Railroads might be the most energy-efficient way to move freight in North America, but it isn’t green. The challenge facing North America’s Class 1 railroads is how to build a greener network — and how to do it fast.

Railroads rightly tout the fact that they’re the most energy-efficient way to move freight, a quarter to a third (depending on the study) of the carbon produced per ton of freight by trucks. However, that doesn’t mean rail, especially in North America, is shaded dark green.

“As sustainable as rail transport is now, there is still considerable room for improvement,” wrote the Boston Consulting Group in a 2022 study.

The study on rail sustainability identified four broad categories of improvements necessary for carbon reduction. They are as follows: electrification, improved energy efficiency, more efficient asset utilization, and shifting to renewable energy.

Class 1 railroads have all pledged to reduce their carbon footprint. BNSF (Burlington Northern Santa Fe) said it would cut greenhouse gas emissions by 30% by 2030, from a 2018 baseline. Union Pacific Rail (UPR) said it would achieve net zero by 2050.

For American railroad operators, efficiencies are already being improved and will continue to be. Renewable energy usage in some forms has arrived; others are on the horizon. But catenary electrification will be exceedingly difficult, and railroads remain resistant to the idea. “Electrification of the US rail network is patently infeasible,” said an official at the Association of American Railroads (AAR).

How to Electrify The Least Electrified Rail Network

North American rail has the dubious distinction of being the least electrified large network in the world. Only 1% of rail is electrified, and that’s limited to passenger trains. All freight trains remain powered by diesel locomotives, 24,000 of which ply American rail.

To put it another way, the US boasts a rail network of about 140,000 miles. Electrifying that network would cost an estimated $7 million per track mile or a stunning $980 billion.

American rail’s almost total dependence on diesel is a function of geography, history, and economics. From the beginning, railroads, tracks, and bridges in the US have been privately held and privately maintained. This stands in stark contrast to Europe and Asia, where governments own the rail networks, and could shoulder the higher cost of electrification, compared to diesel. Then, there are the enormous expanses of US land — desert, plains, mountains — with little, if any other need for electricity. “There are a lot of places where you just can’t get the electricity that you would need to be able to run the freight lines that we run,” said the official.

Add to all this the cost of replacing locomotives. A diesel engine, which these days costs about $3 million to $4 million a pop, has an effective lifespan of 30 to 40 years. Plus, many locomotives are rebuilt and installed with upgraded engines or other systems. Railroads are loathe to mothball assets they see as perfectly useable, and there’s no financial incentive for them to do so.

“They are definitely risk averse,” said James Hoecker, an energy lawyer with Husch Blackwell and a former chair of the Federal Energy Regulatory Commission (FERC). “Electrification, once it occurs, could have major advantages both in terms of costs and operations for them. But getting there is a tough sell.”

Hoecker continued: “Clearly the showstopper for them is the cost of investing in infrastructure to support electrification.”

However, Hoecker, for one, believes that the question of rail electrification isn’t necessarily a complete nonstarter. He co-founded the Rail Electrification Council in 2020. One goal of the council is to explore the use of railroad assets, particularly rail right-of-way, to help with next-generation high-voltage transmission lines.

“It would generate substantial long term revenue for railroads, and it could be done without jeopardizing the safety or operations and communications of the railroads,” Hoecker explained. In the process, he continued, “having those electric facilities close at hand offers the possibility that at some point [railroads] could tap into that power and use that as their mode of energy as opposed to diesel.”

Because onshore wind and solar generation is often located in remote locations, access to electricity wouldn’t be an issue.

Hoecker believes an incremental approach to rail electrification is possible, and that it isn’t all or nothing. He cites Europe, which offers flexible use of shared track, as one model.

Tracks to Decarbonization

Meanwhile, a combination of renewable energy sources, including new and experimental technologies, and highly increased efficiencies in everything from software-led utilization improvements to fleet modernization will certainly help in reducing emissions, as will decarbonizing ancillary equipment such as gantry cranes and yard trucks.

How quickly and how thoroughly the industry can achieve carbon reduction is another matter.

“From the line haul perspective, I don’t know that we have a clear line of sight to a zero-emission technology,” said the official, in a frank response. “All of the class 1 railroads are actively investing in and pursuing less and less emissive technologies. They all have very detailed plans for how to achieve their greenhouse gas reduction goals. They just differ a bit from railroad to railroad.”

Like their electric vehicle counterparts, battery electric locomotives have gained high visibility as one low-carbon solution. But development of this technology for trains lags behind their use in cars and trucks. As with EVs, infrastructure support — read charging stations — remains highly problematic and it is likely railroads will look to the government for support.

For trains, questions remain as to just how quickly and substantially batteries can replace diesel. For the next few years, at least, battery electric locomotives will be used in switching yards or as a hybrid technology, in concert with diesel on long-haul.

Even more uncertainty swirls around hydrogen fuel cell trains. Canadian Pacific began testing a hydrogen powered locomotive late last year in Calgary and its CEO promised hydrogen fuel cell switching trains will be installed in Calgary, Edmonton, and Vancouver by the end of this year.

However, hydrogen fuel cell technology in general, especially that using green hydrogen, has proven extremely expensive and difficult to implement. An article by the trade publication Hydrogen Insight in early August revealed that the most developed hydrogen-powered rail network, in Lower Saxony, Germany, is halting any expansion. State-owned LNVG installed 14 fuel cell-powered passenger trains last year. According to Hydrogen Insight, LNVG announced that an upcoming tender for replacing more than 100 diesel engines would, rather than continue with hydrogen, instead call for battery electric propulsion.

A much more immediate non-polluting energy source is biofuel. Last year, Union Pacific, for one, began testing biomass fuel at a sand and gravel mine in Southern California. The goal, the railroad said, “is to determine the feasibility of using a blend of 80% renewable diesel and 20% biodiesel in Union Pacific’s fleet.”

Incentives to Go Green

Washington can certainly help streamline the process with subsidies and incentives. Again, Europe is a model. According to the Boston Consulting Group study, the European Union has earmarked an impressive €260 billion in rail transport investment. The EU wants to substantially increase the share of freight shipped by rail from 17% of total within EU borders to 30% by 2030.

“Governments will be central in providing the policies, funding, and incentives needed to sustain the industry’s growth,” said the study. “Policies and plans at the national level are needed to promote rail not just as a more efficient and sustainable transport mode but also to meet national sustainability targets.”