How US school buses are going electric, in four charts

The single biggest transportation fleet in the U.S. is made up of one iconic vehicle: the school bus. It’s also run almost entirely on carbon-emitting, air-polluting diesel fuel.

Replacing the U.S. fleet of roughly half a million school buses could cut carbon emissions by around 8 million metric tons per year — and that’s not mentioning the benefits to local neighborhoods and the more than 20 million students who currently breathe in harmful diesel exhaust from buses.

In a few short years, thanks in large part to new federal funding, the idea of making the wholesale switch from diesel to electric school buses has shifted from environmentalist fantasy to unfolding reality.

According to recently updated data from the World Resources Institute’s Electric School Bus Initiative, more than 5,600 electric school buses have been ordered, delivered, put in operation or funded through government awards as of December 2022. That’s equivalent to just over 1 percent of the nation’s total school bus fleet — a milestone that shows both how far the effort has come and how much road it has left to travel.

The primary driver of this growth has been the 2021 infrastructure bill, which directed the Environmental Protection Agency to award $5 billion through 2026 for zero- or low-emissions school bus purchases. Last year, nearly 400 school districts were awarded a total of nearly $1 billion from EPA’s Clean School Bus Program to add more than 2,400 battery-powered buses to their fleets.

This flood of federal funding is making electric school buses available well beyond the borders of the states that have traditionally been EV leaders. To be sure, California still has nearly six times as many electric school buses as the next closest states, like New York, Maryland, Virginia and Florida. That’s not only because California is the most populous state, but also because it has the country’s largest and longest-running programs for electric school buses and the country’s most ambitious mandates for cutting emissions from heavy-duty vehicles.

But the nearly $1 billion awarded by EPA last year has brought at least one electric school bus to each of the 50 states plus Washington, D.C., American Samoa, Guam, Puerto Rico and the U.S. Virgin Islands, according to WRI. It has also been put to use by at least four tribal nations, including the Morongo Band of Mission Indians, Mississippi Band of Choctaw Indians, Lower Brule Sioux Tribe and Soboba Band of Luiseño Indians.

The EPA’s focus on serving lower-income, disadvantaged and rural school districts has played a significant role in this geographic diversity. WRI’s data shows how the Clean School Bus Program has funded the majority of the electric school buses that have gone to school districts in low-income areas, rural and tribal districts, and U.S. territories.

The program has also focused on communities of color and districts with high levels of air pollution linked to diesel exhaust. Two-thirds of electric school buses funded by EPA rebates have gone to school districts the agency has identified as being majority communities of color, and deployments have been twice as high in school districts with higher-than-average particulate air pollution as in districts with less polluted air, according to WRI’s data.

Last month, EPA opened the door for applicants to seek a portion of about $400 million more in Clean School Bus Program grant funding. The new round of funding will be opened to competitive solicitations, a different approach than the first round’s lottery system. It will also aim for bigger fleets — up to 100 buses per district, compared to 25 buses for the first round — and will prioritize districts that can demonstrate public or private-sector cost-sharing and a successful track record of operating existing electric bus fleets in an efficient manner.

EPA’s program also allows districts to apply for funding for buses that burn propane or compressed fossil gas, but 90 percent of districts have so far chosen electric school buses. That indicates a strong preference for vehicles that aren’t just cleaner than their diesel-fueled competitors but are entirely emissions-free — and have lower maintenance and fuel costs.

Electric school buses still cost roughly three times as much as diesel-fueled buses, but prices are coming down thanks to fast-improving battery technology and growing manufacturing capacity. The vehicles are now close to cost-competitive with diesel buses in terms of their lifetime cost of ownership. North America’s three largest school bus manufacturers, Blue Bird, Thomas Built and Lion Electric, each have more than 500 buses on order or delivered to U.S. school districts.

Whether electric school buses end up saving school districts money as well as reducing carbon emissions and air pollution depends on a host of factors, including the cost of financing the vehicles, the time and money spent deploying the chargers needed to keep them on the road, and the cost of training drivers and mechanics to keep them in running order.

But a number of financial models are emerging to help school districts manage the upfront cost of electric school buses and the long-term challenges of scaling up their fleets to a majority of zero-emissions vehicles, according to a new report from Calstart, a nonprofit representing vehicle manufacturers, utilities, other corporations and government agencies on clean transportation policy.

Those models can include contracting with electric-bus-as-a-service or charging-as-a-service providers such as Highland Electric Fleets, Nuvve and Zūm.

These ​“as-a-service” businesses can take over some or all of the capital costs and operating responsibilities of the charging-equipment purchase and installation, the purchase or leasing of the buses themselves, or the broader role of managing a school district’s transportation needs. Highland Electric has contracted with Maryland’s Montgomery County Public Schools to deploy 326 buses, the single largest electric school bus commitment in the country to date.

Utilities can also play a role in covering the upfront cost of going electric for school districts, Calstart noted.

Virginia utility Dominion Energy, North Carolina utility Duke Energy and Michigan utility DTE Energy have won state regulator permission for pilot programs that allow them to pay for some upfront costs of electric buses and charging infrastructure and recover those costs through charges on all customers’ bills. Tapping the capacity of electric school bus batteries when they’re not driving could also help cushion utilities from power-grid stresses via so-called ​“vehicle-to-grid” (V2G) technology.

Additionally, repowering old buses — converting them from internal-combustion engines to electric drivetrains and batteries — can cost as much as 40 percent less than buying a new electric school bus, Calstart’s report noted. But at least for now, there are outstanding questions about whether businesses can figure out a cost-competitive way to scale up repowering services. Some significant efforts are underway that could help answer those questions — WRI highlighted a contract between SEA Electric and Midwest Transit Equipment to repower 10,000 school buses to electric over five years.

Both WRI and Calstart highlight the need for increased levels of public funding to meet increasingly aggressive state-level goals for adoption of electric school buses.

Last year, New York passed a law that will require all newly purchased school buses to be zero-emissions by 2027 and all of the roughly 47,000 school buses in the state to be electric by 2035 — a mandate accompanied by a commitment of $500 million in environmental bond funding. Colorado, Connecticut, Maine, Maryland and New Jersey also passed electric-school-bus mandates and funding laws last year, and similar laws are being proposed in Hawaii, Illinois, Massachusetts and Washington state this year.

Exposure to diesel exhaust is known to cause significant health problems and cognitive development impacts, with children being particularly susceptible. The faster that policymakers, school districts and private-sector players can find ways to overcome the upfront cost and complications of making the switch to electric school buses, the more quickly the long-term health and climate benefits will arrive.