Goodbye, diesel: California school buses drive toward electric age

An electric school buses charges in Sacramento.The buses require several hours to obtain a full charge and are plugged in immediately after a route. An electric school buses charges in Sacramento.The buses require several hours to obtain a full charge and are plugged in immediately after a route. Photo: Austin Steele, Special To The Chronicle Photo: Austin Steele, Special To The Chronicle Image 1 of / 5 Caption Close Goodbye, diesel: California school buses drive toward electric age 1 / 5 Back to Gallery

The classic American school bus — yellow, loud and trailing diesel exhaust — may soon get an electric upgrade.

Each weekday morning, buses running on nothing but battery packs shuttle students to schools in northern Sacramento and the neighboring suburbs. The vehicles — made by Lion Bus of Quebec, Trans Tech Bus of New York state and Motiv Power Systems of Hayward — are cleaner and quieter than their diesel-burning brethren. Since they spend most of the day idle, recharging isn’t a problem.

“It really fits for school districts, with the way we operate,” said Timothy Shannon, director of transportation for the Twin Rivers Unified School District. “The kids are excited about riding them, because they’re electric and they’re new.”

School districts across California are experimenting with electric buses, drawn by the appeal of exhaust-free driving. They are partnering with state and local government agencies to share the high up-front cost — anywhere from $225,000 to $340,000 for an electric bus, versus $100,000 for the fossil-fuel version — while hoping to recoup some of the money through lower maintenance and fuel bills.

“We want to make sure the (environmental) footprint we leave out there is as minimal as possible,” said Terry Guzman, director of transportation for the Napa Valley Unified School District, which had two of its diesel buses converted to electric. “And with the kids, their respiratory systems aren’t fully formed yet. Diesel’s something we want to move away from.”

Photo: Austin Steele, Special To The Chronicle Richard Thomas, a bus driver in Sacramento for the past 12 years,...

All of the country’s major school bus manufacturers, including Blue Bird and Thomas Built Buses, are introducing electric models.

California officials, who view electric vehicles as weapons against global warming, are starting to funnel money to school districts willing to give buses a try. The Legislature last year approved spending $180 million of the proceeds from the state’s climate change cap-and-trade system on vouchers for hybrid or zero-emission trucks and buses. Another $100 million will go to a program that, among other things, pays to replace old school buses.

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In addition, California utility regulators last week approved a $2.2 million Pacific Gas and Electric Co. proposal to study using electric school buses as, in essence, big batteries that can send energy back to the state’s electric grid when needed. School districts could one day get paid by utilities to use their buses for energy storage.

Many districts have been pursuing cleaner buses for years, and they already have alternatives. The majority of the Napa district’s 56 buses, for example, run on compressed natural gas, which puts out almost none of the tiny soot particles that come from burning diesel. Other buses run on propane. Even diesel buses are much cleaner than they once were: Since 2014, California has required large school buses to have filters to trap most of the soot, although the vehicles still emit smog-forming nitrogen oxide as well as the greenhouse gas carbon dioxide.

The idea of a plug-in bus for students isn’t new. Blue Bird built an early version in 1994, with lead-acid batteries. Napa tried those as well, Guzman said, but they took too long to recharge between runs.

“They wouldn’t always accept enough of a charge for us to know we could safely get to American Canyon and back,” he said. “But the technology with batteries has changed so much, that’s not necessarily going to be a problem now.”

Guzman recently drove one of the district’s newly converted buses — switched from diesel to electric by TransPower of Escondido (San Diego County) — to Lake Berryessa as a test, and found that the bus used less electricity on the trip than he expected, despite the hills. But the two converted buses, which use lithium-ion batteries, have been plagued with electronic glitches that appear to be tied to the vehicles’ motherboards, prompting the district to send them back to TransPower for repair.

“I’m not going to risk having a breakdown with kids,” said Guzman, whose district transports 1,100 to 1,300 students per day. “And I don’t want an $800 tow bill, either.”

With a typical range of about 80 to 100 miles per charge, the current crop of electric buses works well on most twice-daily routes. Longer field trips, however, aren’t a good fit, said Mark Plumb, transportation manager for the Torrance Unified School District in Los Angeles County, whose district also has two buses converted from diesel to electric by TransPower.

“They don’t go far enough for us to use them on athletics, after they’ve run a full day,” Plumb said. “They wouldn’t have the range to take a team out to someplace in L.A. and bring them back.”

Joshua Goldman, TransPower’s vice president of business development, said buses with longer ranges will come, as the technology improves. And he acknowledged that Napa’s converted buses have had bugs. Torrance’s, too.

“We recognize that they’re early adopters of new technologies on hand-built buses,” Goldman said. “And a lot of lessons have been learned on those buses, but we’ve still got a ways to go. ... I’ve been working on heavy-duty (vehicles) for 20 years, and the first ones are always the hardest.”

As battery costs drop, and production of electric buses cranks up, Goldman expects the vehicles to reach cost parity with conventional buses sometime between 2025 and 2030. Jim Castelaz, chief executive officer of Motiv Power Systems, which makes electric power trains that manufacturers can integrate into their buses and trucks, also expects prices to drop. But he isn’t sure parity is necessary for the technology to take off.

Like other electric vehicles, plug-in buses should require less maintenance over time than those with internal combustion engines, he said. And the electricity to fuel them will cost substantially less than diesel.

“It costs one-sixth to one-eighth as much to operate as a diesel bus,” Castelaz said. “I don’t think electric buses need to be the same price as diesel buses. It’s a much better product.”

David R. Baker is a San Francisco Chronicle staff writer. Email: dbaker@sfchronicle.com Twitter: @DavidBakerSF