14 ms·

Rolls-Royce calls off bets on electric planes, says low-carbon fuel is future

145 points by burkaman 3y ago

Lord-Jobo 3y ago
I think this may be wise given the rapid pace of development that batteries are still undergoing. Pretty hard to create a design around a battery when you dont even know what chemistry you are working with. And there is a bit of a revolution happening with lower carbon fuels, even though it sucks compared to pure electric, and it still has a lot of work to make sense(https://www.youtube.com/watch?v=OpEB6hCpIGM https://www.youtube.com/watch?v=OpEB6hCpIGM). I was under the impression though that this was a potentially good area for hydrogen fuel? can anyone confirm? Edit: Here is the video i was looking for https://www.youtube.com/watch?v=OpEB6hCpIGM https://www.youtube.com/watch?v=OpEB6hCpIGM Summary: Jet-A/A1 kerosene is the current mass fuel for passenger planes in the United States, and its dirty, but the most economical. Simple biofuels have all sorts of chemical drawbacks that make them a nonstarter. super processed biofuels however, can match the properties of JetA/A1 very closely, but they are very recently developed. Unfortunately, right now, they cost so much energy to develop that they arent environmentally friendly at all, even disregarding the rainforest destruction it provokes (palm oils). hydrogen may work some day but production is still too costly and it requires a complete redesign of planes and engines, unlike super processed biofuels. it also requires expensive and sensitive cryogenic storage to make energy density work. e-fuels, or hydrogen composite fuel (liquid methanol, etc) may solve all of the above problems and grow as a more economical option rapidly, but they will still not match the cost performance of JetA/A1 which means increased costs for travel/shipping are unavoidable. electric is an option with the most uncertainty, but there are already niche use cases that already make more sense than other options. mostly small craft and short flight distances. but that does take a decent chunk out of our current consumption. if battery chemistry keeps moving forward at a rapid pace, this could legitimately replace a lot of the air travel we do, but until those batteries are already coming out of factories, its difficult to design around. so here we are.
- samuelstros 3y ago
  Your statement sounds like a contradiction. If the development of batteries is so rapid, Rolls Royce not investing in electric engines and doubling down on fuel-burning engines instead could open them up for a book story worthy "disruption". By the time batteries/electric plane engines suddenly become good enough, Rolls Royce might face themselves in a "why does nobody want our fuel-burning engines anymore" situation that will require multiple years to catch up to electric engine manufacturers. Multiple years of catching up that Rolls Royce might not have at the time they find themselves in the "nobody wants our engines anymore" situation.
  - deleted 3y ago
    [deleted]
  - nabla9 3y ago
    Rolls Royce is owned by BMW. BMW does strategic investments and R&D for them. They just look what they need for next few models.
    - hgomersall 3y ago
      Different Rolls Royce: https://en.wikipedia.org/wiki/Rolls-Royce_Holdings https://en.wikipedia.org/wiki/Rolls-Royce_Holdings
    - samuelstros 3y ago
      The Rolls Royce company of discussion is not owned by BMW. The car brand Rolls Royce is owned by BMW.
  - bluGill 3y ago
    We know the laws of physics behind batteries. The theoretical best possible battery (which assumes things like spherical cows) is still very heavy compared to burning liquid fuels. Yes battery advancement is happening rapidly, but it can only asymptotically approach the limits which are not very good for the purposes of flight. I believe there as chemists and physicist better qualified than me to tell you what the limits are.
unethical_ban 3y ago
I've not heard of sustainable aviation fuel. Is it snake oil? Why wouldn't it just be "sustainable fuel" suitable for trains and automobiles? And if we simply slowed the world down a little bit I wonder if blimps could take over for a majority of ocean-crossing journeys. Not that it will ever happen.
- denimnerd42 3y ago
  They are developing these fuels for Formula1 and the like. Probably won't see them in road vehicles due to cost. But never know. It's likely normal fuels in hybrids or pure electric vehicles will be better (cheaper and lower carbon). For trains overhead electrification would be better. I'm not sure the fuel itself is that low carbon but the cycle of producing it may be. I'm sure a quick search would reveal they produce slightly less CO2 or something in a suitable engine.
  - handy2000 3y ago
    Do you mean synthetic fuel? Haven't heard of Formula1 being interested in biofuel.
    - rswskg 3y ago
      It's a huge part of the 2026 rule changes.
      - handy2000 3y ago
        E-fuel is different from SAF that is described in this article. E-fuel is carbon-neutral and SAF is low-carbon (made from tallow, algae, etc).
    - denimnerd42 3y ago
      There's no mention of biofuel in the article. But yes any technology designed to reduce the impact of the fuel production/use cycle. In F1 it's branded as synthetic fuel right? It's like a natural gas derived fuel but could be derived from anything the scientists engineers can make work. Jet fuel is heavier so starting with an oil derived from bio matter might make more sense. Either way something designed with less impact than drilling for fuel.
FredPret 3y ago
I would've thought that the main challenge is the density of energy storage. It's hard for a battery to beat kerosene. The article mentions the industry took a hit during Covid. It's interesting to note that a company like Air Lease Corporation (which buys aircraft and leases it to airlines) basically soldiered on unaffected by the pandemic [https://valustox.com/AL https://valustox.com/AL - there's a big dip in profit a year ago, but that's due to the Russian war sanctions].
- anon84873628 3y ago
  Plus burnt jet fuel weighs nothing, whereas a spent battery weighs the same as a fully charged one. It seems there needs to be a radical price difference between electrical and chemical energy before the virtues of the rocket equation are overcome for airline travel.
