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Electric planes

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The main problem with batteries is, landing weight is the same as take-off weight.

Which means EV planes should weigh close to the weight of an ICE plane with empty tanks. I am not even sure today we are anywhere close to that in terms of gravimetric density for even the highest energy density LiOn battery with Co & Ni.
Not a main problem (which is mass), but defiantly a major factor.

For those that do not know, taking off is much easier on landing gear, so it is routine for aircraft to take off with more load than they land. When they ready to land, they mass lost in consumed fuel allows landing within max weight.

Yes, if there is need to emergency land right after take off, the fuel must be dumped (or fly around for few hours) to lessen total mass.
 
FWIW hydrogen as rocket propellant its mostly a mass thing. Compared to a hydrocarbon that has that pesky carbon mass that's sort of dead weight, hydrogen is all business. There's a bunch of downsides though, notably that hydrogen requires much more volume (and so larger/heavier tanks), has a different density than O2 (and so requires more complex pumping solutions), and its generally a right PITA to handle.

As a result, 'new' rocket engines these days (Raptor, Archimedes, BE-4, etc) seem to all be going with methane as the fuel of choice.

Even though methane has carbon?

Anyway, my point was that we're not going to see hydrogen as a fuel in airplanes.

And even if the landing weight vs. takeoff weight is not a serious issue, the weight of batteries vs. the weight of jet fuel is definitely an issue. I doubt if even short-haul commercial battery airplanes will be economically competitive. Hobbyist aircraft are another matter entirely. We know from cars that relatively few people buy cars based on cost of ownership. The fun factor of an electric private plane would make it my top choice, if I were ever to buy a private plane. Which is highly unlikely.
 

It will be very interesting to see how this plays out. I.e., whether or not it can compete economically. Will reduced maintenance and cheaper "fuel" be sufficient to offset the weight disadvantage? I wish them luck. If I had to fly, and if I had a choice, I'd choose electric, even if it cost more. But most people won't. And some people will resist anything new.
 
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This runs on battery that drives a series of electric turbines mounted on the wings?
I wouldn't call them turbines, but rather ducted fans, but yes, that's the setup of the Lilium. Ducted Fan refers to the layout of the propeller, while turbine refers to how it converts stored energy into useful work.

Similar to something like a Harrier Jump Jet, the Lilium directs all airflow from the motors straight down to hover. As it increases airspeed, the wings start generating lift, so the airflow from the motors can be directed to the rear to provide more thrust and less direct lift. As it slows down past the normal stall speed for the wing's airfoil, the "exhaust" again needs to be directed down to keep the aircraft from falling. Edit: in the video, you can see the motors start out pointing almost vertical and then at 45 kts, they are angled at maybe about 45 degrees. As they expand the flight envelope in their flight testing into even higher airspeeds, you'll likely see the motors angle back to almost straight horizontal.

A turbine, particularly in the aviation industry, refers to a gas turbine engine that typically burns Jet A fuel. The turbine is the core of the engine that burns fuel and produces thrust and/or rotation. You can have a gas turbine engine built in several different styles: turboshaft (common on all but the smallest helicopters), turbojet, turbofan, turboprop.
 
This video gives some details:
The CEO calls it a 'Jet Engine' powered by batteries and electric motors and the comments on that video correctly point that out as incorrect terminology.

But that aside, the tech looks sleek and promising. If and when the battery energy density increases to a realistic 350 wh/kg (or alteast 300) then we have a commercial product in our hands.
 
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The CEO calls it a 'Jet Engine' powered by batteries and electric motors and the comments on that video correctly point that out as incorrect terminology.

But that aside, the tech looks sleek and promising. If and when the battery energy density increases to a realistic 350 wh/kg (or alteast 300) then we have a commercial product in our hands.
Aerospace grade batteries are already available today well above 300 Wh/kg from several companies, including Zenlabs at 340 Wh/kg, incidentally 35% owned by Lilium. Aerial Vehicles — Zenlabs

These batteries cost an arm and a leg (North of 1000$/kWh), and don't quite have the same life-cycles capability as car batteries (a few hundreds deep cycles as of now), but that's initially acceptable for this market.
 
