Quote:
Originally Posted by wave46
Notwithstanding the time factor, I'm curious how the energy cost works out vis-a-vis air travel. Diesel locomotive aren't light, but they do have minimal friction losses. I guess it would come down to passenger load and distance - a lightly loaded version of the Canadian would probably be worse than one fully loaded aircraft. It would likely be better than a car (even one at capacity), though.
Edit: found some stuff on Wikipedia, so YMMV.
A320 with 150 seats full going ~4,000km =~2.43L/100km/passenger
Reasonably efficient car with 4 passengers ~2L/100km/passenger. Double that for two people.
Train: ~0.5L/100km/passenger (I'm curious how applicable this number is to VIA's various routes - I'd suspect it would be accurate for a commuter train, but a lower-capacity long-distance train would be somewhat worse)
|
A few comments. First of all, using litres of fuel doesn't work well in this comparison as most airplanes use jet fuel, most trains use diesel fuel and most cars use gasoline, and each fuel has a different energy density and carbon content. They will also produce different amounts of other pollutants. The trend these days is to focus only on carbon emissions, but there are many other factors to consider as well.
Regarding airplanes, they use a lot of fuel for takeoff and landing, but are very efficient at their cruising altitude. So the longer the flight, the more efficient they become.
As you said, diesel locomotives need to be extremely heavy to get enough traction (the coefficient of friction of steel on steel is very low) to pull the train without the wheels slipping. As a result, trains are only efficient if they are transporting a large number of people. Even a single occupant, gas guzzling SUV
could be more efficient than a train
if the train is only transporting a handful of passengers. Fill up that train with several hundred passengers and it becomes extraordinarily efficient.
One thing many people overlook is freight. The opportunity for improvements in energy efficiency (and less pollution) by using rail freight compared to trucks is massive.
Quote:
Originally Posted by Truenorth00
|
I had a look at that link, and the spreadsheet linked seems to have been deleted. The article is from 2009, so the data is probably out of date anyway (for example, the UK has gone from the majority if its electricity being generated from coal a decade ago, to going for weeks at a time without using any of their coal electricity generation plants).
Quote:
Originally Posted by Truenorth00
The other things to keep in mind is that rail can be electrified.
|
Very true, but it is only feasible from a cost perspective on shorter, more heavily used routes. Also, the freight railways also don't want their lines electrified, so electrification needs to be done on dedicated tracks. Alternatively batteries or hydrogen fuel cells could be used, but they also have disadvantages.
Quote:
Originally Posted by Truenorth00
And aircraft have their highest per capita consumption on their climb. Not reaching a higher cruise altitude and spending less time at cruise would increase per capita fuel consumption dramatically.
|
Very true. Some interesting work is being done with electric and hybrid-electric airplanes though. They can even do some regenerative breaking when landing. Of course,
where demand warrants it, intercity trains are a better option for those medium distances that are often said to be to "too far to drive, too close to fly" (150-800km with the sweet spot being at about 400km).
Prev
Linear Mode
