Electric aviation for aircraft larger than 4 passengers is extremely hard. Batteries don't have the energy density needed, and fuel cells are barely at the prototype stage for aviation. ARPA-E has been looking at this for while, see slide 6 in [1] for an overview of payloads by energy storage medium. If you read a little more through the deck you'll see there are also issues with power output of electric motors in this application.
I'm much more optimistic about low-carbon jet fuels. Biofuel options here have already been trialed successfully. And some new synthetic fuel companies [2] that use direct air capture CO2 are looking promising.
It's also hard because batteries don't get lighter as they deplete, so you're landing a plane with the exact same weight as what you took off with, meaning you need much more rugged (and heavy) landing gear. This is extremely significant when you consider that a fully loaded 747-8 is 970,000 lb, of which up to 326,000 lb is fuel (per Wikipedia's numbers).
It's a hard problem, and most proposed solutions are extremely novel and risky, like having an all-battery tugboat that tows the plane up to cruising speed/altitude before returning to the airport to charge or get a battery swap— obviously bad because risky, also adds 50% to runway capacity to land all the tow planes.
> Electric aviation for aircraft larger than 4 passengers is extremely hard.
There is at least one airline transitioning to only electric aircraft already [1]. It's one that focuses on short range flights. And as energy density continues to increase, the range and applications of all-electric aircraft will too.
Solid Oxide Fuel Cells are reaching 2.5kw/kg power densities, Electric motors are reaching 15kw/kg power densities. Combined, that is already better than current jet engines. With cogeneration, SOFCs are reaching 80-85% efficiencies, double that of jet engines. Liquid hydrogen has an energy density of 39kwh/kg, compared to JP8 at 13kwh/kg, but SOFCs could run on pretty much any hydrocarbon. They don't even need cryogenic storage, because fuel consumption rates would be higher than evaporation rates.
All the pieces exist for fuel cell powered jets. They've already got the performance levels needed. All they need is to put them together into a cohesive package, and put a shit ton of effort into reliability engineering.
What doesn't make sense is to use number of passengers as the figure of merit, here. Technically, that's no limit at all. Aircraft scale up just fine from 2 people to 20 to 200 people.[0] "Power" is even less of a concern: fundamentally, electric motors are just as high performance as turbine engines.
The appropriate figure of merit is range and specific energy (i.e. useful energy stored per unit mass), and that IS a limitation, but range of up to 500 miles is feasible for pure electric using existing batteries and structure and aerodynamic efficiency tech. Double or quadruple that is possible with cleverness and more exotic approaches. Even long-haul is possible with certain approaches to pure electric flight (either lithium-air, which has just as high theoretical useful energy as something like gasoline, or staging).
The only way "large aircraft" or "high power" is a limitation is just the speed at which things can be certified. Large passenger aircraft cost billions to bring to market, so companies are super conservative about it. But this isn't a fundamental technical limit of electric flight.
[0]Technically, there are structural scaling laws which detract from efficiency as you get bigger, but they don't become strong until you're very large... And they're countered by perhaps even more important positive Reynolds Number scaling effects, i.e. your lift to drag improves as your scale increases.
Even for aeroplanes with just two people, the most usable, all-electric endurance I've seen is about 1 hour[1]. Just about usable for training (mostly circuits around the airfield), but not much else.
"Electric aviation for aircraft larger than 4 passengers is extremely hard"
To be honest, the worst parts of flying are usually all those other passengers anyways. If you could scale up a fleet on-demand small electric planes. Flying would improve. If you account for all the waiting time, it might be just as fast too.
This is the same for the train and shipping industries. I’ve always thought those vehicles had ample opportunities to capture solar rays and wind since they’re out in the open all the time, but we simply don’t have batteries and engines powerful enough yet.
But from what I gather, it's not just about the batteries, but also about coming up with a design that takes advantage of the possibilities offered by simple electric motors.
I challenged myself to go a year without flying for climate reasons. I thought I would hate it. Work, family, and lifestyle depended on it.
It turns out it was one of the best things I've done. Experience taught me what I never could have imagined -- how much my life improved. Like dropping Facebook on steroids. What I expected to miss I got more without flying, plus improved relationships, community, and connection.
A few months in I decided to go for a second year. I'm 4.5 years in now. I may fly again, I don't know, but I want to less and less.
