California Air Resources Board

Project Goals

Transforming the State school bus fleet to zero-emission is an important component to achieving California’s air quality and climate change goals. Diesel emissions adversely impact individuals and communities, and school-aged children are at higher risk of long-term negative effects from exposure to diesel emissions due to their developing respiratory tracts. Because older, diesel-fueled school buses have less stringent emissions standards, both ZESBI and its predecessor, the Public School Bus Set-Aside, aim to replace the oldest, highest-polluting internal combustion school buses operating in the state. New ZE school buses remove one source of children’s diesel emissions exposure, and help reduce transportation emissions in the state.

Guiding Legislation/Policy Drivers

Historically, CARB has supported school bus emissions reductions through various funding programs such as the Lower-Emission School Bus Program, and Carl Moyer Memorial Air Quality Standards Attainment Program. In recent years, CARB and other public agencies have implemented new funding opportunities such as the Public School Bus Set-Aside and the current ZESBI project to further the goal of a cleaner California school bus fleet.

A primary goal of the State’s portfolio of school bus funding is to ensure that each school district within the state has an opportunity to apply for funding to support the replacement of their school bus fleet. Administered by local air districts, the Carl Moyer Memorial Air Quality Standards Attainment Program represents the oldest source of incentive funding for school bus replacements within California. Funding allocations are in part determined by air district population size, so school districts located within smaller air districts have historically had fewer funding opportunities for clean school bus projects.

Recognizing the inequity of lack of funding to small air districts, CARB began the Rural School Bus Pilot Project for the replacement of old internal combustion school buses with newer, cleaner options, focusing on smaller air districts. The project successfully replaced more than 100 school buses with new ZE school buses and the school districts that received funding continue to experience benefits to their students and communities.

Building on the need for ZE school bus funding, CARB created the Public School Bus Set-Aside to help facilitate the replacement of old school buses with new ZE school buses within communities located in small and medium-sized air districts. The success of Public School Bus Set-Aside, paired with additional state funding appropriated through Senate Bill 114 (Committee on Budget and Fiscal Review, Chapter 48, Statutes of 2023), assisted CARB in creating the ZESBI project which is the most recent school bus incentive program. Having received feedback from participants in previous school bus replacement programs, such as the Public School Bus Set-Aside, ZESBI is available to local educational agencies statewide to support the replacement of old internal combustion school buses with new ZE school buses. Per the direction of  SB 114, ZESBI prioritizes funding for small and rural school districts, school districts serving a high percentage of unduplicated pupils, school districts with the oldest internal combustion school buses, and those purchasing ZE school buses with bi-directional charging capabilities.

Additional information on CARB’s and other state agency school bus incentives can be found in the annual State School Bus Annual Reports. The incentive programs for zero-emission school buses help meet goals set in Executive Order N-79-20, achieve carbon neutrality goals as set forth in AB 1279, and meet the requirements of AB 579, all of which are described below.

The Governor’s Executive Order N-79-20 emphasized the importance of reducing emissions from the transportation sector, and directs on-road medium and heavy-duty fleets, including school buses, to be fully ZE by 2045. The adoption of ZE school buses is particularly urgent due to the adverse health effects of diesel emissions and the increased vulnerability of children to air pollution impacts.

AB 1279 (Muratsuchi, Chapter 337, Statutes of 2022) established the State’s science-based policy to achieve carbon neutrality as soon as possible, but no later than 2045. The California Air Resources Board’s 2022 Scoping Plan Update lays out a comprehensive path to achieve the targets set in in AB 1279 and acknowledges that transitioning the transportation sector to zero-emission vehicles, like ZE school buses, is pivotal to achieving the goals of AB 1279.

AB 579 (Ting, Chapter 445, Statutes of 2023) requires that, starting on January 1, 2035, 100% of all newly purchased or contracted school buses must be zero-emission. This legislation builds upon Executive Order N-79-20 and AB 1279, ensuring the replacement of internal combustion engine school buses with zero-emission school buses to help mitigate the adverse effects of air pollution on children.

Project Funding/Allocations/History

Local Educational Agency School Bus Replacement Grants

*Expected appropriation

HVIP Public School Bus Set-Aside

Funding Breakdown

Project Info/Reports

2023 SB 1403 Report