Electric planes

[SalisburySam]

Um, "huge drones capable of carrying large and heavy armament" (like a Predator, for example) are not electrically powered. They have conventional fossil propulsion. The thing that makes it a "drone" is the fact that there is no human pilot on-board. It is remotely piloted and not autonomous, in case you thought that.

Odd response. You’re correct of course but I was responding to a post that implied drones are not aircraft. Nothing to do with propulsion nor control system.

 

[petit_bateau]

There are two electric planes in this video. The fast one and the slow one. Each has a role. The military is well past the point of getting it.

https://twitter.com/x/status/1609333824424677377

 

[tga]

Sadly in the U.S., Amtrack makes buying a train ticket a p.i.t.a. and is seldom if ever on time and the rolling stock is run-down and uncomfortable. I made several train trips between North Dakota and California.

And don't forget expensive - Boston to DC, one way costs the same for an 8 hour train ride or <2 hr flight (~$100). I've done both many times; even with the airport hassle and arriving two hours ahead, I'd rather fly on that route.

Trains in Europe are almost all electric. Trains in the U.S. are diesel-electric hybrid, which means powered 100% by diesel.

FWIW, the Amtrak northeast corridor south of New Haven is electrified, at least to DC (if not further south). They switch locomotives (diesel/electric) in New Haven. There's been talk of electrifying north of New Haven for years, but I don't know how it's going.

 

[daniel]

And while the northeastern corridor is (I think) well served by rail, the rest of the country is not. To get from Fargo to Denver you have to go through Portland and Los Angeles. In Spain (the only European country I've lived in) you can get from pretty much anywhere to anywhere else by rail. The Spanish rail system is run by RENFE. And there is a radio program called RENFE Presenta which lists every single train in the country that's running late in real time. With thousands of trains running constantly, there are generally 2 or 3 that are running late, generally due to rail construction. I believe the rest of Western Europe is similar. In the US, passenger trains run on freight rails, and freight trains have priority. In Spain (and probably the rest of Western Europe as well) passenger trains run on their own rails. This also makes for much smoother rides, since heavy freight trains are very hard on the rails.

 

[petit_bateau]

And while the northeastern corridor is (I think) well served by rail, the rest of the country is not. To get from Fargo to Denver you have to go through Portland and Los Angeles. In Spain (the only European country I've lived in) you can get from pretty much anywhere to anywhere else by rail. The Spanish rail system is run by RENFE. And there is a radio program called RENFE Presenta which lists every single train in the country that's running late in real time. With thousands of trains running constantly, there are generally 2 or 3 that are running late, generally due to rail construction. I believe the rest of Western Europe is similar. In the US, passenger trains run on freight rails, and freight trains have priority. In Spain (and probably the rest of Western Europe as well) passenger trains run on their own rails. This also makes for much smoother rides, since heavy freight trains are very hard on the rails.

In the UK a lot (but not all) of the rail lines are mixed passenger/freight. That is a penalty of being first-mover to industrialise. Priority is given according to the scheduled timeblock associated with the train/rail section. Increasingly there are passenger-only high speed lines being built so as to free-up freight capacity.

In continental Europe there is more separation of the rail lines between passenger and freight, but it is by no means every line. There are lines I have used in Spain that are mixed. However high speed lines are almost entirely separated and passenger-only. Some chokepoints do share track, e.g. key tunnels and bridges, that is a common characteristic in some specific sections of Europe (e.g. Alpine tunnels, Channel tunnel).

The Chinese high speed network is completely segregated in my experience. I can't speak for all of the rest of the network but my studies show that much is mixed.

For journeys of less than 1000km a high speed train can be very attractive vs a plane.

 

[T.J.]

Perhaps bringing this thread down to earth and off on a new heading...

I have heard about adding electric propulsion for taxiing, firing up the jet engines just before takeoff and shutting them down immediately after touchdown. That seems to make a lot of sense.

Is there enough time at the gate to recharge the batteries if only used for that purpose?

On average, taxi fuel really doesn’t amount to much. The weight and complexity of any electric propulsion for that use would be a wasted effort.

 

[Earl]

On average, taxi fuel really doesn’t amount to much.

True, taxi fuel doesn't really matter, however, taxiing emissions do significantly impact local area air quality. An electric tug to tow the plane out to the runway might have an impact but the cost of another person to drive it there and back are prohibitive.
FSD candidate?

 

[T.J.]

True, taxi fuel doesn't really matter, however, taxiing emissions do significantly impact local area air quality. An electric tug to tow the plane out to the runway might have an impact but the cost of another person to drive it there and back are prohibitive.
FSD candidate?

I believe that idea was tried in Europe. Again, it’s a cost, complexity issue vs benefit. Saying taxi emissions is significant impact is an overstatement. Compared to what? It’s about 1-2% compared to fuel used in flight. From what I understand, using EV trucks over the road and local deliveries would have a greater impact than most things. FYI, electric tugs for push back has been in use since the mid 90’s on regional aircraft Now electric tugs and belt loaders are being used and more everyday at large airports and with transport category aircraft I believe that to be a much bigger impact and much easier to implement. Those two pieces of equipment sit and idle for hours.