  - Ekaros 3y ago
    Considering just how cheap renewable energy can be, even poor efficiency might not matter. If you have process that can be scaled by supply of cheap electric power, it could work even if there is inefficiencies in process and in use.
    - wayfinder 3y ago
      It's not generating the energy -- it's storing it. Fossil fuels are massively more energy dense than our current electric batteries. Fossil fuels are literally dead animals pressurized by Earth... all that energy went into the fuel. Planets work on massively larger scales of energy than human society right now and we're using stored energy created by planets to fly.
      - sokoloff 3y ago
        > Fossil fuels are literally dead animals By mass, fossil fuels are mostly from plants, algae, and bacteria rather than animals.
      - 3y ago
datadrivenangel 3y ago
The future of electric planes is going to be based on drone motor technology at this rate!
bprater 3y ago
Batteries are heavy. Teslas are very heavy cars. Aircraft are extraordinary light, compared to ground-based vehicles. Even in flight, large aircraft will burn a lot of their fuel during ascent. Electric powered aircraft get to drag around the heavy used batteries until recharge. And then you have to figure out how to refuel. Until a significant change in battery density, electric planes aren't going to be a thing.
- ramesh31 3y ago
  >Until a significant change in battery density, electric planes aren't going to be a thing. There's a big caveat there though. Current aircraft engines are extremely expensive to operate and maintain, regardless of fuel costs. Even a simple GA piston engine would cost more to operate than a small commercial EV aircraft's motors. Replacing turbines with electric motors will provide cost savings that actually make small commuter flights economical again. Kerosene and jet engines aren't going anywhere for the long haul flights. But the future for electric aviation is in the sub 300 mile regional commuter market, where it's faster than a train and has the simplicity of catching a bus. See Eviation Alice for an example: https://www.popularmechanics.com/flight/a41453056/eviation-electric-aircraft/ https://www.popularmechanics.com/flight/a41453056/eviation-e... Today's battery tech is just barely good enough at this point to start becoming useful for these kinds of flight profiles.
  - bluGill 3y ago
    Sub 300 miles the train should be faster door to door. Trains a better able to get into the middle of a city - airports both take a lot of space and are noisy so they get pushed to the edge of the city. Trains are also better able to integrate with a public transport system so they are easy to get to. Trains don't have the silly security lines (normally - though planes don't need them either). Trains also don't have large economic benefits from every seat full, so they can better handle someone making a last minute decision to go. Note that I said should above. The reality is North America has terrible train service, and management (congress!) doesn't care: so airplanes end up better despite all reasons they are worse for short trips.
matthewfelgate 3y ago
He's right to gut pointless divisions on fake futures: - Carbon capture is nonsense. - So are flying taxis. - So are electric planes. - Hydrogen planes is even more of a joke.
- hawk_ 3y ago
  Why is hydrogen plane a joke?
  - netrap 3y ago
    The fuel is too dangerous to store..
    - angiosperm 3y ago
      Yet, millions of tons of H2 is produced, stored and transported annually, today. It needs adequate ventilation to ensure that any leakage doesn't accumulate to exceed a 25% mix with air. That is done where H2 is used now. You are not hearing about hydrogen detonations.
  - buildsjets 3y ago
    I am BuildsJets now, but 20 years ago I was BuildsCryoFuelsystems. Go look at the cross section of an actual hydrogen-powered aircraft that has flown actual missions under it's own power, such as the Boeing Phantom Eye. The USSR's TU-155 flying testbed aircraft does not count, it did not fly under hydrogen power or fly an actual mission, it just ran an engine in the air. Observe how much of the airframe's space is used by fuel storage, compared to payload. Now do the same thing for a commercial airliner, and realize that commercial aircraft are just barely profitable with their current payload:fuel weight ratio. Also, did you know that when you refuel a liquid hydrogen tank, a significant portion of the fuel is vented off to the atmosphere? In the case of the Space Shuttle, LH2 filling losses are around 20% of total fuel load. Then there are boil-off significant losses while the vehicle sits around warming up. So to be most efficient, you would need to either fuel up IMMEDIATELY before loading passengers, or hot-loading propellant with passengers on-board, like SpaceX does, and the FAA prohibits for commercial passenger operation. There are also boil-off losses in the transportation and storage equipment to consider, and boil-off losses everytime you transfer to a different storage or transportation medium.
jillesvangurp 3y ago
It's a crowded market and they are targeting planes that can replace jets for medium and longer distance. Which at least short term won't be electric. That would require breakthroughs in fuel cells that I think they are starting to conclude are a combination of expensive and impractical. And there's the whole notion that green hydrogen is more of a promise than a reality right now. Battery electric makes a lot of sense for smaller planes and distances. But that's a very dynamic market with a lot of players and not a lot of clear added value for Rolls-Royce. Also, it's very different from their current market which is basically focused on jet engines for big planes. That stuff is just way out of their comfort zone. IMHO, the commuter plane market will change quite dramatically in the next decade. Basically battery electric is not a drop in replacement for those planes. But instead that market will start shifting to much simpler and smaller planes that are dirt cheap to manufacture and operate. Basically the main cost is the battery and the maintenance. Add autonomous flight or at least vastly simpler operations to the mix and pilot cost goes down as well. That enables flying with much more but smaller planes. Which in turn enables flying to and from much smaller airfields closer to where people want to go. With vtol, potentially even inside cities. Long term commuter jets (with fuel cells or sustainable fuel) won't be able to compete on cost for short hops.
