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New Study Suggests Flying Is Greener Than Driving
New submitter Desert Leap writes: The Washington Post reports a new study that suggests it is more environmentally friendly to fly rather than to drive. Analysis from the University of Michigan Transport Research Institute found that driving uses 57% more energy than flying per passenger mile. This is largely due to the number of occupied plane seats increasing while passengers per car decreased. Of course, "results may vary" for individual trips depending on many factors, such as distance flown (long flights are more fuel efficient) and the kind of car, and how many riders. One factoid is interesting: it takes 4,211 BTUs per person mile to drive. This number will fall as we switch over to electric vehicles. For example, a Tesla Model S takes about 1,100 BTUs per vehicle mile. Will future aircraft be able to also make the switch to electric?
Using the same logic, using a but or going by train is also more efficient since the many seats versus a couple is also true.
Nothing really too new. If you take the bus and the bus is full you are more efficient for the work being performed.
Most of the energy goes into moving the actual machine, only a small fraction goes into moving its content.
That is why the Train shipping companies advertise 1 gallon of fuel, for 500 miles per Ton of goods.
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
Either compare flying a small plane to driving a car, or compare a huge bus to a plane.
Being Robbed by the TSA, Groped and Accosted, or Simply not allowed to fly at all because of your views on social media.
I'd rather drive or walk...
> One factoid is interesting: it takes 4,211 BTUs per person mile to drive.
do we all drive the same car? Is this a chevy suburban or a fiat punto?
If an experiment works, something has gone wrong.
Since when has traveling by car and plane been comparable? For long distances, I suppose. I'm not going to drive between NYC and LA. But on a daily basis it is not. Compare Plane Travel to Boat travel maybe, especially cargo. Or compare planes to trains. Cars should be compared to buses. Same travel medium, more directly comparable. Most cities, at least near me, have moved to around 50% mix of hybrid buses and eco-diesel buses. With that the numbers would be interesting to see.
That's not very forward looking....
People said the same thing about cars & range.
There are two types of people in the world: Those who crave closure
I would think it also depends on when the plane is flying. If it's entire trip is during daylight hours, and it's above the clouds as most larger aircraft flights are, then you may be able to use solar panels in place of the majority of the batteries. Plus you won't have to carry the weight (as much) in fuel.
It's probably not a practical solution currently. But as efficiencies increase, it's at least feasible it may be at some point in the future.
There are already electric small airplanes that take a couple people.
Airplanes are obviously the highest-hanging fruit for switching over to electric drive, but they're not impossible. On the pure electric front you're first going to see the current growth trend in small personal electric airplanes continuing and short-range business uses like crop dusting and the like grow. From there you'll move to the little short hop passenger flights between small regional airports, and then increasingly longer ranges and sizes.
There's also hybrid jet technologies being researched, wherein you greatly simplify your jet engines by removing the turbine, and instead drive the compressor with electric power; the casing becomes the stator and the compressor the rotor of an electric motor. The moving part count is greatly reduced and there's far less resistance to the exhaust gases leaving the engine, meaning more power and better fuel efficiency.
But actually, before all that, there's one electrification system that's just now hitting the market, but it's not where most people might think: the wheels. Jet engines are horribly efficient in running at low powers such as taxiing, and planes burn a lot of fuel just moving about and waiting to take off or heading to the gate - on a short flight a plane may burn 5-10% of its fuel just sitting on the ground. There are now small scale pilot projects out there that have battery-driven electric motors in the landing gear so that one doesn't have to waste all this fuel.
"...but Republicans plan to come back with a new plan, where they just slash the tires on all the ambulances."
Aerospace is a huge hole in our plans for a carbon less energy future; you can replace fossil fuels with ships (nuclear) and transit (electric cars and trains) but I haven't seen any technology (real or imagined) that can do the job in aerospace. Short haul trucking is another hole that's going to be hard to fill, long haul can conceivably be replaced with trains but you're still going to need something to move goods from the rail network to their final destination.