I try to avoid flying as much as possible but purely because I love driving across long distances. I don't particularly dislike flying and for international trips there really is no other alternative.
Recently there has been some talk about banning air miles programs and actually flipping the incentives. Because you have to fly under your government ID it wouldn't be out of the question for people who fly a lot to pay more per mile in taxes.
I've been thinking about this a lot trying to root out the unintended consequences of such a plan, but I can't think of any.
Wouldn't a carbon tax on the source, when fossil fuels are extracted, be more effective?
You'd still be paying more for longer and more frequent flying, but you'd also be hitting personal jets harder than full flights, less fuel efficient planes and flight paths against better ones - and it would be reduced even further if an airline managed to electrify.
Although that still ignores the additional warming effect of radiative forcing caused by flight.
I can see a few with flipping incentives - flight is a subsituable good and a fuzzy one. While not encouraging it for its own sake is fair the alternatives may be worse.
I know of one case where a coworker ended a business trip by taking vacation days and a several day cross Atlantic cruise ship home which was likely worse than even a plane trip to an island as it didn't involve hauling essentially an entire luxury hotel thousands of miles.
I suspect a better idea for encouragement if anything would be subsidizing efficient clear neccessity/better than current baseline transit. Like say if living closer to work was subsidized along with public transit - both replacing or shortening automobile commutes.
You might actually see a huge lift in private aviation as I don’t have to show government ID or otherwise check in with the government for those flights (provided they take off and land in the US). You can’t even necessarily track the tail numbers of the airplane if it operates from non-towered airports away from our largest 150 or so airports and under 10K feet (so piston airplanes).
You would also displace a lot of travel to private autos, with a decrease in safety/increase in fatalities and typically an increase in fuel consumption when comparing a single occupancy car to a fairly full flight. Plus, if I’m going to be driving a car 500 miles pretty regularly, I’m going to splurge for a nice, big, comfy car and it’s not going to be an electric. Since I currently fly rather than drive on road trips, today I can drive a small electric as my daily driver.
I'm pretty sure that there are certain airlines that are nearly unprofitable from their actual airline operations, but only eke a decent profit due to their airline miles programs (specifically their credit card rewards programs). So it seems like you are suggesting that we should remove a huge profit center from airlines.
I think that’s thats brilliant. Many people fly far more than necessary. A carbon tax is important, but this could simply punish the frivolity of most air travel.
Its important to remember the time constraint in these conversations. Engineering is about constraints, and if you simply remove the biggest one (time) it becomes facile and easy to endlessly talk about future, hypothetical, optimistic "someday" solutions. It is vapid empty happy-talk.
When you factor in the time constraint, specifically the timeframes outlined in the IPCC SR 1.5 report, then you simply cannot claim that direct air capture fuels are a meaningful part of the conversation of what to do with air travels footprint.
I am 100% in favor of continued andincreased investment in R&D for DAC. I am 0% delusional that it will be a viable solution in the timeframe we need it to be (same goes for thorium and fusion).
Airplanes are not going to stop flying. We can try raising the price to make them fly less than they would otherwise but there will still be a need to lower the carbon footprint of flight. Synthesizing fuel from captured CO2 seems like a much better pathway than batteries. Also, I don't think its valid to compare it to thorium or fusion. We can make synthetic fuel from captured CO2 today whereas those are science projects. Synthetic fuel isn't cost effective given economic and political realities but its likely this will occur within the next 10 years in at least some places.
Minor point, people seem to marry DAC with synthesizing fuel, probably because Carbon Engineering has gotten a lot of press. Fuel can be synthesized from CO2 from any source. It is my understanding that DAC is currently more expensive than capturing from a point source, like a natural gas power plant. This is due to CO2 being such a small percentage of the atmosphere vs 10%+ from plant flue gases. So, while DAC is more expensive and there are still substantial point sources of CO2, fuel made from DAC will be more expensive from point source capture.
This is an amazing comment that puts it very well into words and sadly it should be added as a disclaimer under about a half of the articles that end up on HN about any future tech.
A quick google suggests that aviation accounts for 2% of global carbon emissions.
Everyone in this thread is pointing out how difficult the engineering is to convert aviation to something emission-free.
To me it seems obvious that we should focus on shrinking the 98% as fast as we can. While we should also work on decarbonizing air travel, I am pretty sure that if we decarbonized everything _else_ that the environmental impact of air (and space!) travel would not be enough to fuel global warming on its own.
