The adoption of zero-emission transit buses in the United States and Canada are on the rise.

In the United States, 5,480 zero-emission buses (ZEBs)—defined as battery-electric or fuel cell electric transit buses—were funded, ordered or delivered as of last September. This is a 66% increase since September 2021, according to a February 2023 report by Calstart, a nonprofit based in Pasadena, Calif., that advocates for clean energy technologies. In Canada, the total number of ZEBs grew to 859, including 219 new full-size buses counted this year.

“Over the last decade, ZEB adoptions have steadily increased across the United States and Canada,” the report’s authors wrote. “The number of ZEBs purchased by transit agencies, universities and private entities has continued to grow as these organizations take advantage of the expanding number of vehicle models available and the advancements in battery-electric and fuel cell electric technologies.”

California has the highest number of ZEBs at 1,977, due in part to a state law that requires that all new transit buses sold must be zero-emission by 2030. The West Coast (California, Oregon and Washington) accounts for 41% of all ZEBs nationwide.

The Federal Transit Administration (FTA) region with the highest growth rate was Region 6—Arkansas, Louisiana, New Mexico, Oklahoma and Texas—with a growth rate of 129% compared to 2021. Texas in particular saw a substantial increase in the number of full-size ZEBs, rising from 100 in 2021 to 271 in 2022.

The median number of full-size ZEBs per transit agency nationwide was five in 2022, while the Los Angeles Metropolitan Transportation Authority had the largest full-size ZEB fleet, with 566 battery-electric buses. The Alameda-Contra Costa Transit District, also in California, has the largest full-size fuel cell electric bus fleet, with 23 buses.

Fuel cell electric buses, while still vastly outnumbered by battery-electric buses, continue to gain traction, with a 64% increase in adoption since the 2021 count. The footprint of small ZEBs—those shorter than 30 feet—has also expanded. The number of small ZEBs in the United States grew by 261 from 2021, representing a 42% increase. Transit agencies in Florida, Hawaii, Illinois, New York and Oregon purchased small ZEBs for the first time.

According to the report, “ZEB adoptions continue to steadily increase year-over-year as transit operators take advantage of advances in zero-emission technology and available funding sources.”

Since President Biden signed the Infrastructure Investment and Jobs Act into law in November 2021, historic levels of funding have been made available for zero-emission transit projects. In 2022, more than $1.6 billion was allocated through the FTA’s Low or No Emission Vehicle Program and the Grants for Bus and Bus Facilities Program. This funding supported investment in 150 transit fleets and facilities throughout the nation, with more than 1,100 vehicles being zero-emission.

A majority (around 63%) of fleets in the United States have 10 or fewer full-size ZEBs, similar to the size in 2012, which suggests that fleets “are having difficulty getting to scale,” according to the report.

“While the number of ZEBs across large transit fleets has increased, most ZEB fleets remain small,” the authors wrote. “There is still a great need for more effort and resources to be devoted to helping smaller fleets overcome barriers to adoption.”