Decarbonizing Air Travel ?

This video examines overall energy use, how electrification comes into play, and focuses on the energy used for air travel. It shows why liquid fuels are the most useful for long-haul fast air travel, and then describes how they could be made from biofuels. It ends with a cautionary note about the challenges ahead and the possible need for other solutions.

[crazycanucknation]

You may have overlooked, or else I missed, another key benefit of liquid fuels in aircraft vs batteries and that is that as the fuel is burned the aircraft actually gets lighter and easier to propel. The weight of a battery has to be carried regardless of whether it is full or depleted. Great video and thank you

[bobqzzi]

Excellent video. Decarbonizing air travel has got to be a much lower priority than doing the easy stuff

[northsimulation]

Excellent video! One point I wanted to add not covered in the video was recharge times, when a plane is on the ground airlines want to have it back in the air as quick as possible, refuelling is very quick, but if a plane is sitting for a few hours (I’d guess at least) to charge up its massive batteries, that might severely affect the turnaround time for planes on the ground. Just another thing to think about.

[thearisen]

As others have noted, the more jet fuel is used the lighter the aircraft gets which makes it more efficient but there's a safety angle as well. If a jet has some kind of emergency and needs to land it can lighten itself by dumping fuel. You see, jets don't really want to land at their max takeoff weight due to the forces involved. It's one thing for a regional aircraft due to the shortness of the flights but long haul and even medium length travel make it difficult.

[Molikai]

Obe big problem with corn->fuel: It is NOT carbon neutral. Hell, Corn->Ethanol is not carbon neutral. Corn doesn't suck up anywhere near enough CO2, especially when you factor in the methods used to convert it.

[alwar]

OMG A GRETA FLEW OVER MY HOUSE, SHE WAS SCREAMING "USE THE TRAINS, EAT THE BUGS REEE"

[rougenaxela]

Corn-based Ethanol doesn't really seem like such a great approach to me, mostly due to a combination of two main reasons: 1) The ethanol fuel energy balance is just kinda bad for corn ethanol, and 2) Land use. It sort of feels like it defeats the purpose. Corn ethanol's biggest advantage seems to be that it has a huge incumbency advantage, so to speak. Lots of investment in it and a lot of political clout to go along with that.

[AvenEngineer]

For flight specifically, jet fuel is the obvious choice. If we electrify most other things from non-GHG sources, there will be plenty of opportunity to offset, or remove the contribution airplanes make. Nature came up with the stuff, and it's positive properties are orders of magnitude better than anything we could possibly invent. Our combustion machines still have room for improvement, but the fuel, for flight, is aces.

[snigwithasword]

I love that something I first heard of in the original Alpha Centauri Civ game is real and practical. It's a crime that this channel does not have a bajillion views.

[markusbellmann]

It started with videos about nuclear reactors 2 years ago. Now I am still here enjoying your videos! Keep up the good work!

[ddSavant]

I preemptively thumbs-up’d you before watching video. Wasn’t disappointed. Keep up the good work

[nicholas]

Thanks Professor! Your videos are of great quality, _consistently_

[topfuelchannel]

"Decarbonizing Air Travel ?"
Answer: Bring back the catapult...
:-)

[cipaisone]

Recently found this gem of a channel.
Great video, as always.
Awesome shirt :)

[MeaHeaR]

Professor is always eloquent, informative unt interesting to listén two

[kiwidiesel]

Yay thank you for another great video lesson, I have been waiting for ages for another release.

[peteranderson]

Whenever there is a discussion about getting rid of fossil fuels in aviation there is nearly always one topic that is overlooked: General Aviation (GA). For those who are not familiar, it's a blanket term that covers everything from Cessnas to Lear Jets. While it is not directly connected to Commercial Aviation (a.k.a. the airline industry) it plays a vital role there because it supplies the industry with all of its pilots.

The GA industry in the US and Canada is so massive that most other countries' airlines outsource their primary pilot training to the US. Meanwhile, GA primary flight instruction in the US remains largely a cottage industry despite the existence of for-profit aviation focused institutions like Embry Riddle. Most of the mom and pop flight schools like the kind that you'd find at your local community airport run on a razor thin profit margin operating aircraft that are often nearly a half a century old.

Approximately 60% of the single-engine piston fleet in the US is comprised of aircraft made before 1980. 20% is composed of mass produced aircraft made after 1980 and the other 20% are amateur built kit aircraft that are intended for personal use and are prohibited form being rented out for flight instruction by FAA regulations (the FFA, on the other hand, has not released any official guidance on these aircraft). This means that unlike the US automotive or airline fleets, the US single-engine piston fleet that teaches nearly the entire world how to fly is not going to simply phase out the vast bulk of its old aviation fuel airplanes after 20 years in favor of new ethanol kerosene or electric models.

Modifying the current ones may be technically possible, but it is economically unfeasible as modifying anything on a type certificated airplane comes with massive costs. Performing an engine swap can cost several thousand dollars just in labor costs while the engines themselves may costs many tens of thousands of dollars, even on a half century old airplane. Meanwhile, new airplanes can costs many hundreds of thousands of dollars. The reasons behind the age of the current GA fleet are many but, as you can see, cost is one of the reasons. This is why the flight training industry in the US still uses these old airplanes.

Any significant change in cost to the GA fleet could lead to a near total collapse of the flight training industry in the US and could turn the pilot shortage situation that currently exists in the airline industry into a crisis. I'm not sure how to solve this issue, but its something that virtually nobody who talks about decarbonizing air transportation even mentions.

[Ryan-lkpu]

Awesome video as always, Prof!
One of my biggest concerns is that here in the UK, electricity is around 15p per kWh and gas is around 3.5p per kWh.
We need to drive this cost way way down before we can move on to everything being electric otherwise our already massive heating bills are going to become literally unaffordable for a lot of people.

[anthonynicoli]

David- thanks for another informative and hopeful video. I love your clear, complete, evidence based explanations.

[stevemickler]

You overlooked ammonia. It can be burned directly in a turbojet if you don't mind the nitrous oxides, but can be easily split by catalyst to burn hydrogen only.