- graphe 3y ago
  Where do you think the term autopilot came from? ;) Smaller planes means more crowded airspace. I bet the permits will be the biggest obstacle. How would you price these? It would be hilarious if small planes took over instead of high speed rail. I could see cheaper helicopters being popular.
  - unglaublich 3y ago
    Oh, wouldn't it be hi· lar· i· ous to see 250 gCO2eq/km/person domestic flights overtake 4 gCO2eq/km/person rail... and the numbers for helicopters are even worse! https://ourworldindata.org/travel-carbon-footprint https://ourworldindata.org/travel-carbon-footprint
    - graphe 3y ago
incomingpain 3y ago
every industry inflection point always has the dinosaurs who go extinct. Those who don't see the inflection and want to keep their momentum in their set direction will find themselves in bankruptcy. Unfortunate that rolls royce seems to have decided not to keep up.
- bluGill 3y ago
  There have been a lot of predicted disasters that never happened. There are fundamental physics in play when I confidentially say that battery airplanes will never be more than a small niche.
  - incomingpain 3y ago
    >battery airplanes will never be more than a small niche. I wish I could take that bet. I'd put whatever amount of money down on that. They say never say never but you are asserting fundamental physics prevents it from happening? Within 5 years I expect to see my local GA manufacturer start pumping out battery electric planes. Within 10 years it will be reasonably possible to get yourself on an electric plane. Regional electric planes will start replacing older planes. The like 20-seater type size. I expect the niche stuff like seaplanes probably start getting certified around this spot. Within 20 years the regional flight will have mostly converted to electric and some of the early adopters will have finished amortizing those planes. within 30 years the massive airliners will be replaced with 20MW or so battery electrics. I will even go further and say these won't look like traditional planes.
    - xcv123 3y ago
      > you are asserting fundamental physics prevents it from happening? The energy density of batteries vs fuels is the current limitation. We don't know if this problem can ever be solved. A business cannot gamble on some magical hopes and dreams. > within 30 years the massive airliners will be replaced with 20MW or so battery electrics And how much will those 20MW batteries weigh? With the current lithium battery technology, you would need a 7,167 metric ton battery to store the same amount of energy as 150 tons of jet fuel, which is typical for a long haul passenger jet.
antisthenes 3y ago
Carbon-neutral generation of hydrocarbon fuels from air with solar energy surplus is the future for applications that need energy density. There will never be a battery that's anywhere close to 13kwh/kg of gasoline or similar fuels. So the 2nd best thing is to generate emission free gasoline and burn it as cleanly as possible.
dghughes 3y ago
I wonder if satellite-based system to use space-based solar power generation and convert to microwaves to beam power to aircraft would work? Store just enough on the plane for take off and emergency landing nearby plus a buffer for in-flight space power. For long flights the plane receives a beam of energy. Everyone would probably die from being cooked but it may work.
- meindnoch 3y ago
  Just to put that into perspective: a 747 uses 90 MW peak power during takeoff. And that's the useful power it needs as thrust, so the engines produce quite a bit more than that.
  - angiosperm 3y ago
    Yeah, microwaves are right out. Lasers, maybe, but lasers that can focus so closely qualify as offensive weapons. Generally, less-focused lasers, picked up by nighttime solar farms that absorb sunlight directly in the daytime, are a much more likely medium for orbital power than microwaves. Monochromatic light can be converted to electrical power with much higher efficiency than can blackbody solar radiation. Lasers producing no greater intensity than sunlight worry people less than microwave radiation.
- Ekaros 3y ago
  What is the surface area of the top of a plane? How much power do you need? How much power per area do you need to deliver and with what efficiency?
  - Someone 3y ago
    https://energycentral.com/c/ec/flying-without-fossil-fuels-need-high-energy-density https://energycentral.com/c/ec/flying-without-fossil-fuels-n...: “Mid-flight a Boeing 747 uses around 4 litres of jet fuel per second. Therefore given the energy density of jet fuel, approximately 35 MJ/litre, a Boeing 747 consumes energy at a rate of around 140 MW (million watts). We can then convert this rate of energy consumption into power density, that is the rate of energy consumption per square metre. Typically this is measured in watts per square metre (W/m2 ). A Boeing 747 is 70 by 65 metres. So the power density over this 70 by 65 metre square is approximately 30,000 W/², and of course the power density over the surface area of the plane will be a few times higher, over 100,000 W/m²” There may be gains there if electric motors are more efficient than jet engines (are they?), but overall, you’d need a lot more power than solar. I think that density is attainable, but wouldn’t bet on it being practical except, maybe, for military use, and probably not for planes but for ground use (beaming energy to a base in Iraq may be easier than transporting oil there via trucks driving through a war zone) For powering planes, I guess you’ll have to give up speed. That drastically decreases power need at level flight (the planes that flew around the world on solar energy were slow for a reason) You also will have to track the plane withyour energy beam as it moves.
Slava_Propanei 3y ago
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izzydata 3y ago
What are the chances that planes are just not a viable mode of travel in 100 years time? It would be interesting if it only existed for less than 200 years throughout all of human history.
- cherryteastain 3y ago
  What do you propose would replace them?