Further, because the impact is so much smaller, it might be more feasible for air travel to eventually be required to perform offsetting direct carbon capture than to replace jet fuel with an alternative. That would make flying more expensive, which I think is fine, but it wouldn’t make flying _impossible_ which I think is at least highly undesirable.
To me it seems obvious that we should focus on shrinking the 98% as fast as we can.
The other 98% is made up of lots of industries that account for 1% here, 2% there, 0.1% somewhere else, and so on. We can't afford to ignore something because it's 'only' 2% of the total because that would mean ignoring everything. The reality is that we need to shrink 100% of global carbon emissions, including what's caused by aviation, and everything else.
Clickbait title. Read the article hoping for great news in the emerging aerospace sectors. What I actually found was a rather large serving of humblebrag with a generous side of monetary privilege.
Really? The article just says its author hope for a low-carbon future for the air transport, and mentions some tiny plans by jet makers and early startups to plan to 'hybridify' airplanes.
How much low-carbon would that be? As far as I could read, the author does not even try to evaluate that and blindly hope that it should be helpful, somehow. As if he can't bear flight shame, and tries to share/sell some "hope" to cope with that.
There are electrification gains to be made on the ground. Aircraft manufacturers are already experimenting with using electric motors for taxiing so that they can wait to start the turbines until close to the runway.
And longer term, electromagnetic catapults embedded in runways can be used to launch aircraft using renewable power. The engineering challenges will be huge and a new generation of airliners will be needed to make it work, but the concept is technically feasible.
I'm curious if anyone here can answer this: what part of flight consumes the most energy/fuel? Is it the take-off? Landing? Cruising? So would a hybrid model plane make sense to use jet fuel or equivalent for the most energy consuming part, then electric batteries for the least intensive parts?
For long-haul, it's cruise. And the energy required can thus be improved directly proportional to lift to drag ratio. What I find promising is work NASA is doing and has done on truss-braced wings to enable a ~doubling of current transonic lift to drag ratios by using an extremely high aspect ratio wing.
take-off uses far more fuel per ground-miles travelled, because in addition to trying to go forward, you're also lifting hundreds of tons of steel, several miles into the air.
but take-off and cruise use probably ROUGHLY the same amount per minute flown - because why waste time cruising at a significantly lower power setting?
> So would a hybrid model plane make sense to use jet fuel or equivalent for the most energy consuming part, then electric batteries for the least intensive parts?
Not at all, because energy is just energy, and full batteries weigh just as much as empty ones, but full fuel tanks weigh a LOT more than empty ones. And empty ones are more efficient to keep aloft.
Also: regardless of acceleration or climb, air resistance is a major factor. This is why most aircraft cruise at 30k-40k feet. Flying the same route and speed at 5k feet burns significantly more fuel.
I think it’s takeoff, regardless of the power plant in the aircraft.
Fueled planes are heaviest when taking off, and fighting gravity, and Electric are still fighting gravity.
Why not use renewable energy to synthesize the regular airplane fuel? That would be carbon neutral, and it would avoid all the issues with heavy batteries and upgrading or replacing existing planes.
It likely wouldn't be Jet-A that's synthesized, it would be some sort of bio diesel that would have to get approval. GA still uses leaded gas because the industry is so slow to change and everyone is terrified of having to re-certify (STC) existing aircraft or add additional fueling infrastructure. It's a far more complex issue than I can describe here but it works as a useful analogy.
Electric aircraft, however, sound really good in a boardroom because the logistics are "simpler" (disregarding the issue of charging gigawatt-hour batteries somehow).
No discussion of Synthetic Natural Gas => LNG powered jetliners? To me that seems a lot more realistic than banning flight altogether or battery/electric powered aircraft.
What if we work to make air travel less useful. Find reasons why people air travel and eliminate them. For example, conferences where a whole lot of nothing happens - and they 're usually seen as an excuse for mini vacation. Business travel is often a game of persuasion that should be done over skype. Apparently the #1 reason people travel is education & training.
The idea of a battery plane sounds too good to be true , and it 's probably decades away
With the weight of batteries it would definitely be a challenge. Fuel is heavy too, but there is still a factor between their energy density that is close to 100.
Owners of electrical drones know that the fun often ends after around 20 minutes with the battery being the heaviest part by far. I remember there being a drone that could fly for 2 hours with the whole body basically being the battery.
