Energy Savings of Electric Trains

STRACNET is not an acronym many people are accustomed to rolling trippingly off their tongues, although I think its a really good acronym as far as aggressively brawny military acronyms go ... STrategic Rail Corridor NETwork. Its the Department of Defense designated network of railroads for "Preserving Strategic Rail Mobility".

And the STRACNET is an aggressively brawny thing, or at least when its written up for a DoD-ish audience:

Tell any mechanized maneuver commander he has to fight a battle without his Abrams tanks or Bradley fighting vehicles, and you probably will see a puzzled look on his face that could be interpreted as, "What planet are you from?" or, "What language are you speaking?" Since it is doubtful that a major conflict will occur just outside the gates of Fort Stewart, Georgia, or Fort Hood, Texas, a key element of a successful engagement will be getting combat power wherever it is needed on time.

Without a reliable commercial rail infrastructure, it is doubtful the tanks and Bradleys will make it to their place of business. To make sure they do, the Military Traffic Management Command developed the Railroads for National Defense (RND) Program in 1976. In 1991, the RND Program was assigned to the Military Traffic Management Command Transportation Engineering Agency (MTMCTEA), which now executes the program on behalf of the U.S. Transportation Command. This program ensures that the commercial rail infrastructure in the United States meets Department of Defense (DOD) requirements for deploying a force. The RND Program works to preserve our strategic rail mobility.

And National Defense is precisely what sustainable electrification of STRACNET provides ... the ability to move freight and passengers from coast to coast and north to south, with sustainable, domestically harvested power, is direct defense of our transportation system from resource depletion, supply interruptions, and currency crises.

And, yes, the ability to move Bradley Tanks even if those nasty furriners interrupt "our" supplies of crude oil (that happen to be formally located in somebody else's country) ... that is open to crass, blatantly self-interested appeals to the crude militarism that infests our body politic. In other words, if some self-styled "conservative" opposes this program, "to ensure that the rail transportation that our military depends upon can never be held hostage by foreign oil producers", why, they are obviously not supporters of the military and, indeed, are not supporting the troops. Indeed, that opposition ought to raise suspicion that they are agents of foreign governments in disguise.

OK, but how much energy savings are we talking about here?

Brace yourself. This is discussed in Alan Drake's proposal, previously linked to in Part 1:

The USA has 177,000 miles of railroads, with the Department of Defense classifying 32,421 miles as strategic (STRACNET). These selected rail lines correlate closely, but not exactly, with what are considered "main line" railroads. DoD only selected one rail line when two main lines parallel and a few main lines are not considered strategic. 36,000 miles should cover all of the main lines.

The Pareto Principle (also known as the 80/20 rule) suggests that the 36,000 miles of main line railroad should carry 80% of the railroad ton-miles, and burn 80% of the fuel (there being no electrified freight lines in the USA), or 185,000 barrels/day.

However, this calculation of 185,000 barrels of oil/day saved seriously underestimates the fuel saving potential, especially in an oil constrained future, Transferring just 8% of the truck ton-miles to electrified rail would save another 204,000 barrel/day. Transferring half would save 1,276,000 barrels/day, plus the 185,000 barrels/day for 1,461,000 barrels/day saved (roughly equal to ANWR at its peak, but electrified rail does not deplete - which ANWR inevitably will). Transferring 85% of truck freight to rail, and electrifying half of US railroads, which the author considers to be possible with a large enough investment (see Appendix Four), would save 2.3 to 2.4 million barrels/day. That is 12% of USA oil used today for all purposes, not just transportation.

Just take the mid-line value ... transferring half of diesel truck freight to electric rail, plus the effect of electrifying diesel rail, would save roughly 7% of US oil consumption, or roughly 10% of US oil imports.

And it could be complete, under maximum commercial urgency, in eight years or less. Even taking one year of lobbying to get this into the consciousness of the general public and the political elites ... it could be finished within an eight year Presidential administration.

1.461m barrels of oil a day is 533m barrels annually ... $21b at $40/barrel, $75b at $140/barrel. At a cost of $250b, for the 79mph network, that is an 8.4% return in terms of import savings at $40/barrel, 30% return at $140/barrel. At a cost of $450b, for the 110mph network, in terms of import savings that is a 4.7% return at $40/barrel, 16.7% at $140/barrel.

Now, what about the energy cost ... electricity aint free, after all. Well, here the numbers are even more dramatic:

Transferring freight from truck to electrified rail trades 17 to 21 BTUs of diesel for one BTU of electricity. Simply electrifying existing rail freight would trade 2.6 to 3 BTUs of diesel for one BTU of electricity.