  - izzydata 3y ago
    The thing that existed before planes. Boats and trains.
    - njarboe 3y ago
      Before that. Walking.
    - iancmceachern 3y ago
      Those burn the same fuel...
      - nicoburns 3y ago
        Boats do, but trains are mostly electric.
        iancmceachern 3y ago
        Not in the US, their mostly diesel here
      - izzydata 3y ago
        Boats aren't constrained by weight like planes are. You could put any amount of batteries on a boat and get it to float and move on water. They can also be moved by wind. I may be wrong, but I also thought there existed some nuclear powered boats.
robocat 3y ago
It isn't just about electric planes: Rolls-Royce were trying to be G.E. and failing. slashing divisions such as R2 Factory, an in-house artificial intelligence software unit, and a direct air carbon capture project. Rolls-Royce said it would cut 2,500 management and administration jobs. The next head to roll is its electrical business, which develops propulsion systems for flying taxis and other aircraft. Did Rolls-Royce think they were a VC/incubator for inventions with multi-decade payoffs? Tough market. Rolls-Royce continue to develop for the nuclear power market - I'm guessing driven by government/military money. Compare to GE Hitachi: https://www.gevernova.com/nuclear https://www.gevernova.com/nuclear Then again, looking at the General Electric website makes me want to short GE! Read and weep their AI initiative to develop buzzwords: https://www.ge.com/research/initiative/industrial-ai https://www.ge.com/research/initiative/industrial-ai Or the bigger picture: Q: What is GE's mission/purpose statement? A: GE's newly defined Purpose is “We rise to the challenge of building a world that works.” Q: What industries does GE operate in? A: GE has long been a leader in Power, Renewable Energy and Aerospace. Today, GE also leads in delivering solutions across Additive Manufacturing, materials science and data analytics. Financially, a basket of options is worth more than an option on a basket (RR share price). https://medium.com/@kentbeck_7670/decisions-decisions-or-why-baskets-of-options-dominate-9ac63658b593 https://medium.com/@kentbeck_7670/decisions-decisions-or-why... Rolls-Royce blurb: Rolls-Royce develops and delivers complex power and propulsion solutions for safety-critical applications in the air, at sea and on land. Strategic initiatives: Detailed divisional plans that will focus on opportunities where key drivers give us competitive advantage: widebody aircraft, business aviation, transport & patrol, combat, submarines, governmental and marine.
- scrlk 3y ago
  > Rolls-Royce continue to develop for the nuclear power market - I'm guessing driven by government/military money. Correct - RR are the manufacturer of the PWR reactors that power the Royal Navy's submarines. They are trying to capitalise on this by branching out in to SMRs.
phkahler 3y ago
I still wonder if most of the human impact on climate is not the CO2 but the water vapor put out by planes. See the post 911 weather, and more recently around here a lot of people know what "covid sky" means. The sky was very clear and blue during the early shutdowns. If this hypothesis is correct then low-carbon fuels (say methane) are the wrong answer. Low hydrogen fuel would be better. Bring on the coal fired airplanes!! Sounds so silly, but hey...
xp84 3y ago
Is there a primer on what exactly "SAF" or "low-carbon fuel" actually is? It's not "just" hydrogen, or is it? It just sounds too convenient to be a real thing. "Oh, just use the LOW-carbon fuels. There's your problem!" Edit: Not disputing the fact that electrical airplanes present a staggering affront to the laws of physics due to weight. Just seems like the "third alternative" here (to status quo or battery) is being taken for granted.
- cobrabyte 3y ago
  It's sort of still being defined. There's a rush to develop a universal SAF, but companies can develop blends of alternative fuel sources and get money back from the US government in the process. https://afdc.energy.gov/fuels/sustainable_aviation_fuel.html https://afdc.energy.gov/fuels/sustainable_aviation_fuel.html
- angiosperm 3y ago
  LH2 may, in fact, be low-carbon fuel, depending of course on how it was produced. An LH2-powered aircraft would use exactly the electric turbines that Rolls-Royce just cancelled work on. Once LH2-powered aircraft enter any given market, kerosene-powered craft would be wholly unable to compete. But it will take a long time to build up infrastructure for it. Ultimately, international airports will electrolyse their own LH2 using power delivered from regional solar and wind farms, but don't expect to see much of it before 2050.
  - JonChesterfield 3y ago
    > Once LH2-powered aircraft enter any given market, kerosene-powered craft would be wholly unable to compete. Liquid hydrogen has about 1/4 the energy density of kerosene by volume. It's better per kilo which is nice for aircraft but you're still looking at finding lots more space in the structure for fuel or accepting that you can't fly very far. I don't see that being competitive with kerosene.
    - angiosperm 3y ago
      LH2 would not fit in the wings, but would fit handily in nacelles slung under them. Space aboard aircraft is cheap; it is weight that costs.
zzzcsgo 3y ago
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simonblack 3y ago
Until we can actually find something with an energy/mass ratio as good as chemical fuels, we going to have to continue using those chemical fuels indefinitely. No matter what the good intentions of the day happen to be.
dr_dshiv 3y ago
Can’t we have high energy density liquid fuels and electric engines?
- JonChesterfield 3y ago
  Sure. Run a genset off the fuel and drive a motor with that. Works fine. Not very sensible in terms of drivetrain mass or efficiency.
  - dr_dshiv 3y ago
    You wouldn’t get any of the benefits of hybrid electric cars, you are saying.
    - JonChesterfield 3y ago
      I believe genset+motor is the implementation of some hybrid cars, possibly calling it a range extender. Some others have a combustion engine and motors attached to the same gearbox (iirc that's the Prius setup). However I'm not very clear on what non-marketing advantages there are supposed to be to having both petrol and lithium fuels on board.