These batteries cost an arm and a leg (North of 1000$/kWh), and don't quite have the same life-cycles capability as car batteries (a few hundreds deep cycles as of now), but that's initially acceptable for this market.
How is a few hundred deep cycles acceptable for the market? Aircraft that make money would need to charge 3-4 times per day, 7 days a week. That would mean the batteries would only last 2 months.
 
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How is a few hundred deep cycles acceptable for the market? Aircraft that make money would need to charge 3-4 times per day, 7 days a week. That would mean the batteries would only last 2 months.
Acceptable is not the same as initially acceptable. While the yearly improvements on energy densities are frustratingly slow, improvements on life cycles (and economics) have been comparatively quite significant. I am hearing 5000 cycles above 300 Wh/kg after the 2030's which are not that far off.

As @nativewolf mentions, the economics don't make sense today but will at some point. Hopefully anyway.
 
Batteries are constantly improving. A large-capacity short-life battery today bodes well for a large-capacity long-life battery in the future. That said, I don't believe batteries will ever come close to hydrocarbon fuels for Wh/kg, and therefore will never be economical for large commercial aircraft until the price of hydrocarbons goes so high they become unaffordable. If I were a private pilot I'd choose an electric plane in spite of the cost, just as I drive a Tesla in spite of the price. But a corporation needs to maximize profit and batteries are unlikely to ever get light enough for an electric long-range commercial airplane to be more profitable than a conventional jet.

"Possible" and "economically competitive" are two very different things. Competition is intense in commercial aviation, and the vast majority of people will fly with whichever airline offers the lowest ticket price.
 
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Batteries are constantly improving. A large-capacity short-life battery today bodes well for a large-capacity long-life battery in the future. That said, I don't believe batteries will ever come close to hydrocarbon fuels for Wh/kg, and therefore will never be economical for large commercial aircraft until the price of hydrocarbons goes so high they become unaffordable. If I were a private pilot I'd choose an electric plane in spite of the cost, just as I drive a Tesla in spite of the price. But a corporation needs to maximize profit and batteries are unlikely to ever get light enough for an electric long-range commercial airplane to be more profitable than a conventional jet.

"Possible" and "economically competitive" are two very different things. Competition is intense in commercial aviation, and the vast majority of people will fly with whichever airline offers the lowest ticket price.
True, but every EV plane that replaces a conventional plane reduces the demand for conventional planes, just as every BEV reduces the demand for ICE cars. Yes, it will be small at first, but demand will grow as prices go down and capability goes up.
 
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True, but every EV plane that replaces a conventional plane reduces the demand for conventional planes, just as every BEV reduces the demand for ICE cars. Yes, it will be small at first, but demand will grow as prices go down and capability goes up.

You cannot compare commercial aviation to personal cars. Commercial aviation, like all other business, is driven by economics: Its purpose is to make money. If Island-Hopper Airways buys an electric plane to fly around Puget Sound, it does not reduce the demand for long-haul jetliners. It would be nice for a micro-segment of aviation to adopt a few electric planes, but it will have no effect on commercial aviation overall, which is dominated by large airlines operating long-haul flights and concerned about nothing but bottom-line profits.

Personal cars, OTOH, are marketed to people who have a wide variety of criteria for choosing their cars. A few people want the most economical transportation, so Honda and Toyota do very well selling small, efficient, reliable cars. But most people want something other than the most efficient transportation. If everybody chose their cars the way airlines choose planes, Tesla would never have gotten off the ground. And the weight of batteries is far less important in a car than it is in an airplane.

I bought my Tesla because I like electric transportation. And I wanted autopilot, which no other car had. If I were CEO of an airline and bought electric jets because I think electric transportation is cool, I'd be out of a job.

Electric planes are great. If I were a hobbyist pilot I'd have one. But they're never going to be more than a tiny niche market. Aviation will always be dominated by liquid fuels, probably hydrocarbons, and maybe some day synthetic ones made from renewable energy.