Electric planes

[Kandiru]

Pipistrel Taurus Electro looks a great electric glider. I may buy it for $15 when it becomes available, on Condor of course.

I am also moving forward with my virtual glider training, working on Condor 2 and soon start training for my
condor-club.eu certificates. Will likely remain in my simulator cockpit for a long time as I live 4h from the nearest
gliderport.

 

[lolachampcar]

Gliders are a wonderful way to learn how to fly. Our European friends most certainly have this figured out.

 

[daniel]

When I was in Spokane there was a club nearby called the Quiet Flyers. They flew RC electric planes. Some of them were pure gliders launched by a catapult. Others had electric motors. IIRC the motored ones used the motor to take off and then glided. It was pretty cool. I never got into it because I figured I'd probably crash it first try. They had contests where the goal was land as close as you could to a marked spot and a specific total flight time. I thought it would be more fun to just see how long you could stay up in glide mode. Idk, maybe they had those contests also.

I drove the Roadster out to their field to watch, and they were very impressed by the car.

 

[swaltner]

I saw this announcement on the OGN (Open Glider Network) Google Group.

Next Sunday Pipistrel Velis Electro HB-SYE will take off from
Schaenis (Switzerland) and attempt to break 7 world records on a trip
to Norderney (Northern Germany).

The aircraft carries a FLARM device, so it will be visible on all the
OGN tracking sites. We invite you to follow the flights online and/or drop
by at any of the intermediate stops.

Das Projekt - elektro-weltrekordflug.eu

My German skills are non-existent and I’m too lazy to use Google translate, so not really able to give many details. It sounds like the are doing a first long-distance trip with a fledgling charging network that they have established. The Pipistrel Velis Electro is an all-electric airplane based off the Pipistrel Virus. This has apparently obtained a type-certificate in the EU. This flight is starting tomorrow, and will happen over a few days. It appears as though Switzerland and Germany are UTC +2:00, so 6 hours ahead of Eastern time zone in the US for correcting the schedule to your local timezone if you want to follow along on their progress.

Edit: Electrek posted an article in English on this flight with a fair amount of details
This electric airplane is setting out to break 7 world records in one flight

 

[daniel]

Cool. Somewhat limited in utility, but as a first step in consumer-available electric aviation I applaud it.

 

[swaltner]

After a little bit of a delay from the original production timeline that was quoted, I just received word that my Pipistrel Taurus Electro has left the factory and is on the way to the US. The last 7.5 months waiting on production have been painful, but the next month waiting on the shipping container is going to be even worse. My day-1 Model 3 reservation maybe prepared me for the wait, but only slightly. I hope to get a month of flying in before it gets put in storage for the winter.

When the glider finished production and was ready for production flight test, they sent me a couple teaser photos of the cabin to make the waiting even more unbearable.

 

[daniel]

Oh, my gosh! I want to ride in that! Not badly enough to leave Maui, especially these days, but that is so cool!!! I googled it and saw a video. Electric-powered takeoff glider.

 

[Thekiwi]

Wright Selected for Prestigious U.S. Department of Energy Electric Aircraft Program

 

[JRP3]

A video about Eviation's electric passenger plane Alice:
Inside a $4 million electric plane, the first full-size, all-electric passenger aircraft in the world

 

[daniel]

A video about Eviation's electric passenger plane Alice:
Inside a $4 million electric plane, the first full-size, all-electric passenger aircraft in the world

Thanks for posting this. It's pretty cool. One nit: The reporter says that this plane will be good for popular short routes. Popular routes by definition have a lot of passengers. That's why they use big planes. A nine-passenger plane can't serve a high-traffic route.

But there are routes served by very small turbo-prop planes, and that's the market for Alice. I've been on such planes, and given the choice I'd have flown electric. As recently as a couple of years ago I flew on a small piston-prop plane. (Seattle to San Juan Island.) An electric plane could serve that market, if it's powerful enough to take off from water, as it was a seaplane.

By virtue of its small size Alice won't make a dent in the carbon footprint of overall air travel. But it's a start. As batteries get lighter Alice's offspring can get bigger. I do wonder, however, if a better solution for air travel might be synthetic fuels produced from renewable energy (solar and wind) as being so much lighter than batteries for the foreseeable future.

I'd still prefer electric.

 

[Etna]

Thanks for posting this. It's pretty cool. One nit: The reporter says that this plane will be good for popular short routes. Popular routes by definition have a lot of passengers. That's why they use big planes. A nine-passenger plane can't serve a high-traffic route.

But there are routes served by very small turbo-prop planes, and that's the market for Alice. I've been on such planes, and given the choice I'd have flown electric. As recently as a couple of years ago I flew on a small piston-prop plane. (Seattle to San Juan Island.) An electric plane could serve that market, if it's powerful enough to take off from water, as it was a seaplane.