Is this really more environmentally friendly if the electricity comes from a coal plant driving a turbine? With a gas aircraft, it's still fossil fuels driving a turbine. Sometimes they're very similar turbines: https://www.ge.com/power/gas.
Hmm, when fuel is around 5% of your total ticket cost, something says that there are much more inefficiencies to solve than just the flight itself.
Being forced into security theatre, not allowed your drink or food, forced to overpay in airport... Smells a lot like how housing market is regulated by councils or NY trains having higher carbon emission than Prius due to admin costs...
Most of stewardess could be replaced with a vending machine. Bunk beds made using compliant mechanisms. Tax charge passengers by weight, not by height.
Here's something even more ambitious - it's really bizarre that airlines buy airplanes and then decide to skimp on maintenance. They should really be leasing them from manufacturer who does all the maintenance. Same with pilots, but perhaps they could be airport staff (especially crew). Airline should only focus on ticketing and routing (similar to how energy and telco markets are "deregulated" in some countries).
We just need someone to develop an air-to-air battery replenishment system (same theory/model that you see in use with military tanker aircraft for air-to-air refueling).
I can see it now. Max weight/batteries on take off. Controller to drain batteries serially, and as each one is exhausted, chuck it out the bottom of the plane (with some kind of landing/recovery mechanism). When you start running low on batteries, re-fuel at the nearest tanker.
Obviously I'm kidding. The tanker model is ridiculously expensive. That's why you only see it used for extremely critical things (military).
#1 - this article is a great example of how the conversation is shifting, but the mid-point we're at now is a wasteland of nonsense and cognitive dissonance. the text of the article is about the truth of what things matter to reduce your footprint (kids, flying, cars, beef), but the tone of the article and the headline is one of "things are gonna be fine because the whiz kids are working on it" soft-denialism.
#2 - the co2 footprint from jet travel is somewhere between half and 1/4th of the overall greenhouse gas emission footprint of flying. this is because nitrogen oxide and water vapor are also greenhouse gasses (particularly at altitude). It gets very complicated to factor, but at a high level you should simply 3x the carbon cost of flights for the "CO2e" total: https://en.wikipedia.org/wiki/Environmental_impact_of_aviati...
#3 - the electrification of air travel is very well under way. it will not replace trans-oceanic flights in our lifetimes, but it can replace a massive amount of regional travel, and customers can be forced to adapt to a multi-hop world (jfk <-> ord <-> den <-> sfo). If you'd like to learn a ton about the state of the art 1 year ago, check out this playlist from the Sustainable Aviation Summit last year: https://www.youtube.com/watch?v=6LDU0Wgn0Lk&list=PLWUnMAqjJ9...
Didn't see it listed as an option here, but are the travel-via-ICBM options that SpaceX has been touting going to actually be cleaner options than burning jet-fuel? If you remove the cruise speed requirements for longer-haul flights and put them in space, maybe that helps? Hard to say without any real numbers out there (and even if I had real numbers I'm probably not in a position to synthesize them vs. aircraft)
Probably the best way to cut air travel pollution is with a combination of high-speed electric trains between all major cities (make it convenient to get around without flying) along with a ration book for air travel - everyone is allotted one trip per year, second trip has a surcharge, third and subsequent trips have massive surcharges growing to astronomical numbers.
The average person does not fly in a given year. Those that do fly tend to take no more than one trip. A very small percentage of frequent flyers account for the bulk of air travel. An explicit rationing system would allow "regular" people to still fly occasionally and would have huge benefits for cutting air travel overall while impacting only the frequent flyers. People would be forced to ask if they REALLY need to fly out to NY for that meeting.
The boosts to the VR/Skype/virtual presence/hologram/conferencing field would be enormous.
As a California resident, this reads like a fantasy novel. Sure it would be great to have high-speed trains linking every city, but we cant' even link the two biggest cities in California.
Maybe I'm not as typical as I think, but all your proposal has done is cause me to drive to the one or two conferences I go to each year. Probably not a win at all since I don't drive and EV.
[+] [-] maliker|6 years ago|reply
I'm much more optimistic about low-carbon jet fuels. Biofuel options here have already been trialed successfully. And some new synthetic fuel companies [2] that use direct air capture CO2 are looking promising.
