Energy consumption of a class of existing and proposed high-speed passenger trains in Sweden has been already number crunched by
Ostlund, S., "Performance of future regional high speed trains," Railroad Conference, 1998. Proceedings of the 1998 ASME/IEEE Joint , vol., no., pp.21-28, 15-16 Apr 1998.
Stefan Ostlund's affiliation is with the Railway Group of the Royal Institute of Technology (KTH) in Stockholm, Sweden.
Everything in that paper is metric and electric -- I will use the 85% transmission efficiency of the catenary given in the paper, assume 40 percent thermal conversion efficiency of fuel BTUs (low-heat value) into electricity of modern power plants, and a conversion of 1.6 kilometers to the mile. The paper assumes stops every 30 km, not much different from the Hiawatha train. The paper also assumes an average load factor of 40 percent -- somewhat higher than the Hiawatha, but well below the high load factors that require airline-style trip-time bargaining.
kWHr/Pkm BTU/PM P-MPG
Hiawatha 2240` 56 (my estimates)
Sweden InterRegio .13 2080 60 (from Ostlund)
Sweden X-2000 .1 1600 78
250 km/Hr EMU .096 1667 81
250 km/Hr EMU 2+3 seats .076 1216 103
160 km/Hr EMU .051 816 153
The proposed EMU (electric multiple unit) train of Ostlund is operated at either 250 km/Hr peak speed (about 150 MPH) or 160 km/Hr (about 100 MPH) in this comparison. The 2+3 seats indicates raising the seating from 4-across to 5-across as is common on Japanese trains and on US East Coast commuter trains. The 150 MPH trains averages 98 MPH stop-to-stop and the 100 MPH averages 76 MPH. The current Hiawatha averages 54 MPH.
Ostlund's proposed train has reduced resistance (presumably through streamlining) than the current X-2000, but the paper does not quote drag coefficients for either train. The proposed train is lightweight -- about 95,000 lbs per MU car, including the propulsion system, which is comparable to recent designs in Japan. The train approaches about 1200 lbs/seat, in contrast with the 2800 lbs/seat of the Hiawatha. The assumed 40 percent load factor is somewhat higher than current Hiawatha load factor.
The Swedish trains are also electric with the advantages of the broader set of fuel sources of electric power compared with the liquid fuel required for a Diesel train, although the liquid fuel could in concept be made from coal, for comparison with electricity made by burning coal. The Ostlund trains, however, benefit from regenerative braking to recover the energy required to accelerate the train that is not recovered by the Hiawatha train.
Based on these data, it may be reasonable to assume that a high-speed train could have 2-3 times the passenger-MPG of an equivalent airline service. This improvement is substantial, but it is somewhat less than the factor of 10 that someone quoted. The fact that the energy is electric instead of petroleum fuel is significant. Also important is that the trains reduce energy usage through streamlining, MU cars in place of locomotives, light weight, and electric regenerative braking. The high-speed short-distance service means less time on the train, but the service experience is closer to airline seating, although perhaps with more legroom, than to the expectation for US long-distance trains of offering private sleeping cabins, dining and lounge car.
If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?
My recollection was that Sweden got about 40% of its electricity from hydro, 40% nuclear and maybe 20% fossil fuel.
As you said, one advantage of electric operation is a broader selection of fuel sources, and probably a more efficient use of fossil fuels. The latest combined cycle plants are capable of 60% thermal efficiency, and while a typical coal plant is doing well to achieve 33% efficiency, that is still probably more efficient than trying to convert it into a liquid fuel.
On the thermal efficiency of electric power generation, that 60 percent number for combined-cycle is for natural gas fired -- coal-fired combined cycle is somewhat lower. Also, if I remember correctly, that 60 percent efficiency on natural gas is for the low heat value (LHV), and the efficiency is reduced if you account for the high heat value (HHV).
On account of its high hydrogen content, natural gas has the largest spread between LHV and HHV on account of the large water vapor content of the combustion gases and the large latent heat of condensation of that water vapor owing to the polar bond of the water molecule. The difference between LHV and HHV of natural gas is typically the difference between an 80 percent efficient gas furnace and a 95 percent efficient "condensing" or "high efficiency" gas furnace. Home furnaces typically work off the HHV because there are the more expensive furnaces that condense the water vapor in the combustion gases to extract that extra heat at the expense of a furnace that needs to be corrosion resistant. Power plan efficiencies are often quoted for the LHV because it is not practical to extract heat from the combustion gases at the temperature at which water condenses at atmospheric pressure.
The most recent generation of coal-fired steam power plant using what is called an ultra-supercritical steam cycle gets 40 percent efficiency from the LHV of coal. They have them in Europe, Japan, and one in Canada. Don't know if we have any in the US. The price of coal and the current environmental restrictions may not require such a plant here and the electric power utility people here are a stodgy as railroad people when it comes to new tech, and the environmental people have better lawyers here than in any other country, and it is really hard to get any kind of coal plant built. We say we are against Kyoto and the Europeans are for it, but the Europeans will build a coal-fired electric plant if they need it using the highest available efficiency and environmental controls, but coal-fired plants are barely getting built here, even though there is substitution of electricity for oil in parts of the economy.
