To an outside observer watching this new train chugging along a track in California’s Central Valley, everything would appear ordinary. But inside a bright-red locomotive near the front, instead of a typical diesel engine, there are 18,000 battery cells—as much energy as 24 Teslas.
Like an electric car, the batteries are topped up with charge every time the train brakes. “That’s free electricity that you’re getting back,” says Eric Gebhardt, executive vice president and chief technology officer at Wabtec, the company that designed the technology, called the FLXdrive Battery Locomotive, the winner in the transportation category of Fast Company’s 2021 World Changing Ideas Awards. Slowing down a train hauling thousands of tons of cargo creates a huge amount of energy, but in the past, it was wasted as heat. The new technology puts it to use to help reduce the train’s emissions.
In a pilot test supported by a $22 million grant from the California Air Resources Board, the state agency focused on air pollution, Wabtec has been working with BNSF, the largest railroad in the U.S., to test the locomotive in a freight train running in the San Joaquin Valley. Because the area is surrounded by mountains, pollution from trucks, trains, and other sources tends to get trapped there, making it one of the most polluted regions in the country.
The train is a hybrid, and also uses two diesel locomotives. But adding the new battery-electric drive can cut emissions by 10%. A larger version with more batteries can cut emissions by nearly a third. As the train runs along the 350-mile track in the pilot, the batteries fully recharge twice through the regenerative braking system. When it pulls into a rail yard, the train can switch off the diesel locomotives to run in a “near-zero emission” mode. Software on the train calculates the best way to run the locomotive along the route and how much to charge the battery once it’s done with its journey.
In Europe, some new commuter trains will run fully on electricity, using overhead wires to charge batteries along the route. The new alternative could work better for freight trains in the U.S. that have to travel longer distances. In the future, the locomotive could be paired with engines running on green hydrogen, rather than diesel, to fully eliminate the carbon footprint of using trains. Trains already have a far lower footprint than shipping goods on trucks, but the industry now needs to go farther. “We’re trying to get it even better,” Gebhardt says. “And that’s where the battery-electric comes in.”