Most school buses run on diesel fuel, which not only contributes to carbon emissions but also poses health risks due to the many harmful pollutants in diesel exhaust. For example, the landmark Children’s Health Study found that high exposure to particulate matter (PM) hampers lung development and can have lasting health effects that persist throughout life. Later, the Children’s School Bus Exposure Study (2003) found that school bus exhaust increases children’s exposure to PM.
Recognizing the urgent need for cleaner and healthier transportation options for schoolchildren, organizations and activists like the Electric School Bus Initiative, Electric School Bus Coalition, Moms Clean Air Force, and even the American Lung Association have been advocating for the adoption of electric buses.
The vehicles have gained major traction in the U.S. in recent years. At the end of 2022, there were 1,398 electric school buses either operating, delivered to school districts, or on order. By April 2023, there were 5,612 committed electric school buses, according to the Electric School Bus Initiative. These commitments come from all 50 states, the District of Columbia, four U.S. territories, and four tribal nations.
Bloomberg recently covered these efforts throughout the U.S. to replace aging diesel school bus fleets with modern, cleaner electric versions.
Environmental and Health Benefits of Electric Buses
Electric school buses offer a compelling solution to address both the environmental and health concerns associated with traditional diesel buses.
According to Argonne National Laboratory, the carbon footprint of a diesel school bus is approximately 3.3 pounds of carbon dioxide equivalent (CO2e) per mile. This is more than two times the emissions of an electric bus, which emits 1.5 pounds of CO2e per mile when powered by the average U.S. electric grid.
Moreover, electric buses eliminate the harmful exhaust emissions that diesel buses produce. By replacing diesel engines with electric motors, the release of PM and nitrogen oxides is eliminated, significantly improving air quality around schools and for students traveling on the buses.
Electrifying a significant portion of the American school bus fleet—the largest mass transportation system in the country, though not centrally managed—would result in a substantial reduction in emissions and improvements in public health.
Range and Charging Considerations
However, the transition to electric school buses is not without its challenges. One key consideration is the range of an electric bus and its ability to handle different routes. While shorter trips, such as a 13-mile round trip to a local destination, are well within the range capabilities of electric buses, longer field trips may require additional planning due to potential range limitations. Factors such as heating the buses during colder months and consistent high-speed driving can also impact the mileage per charge.
To address these challenges, electric buses are typically charged overnight at the bus depot to ensure a full charge for the following day’s routes. Charging times vary, but typically take around four hours to reach 100% capacity, depending on the amount of charge remaining. Despite these concerns, many morning and afternoon routes can be completed on a single charge.
Gradual Adoption and Increasing Demand
While the adoption of electric buses is gaining momentum, they still represent less than 1% of the school buses on U.S. roads. However, increased demand, technological advancements, and a streamlined supply chain may drive change in the industry, as noted in the Bloomberg story. Many school districts across the country are starting small, with initial purchases of one or a few electric buses. This gradual approach allows districts to test and assess the feasibility and benefits of electric buses in their specific contexts.
For instance, Montgomery County Public Schools in Maryland, one of the largest school bus fleets in the U.S., has plans to operate an additional 240 electric buses by the end of 2024, in addition to the 86 already in service. This significant commitment demonstrates the growing interest in electric buses and sets an example for other districts to follow suit.
Scaling Up: Infrastructure and Financial Support
Expanding electric bus fleets requires careful coordination with utilities to ensure sufficient charging infrastructure and support. School districts like Montgomery County contract with private companies that oversee the purchasing of buses, charging infrastructure management, and utility cost coverage. This collaborative approach can ease the financial burden associated with the initial investment in electric buses and their infrastructure.
To further reduce the cost of electrification, some districts are exploring the option of repowering existing fossil fuel buses with electric systems. These repowered buses can be a more affordable alternative to purchasing entirely new electric buses. A caveat is that repowered buses may not have the same lifespan as new ones.
Financial support from both state and federal governments is playing a crucial role in accelerating the transition to electric school buses. Incentives and funding programs have been introduced to assist school districts in shouldering the costs of adopting cleaner bus technologies.
The Bloomberg story explains that the passage of the Bipartisan Infrastructure Law in 2021 bolstered support for electric school buses. The law’s funding includes the Clean School Bus Program, which has a $5 billion budget through fiscal year 2026, making it the largest single funding source for low- and zero-emission buses. The U.S. Environmental Protection Agency (EPA) has already distributed significant amounts of funding, with plans to continue providing approximately $1 billion annually.
Future Outlook
The adoption of electric buses in school fleets holds tremendous potential for reducing emissions, improving air quality, and safeguarding the health of students.
Although the transition is still in its early stages, increasing demand, financial support, technological innovation, and collaboration among stakeholders are propelling the growth of electric bus fleets.
With continued efforts and investment, electric buses are poised to become the new norm in the transportation of students, paving the way to a cleaner and healthier future.