
Train vs. Airplane Energy Efficiency (2010) - Tomte
http://www.lafn.org/~dave/trans/energy/rail_vs_airEE.html
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homerowilson
These numbers are pretty different than the ones here:

[https://en.wikipedia.org/wiki/Fuel_efficiency_in_transportat...](https://en.wikipedia.org/wiki/Fuel_efficiency_in_transportation)

citation:

Davis, Stacy C.; Susan W. Diegel; Robert G. Boundy (2011). Transportation
Energy Data Book: Edition 30. US Department of Energy. pp. Table 2.12.
ORNL-6986 (Edition 30 of ORNL-5198). Retrieved 2012-02-22.

Passenger trains are more efficient than planes, even when low capacity is
assumed.

What surprised me is how efficient air travel has become, it really is quite
impressive.

~~~
cpncrunch
The wikipedia page uses 2009 figures, versus 2005 from the article. Overall
the wikipedia page is a more useful article.

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tempestn
Regenerative braking on trains seems like low-hanging fruit these days. Ah,
yes, just did a bit of Googling and apparently it is standard equipment on
most new trains:

[http://www.climatetechwiki.org/technology/regenerative_braki...](http://www.climatetechwiki.org/technology/regenerative_braking_in_trains)

Older, especially freight, trains where all power comes from locomotives still
tend to lack regenerative braking though.

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kepano
Neat. One thing that isn't addressed however is the sustainability of the
energy source. Until we have electric airplanes, trains will continue to have
a lower carbon footprint.

~~~
icanhackit
_Until we have electric airplanes_

While I believe battery-powered cars like the Tesla S make more sense than
hydrogen/fuel-cell based cars, perhaps fuel cells make sense in airplanes. For
cars, the weight of batteries are an advantage as they provide down-force and
can be readily charged by virtue of being close the ground where there's
infrastructure, in stark contrast to flying at 36,000ft where infrastructure
is non-existent.

Addendum: The infrastructure issues that come with fuel-cell distribution and
refueling would be eliminated thanks to the centralized nature of airports.

~~~
danielbarla
I've seen a number of back of the napkin calculations involving electric
airplanes, but even when compared with fuel cells, traditionally fuelled
airplanes have the advantage that their weight greatly decreases as they use
fuel. Apparently a significant portion of the range of an airplane comes from
when the tanks have < 50% fuel. This shifts the economics even further in
their favour, aside from simple energy density calculations (as you're lugging
the now useless, yet still very heavy batteries / fuel cells all the way to
the destination).

While I'd love to see a shift in a more sustainable direction, I wonder if
we're going to be close to that anytime soon.

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morsch
Two things that are out of scope for this article: Emission altitude may
change how certain emissions affect the environment and specifically the
climate: "Emissions weighting factor (EWFs) i.e., the factor by which aviation
CO2 emissions should be multiplied to get the CO2-equivalent emissions for
annual fleet average conditions is in the range 1.3–2.9."[0]

The other thing is that apart from the emissions per mile, you tend to travel
more miles when you use a plane -- a magnitude more. Regardless of whether you
take a car, a train or a plane, motorized mobility is only sustainable up to a
point, and planes make it very easy to go (fly) beyond that point.

[0]
[https://en.wikipedia.org/wiki/Energy_efficiency_in_transport...](https://en.wikipedia.org/wiki/Energy_efficiency_in_transportation)

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justinator
I seem to remember reading that plane travel is inherently more disastrous to
the planet, because of where planes fly - the pollutants are deposited 30,000
feet in the air, rather than near ground level. I seem to have not found a
reference for this though.

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justinator
This is what I am referring to (sorry to have used such layman's terms, I am
in fact: not a scientist) :

[https://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-2...](https://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-2.html)

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chvid
Interesting article. I too assumed trains to be much efficient than airplanes.

The big difference between rail and air is that it is possible to have a
functioning market economy with true competition between airlines whereas rail
seems to be stuck with bureaucratic monopolies.

That causes air travel to get cheaper and cheaper, better and better while the
train travel just falls more and more behind.

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cpncrunch
It doesn't mention one of the main advantages of planes: air resistance is
much lower at 40,000ft (although that is obviously offset by increased speed
of jets compared to trains, which results in increased resistance).

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adrianhoward
Another factor is the energy cost of building & maintaining the
infrastructure. Aiports, ATC, etc. vs stations, tracks, etc.

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tritium

      Thus one may say that passenger trains are potentially 
      energy efficient, but in actual practice such trains turn 
      out to be little more energy-efficient than the airplane. 
      What institution changes are needed to realize the 
      potential of rail's inherent energy-efficiency are not 
      clear.
    

Three things:

    
    
      1. Render the skill set necessary for piloting any 
         aircraft down to a level of ease as trivial as 
         operating any train. This is not to say that operating
         a train is trivial. Nor that such a feat of 
         equivocation is even possible.
    
      2. Reduce the failure mode of every aircraft to failure
         modes on par with those of stalled trains, such that 
         a stalled aircraft merely risks mid-air collisions
         with other aircraft still in motion, with outcomes 
         similar to those of a moving train colliding with a 
         stalled train, stuck on the same track. This includes
         accounting for the level of inconvenience and options 
         available for re-routing and remediation of stalled 
         passenger flights, stranded in mid-air, as if they were
         trains stalled on a track. 
    
      3. Provide insurance coverage that promises that should
         the two preceding requirements not be met, when an air
         disaster does eventually occur, financial costs are 
         reduced to costs comparable to scenarios under which 
         a train might have suffered a similar scale of 
         disaster. Consider the Lac-Mégantic rail disaster [1], 
         for industrial incidents, consider passenger train 
         derailments occurring on bridges [2] for incidents 
         involving passenger fatalities. Obviously financial 
         compensation cannot redress the loss of human lives, 
         but only serve to bankrupt negligent operations that 
         fail to properly protect the lives of the passengers 
         and bystanders that entrust their territories and 
         well-being to said services.
    

[1] [https://en.wikipedia.org/wiki/Lac-
Mégantic_rail_disaster](https://en.wikipedia.org/wiki/Lac-
Mégantic_rail_disaster)

[2]
[https://en.wikipedia.org/wiki/Tangiwai_disaster](https://en.wikipedia.org/wiki/Tangiwai_disaster)

Based on this, I would assume that a natural equilibrium in human motivation
to take on roles either in rail transportation or air transportation would
attract a similar or even interchangeable class of personnel, and thus provide
similar capacities of efficiency to both sectors of the transportation
industry, based on the relative equivalence in the quality of the staff
occupying similar positions in each type of service.

Working on railroads is not as sexy as working in airplanes, both in terms of
the perception of danger, as well as perception of implicit social status.
Level the playing field between the task of operating railways with that of
flying airplanes, and maybe people will be just as motivated to deliver super-
efficient rail travel, as they are to deliver world-class airline service.

~~~
stuaxo
Air travel has become pretty prosaic now.

I'm in Taiwan at the moment, and there is something pretty pleasing about
travelling on the HSR rail here - it seems more in line with the bullet trains
of Japan, than the fast trains in Europe (which are still good - discounting
the UK, which just has the Eurostar).

The trains all go extremely fast on mostly dedicated lines and the stations
are the larger modern type - reminiscent of airports, but without the mega
long walks or security.

Google image search -

[https://www.google.com.tw/search?q=high+speed+rail+taiwan&so...](https://www.google.com.tw/search?q=high+speed+rail+taiwan&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjTr96mi7rJAhUI6CYKHRC_AcAQ_AUICCgB&biw=1280&bih=661)