[1] https://arpa-e.energy.gov/sites/default/files/Grigorii-Solov... [2] https://en.wikipedia.org/wiki/Carbon_Engineering
[+] [-] mikepurvis|6 years ago|reply
It's a hard problem, and most proposed solutions are extremely novel and risky, like having an all-battery tugboat that tows the plane up to cruising speed/altitude before returning to the airport to charge or get a battery swap— obviously bad because risky, also adds 50% to runway capacity to land all the tow planes.
[+] [-] SECProto|6 years ago|reply
There is at least one airline transitioning to only electric aircraft already [1]. It's one that focuses on short range flights. And as energy density continues to increase, the range and applications of all-electric aircraft will too.
[1] https://electrek.co/2019/03/26/harbour-seaplanes-electric-ai...
[+] [-] darksaints|6 years ago|reply
All the pieces exist for fuel cell powered jets. They've already got the performance levels needed. All they need is to put them together into a cohesive package, and put a shit ton of effort into reliability engineering.
[+] [-] Robotbeat|6 years ago|reply
The appropriate figure of merit is range and specific energy (i.e. useful energy stored per unit mass), and that IS a limitation, but range of up to 500 miles is feasible for pure electric using existing batteries and structure and aerodynamic efficiency tech. Double or quadruple that is possible with cleverness and more exotic approaches. Even long-haul is possible with certain approaches to pure electric flight (either lithium-air, which has just as high theoretical useful energy as something like gasoline, or staging).
The only way "large aircraft" or "high power" is a limitation is just the speed at which things can be certified. Large passenger aircraft cost billions to bring to market, so companies are super conservative about it. But this isn't a fundamental technical limit of electric flight.
[0]Technically, there are structural scaling laws which detract from efficiency as you get bigger, but they don't become strong until you're very large... And they're countered by perhaps even more important positive Reynolds Number scaling effects, i.e. your lift to drag improves as your scale increases.
[+] [-] cjrp|6 years ago|reply
[1] https://www.pipistrel-aircraft.com/aircraft/electric-flight/...
[+] [-] brohee|6 years ago|reply
This is more on an engineering challenge, unlike much better batteries which will require a fundamental scientific breaktrough.
https://en.wikipedia.org/wiki/Beam-powered_propulsion
[+] [-] swalsh|6 years ago|reply
To be honest, the worst parts of flying are usually all those other passengers anyways. If you could scale up a fleet on-demand small electric planes. Flying would improve. If you account for all the waiting time, it might be just as fast too.
[+] [-] miles_matthias|6 years ago|reply
[+] [-] simion314|6 years ago|reply
[+] [-] olau|6 years ago|reply
... today.
There's a lot of money in batteries these days.
But from what I gather, it's not just about the batteries, but also about coming up with a design that takes advantage of the possibilities offered by simple electric motors.
[+] [-] spodek|6 years ago|reply
It turns out it was one of the best things I've done. Experience taught me what I never could have imagined -- how much my life improved. Like dropping Facebook on steroids. What I expected to miss I got more without flying, plus improved relationships, community, and connection.
A few months in I decided to go for a second year. I'm 4.5 years in now. I may fly again, I don't know, but I want to less and less.
EDIT: Amazingly, my TEDx talk on this experience went live minutes ago: https://youtu.be/sTYiHr1lu10.
[+] [-] mhb|6 years ago|reply
[+] [-] trianglem|6 years ago|reply
[+] [-] criddell|6 years ago|reply
I've been thinking about this a lot trying to root out the unintended consequences of such a plan, but I can't think of any.
[+] [-] dashundchen|6 years ago|reply
You'd still be paying more for longer and more frequent flying, but you'd also be hitting personal jets harder than full flights, less fuel efficient planes and flight paths against better ones - and it would be reduced even further if an airline managed to electrify.
Although that still ignores the additional warming effect of radiative forcing caused by flight.
https://curiosity.com/topics/airplane-contrails-are-contribu...
[+] [-] Nasrudith|6 years ago|reply
I know of one case where a coworker ended a business trip by taking vacation days and a several day cross Atlantic cruise ship home which was likely worse than even a plane trip to an island as it didn't involve hauling essentially an entire luxury hotel thousands of miles.
I suspect a better idea for encouragement if anything would be subsidizing efficient clear neccessity/better than current baseline transit. Like say if living closer to work was subsidized along with public transit - both replacing or shortening automobile commutes.
