Results from a National Renewable Energy Laboratory (NREL) evaluation of hydrogen fuel cell electric buses (FCEBs) at Alameda Contra-Costa Transit District (AC Transit) in California show that FCEBs have made significant progress toward commercialization, surpassing the U.S. Department of Energy's (DOE's) ultimate technical targets for fuel cell operating hours and reliability.

NREL collects and analyzes transit agency data to validate FCEB performance and cost as compared to DOE and U.S. Department of Transportation (DOT) targets and conventional transit technologies like diesel or compressed natural gas. The DOE Fuel Cell Technologies Office (FCTO) in the Office of Energy Efficiency and Renewable Energy and DOT's Federal Transit Administration fund NREL's evaluations and the results provide feedback and direction to early-stage research and development.

In a recent FCTO webinar, Leslie Eudy, NREL's project lead for FCEB evaluations, reviewed and presented data and accomplishments from several demonstration projects, including AC Transit. This partner operates the largest FCEB fleet in NREL's evaluation project with 13 advanced-design fuel cell buses and two hydrogen fueling stations.

AC Transit shares FCEB data with the NREL team including fuel cell hours, fueling records, and roadcalls. Two results — fuel cell hour accumulation and reliability — have surpassed DOE-DOT technical targets. As of April 2018, two fuel cell systems in AC Transit's FCEBs exceeded the DOE-DOT fuel cell hour ultimate target of 25,000 hours accumulated and all but one bus exceeded the DOE-DOT interim target of 18,000 hours.

NREL measures fuel cell reliability as miles between roadcalls (MBRC). The cumulative fuel-cell-system-related MBRC in AC Transit's FCEB fleet surpassed the ultimate target with 24,200 MBRC as of January 2018. DOE-DOT targets for reliability are 15,000 miles for the interim target and 20,000 for the ultimate target.

AC Transit had another notable achievement — the successful transition of all FCEB maintenance work to transit staff. While maintaining FCEB buses each day, in-house AC Transit staff can anticipate, troubleshoot, and repair issues before they cause an in-service failure. This increases reliability and reduces labor costs as the staff becomes more familiar with the systems, both of which help drive competition with conventional and other zero-emission transit technologies.

Although detailed evaluation of AC Transit's current fleet has ended, fuel cell hours accumulated will continue to be tracked.

View the webinar 2018 Fuel Cell Electric Buses: Progress Toward Meeting Technical Targets.

Learn more about NREL's fuel cell electric bus evaluations.