 

[JRP3]

There was a company working on integrated motors in the landing gear for taxiing purposes, can't remember the name offhand. Just came to me, WheelTug WheelTug

 

[JRP3]

For both air and sea there are quite a few other issues to consider:
-regeneration from capturing turbulence, using wing flex for airplanes, wave modulation in ships;
- complete restructuring of airplane temperature management, i.e. at altitude no more turbine heat capture for cabin temperature management;
-new approaches to inflight deicing;
-new approaches to all operational systems in both ships and airplanes.
-Totally radical approach to regulation (FWIW existing regulations for aircraft and pilots are established in terms of engine type) even imagining an electric aircraft forces everything to change.
There's much, much more.
A close friend of mine is working on a the aircraft solution. A decade in they're making progress but there are many technological problems to solve.
Battery advances are actually less difficult to solve than are a host of other issues, not all of which are even close to complete definition much less solving.
- some examples:
. aerodynamic advantages are very substantial when eliminating engine weight and drag;
. especially long distance, fuel weight can be in excess of useful load.
. Boeing 787-900 one of the most fuel efficient long range large airplanes today, must carry about 50% of useful load in fuel for a typical nine hour flight (I actually flight planned for GIG-MIA because I've memorized the data, having flown it regularly. I hold an Airline Transport Pilot rating and used flight planning software for the purpose)

Those facts explain why Airbus makes large investments in research and experimental airplanes, it also explains why the first commercial ones will be short range commuter airplanes. Above all that is why Tesla, to date, is concentrating on other more mature alternatives.

Frankly the impediments are the same for aircraft as they have been for cars and trucks, which is that the established makers all want to put batteries in an existing product and expanse that to work. As Tesla repeatedly has proven and just has again with Semi, build for purpose is the only solution.

Tesla, as we often note, has huge potential addressable markets in many areas. The Limiting Factor, as Elon says so often, is finding enough qualified engineers. As we so often point out, even within only cars Tesla has only scratched the surface, and trucks even less, energy impeded by raw materials shortages. And, in all of them, there are major issues in scaling o support.

This post is primarily to suggest that it is quite academic, at best, to discuss new product categories since the present ones are so replete with opportunity. That said, we also know that our CEO always is attacking new topics. Since there's already SpaceX, The Boring Company, Neuralink, Starlink and 'a bluebird that is not a bus company or ancient Datsun' it may be unwise to suggest promoting expansion of existing Tesla products to conquer market share for Tesla like the existing market share of SpaceX.

It seems to me none of this matters until pack density reaches a certain level. Cabin heat, deicing, flight distance, will all require more energy from the pack. Since batteries don't get lighter as you travel you will always have 100% of "fuel" weight on board.

 

[unk45]

It seems to me none of this matters until pack density reaches a certain level. Cabin heat, deicing, flight distance, will all require more energy from the pack. Since batteries don't get lighter as you travel you will always have 100% of "fuel" weight on board.

Obviously true. My point does not dispute that. It only assets that traditional aircraft power processes assume complete delinking between power and aircraft design, so the assumption is that multiple engine types can be used without significant alterations. With BEV versions, it obviously would be possible to have different battery options, or even motors, but any changes, even battery size, would alter the aircraft substantially. It is not equivalent to simply adding fuel tanks for longer range, although that can involve major modifications too.

Nobody I know of would suggest that major decreases in pack weight and increases in energy density are essential. Concurrently there must also be major improvements in C rate (for both charging and takeoff).

Above those substantial improvements in battery stability snd BMS structure. Regulators and operators still remember clearly the B787 li-ion problems and some crashes while carrying li-ion batteries, and other incidents in US Navy nuclear submarines. Most of those have since had mitigates, but there still are periodic ships with BEV runaway at sea with catastrophic consequences.

My overall point is that entirely new approaches are needed to make all of this safe, practical and commercially viable. All of that could happen quickly and may take decades. Right now nobody knows for certain.

 

[JRP3]

Concurrently there must also be major improvements in C rate (for both charging and takeoff).

I'm not clear as to why. Enough energy density for distance means a large kWh pack. Such a pack would have plenty of power for takeoff at a relatively low C rate. Short range EV planes already have enough C rate for takeoff even though they can't fly that far. I don't know the turnaround time for the average plane but I would guess current charging rates would be enough for most planes if it's around 30 minutes or more.

 

[daniel]

... Nobody I know of would suggest that major decreases in pack weight and increases in energy density are essential. ...

Really? They don't think that lighter weight of the battery pack is essential for commercially viable electric planes? Certainly it's not needed for there to be a small hobbyist market. But for large-scale aviation, I would think that lighter batteries are indeed essential. There's no way electric planes are going to get the kind of range and payload capacity necessary for economical commercial operation on today's batteries.

 

[JRP3]

A piece on EVTOLS taking on the short trip market

 

[MC3OZ]

Includes some electric planes and Fossil fuel planes.

 

[JRP3]

Chicago to debut first commercial electric air taxi route

Chicagoans may soon be able to cut their commute times from more than an hour to just 10 minutes.

www.yahoo.com

 

[daniel]

Chicago to debut first commercial electric air taxi route

Chicagoans may soon be able to cut their commute times from more than an hour to just 10 minutes.

www.yahoo.com

Sounds sketchy to me. $100 to $150 per person? To ride in a 4-passenger aircraft and shave 20 minutes off a half-hour car trip? If it ever happens (and it would be an air traffic control nightmare) I'll bet it would cost closer to $500.

 

[RichAZ/CapeCod]

Sounds sketchy to me. $100 to $150 per person? To ride in a 4-passenger aircraft and shave 20 minutes off a half-hour car trip? If it ever happens (and it would be an air traffic control nightmare) I'll bet it would cost closer to $500.

Lots of wishful thinking here!

Rich

 

[ThomasD]

4 people at 150 a person will barely cover a Pilot's salary for 8 hours

 

[daniel]

4 people at 150 a person will barely cover a Pilot's salary for 8 hours

To be fair, it's not an 8-hour flight. I think they said it's a 10-minute flight. With recharging and turn-around time they should be able to do at least one round trip per hour. At 50% occupancy that's $600/hour. I still don't think they'll be able to operate at that price.