145 points by burkaman 3y ago

I think this may be wise given the rapid pace of development that batteries are still undergoing. Pretty hard to create a design around a battery when you dont even know what chemistry you are working with. And there is a bit of a revolution happening with lower carbon fuels, even though it sucks compared to pure electric, and it still has a lot of work to make sense(https://www.youtube.com/watch?v=OpEB6hCpIGM https://www.youtube.com/watch?v=OpEB6hCpIGM). I was under the impression though that this was a potentially good area for hydrogen fuel? can anyone confirm? Edit: Here is the video i was looking for https://www.youtube.com/watch?v=OpEB6hCpIGM https://www.youtube.com/watch?v=OpEB6hCpIGM Summary: Jet-A/A1 kerosene is the current mass fuel for passenger planes in the United States, and its dirty, but the most economical. Simple biofuels have all sorts of chemical drawbacks that make them a nonstarter. super processed biofuels however, can match the properties of JetA/A1 very closely, but they are very recently developed. Unfortunately, right now, they cost so much energy to develop that they arent environmentally friendly at all, even disregarding the rainforest destruction it provokes (palm oils). hydrogen may work some day but production is still too costly and it requires a complete redesign of planes and engines, unlike super processed biofuels. it also requires expensive and sensitive cryogenic storage to make energy density work. e-fuels, or hydrogen composite fuel (liquid methanol, etc) may solve all of the above problems and grow as a more economical option rapidly, but they will still not match the cost performance of JetA/A1 which means increased costs for travel/shipping are unavoidable. electric is an option with the most uncertainty, but there are already niche use cases that already make more sense than other options. mostly small craft and short flight distances. but that does take a decent chunk out of our current consumption. if battery chemistry keeps moving forward at a rapid pace, this could legitimately replace a lot of the air travel we do, but until those batteries are already coming out of factories, its difficult to design around. so here we are.

samuelstros 3y ago
Your statement sounds like a contradiction. If the development of batteries is so rapid, Rolls Royce not investing in electric engines and doubling down on fuel-burning engines instead could open them up for a book story worthy "disruption". By the time batteries/electric plane engines suddenly become good enough, Rolls Royce might face themselves in a "why does nobody want our fuel-burning engines anymore" situation that will require multiple years to catch up to electric engine manufacturers. Multiple years of catching up that Rolls Royce might not have at the time they find themselves in the "nobody wants our engines anymore" situation.
- deleted 3y ago
  [deleted]
- nabla9 3y ago
  Rolls Royce is owned by BMW. BMW does strategic investments and R&D for them. They just look what they need for next few models.
  - hgomersall 3y ago
    Different Rolls Royce: https://en.wikipedia.org/wiki/Rolls-Royce_Holdings https://en.wikipedia.org/wiki/Rolls-Royce_Holdings
  - samuelstros 3y ago
    The Rolls Royce company of discussion is not owned by BMW. The car brand Rolls Royce is owned by BMW.
- bluGill 3y ago
  We know the laws of physics behind batteries. The theoretical best possible battery (which assumes things like spherical cows) is still very heavy compared to burning liquid fuels. Yes battery advancement is happening rapidly, but it can only asymptotically approach the limits which are not very good for the purposes of flight. I believe there as chemists and physicist better qualified than me to tell you what the limits are.

unethical_ban 3y ago

I've not heard of sustainable aviation fuel. Is it snake oil? Why wouldn't it just be "sustainable fuel" suitable for trains and automobiles? And if we simply slowed the world down a little bit I wonder if blimps could take over for a majority of ocean-crossing journeys. Not that it will ever happen.

denimnerd42 3y ago
They are developing these fuels for Formula1 and the like. Probably won't see them in road vehicles due to cost. But never know. It's likely normal fuels in hybrids or pure electric vehicles will be better (cheaper and lower carbon). For trains overhead electrification would be better. I'm not sure the fuel itself is that low carbon but the cycle of producing it may be. I'm sure a quick search would reveal they produce slightly less CO2 or something in a suitable engine.
- handy2000 3y ago
  Do you mean synthetic fuel? Haven't heard of Formula1 being interested in biofuel.
  - rswskg 3y ago
    It's a huge part of the 2026 rule changes.
    - handy2000 3y ago
      E-fuel is different from SAF that is described in this article. E-fuel is carbon-neutral and SAF is low-carbon (made from tallow, algae, etc).
  - denimnerd42 3y ago
    There's no mention of biofuel in the article. But yes any technology designed to reduce the impact of the fuel production/use cycle. In F1 it's branded as synthetic fuel right? It's like a natural gas derived fuel but could be derived from anything the scientists engineers can make work. Jet fuel is heavier so starting with an oil derived from bio matter might make more sense. Either way something designed with less impact than drilling for fuel.

