Union Pacific is moving forward with its hybrid-battery electric locomotive pilot, developed in cooperation with Canadian supplier ZTR. Following testing and proof-of-concept work at the Jenks Locomotive Shop in North Little Rock, Arkansas, the first unit is expected to begin field trials in a live yard environment.
The pilot unit entered testing in 2024 and combines conventional diesel power with a rechargeable battery system. The hybrid configuration allows operation on stored electrical energy or internal combustion, with the battery recharging during diesel use. Depending on use case, the design is projected to lower fuel consumption by up to 80%.
Union Pacific has not disclosed specific technical parameters, locomotive type used for conversion, or battery specifications. The rollout schedule foresees the next unit being prepared for testing in 2025, while the pilot is scheduled to run through 2026.
The hybrid units are aimed at yard operations, where lower average speeds and frequent idling present opportunities for energy recovery and reduced fuel use. ZTR, which provides modular locomotive control and energy systems, is delivering the hybrid conversion package.
Converted units will be evaluated in daily use at Union Pacific yards once the test phase begins. The project is currently confined to a small-scale deployment without confirmed expansion plans.
