Electric school buses lose one-third of range in cold weather

Advocates of electric vehicles depict he electric school bus as the future of school transportation. An op-ed this week in The Detroit News went so far as to claim these buses “boost learning” among students. But the federal government admits that electric school buses can lose one-third of their range in cold weather — with cold defined as 25 degrees Fahrenheit.

The Environmental Protection Agency says electric buses can even empower the grid during a power outage. That’s one of the reasons it has poured $5 billion into the Clean School Bus Program, to transition school buses from diesel to electric. Michigan plans to spend $125 million from that fund in 2024, and this will buy just under 350 buses.

But that claim is questionable where cold weather is involved. Michigan is a northern, cold-weather state.

The U.S. Department of Energy last November issued a piece of technical guidance to buyers considering electric school buses, called “Cold Weather Impacts on Electric School Buses.”

“ESBs (electric school buses) are proven to operate effectively in cold weather; however, cold temperatures will impact their range and efficiency. School bus fleets can effectively manage these impacts on ESB operations by considering effective safeguards during deployment planning,” the guidance read.

The Department of Energy says 55 degrees Fahrenheit is an ideal temperature for a school bus. Without the need to warm the bus itself, the bus “can utilize all or most of the batteries toward propulsion of the vehicle to achieve peak driving ranges,” it explains.

It’s when temperatures drop that problems set in.

“The energy used by ESB electric cabin heaters is second only to the energy used to propel the vehicle,” the guidance explains, citing a 2022 study. “This energy need also increases as temperatures drop. A battery-electric transit bus study showed range decreased by 33% when air temperature was 25°F, a 30-degree decrease from its ideal conditions of 55°F–60°F.”