FredPret 3y ago

I would've thought that the main challenge is the density of energy storage. It's hard for a battery to beat kerosene. The article mentions the industry took a hit during Covid. It's interesting to note that a company like Air Lease Corporation (which buys aircraft and leases it to airlines) basically soldiered on unaffected by the pandemic [https://valustox.com/AL https://valustox.com/AL - there's a big dip in profit a year ago, but that's due to the Russian war sanctions].

anon84873628 3y ago
Plus burnt jet fuel weighs nothing, whereas a spent battery weighs the same as a fully charged one. It seems there needs to be a radical price difference between electrical and chemical energy before the virtues of the rocket equation are overcome for airline travel.
- Ekaros 3y ago
  Considering just how cheap renewable energy can be, even poor efficiency might not matter. If you have process that can be scaled by supply of cheap electric power, it could work even if there is inefficiencies in process and in use.
  - wayfinder 3y ago
    It's not generating the energy -- it's storing it. Fossil fuels are massively more energy dense than our current electric batteries. Fossil fuels are literally dead animals pressurized by Earth... all that energy went into the fuel. Planets work on massively larger scales of energy than human society right now and we're using stored energy created by planets to fly.
    - sokoloff 3y ago
      > Fossil fuels are literally dead animals By mass, fossil fuels are mostly from plants, algae, and bacteria rather than animals.
    - 3y ago

datadrivenangel 3y ago

The future of electric planes is going to be based on drone motor technology at this rate!

bprater 3y ago

Batteries are heavy. Teslas are very heavy cars. Aircraft are extraordinary light, compared to ground-based vehicles. Even in flight, large aircraft will burn a lot of their fuel during ascent. Electric powered aircraft get to drag around the heavy used batteries until recharge. And then you have to figure out how to refuel. Until a significant change in battery density, electric planes aren't going to be a thing.

ramesh31 3y ago
>Until a significant change in battery density, electric planes aren't going to be a thing. There's a big caveat there though. Current aircraft engines are extremely expensive to operate and maintain, regardless of fuel costs. Even a simple GA piston engine would cost more to operate than a small commercial EV aircraft's motors. Replacing turbines with electric motors will provide cost savings that actually make small commuter flights economical again. Kerosene and jet engines aren't going anywhere for the long haul flights. But the future for electric aviation is in the sub 300 mile regional commuter market, where it's faster than a train and has the simplicity of catching a bus. See Eviation Alice for an example: https://www.popularmechanics.com/flight/a41453056/eviation-electric-aircraft/ https://www.popularmechanics.com/flight/a41453056/eviation-e... Today's battery tech is just barely good enough at this point to start becoming useful for these kinds of flight profiles.
- bluGill 3y ago
  Sub 300 miles the train should be faster door to door. Trains a better able to get into the middle of a city - airports both take a lot of space and are noisy so they get pushed to the edge of the city. Trains are also better able to integrate with a public transport system so they are easy to get to. Trains don't have the silly security lines (normally - though planes don't need them either). Trains also don't have large economic benefits from every seat full, so they can better handle someone making a last minute decision to go. Note that I said should above. The reality is North America has terrible train service, and management (congress!) doesn't care: so airplanes end up better despite all reasons they are worse for short trips.

matthewfelgate 3y ago

He's right to gut pointless divisions on fake futures: - Carbon capture is nonsense. - So are flying taxis. - So are electric planes. - Hydrogen planes is even more of a joke.

hawk_ 3y ago
Why is hydrogen plane a joke?
- netrap 3y ago
  The fuel is too dangerous to store..
  - angiosperm 3y ago
    Yet, millions of tons of H2 is produced, stored and transported annually, today. It needs adequate ventilation to ensure that any leakage doesn't accumulate to exceed a 25% mix with air. That is done where H2 is used now. You are not hearing about hydrogen detonations.
- buildsjets 3y ago
  I am BuildsJets now, but 20 years ago I was BuildsCryoFuelsystems. Go look at the cross section of an actual hydrogen-powered aircraft that has flown actual missions under it's own power, such as the Boeing Phantom Eye. The USSR's TU-155 flying testbed aircraft does not count, it did not fly under hydrogen power or fly an actual mission, it just ran an engine in the air. Observe how much of the airframe's space is used by fuel storage, compared to payload. Now do the same thing for a commercial airliner, and realize that commercial aircraft are just barely profitable with their current payload:fuel weight ratio. Also, did you know that when you refuel a liquid hydrogen tank, a significant portion of the fuel is vented off to the atmosphere? In the case of the Space Shuttle, LH2 filling losses are around 20% of total fuel load. Then there are boil-off significant losses while the vehicle sits around warming up. So to be most efficient, you would need to either fuel up IMMEDIATELY before loading passengers, or hot-loading propellant with passengers on-board, like SpaceX does, and the FAA prohibits for commercial passenger operation. There are also boil-off losses in the transportation and storage equipment to consider, and boil-off losses everytime you transfer to a different storage or transportation medium.

jillesvangurp 3y ago

It's a crowded market and they are targeting planes that can replace jets for medium and longer distance. Which at least short term won't be electric. That would require breakthroughs in fuel cells that I think they are starting to conclude are a combination of expensive and impractical. And there's the whole notion that green hydrogen is more of a promise than a reality right now. Battery electric makes a lot of sense for smaller planes and distances. But that's a very dynamic market with a lot of players and not a lot of clear added value for Rolls-Royce. Also, it's very different from their current market which is basically focused on jet engines for big planes. That stuff is just way out of their comfort zone. IMHO, the commuter plane market will change quite dramatically in the next decade. Basically battery electric is not a drop in replacement for those planes. But instead that market will start shifting to much simpler and smaller planes that are dirt cheap to manufacture and operate. Basically the main cost is the battery and the maintenance. Add autonomous flight or at least vastly simpler operations to the mix and pilot cost goes down as well. That enables flying with much more but smaller planes. Which in turn enables flying to and from much smaller airfields closer to where people want to go. With vtol, potentially even inside cities. Long term commuter jets (with fuel cells or sustainable fuel) won't be able to compete on cost for short hops.