By virtue of its small size Alice won't make a dent in the carbon footprint of overall air travel. But it's a start. As batteries get lighter Alice's offspring can get bigger. I do wonder, however, if a better solution for air travel might be synthetic fuels produced from renewable energy (solar and wind) as being so much lighter than batteries for the foreseeable future.

I'd still prefer electric.

One of the surprising things about electric planes that very few people know about, even in the industry, is that larger aircraft can go just as far as smaller one. It's all about weight fraction.

For example, if batteries represent 30% of the takeoff weight in a 10 seat and in a 40 seat airplane, they will both have the same range. If the 40 seat airplane is three times as heavy as the 10 seat airplane, it will have three times the battery weight and it happens that it will need three times as much energy to cover the same range. It's all proportional (in reality the larger airplane enjoys the advantage of lower ratio of takeoff weight per passenger which results in longer ranges, everything else being equal, but I keep this comparison simple)

This widely held misconception may originate from the fact that larger airplanes typically operating longer routes. But if you can fly 100 nautical miles with 240 Wh/kg batteries, you can do it with a 50 seat aircraft just as well as a 10 seat aircraft.

So basically, there is a direct correlation between battery energy density and range, regardless of aircraft size. Larger aircraft require higher power levels though, with motors and cables capable of handling higher currents and voltages. But this can be mitigated with distributed propulsion systems, which are economically feasible with electric propulsion, unlike turbine engines.

Synthetic fuels hold a lot of promises for longer ranges, less dubious than hydrogen, IMHO. Very short range flights (<200 nm for 400 Wh/kg) will be dominated by electric airplanes eventually.

 

[daniel]

The real determining factor is cost. Right now electric cars cost more than gas cars with similar features because of the cost of batteries. The cost per passenger mile over the life of the airplane will determine who wins. Expensive batteries are a liability. If oil becomes significantly more expensive, then electricity gains an advantage. But when 60% of the weight of your plane is batteries, and the energy in those batteries must lift the batteries as well as the passengers and the plane itself, there's a cost penalty right there. Cheaper, lighter batteries would be needed.

I'd be interested to know the total lifetime cost comparison between Alice and a conventional airplane of the same range and capacity.

I'd love to fly in an electric plane.

 

[Etna]

I'd be interested to know the total lifetime cost comparison between Alice and a conventional airplane of the same range and capacity.

The big driver is battery cycles. Today we're at 1500 cycles and a 920 kWh battery costs a minimum of half a million dollar (assuming 500$/kWh which would be aggressive pricing for aviation grade batteries). So that's 330 $/flight. As a comparison the cost of electricity for that 440 nm range flight is 64$/flight.

A PC12 flying 440 nm at long range cruise speed needs 140 gallons of fuel or about 280 $/flight at 2$/gal. You have to add to that the maintenance cost of the turbine engine, compared to an electric engine which is virtually maintenance free.

Thus I would say that today already, an electric aircraft has similar or slightly lower operating costs compared to a turbine aircraft.

However this will improve very quickly as battery life cycles get near and beyond 5000 cycles. Assuming 4500 cycles and 250$/kWh, likely achievable before 2030, we're down from 330 $/flight to 55 $/flight for the battery cost.

So including everything like single pilot crew, financing, maintenance etc (thus the whole life cycle cost), the 440 nm flight will set you back approximately 2000$ in a PC12 and probably in the range of 1600 $ in a similarly sized all-electric aircraft, maybe 1400$ if revolutionizing airframe maintenance costs (doubtful). Most electric aircraft companies will claim substantially higher savings in operating costs, but they focus too much on electricity costs and miss the big picture.

I am using the range and battery size numbers of Eviation here, which are wildly optimistic, but the conclusion holds.

 

[PatrickCH4313]

We have one pilot school in Switzerland (LSZX) using the Velis Electro from Pipistrel Aircraft for training. It has been certified for Europe (EASA) this year.
Velis Electro EASA TC – Pipistrel Aircraft

 

[daniel]

Velis Electro EASA TC – Pipistrel Aircraft

That is so cool!

 

[Thekiwi]

The big driver is battery cycles. Today we're at 1500 cycles and a 920 kWh battery costs a minimum of half a million dollar (assuming 500$/kWh which would be aggressive pricing for aviation grade batteries). So that's 330 $/flight. As a comparison the cost of electricity for that 440 nm range flight is 64$/flight.

A PC12 flying 440 nm at long range cruise speed needs 140 gallons of fuel or about 280 $/flight at 2$/gal. You have to add to that the maintenance cost of the turbine engine, compared to an electric engine which is virtually maintenance free.

