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-   -   Electric Train Power Usage (https://www.flyertalk.com/forum/travelbuzz/1237870-electric-train-power-usage.html)

gfunkdave Jul 17, 2011 9:20 am

Electric Train Power Usage
 
I'll put this here because, well, it is a general travel question I suppose. :)

How many watts does a typical subway train use? Anyone have any idea?

What about a bigger higher speed train, like the Eurostar, Shinkansen, or Acela?

I've Googled and Googled but can't find anything.

Help the idly curious! Thanks. :)

Ocn Vw 1K Jul 17, 2011 9:33 am

I found an extensive report on this from 2007 as to the S.F. Bay Area (BART) commuter rapid transit system: http://www.bart.gov/docs/BARTenergyreport.pdf

Analysis was done on a per-car/mile basis. Per the chart on page 2-1, car usage averaged between 3.37 and 3.62 kWh per car-mile. Later charts in the report show propulsion accounting for 83% of the total electrical usage.

gfunkdave Jul 17, 2011 9:37 am

Hmm, interesting. So using these numbers, a typical train of ~10 cars (as on the NYC subway) would use only about 35 kWh to get the one mile from, say, Union Square to Penn Station? That seems very low to me.

clacko Jul 17, 2011 9:46 am

hopefully, newer units are more efficient...

homelyboy Jul 17, 2011 10:08 am


Originally Posted by gfunkdave (Post 16743346)
How many watts does a typical subway train use?

Do you mean average for a trip or top rate?

Average depends very strongly on particular conditions of the line taken. For example, average distance between stops: in Paris Metro 550 m, in St. Petersburg Metro 1850 m. In Paris lots of 75 m tight curves, in St. Petersburg minimum curvature is 600 m. Some lines have steep sections, others are flat. Technologies introduce difference as well.

I only have data for Moscow Metro (as of 2007). The average power consumption here is 52 W*h per t*km. An average train is about 305 tons, so it is 15.86 kW*h/km.

Top rates you can find for different rolling stock models:
http://en.wikipedia.org/wiki/R142_%2..._Subway_car%29
http://en.wikipedia.org/wiki/E1_Series_Shinkansen
http://en.wikipedia.org/wiki/81-717/714
and so on... See "power outut" in the information box.

Ancien Maestro Jul 17, 2011 2:11 pm


Originally Posted by gfunkdave (Post 16743413)
Hmm, interesting. So using these numbers, a typical train of ~10 cars (as on the NYC subway) would use only about 35 kWh to get the one mile from, say, Union Square to Penn Station? That seems very low to me.

The capital outlay would seem more prohibitive then the energy usage..

It wouldn't make sense to capitalize billions of dollars, ir the variable costs are high as well.

Palal Jul 17, 2011 2:24 pm

Here's an interesting report by UIC on train consumption.
According to this, a Spanish AVE train consumes 13.83 kWh per km.

Palal Jul 17, 2011 2:34 pm


Originally Posted by homelyboy (Post 16743532)
I only have data for Moscow Metro (as of 2007). The average power consumption here is 52 W*h per t*km. An average train is about 305 tons, so it is 15.86 kW*h/km.

Sounds a bit excessive, although the 817/14 rolling stock have DC motors that consume more than AC motors, and also are pretty heavy trains.

NYC Subway is on the order of 3.2 kWh/km (given data from these two pages)

homelyboy Jul 17, 2011 2:52 pm


Originally Posted by Palal (Post 16744946)
NYC Subway is on the order of 3.2 kWh/km

I guess it is per car, not per train?

homelyboy Jul 17, 2011 3:02 pm


Originally Posted by Palal (Post 16744946)
although the 817/14 rolling stock have DC motors that consume more than AC motors, and also are pretty heavy trains.

Well, quite heavy, but NYCS' very modern R142B weights 1923 kg per meter of length, while 81-717 only 1770 kg per meter of length (though being wider!).

Of course, there are some lighter trains around the world...

Palal Jul 17, 2011 3:27 pm


Originally Posted by homelyboy (Post 16745029)
I guess it is per car, not per train?

Yea. Then it's all in the same order of magnitude.

gfunkdave Jul 17, 2011 6:04 pm

Interesting. Thanks y'all. Now I guess the other info I'd like for comparison is the W/km for a given car.

Palal Jul 17, 2011 6:09 pm


Originally Posted by gfunkdave (Post 16745867)
Interesting. Thanks y'all. Now I guess the other info I'd like for comparison is the W/km for a given car.

Check out this article

gfunkdave Jul 17, 2011 6:31 pm


Originally Posted by Palal (Post 16745882)

OK, so about 34 kWh/gallon of gas. A 20 mpg car would yield 1.7 kWh per mile; a 40 mpg car would yield 3.4 kWh per mile. Converting that to km yields:

Code:

MPG      kWh/mile      kWh/km
20          1.7              1.05
40          3.4              2.1

So a generic car is more efficient than a train car? I suppose this makes sense since a train car is much heavier. But trains are, in fact, more efficient because one train car holds dozens of people while an automobile only holds around 5-6 people, and frequently less.

Interesting...

cordelli Jul 17, 2011 6:44 pm


Originally Posted by gfunkdave (Post 16745972)
But trains are, in fact, more efficient because one train car holds dozens of people while an automobile only holds around 5-6 people, and frequently less.

Interesting...

Dozens?

The New York City subway R160's for example used on the J, F, M, Z, L, N, E and Q lines can hold between 230 and 250 depending on which order of cars they were. Metro North M8's, the new cars they are putting on the New Haven line seat either 110 or 101 people (two configurations) and another 30+ can be standing.


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