graphe 3y ago
Where do you think the term autopilot came from? ;) Smaller planes means more crowded airspace. I bet the permits will be the biggest obstacle. How would you price these? It would be hilarious if small planes took over instead of high speed rail. I could see cheaper helicopters being popular.
- unglaublich 3y ago
  Oh, wouldn't it be hi· lar· i· ous to see 250 gCO2eq/km/person domestic flights overtake 4 gCO2eq/km/person rail... and the numbers for helicopters are even worse! https://ourworldindata.org/travel-carbon-footprint https://ourworldindata.org/travel-carbon-footprint
  - graphe 3y ago

incomingpain 3y ago

every industry inflection point always has the dinosaurs who go extinct. Those who don't see the inflection and want to keep their momentum in their set direction will find themselves in bankruptcy. Unfortunate that rolls royce seems to have decided not to keep up.

bluGill 3y ago
There have been a lot of predicted disasters that never happened. There are fundamental physics in play when I confidentially say that battery airplanes will never be more than a small niche.
- incomingpain 3y ago
  >battery airplanes will never be more than a small niche. I wish I could take that bet. I'd put whatever amount of money down on that. They say never say never but you are asserting fundamental physics prevents it from happening? Within 5 years I expect to see my local GA manufacturer start pumping out battery electric planes. Within 10 years it will be reasonably possible to get yourself on an electric plane. Regional electric planes will start replacing older planes. The like 20-seater type size. I expect the niche stuff like seaplanes probably start getting certified around this spot. Within 20 years the regional flight will have mostly converted to electric and some of the early adopters will have finished amortizing those planes. within 30 years the massive airliners will be replaced with 20MW or so battery electrics. I will even go further and say these won't look like traditional planes.
  - xcv123 3y ago
    > you are asserting fundamental physics prevents it from happening? The energy density of batteries vs fuels is the current limitation. We don't know if this problem can ever be solved. A business cannot gamble on some magical hopes and dreams. > within 30 years the massive airliners will be replaced with 20MW or so battery electrics And how much will those 20MW batteries weigh? With the current lithium battery technology, you would need a 7,167 metric ton battery to store the same amount of energy as 150 tons of jet fuel, which is typical for a long haul passenger jet.

antisthenes 3y ago

Carbon-neutral generation of hydrocarbon fuels from air with solar energy surplus is the future for applications that need energy density. There will never be a battery that's anywhere close to 13kwh/kg of gasoline or similar fuels. So the 2nd best thing is to generate emission free gasoline and burn it as cleanly as possible.

dghughes 3y ago

I wonder if satellite-based system to use space-based solar power generation and convert to microwaves to beam power to aircraft would work? Store just enough on the plane for take off and emergency landing nearby plus a buffer for in-flight space power. For long flights the plane receives a beam of energy. Everyone would probably die from being cooked but it may work.

meindnoch 3y ago
Just to put that into perspective: a 747 uses 90 MW peak power during takeoff. And that's the useful power it needs as thrust, so the engines produce quite a bit more than that.
- angiosperm 3y ago
  Yeah, microwaves are right out. Lasers, maybe, but lasers that can focus so closely qualify as offensive weapons. Generally, less-focused lasers, picked up by nighttime solar farms that absorb sunlight directly in the daytime, are a much more likely medium for orbital power than microwaves. Monochromatic light can be converted to electrical power with much higher efficiency than can blackbody solar radiation. Lasers producing no greater intensity than sunlight worry people less than microwave radiation.
Ekaros 3y ago
What is the surface area of the top of a plane? How much power do you need? How much power per area do you need to deliver and with what efficiency?
- Someone 3y ago
  https://energycentral.com/c/ec/flying-without-fossil-fuels-need-high-energy-density https://energycentral.com/c/ec/flying-without-fossil-fuels-n...: “Mid-flight a Boeing 747 uses around 4 litres of jet fuel per second. Therefore given the energy density of jet fuel, approximately 35 MJ/litre, a Boeing 747 consumes energy at a rate of around 140 MW (million watts). We can then convert this rate of energy consumption into power density, that is the rate of energy consumption per square metre. Typically this is measured in watts per square metre (W/m2 ). A Boeing 747 is 70 by 65 metres. So the power density over this 70 by 65 metre square is approximately 30,000 W/², and of course the power density over the surface area of the plane will be a few times higher, over 100,000 W/m²” There may be gains there if electric motors are more efficient than jet engines (are they?), but overall, you’d need a lot more power than solar. I think that density is attainable, but wouldn’t bet on it being practical except, maybe, for military use, and probably not for planes but for ground use (beaming energy to a base in Iraq may be easier than transporting oil there via trucks driving through a war zone) For powering planes, I guess you’ll have to give up speed. That drastically decreases power need at level flight (the planes that flew around the world on solar energy were slow for a reason) You also will have to track the plane withyour energy beam as it moves.