I want peace on earth and goodwill toward man.
We are the United States Government! We don't do that sort of thing.
Show me the math for both ICE cars and Tesla, from well-head to road. Because generating electricity takes energy, and there are losses in the distribution system, and the charging systems are not 100% efficient either. Of course, getting oil out of the ground, refining it into gasoline, and moving the gasoline to refueling stations takes energy, too. Show me the end-to-end math, and then let's talk. A 4:1 advantage for the Tesla seems optimistic to me.
I have the same gripe with calling Teslas "zero emission vehicles". They are not. They are "displaced emission vehicles". Of course, it is easier to control pollution at a single point, and pollution controls scale up quite well, so the overall emissions are less for a Tesla versus an ICE vehicle. But don't claim the emissions are zero, they are just someplace else. (And I will grant that there are benefits to simply displacing emissions -- the Los Angeles valley, for instance, is a bowl, and so pollution tends to hang around in the air for a long time certain months of the year. Displacing the emissions outside the bowl has it's own benefits.)
Flying costs a lot more, and involves a period of being completely at the mercy of the no-background-check employees of the TSA.
I don't care if it is green. The TSA is horrible. Get rid of it, and I might fly again. Until then, I will spring for the road trip.
I also value my time, which I don't want to waste on a 200 mile trip waiting in line, and security theater
“He’s not deformed, he’s just drunk!”
"Fast" is not an issue. Electric motors have a much better power to weight ratio than combustion motors, and li-ion batteries have no trouble feeding it. The reason things like solar impulse fly slowly is to reduce air resistance and thus minimize their power consumption needs.
Batteries have advanced tremendously in the past several decades and show no signs of slowing down. The transition of air travel will be more difficult and longer in the making than that of ground travel, mind you.
"...but Republicans plan to come back with a new plan, where they just slash the tires on all the ambulances."
While interesting, this study is also sort of meaningless for making any sort of policy decision. I take far away vacations because the plane makes it possible. If planes weren't an option (due to price or policy), then I would shift to taking vacations closer to home (with maybe 1 trans-Atlantic cruise to explore Europe late in life), and my business travel would shift to teleconferencing. Would the resulting environmental footprint be better or worse? Hard to say. And presumably train usage would (after a few years of infrastructure investment) boom under this scenario, changing things again...
There are too many variables interacting for this study to "prove" anything.
-1, Too Many Layers Of Abstraction
Oh sure it is... The issue is ENERGY density.
Aircraft are more efficient when the energy storage is lighter and smaller. Batteries are not lighter and smaller than liquid hydrocarbons that contains the same amount of energy. Not to mention that as you burn off liquid fuel, the aircraft weighs less and gets more efficient as a result.
So, until batteries get small enough and light enough to have the same range with the same payload, liquid hydrocarbons will be the fuel of choice. I don't think we will be at that point for a LONG time yet as we are currently pushing the limits of battery technology to do a car, where weight isn't a big deal, at least as big a deal as it is in airplanes.
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Please direct your attention towards the front of the cabin as our flight attendants demonstrate the safety features of this craft.
In the event of pressure loss, an oxygen mask will drop from the overhead compartment. Please pull the mask to extend it completely and start the flow of oxygen, then place the mask over your nose and mouth and place the strap around your head to hold it in place. Put on your mask before helping children or others in need of assistance.
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If I have been able to see further than others, it is because I bought a pair of binoculars.
The system is actually not that big. The batteries are small because, despite the weight of the plane, the distances traveled are very short; and electric motors pack a lot of power into a small package. Having it all built into the plane reduces ground delays, ground staff, and additional ground hardware. It's a "pushback and go" system, the pilot can move the instant he gets clearance to, he doesn't have to wait for anyone else. It's estimated to save about 2 minutes over using tugs, which may not sound like a much, but each flight at the gate represents about $100k worth of revenue, so squeezing an extra flight in every couple days is a lot of money.
