5.5l/100km. This is a long term average fuel consumption of my family car, that is larger (thus better to utilize), simpler to manufacture (thus environmentally friendlier), easy to maintain. If hybrid does not work in automotive, how can it work in aviation?

The Sunflyer is interesting, but the specs lack an important detail- at what speed is the endurance measured? 3 @100kt is all I need for my normal flights, @55kt its purely for training..

The Sunflyer specs lacks many relevant details (battery capacity, range, power consumption at different cruise speeds), instead headlining with catchy per-hour costs (surely not including battery replacement fund) … misleading marketing at its best (worst) … make what you want out of that … surely not impressing me

Pavel wrote:

Just recently in an US car rental I got a Ford hybrid. The instrument panel was like a video game, flashing, saying how much does the car consume, how much does it recuperate, and how much is the gas mileage. I was getting a steady 5.5l/100km. This is a long term average fuel consumption of my family car, that is larger (thus better to utilize), simpler to manufacture (thus environmentally friendlier), easy to maintain. If hybrid does not work in automotive, how can it work in aviation?

I won’t reply to the first part of your comment as that is just personal opinion. Re. average fuel consumption:
BMW X5 xDrive40e achieves an equivalent fuel consumption of 4 l/100km
BMW i3 REx 94 Ah achieves 2.0 l/100km.
Toyota Prius achieves 2.0 l/100 km.
So you assumption is incorrect and hybrid works in automotive.

esteban wrote:

The Sunflyer specs lacks many relevant details (battery capacity, range, power consumption at different cruise speeds), instead headlining with catchy per-hour costs (surely not including battery replacement fund) … misleading marketing at its best (worst) … make what you want out of that … surely not impressing me

Battery capacity 83 kWh
Yes for $19/hour it does include battery-replacement reserve, motor inspections and consumables like tires.
Re. misleading marketing, I disagree. It’s marketed clearly and predominantly as an electric flight trainer… I think @ivark is right about range as they only quote endurance. If what we don’t know, but if the endurance is only achieved at 55kts, the range becomes 165nm nil wind. Note that the Pipistrel Alpha only has 60 min endurance, so that has maybe a 60 nm range.