A Cleaner Freight Train

A typical freight train runs only on polluting diesel fuel, but a new locomotive built by Pittsburghbased Wabtec includes 18,000 battery cells, producing roughly as much energy as 24 of the most powerful Teslas. Like those in an electric car, the batteries recharge every time the train brakes. And slowing down a train hauling thousands of tons of cargo creates a huge amount of energy that in the past was wasted. “That’s free electricity you’re getting back,” says Eric Gebhardt, Wabtec’s executive vice president and chief technology officer. Wabtec’s work on the new technology received a grant from California Climate Investments, a statewide program to encourage reductions in greenhouse gas emissions, particularly those affecting disadvantaged communities. For the past few months, the company has been working with BNSF, the largest railroad in the U.S., to test its Flxdrive Battery Locomotive in a freight train that runs in California’s polluted San Joaquin Valley. This BNSF hybrid is pulled by three locomotives—two diesel, plus one powered by the new battery. As the train runs along the 350-mile track, the batteries recharge twice through the regenerative braking system. Software on the train calculates the best way to run the locomotive

along the route and how much to charge the battery in a rail yard. By reducing reliance on the diesel engines, the new batteryelectric system can cut emissions by 10%, and the train can run in a near-zeroemissions mode when it travels through areas with the worst air quality. A larger version with more batteries can cut emissions by nearly a third, and in the future, it could be paired with hydrogen engines to fully eliminate the carbon footprint. While trains already have a far lower overall footprint than the trucking industry, reducing emissions could entice more companies to choose rail to lower their own carbon footprint.