[+] [-] t34543|6 years ago|reply
[+] [-] sokoloff|6 years ago|reply
You would also displace a lot of travel to private autos, with a decrease in safety/increase in fatalities and typically an increase in fuel consumption when comparing a single occupancy car to a fairly full flight. Plus, if I’m going to be driving a car 500 miles pretty regularly, I’m going to splurge for a nice, big, comfy car and it’s not going to be an electric. Since I currently fly rather than drive on road trips, today I can drive a small electric as my daily driver.
[+] [-] OrangeMango|6 years ago|reply
Record keeping, administration, etc.
You could replace it all with simple calculations:
Landing Tax: (tax rate) * (landing weight) * (distance traveled within US airspace)
Takeoff Tax: (tax rate) * (takeoff weight)
[+] [-] cycrutchfield|6 years ago|reply
[+] [-] oh_sigh|6 years ago|reply
[+] [-] markkanof|6 years ago|reply
[+] [-] throwawayhhakdl|6 years ago|reply
[+] [-] cagenut|6 years ago|reply
When you factor in the time constraint, specifically the timeframes outlined in the IPCC SR 1.5 report, then you simply cannot claim that direct air capture fuels are a meaningful part of the conversation of what to do with air travels footprint.
I am 100% in favor of continued and increased investment in R&D for DAC. I am 0% delusional that it will be a viable solution in the timeframe we need it to be (same goes for thorium and fusion).
If you're not solving for the time constraint and the curve shape in this graph, you're not talking about "solutions" you're just chit chatting about (cool) tech: https://www.ipcc.ch/site/assets/uploads/sites/2/2019/02/SPM3...
[+] [-] thinkcontext|6 years ago|reply
Minor point, people seem to marry DAC with synthesizing fuel, probably because Carbon Engineering has gotten a lot of press. Fuel can be synthesized from CO2 from any source. It is my understanding that DAC is currently more expensive than capturing from a point source, like a natural gas power plant. This is due to CO2 being such a small percentage of the atmosphere vs 10%+ from plant flue gases. So, while DAC is more expensive and there are still substantial point sources of CO2, fuel made from DAC will be more expensive from point source capture.
[+] [-] Erlich_Bachman|6 years ago|reply
[+] [-] burlesona|6 years ago|reply
Everyone in this thread is pointing out how difficult the engineering is to convert aviation to something emission-free.
To me it seems obvious that we should focus on shrinking the 98% as fast as we can. While we should also work on decarbonizing air travel, I am pretty sure that if we decarbonized everything _else_ that the environmental impact of air (and space!) travel would not be enough to fuel global warming on its own.
Further, because the impact is so much smaller, it might be more feasible for air travel to eventually be required to perform offsetting direct carbon capture than to replace jet fuel with an alternative. That would make flying more expensive, which I think is fine, but it wouldn’t make flying _impossible_ which I think is at least highly undesirable.
[+] [-] onion2k|6 years ago|reply
The other 98% is made up of lots of industries that account for 1% here, 2% there, 0.1% somewhere else, and so on. We can't afford to ignore something because it's 'only' 2% of the total because that would mean ignoring everything. The reality is that we need to shrink 100% of global carbon emissions, including what's caused by aviation, and everything else.
[+] [-] 0x7265616374|6 years ago|reply
[+] [-] rcMgD2BwE72F|6 years ago|reply
Really? The article just says its author hope for a low-carbon future for the air transport, and mentions some tiny plans by jet makers and early startups to plan to 'hybridify' airplanes.
How much low-carbon would that be? As far as I could read, the author does not even try to evaluate that and blindly hope that it should be helpful, somehow. As if he can't bear flight shame, and tries to share/sell some "hope" to cope with that.
[+] [-] nradov|6 years ago|reply
https://en.wikipedia.org/wiki/EGTS
And longer term, electromagnetic catapults embedded in runways can be used to launch aircraft using renewable power. The engineering challenges will be huge and a new generation of airliners will be needed to make it work, but the concept is technically feasible.
https://www.theregister.co.uk/2012/09/07/airbus_smarter_skie...
[+] [-] brianbreslin|6 years ago|reply
[+] [-] Robotbeat|6 years ago|reply
[+] [-] knodi123|6 years ago|reply
but take-off and cruise use probably ROUGHLY the same amount per minute flown - because why waste time cruising at a significantly lower power setting?
