Future Trends in Rail Fuel Efficiency
The following is from pages 101 to 103 of the Federal Railroad Administration Report Comparative Evaluation of Rail and Truck Fuel Efficiency on Competitive Corridors Dated November 19, 2009.
Long-Term and Speculative Developments
A number of longer term and speculative technology and operations developments could be applied over the next 20+ years to improve fuel efficiency of freight railroads and to facilitate the use of alternative power plants, alternative fuels, and renewable energy sources. Not all these developments would necessarily improve fuel efficiency, but all would affect the mix of energy sources and consequently the fuel efficiency and carbon footprint of freight (and passenger) railroads.
Locomotives operating on electrified railroads draw electric power from an overhead catenary or a third rail for traction. The technology for electric locomotives and power distribution systems is very well established, and there are numerous electric railroads throughout the world, used for all types of rail service from high-speed passenger to heavy-haul freight. Indeed, a heavy electric freight locomotive will be very similar to a diesel-electric locomotive, with the primary difference being that a transformer will replace the diesel engine and alternator. The usual choice today for a new main-line electrification project is to energize the catenary at 25,000 volts, 60HZ AC, and third rail low voltage DC electrification is typically used only in subway and commuter passenger rail systems.
Advantages of Electric Traction
The locomotives are non-polluting at the point of use, and can contribute to air quality improvement goals in the locations where they are used. Overall Green House Gas (GHG) emissions may or may not be reduced depending on what fuels are used at electric power plants; (Energize Northwest electricity will be GHG free.)
Once the electrification is in place, operating and maintenance costs may be reduced significantly. Depending on the energy source, electric power may be cheaper than diesel, and electric locomotives might need less maintenance and are more reliable than the diesel equivalent;
Braking power can be fed back into the catenary, to be used by other trains in the vicinity or stored by wayside power storage devices for later use. Wayside energy storage may also be useful if the railroad relies in part on intermittent power sources such as solar or wind.
In spite of these potential advantages, mainline freight railroads in the U.S. have not been electrified. The primary reason has been that the financial case has only been attractive during periods of high petroleum prices. In addition, there is the difficulty of funding the very large capital investment required, much of which must be done in a single project. Full benefits are only realized after a critical mass of electrified territory is in service. However, the financial and policy advantages of electrification are becoming stronger, with the likelihood of sustained high petroleum prices and concerns over GHG emissions and the volume of oil imports. In addition, rail traffic density on principal main lines is much higher than in the past. Electrification economics improve markedly at high traffic density, where the largely fixed cost of the catenary and power supply is supported by a greater volume of traffic.
The principal technical challenge of implementing main line electrification in the U.S. is arranging for power supplies to trackside. An electric railroad using 25kv overhead power supply requires a substation approximately every 40 miles. Many main lines, especially on western railroads, run through sparsely populated territory remote from major transmission lines. One solution is to construct the transmission line along the railroad right of way, above the contract catenary. This solution is far from new – the Pennsylvania Railroad provided a transmission line (which is still in place) above the railroad when electrifying between New York and Washington DC in the 1920s and 1930s. There is some opposition to the concept of overhead transmission lines because of derailment potential, as well as track maintenance and signaling issues. (Or we could bury superconducting transmission lines along side the tracks. ENW)
The second issue is the quantity of power needed and the fuel source used. A rough calculation suggests that the BNSF Railway main line from Chicago to Los Angeles (a leading electrification candidate) would consume about 1,500 MW, the equivalent of about three large conventional power plants. (or one large nuclear plant. ENW) New capacity would be needed, requiring numerous decisions regarding plant size, type and location, sitting of transmission lines, how to best minimize carbon emissions etc.
Fuel Cell Locomotives
Fuel cells have obvious potential for railroad locomotive applications. As in other transportation applications, the advantages of fuel cells are that there are no greenhouse gas or other emissions at the point of use (assuming hydrogen fuel is used and the locomotive does not have an on-board reformer to convert a fuel source, such as natural gas, into hydrogen fuel), and overall thermal efficiency is better than an internal combustion engine. The disadvantages are likewise similar: high cost, on-board storage of a hazardous fuel, and the inability to quickly increase or decrease power output.
The most current development is by BNSF Railway, which plans to convert a “Green Goat” hybrid switching locomotive to fuel cell power. If this experiment is successful, then further developments leading to a production fuel cell locomotive could follow. Railroads are likely to be followers rather than leaders in fuel cell applications. If the cells and associated systems are available from developments outside the rail industry at a competitive price and performance, then rail applications will likely follow.
The combination of PTC, comprehensive on-board monitoring and diagnostic systems, and in-cab video cameras means that fully automated train operations are technically possible. Almost all train crew functions can be performed remotely, the exception being occasional en-route repairs, such as replacing a couple knuckle, performed by the crew. Automatic operation is being used today on a couple of short, dedicated coal mine to power-plant lines, and is used on many metro systems around the world. Conventional freight railroad applications will likely develop in stages, first reducing train crew to a single person (common on passenger trains and many European freight trains), then eliminating the in-cab crew entirely on selected route segments. Fuel efficiency benefits could result from the precision of automated operation, but would likely be modest.
Dedicated High Performance Corridors
At present, railroad main lines carry a mix of traffic types, with the inevitable inefficiencies that follow from operating a mix of trains with different acceleration and braking capabilities and top speeds. As traffic becomes more concentrated on key corridors and capacity is added in the form of additional running tracks, opportunities grow to dedicate one track or a pair of tracks to one type of service, for example intermodal service or coal unit trains. Where parallel routes exist, specific types of traffic can be concentrated on each route.
The fuel efficiency benefits follow from a reduction in train delays due to conflicts between different train types and the opportunities to run the railroad in a highly disciplined “conveyor belt” fashion. Other benefits include quicker and more predictable customer service, better asset utilization, and the ability to optimize infrastructure, trains and operations without having to accommodate multiple train types. While it will likely take 20 years or more for a true high performance freight corridor to emerge in the U.S., some of the building blocks can be observed today. Dedicated mineral railways such as the iron ore railways in Northwest Australia achieve tremendous productivity, far ahead of any multipurpose railroad. Netherlands Railways has built a dedicated freight line from a point near Rotterdam to the German border, primarily for containerized freight to and from the port. The Alameda Corridor in Los Angeles, though shorter has a similar function.
In Washington State, long range plans for passenger service envisage a dedicated high-speed passenger line parallel to freight lines in the corridor between Seattle and Portland. A third running track has been added in very high density freight railroad route segments in several locations around the U.S. (With a separate electrified passenger track, automated single rail cars could carry people between Seattle, Tacoma, Olympia, and Portland every 30 minutes.There is much talk about building high-speed, like 200 mph, rail system from Seattle to Portland. Building right-of-way for this speed is very difficult and expensive. We think if you ask prospective riders which they would rather do, wait two hour for a train that can make the trip in under an hour, or wait 30 minutes for a train that can get them there in about an hour and a half, they will choose the latter. ENW)
The above is copied from pages 101 to 103 of the 156 page report
Comparative Evaluation of Rail and Truck Fuel Efficiency on Competitive Corridors
Dated November 19, 2009
Prepared for: U.S. Department of Transportation
Federal Railroad Administration
Office of Policy and Communications
1200 New Jersey Avenue SE
9300 Lee Highway
Fairfax, VA 22031
Link to the full report.