Ultimately they want to turn it into a fully automated airport traffic flow, where each plane moves from the runway to the gate and vice versa in a fully automated, optimized manner.
"...but Republicans plan to come back with a new plan, where they just slash the tires on all the ambulances."
And that's why I finished my post with the following: "It's probably not a practical solution currently. But as efficiencies increase, it's at least feasible it may be at some point in the future."
Battery tech has also been improving recently. There's no reason that it may become much lighter in the future and a combination of PV and batteries may become practical. It's also entirely possible that PV will never reach the necessary efficiencies and batteries don't reach the energy density necessary. That's why I said "may" in both cases.
Electric traction motors are far more efficient than ICEs. That's why diesel locomotives don't actually connect the diesel engine to the wheels. The diesel engine generates electricity, which turns electric traction motors.
Same with the really big earthmoving equipment - those gigantic dump trucks down at the strip mine are using electric traction motors powered by diesel generators.
Why don't we do this in cars? Space and complexity.
So what's the point of all electric cars? It separates the energy generation from the energy consumption, allowing flexibility in the energy generation. That coal plant you decry is a lot more efficient than an ICE. And other electricity generation sources have other benefits. The problem has been getting the power from the power plant to the car so that you can use electric traction motors.
I have the same gripe with calling Teslas "zero emission vehicles". They are not.
True, but unlike petrol driven cars they could be. Both renewable and nuclear power power are zero carbon methods of generating power and while renewable has issues with cost, limited locations and variability if it were supplemented by nuclear we could significantly reduce greenhouse gas emissions. In fact if you charge your Tesla in France then 75% of that power comes from nuclear so you might not be zero emission but you will be getting close.
Yeah it's true. Battery technology has a long way to go for flight. Non-production electric airplanes *could* be a curiosity in about 15 years, but we're probably closer to 30 years for truly viable electric aircraft... and that's assuming we ever get to the point where energy density of batteries are able to close in on the energy density of petroleum distillates.
Will future aircraft be able to also make the switch to electric? Yes, of course. Electric driven propellers should do the trick.
Of course, the size of the batteries needed will preclude carrying any passengers or cargo.
I don't think that is necessarily true. One option is to build hybrid electrical airplanes. And if battery power density and durability continues to improve, I think you might be surprised what is possible if you fill the wings of an airplane with electrochemical cells. Elon Musk has speculated that electric airplanes might be possible if we go beyond the incremental improvements of the current players.
This and no other is the root from which a tyrant springs; when first he appears as a protector - Plato (423 to 327 BC)
Small prop driven aircraft, ALREADY.
The market was almost nonexistent about five years ago but it's growing quite fast. Don't underestimate what the major and ongoing advances in motors, controllers, and batteries will bring in the future. There's many radically new technologies in the works to partially or completely electrify aircraft transportation, far beyond just electrically driven propellers.
"...but Republicans plan to come back with a new plan, where they just slash the tires on all the ambulances."
Probably no, as about 10 inches of water shield nearly all radiation that comes from the wreck of the plane.
The problem with your theory is that the primary cost to airlines IS fuel and they set up those routing systems to maximize the fuel economy of the whole network.
The issue is the big jumbo jets when full of passengers are pretty much as efficient as it gets. Planes get less efficient per person as they get smaller.
So the concept is that you have small planes FULL of people traveling to the nearest hub, then you have as many people as possible moved from Hub to Hub via a jumbo jet. And then finally you have any final leg of the trip handled by a smaller plane.
The per person fuel economy would be lower if you had a small plane go directly from point A to point B over a long distance.
Again, as evidence, the airlines cite fuel as their largest operating cost and it is in their interest to maximize the per passenger fuel economy because that translates directly into per passenger profit.
The market is really quite good at managing these things. I don't know why people have such little confidence in it. You can see the effect of the market in streamlining things throughout our economy all the time.
I've decided to stop wasting my time responding to AC trolls/sockpuppets... so if you want a response from me... login.
What third world hell hole do you live in where they still build grocery stores within walking distance?