That is, electric rail freight requires between 33% to 38% of the energy of diesel rail freight, and electric rail freight requires between 5% to 6% of the energy of diesel road freight. So the additional electrical energy required is a small fraction of the liquid fuel energy saved. In other words:

Electrifying 80% of railroad ton-miles and transferring half of current truck freight to rail would take about 1% of US electricity.

Rapid Electric Rail

Our rail system at present is designed to carry the heavy bulk freight where the greater energy and labor efficiency of (diesel) rail allows rail to be cost competitive with road freight, even given the fact that the federal funding of freight rail infrastucture is largely YOYO ... You're On Your Own ... while long haul trucks get massive subsidy in the form of a cross subsidy scheme where by more than 90% of road damage is done by heavy axle load vehicles, which pay far less than 90% of the user fees in terms of fuel taxes, and in turn user fees in the form of gas taxes only pay roughly 80% of the cost of roadworks in the country ... which, of course, means that all road vehicles together get a complete free ride on all of the external costs that they impose.

To add insult to injury, as privately owned infrastructure, heavy freight rail is assessed local property taxes, while public roads are not.

This is, indeed, one of the reasons that private railroads have not invested in rail electrification, despite its substantial advantages. Rail electrification is a capital intensive process, and would add a substantial amount to the debt burden of a rail road, as well as to the annual overheads in the form of higher property tax assessments.

So the proposal here is to level the playing field: the rail electrification infrastructure will be owned by a public authority, receiving a perpetual lease from the private owner of the right of way of air rights and the footprint of electrical stanchions and masts. It will sell the power to the railroad for the cost of the power and a user fee.

Now, that's the electric ... where's the rapid?

As explained in part 1, we have been slowing down our rail for decades, now. Rather than invest in more capacity, freight railroads in the past half century have been investing in less capacity. Shippers of heavy bulk freight that is cost sensitive are, by the same token, not time sensitive. They are willing to trade off uncertain delivery schedules for lower costs per ton-mile. One way that railroads have responded has been to replace double track systems with single track systems, that have sidings to allow trains going in opposite directions to pass each other.

And while the "Positive Train Control" (PTC) systems that would allow safer operation at high speeds was first proposed in the US in the 1920's, freight railroad continue to fight it.

So this is the flip side of the deal being offered to the freight railroads. In order to be first in line to get electrification of their existing lines, they must provide a plan to offer new "Rapid Rail" paths in their right of way. This Rapid Rail path features:

• Positive Train Control for all trains in the path
  
• Speed limits of 110mph or more, or else as high as technically feasible within the physical limitations of the right of way
  
• All trains in the path have sufficient crash avoidance capability to share the path with modern lightweight electric passenger trains
  

Now, there are many ways to offer these Rapid Rail paths. The cheapest is to "time slice" the track, setting up the track so that it is allocated to heavy freight for part of the day and Rapid Rail for part of the day, with portions of Rapid Rail specific track, especially around curves where Rapid Rail requires steeper banking than heavy freight. The most expensive is to place double track freight rail and double track Rapid Rail lines side by side.

Where there is a commercial case for it, and where the owner of the right of way agrees to provide a perpetual lease, the public electrification authority can itself construct Rapid Rail lines, charging an access fee to users of the line, and with the  same commercial advantages in terms of lower cost public finance and freedom from property tax as enjoyed by the Interstate Highway system.

Clearly, we do not want to have the public authority building the electric infrastructure in 2012 and then rebuilding it in 2018 in response to the expansion of rail capacity and provision of rail paths. So part of this capacity bidding process involves the presentation of the detailed capacity expansion path, so that electrical infrastructure can be built with the requirements of expansion in mind.

It is clear what the minimum acceptable bid for provision of electrical infrastructure would be: maintenance of the existing heavy rail capacity, and provision of additional Rapid Rail capacity, in a way that allows for reliable, on-schedule deliveries of freight carried on the Rapid Rail system.

What About Passenger Trains

Now, what about passenger trains? First, the Rapid Freight Rail system addresses many of the problems of Amtrak. Rapid Freight Rail paths will be designed to support higher speed operations, and to support more reliable operations for freight that must be delivered on schedule. Second, electrification would allow Amtrak to operate lighter weight, more energy efficient, faster accelerating and higher speed Electric Multiple Unit (EMU) trains, so the reduction in trip times and increase in reliability will come combined with lower operating costs. That means that the same subsidy to Amtrak regional train services can support a larger and more frequent route structure.