> So would a hybrid model plane make sense to use jet fuel or equivalent for the most energy consuming part, then electric batteries for the least intensive parts?
Not at all, because energy is just energy, and full batteries weigh just as much as empty ones, but full fuel tanks weigh a LOT more than empty ones. And empty ones are more efficient to keep aloft.
cite: https://www.usatoday.com/story/travel/columnist/cox/2014/11/...
[+] [-] _ah|6 years ago|reply
[+] [-] pininja|6 years ago|reply
[+] [-] aaron_m04|6 years ago|reply
[+] [-] AWildC182|6 years ago|reply
Electric aircraft, however, sound really good in a boardroom because the logistics are "simpler" (disregarding the issue of charging gigawatt-hour batteries somehow).
[+] [-] geogra4|6 years ago|reply
[+] [-] buboard|6 years ago|reply
The idea of a battery plane sounds too good to be true , and it 's probably decades away
[+] [-] raxxorrax|6 years ago|reply
Owners of electrical drones know that the fun often ends after around 20 minutes with the battery being the heaviest part by far. I remember there being a drone that could fly for 2 hours with the whole body basically being the battery.
[+] [-] starpilot|6 years ago|reply
[+] [-] dzhiurgis|6 years ago|reply
Being forced into security theatre, not allowed your drink or food, forced to overpay in airport... Smells a lot like how housing market is regulated by councils or NY trains having higher carbon emission than Prius due to admin costs...
Most of stewardess could be replaced with a vending machine. Bunk beds made using compliant mechanisms. Tax charge passengers by weight, not by height.
Here's something even more ambitious - it's really bizarre that airlines buy airplanes and then decide to skimp on maintenance. They should really be leasing them from manufacturer who does all the maintenance. Same with pilots, but perhaps they could be airport staff (especially crew). Airline should only focus on ticketing and routing (similar to how energy and telco markets are "deregulated" in some countries).
[+] [-] AtlasBarfed|6 years ago|reply
All electric will require lower speeds and probably a hybrid airship airwing design
[+] [-] GhettoMaestro|6 years ago|reply
I can see it now. Max weight/batteries on take off. Controller to drain batteries serially, and as each one is exhausted, chuck it out the bottom of the plane (with some kind of landing/recovery mechanism). When you start running low on batteries, re-fuel at the nearest tanker.
Obviously I'm kidding. The tanker model is ridiculously expensive. That's why you only see it used for extremely critical things (military).
[+] [-] cagenut|6 years ago|reply
#1 - this article is a great example of how the conversation is shifting, but the mid-point we're at now is a wasteland of nonsense and cognitive dissonance. the text of the article is about the truth of what things matter to reduce your footprint (kids, flying, cars, beef), but the tone of the article and the headline is one of "things are gonna be fine because the whiz kids are working on it" soft-denialism.
#2 - the co2 footprint from jet travel is somewhere between half and 1/4th of the overall greenhouse gas emission footprint of flying. this is because nitrogen oxide and water vapor are also greenhouse gasses (particularly at altitude). It gets very complicated to factor, but at a high level you should simply 3x the carbon cost of flights for the "CO2e" total: https://en.wikipedia.org/wiki/Environmental_impact_of_aviati...
#3 - the electrification of air travel is very well under way. it will not replace trans-oceanic flights in our lifetimes, but it can replace a massive amount of regional travel, and customers can be forced to adapt to a multi-hop world (jfk <-> ord <-> den <-> sfo). If you'd like to learn a ton about the state of the art 1 year ago, check out this playlist from the Sustainable Aviation Summit last year: https://www.youtube.com/watch?v=6LDU0Wgn0Lk&list=PLWUnMAqjJ9...
[+] [-] sailfast|6 years ago|reply
[+] [-] jellicle|6 years ago|reply
The average person does not fly in a given year. Those that do fly tend to take no more than one trip. A very small percentage of frequent flyers account for the bulk of air travel. An explicit rationing system would allow "regular" people to still fly occasionally and would have huge benefits for cutting air travel overall while impacting only the frequent flyers. People would be forced to ask if they REALLY need to fly out to NY for that meeting.
The boosts to the VR/Skype/virtual presence/hologram/conferencing field would be enormous.
[+] [-] 0xffff2|6 years ago|reply
Maybe I'm not as typical as I think, but all your proposal has done is cause me to drive to the one or two conferences I go to each year. Probably not a win at all since I don't drive and EV.