Full steam ahead for electric freight trains

Electricity is taking over the transportation sector, with batteries replacing fossil-fuel engines in a growing number of passenger cars, big-rig trucks, school buses, delivery vans, speedboats and ferries. Yet one category in particular is only just starting to get on board with battery power: freight trains.

In the United States, tens of thousands of locomotives rumble down railroads every year, pulling cars that collectively carry around 20 billion tons of cargo. All of these powerful engines run on diesel fuel — and, as a result, generate both planet-warming emissions and harmful air pollution that afflicts communities surrounding rail yards and railways.

This week, Wabtec Corp., a rail technology company, took what it says is a ​“major step” toward electrifying this heavy-duty industry.

At a ceremony in Erie, Pennsylvania, Wabtec unveiled the world’s first battery-powered, heavy-haul locomotive that will be used for mainline service. The hulking vehicle has a battery capacity of 7 megawatt-hours, or roughly the same capacity as 100 Tesla Model Ys, the country’s best-selling electric vehicle.

“We’ve been working on this technology for decades,” Alan Hamilton, Wabtec’s vice president of engineering, told Canary Media ahead of the October 31 event. ​“But only in the past five years or so has energy storage technology gotten to the point that you can start to think about how to practically deploy this.”

If widely adopted, battery-electric trains could slash the U.S. industry’s annual carbon dioxide emissions by more than half, while also avoiding roughly $6.5 billion in yearly health costs linked to air pollution, according to a 2021 study by the Department of Energy’s Lawrence Berkeley National Laboratory, the University of California, Berkeley, and UCLA.

“For years and years, people living near railroads have had to breathe in diesel pollution from locomotives,” said Yasmine Agelidis, a lawyer with the environmental nonprofit Earthjustice. ​“But it’s very possible for there to be a zero-emission option.”

Wabtec’s 7 MWh locomotive is a more powerful version of the company’s earlier pilot model.

In 2021, the manufacturer built a 2.4 MWh ​“technology demonstrator” in partnership with BNSF Railway — the country’s largest freight railroad operator — and the California Air Resources Board, which awarded a $22.6 million grant for the project.

Hamilton explained that, at this early stage in their development, battery-powered locomotives function more like a hybrid Toyota Prius than an all-electric Tesla.

Typically, a group of locomotives work together as a ​“consist” to pull all the railcars in a train. For now, the idea is to replace one of the diesel locomotives with the zero-emissions model, which recharges its battery through regenerative braking. Using energy management software, the train then draws energy from the batteries at optimal times or leaves it to recharge and taps the diesel engines instead.

In early 2021, Wabtec and BNSF tested this hybrid approach on tracks over the hilly terrain of San Joaquin Valley in California. They found the 2.4 MWh locomotive helped reduce fuel use by an average of 11 percent over a three-month period. That’s the equivalent of avoiding burning 6,200 gallons of diesel fuel.

“We showed that this technology could be deployed safely within the railroad environment, and it could do so in a relatively reliable manner,” Hamilton said. ​“Now, we’re taking that next step” with the 7 MWh model.

The bigger version is similarly expected to achieve ​“double-digit fuel savings,” although the exact percentage will depend on the geography and climate where trains operate and the weight of the cargo they carry, he said.

Wabtec’s launch customer is Roy Hill, a major iron-ore mining operation in Western Australia. Once deployed next year, the new battery-powered locomotive will help deliver minerals from mines to port facilities in Australia’s sweltering Pilbara region. Wabtec is separately working with Union Pacific, America’s second-largest railroad operator, to build and supply electric ​“switcher” trains for rail-yard operations over the next couple of years.

With trains, as with long-haul trucks, the weight and size of batteries compared to diesel engines pose a major challenge. Engineers must figure out how to install as much battery capacity as possible without making the locomotive difficult or hazardous to operate. They also have to mitigate the risk of thermal runaway, which happens when battery components overheat and feed off each other, causing extremely hot explosions and releasing toxic gas.

Wabtec has designed such safety systems so that its battery-powered model can pull any type of cargo, no matter how flammable or volatile, Hamilton said.

Another key hurdle facing the clean-energy technology is that, right now, U.S. rail operators aren’t required or incentivized to make the switch.

Although California adopted a first-in-the-nation rule on rail pollution earlier this year, the policy is facing litigation from the industry’s top trade associations. In late April, the California Air Resources Board (CARB) adopted short-term measures for reducing nitrogen oxide and diesel particulate matter — along with longer-term rules stating that any locomotive built in 2035 or after will have to use ​“zero-emissions configurations” while operating in California, even if coming from another state.

A separate initiative in Southern California is similarly facing pushback. Proposed regulations to reduce rail-yard pollution may instead be replaced by voluntary agreements with rail companies.

The Association of American Railroads, which is suing CARB in the Eastern District of California, said the agency’s regulations would limit the useful life of existing locomotives, while mandating their ​“premature replacement” with technologies that haven’t yet been sufficiently tested in prototype or operational uses and which aren’t yet commercially available.

“Railroads are working toward reliable, efficient zero-emissions technologies; however, they cannot simply be willed into immediate existence by policymakers,” Ian Jefferies, the association’s president and CEO, said in a June 16 statement announcing the lawsuit.

Proponents of California’s regulations, including Earthjustice’s Agelidis, argue that such measures are necessary to drive investment in less-polluting rail technologies and make solutions available on a wider scale. That includes not just adding battery-electric locomotives but also potentially electrifying rail networks with overhead catenary lines or conductive third rails. About one-third of the world’s track miles are electrified, though America’s freight infrastructure remains dominated by diesel.

“There’s really no reason to backpedal” on policy, Agelidis said.

However California’s policy battles shake out, as the rail industry moves to reduce emissions, companies are likely to use combinations of technologies to haul freight over tens of thousands of tracks. Hamilton said that could include pairing battery-electric locomotives with overhead lines to reduce the demand for the on-board battery packs. It could also mean pairing overhead lines with hydrogen — a technology that’s far earlier along the development curve when it comes to freight trains.

“It’ll be an exciting time over the next decade as these different options start to emerge,” he said.