Slava_Propanei 3y ago

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izzydata 3y ago

What are the chances that planes are just not a viable mode of travel in 100 years time? It would be interesting if it only existed for less than 200 years throughout all of human history.

cherryteastain 3y ago
What do you propose would replace them?
- izzydata 3y ago
  The thing that existed before planes. Boats and trains.
  - njarboe 3y ago
    Before that. Walking.
  - iancmceachern 3y ago
    Those burn the same fuel...
    - nicoburns 3y ago
      Boats do, but trains are mostly electric.
      - iancmceachern 3y ago
        Not in the US, their mostly diesel here
    - izzydata 3y ago
      Boats aren't constrained by weight like planes are. You could put any amount of batteries on a boat and get it to float and move on water. They can also be moved by wind. I may be wrong, but I also thought there existed some nuclear powered boats.

robocat 3y ago

It isn't just about electric planes: Rolls-Royce were trying to be G.E. and failing. slashing divisions such as R2 Factory, an in-house artificial intelligence software unit, and a direct air carbon capture project. Rolls-Royce said it would cut 2,500 management and administration jobs. The next head to roll is its electrical business, which develops propulsion systems for flying taxis and other aircraft. Did Rolls-Royce think they were a VC/incubator for inventions with multi-decade payoffs? Tough market. Rolls-Royce continue to develop for the nuclear power market - I'm guessing driven by government/military money. Compare to GE Hitachi: https://www.gevernova.com/nuclear https://www.gevernova.com/nuclear Then again, looking at the General Electric website makes me want to short GE! Read and weep their AI initiative to develop buzzwords: https://www.ge.com/research/initiative/industrial-ai https://www.ge.com/research/initiative/industrial-ai Or the bigger picture: Q: What is GE's mission/purpose statement? A: GE's newly defined Purpose is “We rise to the challenge of building a world that works.” Q: What industries does GE operate in? A: GE has long been a leader in Power, Renewable Energy and Aerospace. Today, GE also leads in delivering solutions across Additive Manufacturing, materials science and data analytics. Financially, a basket of options is worth more than an option on a basket (RR share price). https://medium.com/@kentbeck_7670/decisions-decisions-or-why-baskets-of-options-dominate-9ac63658b593 https://medium.com/@kentbeck_7670/decisions-decisions-or-why... Rolls-Royce blurb: Rolls-Royce develops and delivers complex power and propulsion solutions for safety-critical applications in the air, at sea and on land. Strategic initiatives: Detailed divisional plans that will focus on opportunities where key drivers give us competitive advantage: widebody aircraft, business aviation, transport & patrol, combat, submarines, governmental and marine.

scrlk 3y ago
> Rolls-Royce continue to develop for the nuclear power market - I'm guessing driven by government/military money. Correct - RR are the manufacturer of the PWR reactors that power the Royal Navy's submarines. They are trying to capitalise on this by branching out in to SMRs.

phkahler 3y ago

I still wonder if most of the human impact on climate is not the CO2 but the water vapor put out by planes. See the post 911 weather, and more recently around here a lot of people know what "covid sky" means. The sky was very clear and blue during the early shutdowns. If this hypothesis is correct then low-carbon fuels (say methane) are the wrong answer. Low hydrogen fuel would be better. Bring on the coal fired airplanes!! Sounds so silly, but hey...

xp84 3y ago

Is there a primer on what exactly "SAF" or "low-carbon fuel" actually is? It's not "just" hydrogen, or is it? It just sounds too convenient to be a real thing. "Oh, just use the LOW-carbon fuels. There's your problem!" Edit: Not disputing the fact that electrical airplanes present a staggering affront to the laws of physics due to weight. Just seems like the "third alternative" here (to status quo or battery) is being taken for granted.

cobrabyte 3y ago
It's sort of still being defined. There's a rush to develop a universal SAF, but companies can develop blends of alternative fuel sources and get money back from the US government in the process. https://afdc.energy.gov/fuels/sustainable_aviation_fuel.html https://afdc.energy.gov/fuels/sustainable_aviation_fuel.html
angiosperm 3y ago
LH2 may, in fact, be low-carbon fuel, depending of course on how it was produced. An LH2-powered aircraft would use exactly the electric turbines that Rolls-Royce just cancelled work on. Once LH2-powered aircraft enter any given market, kerosene-powered craft would be wholly unable to compete. But it will take a long time to build up infrastructure for it. Ultimately, international airports will electrolyse their own LH2 using power delivered from regional solar and wind farms, but don't expect to see much of it before 2050.
- JonChesterfield 3y ago
  > Once LH2-powered aircraft enter any given market, kerosene-powered craft would be wholly unable to compete. Liquid hydrogen has about 1/4 the energy density of kerosene by volume. It's better per kilo which is nice for aircraft but you're still looking at finding lots more space in the structure for fuel or accepting that you can't fly very far. I don't see that being competitive with kerosene.
  - angiosperm 3y ago
    LH2 would not fit in the wings, but would fit handily in nacelles slung under them. Space aboard aircraft is cheap; it is weight that costs.

zzzcsgo 3y ago

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simonblack 3y ago

Until we can actually find something with an energy/mass ratio as good as chemical fuels, we going to have to continue using those chemical fuels indefinitely. No matter what the good intentions of the day happen to be.

dr_dshiv 3y ago

Can’t we have high energy density liquid fuels and electric engines?

JonChesterfield 3y ago
Sure. Run a genset off the fuel and drive a motor with that. Works fine. Not very sensible in terms of drivetrain mass or efficiency.
- dr_dshiv 3y ago
  You wouldn’t get any of the benefits of hybrid electric cars, you are saying.
  - JonChesterfield 3y ago
    I believe genset+motor is the implementation of some hybrid cars, possibly calling it a range extender. Some others have a combustion engine and motors attached to the same gearbox (iirc that's the Prius setup). However I'm not very clear on what non-marketing advantages there are supposed to be to having both petrol and lithium fuels on board.