Integrated gasification combined cycle (IGCC) coal plants are the next big thing on account of environmental controls and possiblity of CO2 storage, but they are still a very experimental thing even "over there" in Europe in Japan. Their thermal efficiency is nowhere near the 60 percent (relative to LHV) of natural-gas fired on account of the heat consumed in converting coal to gas.
Even taking the LHV/HHV difference nto account, the combined cycle plants are still ~55% efficient. Other than heating, I can't think of many applications that could make use of the HHV, the combustion products of methane would have to be cooled down to ~140F to get condensation.
IIRC, the efficiency of modern US coal fired plants are limited by the pollution control systems, otherwise achieving 40% efficiency would be relatively easy. One advantage of the IGCC is that most of the crap in the coal is cleaned before the resulting gas is fed to the combustion turbine, and therefor not a lot of energy is needed to clean up the exhaust. I seem to recall that it is also relatively easy to get an almost pure CO2 stream from an IGCC, would wouldmake sequestering the CO2 less energy intensive (e.g. pumping the CO2 into a depleted natural gas reservoir).
Some breeder reactor proposals from the late 60's were aiming for a 44% thermal efficiency with supercritical steam pressure and temps of 1050 to 1100F - no stack losses. The prjected temperatures and efficiencies were scaled back when it was found that the resulting cladding temperature caused problems with swelling due to fast neutron damage.
Getting back to IGCC versus Coal to Liquids. I would contend that one could get significantly more useful energy (e.g. energy delivered to the rail) using IGCC and electrification as opposed to running diesels or combustion turbines on liquid fuels from coal. On the other hand, coal is cheap enough that the overall costs may favor the coal to liquids approach.
Maybe OT: As far as biofuels are concerned - we'd be much better off with PV - which again favors electricified railroads for long distance travel, but battery operated cars would be fine for short distance travel. (And yes, I am ignoring the issue of energy storage needed to make PV workable on a large scale.)
(added comment). I'm wondering what's the underlying concern with energy consumption? Is it the amount of petroleum consumed, the amount of CO2 produced or something else? As long as the competing modes of transportation rely on petroleum, comparing BTU's per passenger-mile is entirely vaild (and simple). If some modes start operating on electricity (electrification for RR's, batteries for cars), then comparing by BTU becomes more complicated.
With respect to the Hiawathas, a 5-car train (all-coach) has 340 seats for peak demand for #330 and #339. Averaging 100 passengers per train from recent Amtrak data results in a load factor of only 33% for the service as a whole. Assuming the peak trains average 310 passengers, the resulting average load of the other trains is only 65 passengers. Notwithstanding the traffic between Milwaukee and Chicago; you have to wonder if it's worth making half the runs.
I've said before that one deterent seems to be Amtrak's fare strategy. A 1/3 reduction in the 1-way fare to roughly $14 may double ridership. It's roughly as cheap as gas, let alone for parking and tolls. At 180 miles round trip, 25 mpg, and $4/gal (higher in Chicago), gas for the trip costs $28.80. Realistically, anyone taking the train has expenses for parking, bus, Metra, or taxi.
Another problem is the capacity crunch on Metra generally; and the Milwaukee North is no exception. So far, Metra has managed to co-exist with a 7:57am arrival and a 5:08pm departure at Chicago. I question whether a 7:30am and 8:30am arrival or 5:30pm departure could be accommodated that would serve substantial demand cut off by the current schedule. This assumes equipment would be available.
One strategy would be to run "Amtrak" cars as part of a Metra express that would continue to Milwaukee. For 25 miles, the train could carry 1,100 passengers, 840 Metra seats and 360 Amtrak seats, in 10 gallery cars with an Amtrak P42 for the extra horses. This works out to a respectable 992 lbs per seat and 1,082 lbs per passenger.
Fuel consumption may be higher than for the existing Hiawathas with more time in accelerating and more power for maintaining the limit; but this is mitigated by sharply higher number of passengers, even for a third of the distance.
More later.
More on Hiawathas.
My Idea of running combined Metra-Amtrak Hiawatha peak trains has a number of interesting aspects.
Two additional trains in both the morning and evening rush periods may capture 400-500 more commuters presently prevented by schedules that arrive too late or depart too early. This estimate is based on the volume of commuters entering the Loop by half hour period This may divert a small percentage of current riders to a following or preceding train.
Because of train length, capacity, and Metra compatibility, gallery cars (like the Bi-Level 400's) with 90 high-backed, reclining, folding tray seats and accessibility lifts would be preferrable to the Horizon cars. Anyway, Amtrak equipment is in short supply; so using Horizon cars may be moot. A 62-ton Horizon car with 68 seats comes to 1,529 lbs per seat while a 67-ton gallery car with 90 seats would come to a slightly lower 1,489 lbs.
Since rush hour traffic for Chicago and Milwaukee is offset by the running time, existing equipment could be used for trains from Madison and Chicago to Milwaukee and continuing to the far terminal. With better pricing, lower volume midday and reverse-commute trips may be viable. Operating outside the peak period, scheduling should pose little conflict.
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