Second, there are the range of semi-HSR systems at various stages of planning, from earliest technical evaluation to "ready to start spending real money". The public rail electrification authority will already possess the technical capabilities to plan and build electric overhead and the civil engineering expertise on coping with difficult problems in vertical clearances. So all of the many Rapid Passenger Rail systems will also be permitted to apply to the rail electrification authority to electrify their routes. If they can provide appropriate guarantees on minimum annual access fees, this could also extend to the construction of Rapid Rail train paths for the use of passenger trains, outside of the STRACNET system.

And for true HSR systems, the availability of Rapid Rail paths means that true HSR trains can start running when a given HSR corridor is completed, and then continue on a Rapid Rail path to its destination. Then, each HSR corridor completed leads to a reduction in travel time, and the process of building the passenger base can begin well before the full HSR route network is completed.

What About Sustainable Power?

It could be claimed that the electrification of STRACNET is from "60% to 95% sustainable", based on energy saving over diesel rail freight and diesel road freight. However, we can go further than that.

The US DoE publication, 20% Wind Energy by 2030 discusses the requirements of generating 20% of the nation's electricity by harvesting wind power. Chapter 4 (pdf) of the report covers "Transmission and Integration into the U.S. Electric System".

One common misconception about large scale roll-out of wind-power is the idea that somehow the variability of each wind turbine must be balanced, using some form of energy storage, to create a manageable system. However, at 20% energy penetration, this would be a massively wasteful approach:

Some suggest that hydropower capacity, or energy storage in the form of pumped hydro or compressed air, should be dedicated to supply backup or firming and shaping services to wind plants. Given an ideally integrated grid, this capacity would not be necessary because the pooling of resources across an electric system eliminates the need to provide costly backup capacity for individual resources. Again, it is the net system load that needs to be balanced, not an individual load or generation source in isolation. Attempting to balance an individual load or generation source is a suboptimal solution to the power system operations problem because it introduces unnecessary extra capacity and an associated increase in cost. Hydro capacity and energy storage are valuable resources that should be used to balance the system, not just the wind capacity. (pp. 80-1)

The greater the number of wind turbines operating in a given area, the less their aggregate production variability. (p. 89)

Similarly, as more wind turbines are installed across larger geographic areas, the aggregated wind generation becomes more predictable and less variable. The benefits of geographical diversity can be seen in Figure 4-8, which shows the change in wind plant hourly capacity factor over one year for four different levels of wind plant aggregation. This figure shows the operational capacity factor of wind turbines aggregated over successively larger areas--first over southwest Minnesota, then across southwest and southeast Minnesota, then across the entire state, and finally across both Minnesota and central North Dakota. There is a decrease in the number of occurrences of very high and very low hourly capacity factors in the tails of the distribution as the degree of aggregation increases. A considerable benefit is also realized across a broad mid-range of capacity factors from 20% to 80% (EnerNex 2006). (p. 90)

There are, therefore, two distinct transmission requirements for Wind Power. The first is the problem of "Stranded Wind", where a major wind resource area has far more wind resource than local electricity demand. The second is the problem of interconnecting consuming grids to permit load balancing across a wider area.

One of the problems, of course, is:

Local opposition to proposed transmission lines is often a major challenge to transmission expansion. An AC transmission line typically benefits all users along its path by increasing reliability, allowing for new generation and associated economic development, and providing access to lower-cost resources. Local owners, however, do not always value such benefits and frequently have other concerns that must be addressed. (p. 99)

Which points to the third piece of the plan. Rail lines tend to go to places where people live. And, being ground transportation, transcontinental rail lines have to pass through areas where no so many people live.

And if we are electrifying STRACNET, that means that there will be capital works proceeding all along those rail corridors, bringing project management and work crews all along the rail lines being constructed.

And unlike many property owners, the owner of the right of way would have a direct stake in the provision of transmission corridors, since the railway will be an electricity consumer, once the railway line has been electrified.

Now, railways rights of way do not not always provide the straight as an arrow alignment that would be preferred for a transmission line. However, they do provide one owner to negotiate with, rather than hundreds or thousands, which owner will also be an electricity consumer, and substantial opportunities to share construction and project management costs.

So the third piece of this puzzle is the public rail electrification authority offering the air space over rail right of way for use in providing the Electricity Superhighways that are part of the expansion of wind generation capacity in the US.

Well, so, that's what I want for Christmas

I know that this has been quite a long letter, Joe, but as I noted up top, I'm feeling greedy. Now, its a patient sort of greedy ... I'm fine with the sustainable electric High Speed train being given Christmas 2012, or Christmas 2016, or even Christmas 2020. But that is quite definitely what I want for Christmas.