Thus I would say that today already, an electric aircraft has similar or slightly lower operating costs compared to a turbine aircraft.

However this will improve very quickly as battery life cycles get near and beyond 5000 cycles. Assuming 4500 cycles and 250$/kWh, likely achievable before 2030, we're down from 330 $/flight to 55 $/flight for the battery cost.

So including everything like single pilot crew, financing, maintenance etc (thus the whole life cycle cost), the 440 nm flight will set you back approximately 2000$ in a PC12 and probably in the range of 1600 $ in a similarly sized all-electric aircraft, maybe 1400$ if revolutionizing airframe maintenance costs (doubtful). Most electric aircraft companies will claim substantially higher savings in operating costs, but they focus too much on electricity costs and miss the big picture.

I am using the range and battery size numbers of Eviation here, which are wildly optimistic, but the conclusion holds.

Thanks for that post - some interesting stuff there.

A couple of thoughts:

- What happens to the battery after those projected cycle counts? Is it unusable and have to be replaced? Or does it simply start to reduce in maximum capacity and so can still be used on shorter routes and/or less flights between charging?

- I wonder if airlines should start expecting higher carbon emission costs on fuel in future fleet purchase plans, which I can see increasing in many markets once viable EV planes become available. Once the transition in cars to EVs, and battery energy storage is well underway, I imagine regulators will start turning to the next lowest hanging fruit for emission reductions - which could be airlines.

 

[daniel]

- What happens to the battery after those projected cycle counts? Is it unusable and have to be replaced? Or does it simply start to reduce in maximum capacity and so can still be used on shorter routes and/or less flights between charging?

This has been discussed with reference to car batteries. As batteries degrade they hold less and less charge. Good battery management can slow the loss, which is why Teslas do so much better than Nissans in this respect. A smart car buyer buys a battery size that will provide the needed range for the expected lifetime of the car.

But the batteries are not useless after that. Cars (and airplanes even more so) are hampered by weight. But batteries for home or grid solar and wind storage don't need to be small or light. A car battery with half its original capacity is perfectly good for stationary storage.

 

[Etna]

Thanks for that post - some interesting stuff there.

A couple of thoughts:

- What happens to the battery after those projected cycle counts? Is it unusable and have to be replaced? Or does it simply start to reduce in maximum capacity and so can still be used on shorter routes and/or less flights between charging?

- I wonder if airlines should start expecting higher carbon emission costs on fuel in future fleet purchase plans, which I can see increasing in many markets once viable EV planes become available. Once the transition in cars to EVs, and battery energy storage is well underway, I imagine regulators will start turning to the next lowest hanging fruit for emission reductions - which could be airlines.

- As @daniel says. And you are correct, if that still provides enough range they can keep it for shorter routes but in general that is going to be an issue because the range is not great to start with.

- This is what I am expecting. For example the same cities or countries that have already announced a ban on gasoline cars in a few years will simply ban airplane categories as soon as an electric alternative will become available, as a matter of consistency. There are a few low hanging fruits such as inter-islands in Hawaii and Indonesia, or Fjord-hopping milk runs in Norway. Anything beyond 250-300 nautical miles will remain out of reach of all-electric propulsion without a significant breakthrough.

 

[daniel]

Note that it's not just short range routes, but short-range routes that have such low traffic that they can be handled by planes that carry 8 to 10 passengers. This plane will not replace a jet or a 50-passenger turbo-prop even on short routes. Small planes typically serve very small communities or isolated resorts. If they can replace those, it's great. But it won't make a dent in overall world-wide air travel. I've taken very small planes in Kenya from one game park to another, and from Seattle to San Juan Island. But even the very short hop from Ft. Lauderdale to the tiny island of Bimini is served by a much larger plane than this.

I think it's great that people are working on electric aviation. But to really make a dent in the carbon footprint of commercial aviation I think we need synthetic fuels made from green electricity.

 

[CorneliusXX]

Note that it's not just short range routes, but short-range routes that have such low traffic that they can be handled by planes that carry 8 to 10 passengers. This plane will not replace a jet or a 50-passenger turbo-prop even on short routes. Small planes typically serve very small communities or isolated resorts. If they can replace those, it's great. But it won't make a dent in overall world-wide air travel. I've taken very small planes in Kenya from one game park to another, and from Seattle to San Juan Island. But even the very short hop from Ft. Lauderdale to the tiny island of Bimini is served by a much larger plane than this.

I think it's great that people are working on electric aviation. But to really make a dent in the carbon footprint of commercial aviation I think we need synthetic fuels made from green electricity.

It does create the economic forcing function which allows for increased R&D as there is now a market for an electric plane where incremental improvements will be valued.