Clean diesel grants

Transportation is the largest source of climate pollution in Washington, accounting for nearly half of total greenhouse gas emissions. Diesel exhaust is responsible for 70 percent of Washington’s airborne cancer risk. The Governor and Legislature are leading policies and initiatives to reduce impacts from climate change and improve public health by accelerating the transition from fossil fuels to a zero emission transportation system. Clean diesel grants will reduce greenhouse gases and protect people from toxic diesel emissions. This grant's primary purpose is to electrify school buses. It also supports idle reduction and other diesel equipment engine replacements.

Funding cycle

  • Amount of funding available: Varies – see individual grant guidelines for eligibility
  • Grant award limit: Varies – see individual grant guidelines for eligibility
  • Amount of matching funds required: Varies – see individual grant guidelines for eligibility

Applications are currently being accepted.

Open and future grants

Grant Application materials Application
due date
Award notifications
Air Quality Clean Diesel Grant Program 2024–2025 (diesel marine engines and training pilot programs)

April 10, 2024 – June 13, 2024

Third quarter 2024
Air Quality Clean Diesel Grant Program 2024 (electric yard trucks, round 2) available by third quarter 2024 Third quarter 2024 Fourth quarter 2024
Air Quality Clean School Bus Grant Program 2023–2025 (round 2)
We are having technical problems, and this grant’s application process is currently unavailable. We are working to fix the issue as soon as possible. Thank you for your patience. [6/12/2024] 
May 15, 2024 – August 15, 2024 Fourth quarter 2024

Closed grants

Grant Application materials Award notifications
Air Quality Clean Diesel Grant Program 2023–2025 (fuel cell transit buses and zero emission yard trucks) First quarter 2024
Air Quality Clean School Bus Grant Program 2023–2025 (round 1) First quarter 2024

Funding is available for the following entities:

Air Quality Clean School Bus Grant Program 2023–2025

Air Quality Clean Diesel Grant Program 2023–2025 AND 2024 (electric yard trucks, round 2)

  • Businesses (2024 grant program only)
  • Cities
  • Counties
  • Local clean air agencies
  • Non-profit organizations
  • Ports
  • Public utility districts/co-ops
  • School districts
  • State government
  • Transit authorities
  • Tribes

Air Quality Clean School Bus Grant Program 2023–2025

  • Scrap and replace diesel school buses with zero emission school buses.

Air Quality Clean Diesel Grant Program 2023–2025

  • Scrap and replace diesel yard trucks with zero emission yard trucks
  • Scrap and replace diesel transit buses with zero emission transit buses

Air Quality Clean Diesel Grant Program 2024 (electric yard trucks, round 2)

  • Scrap and replace diesel yard trucks with electric yard trucks

Air Quality Clean Diesel Grant Program 2024–2025

  • Scrap and replace diesel marine engines with all-electric or hybrid electric system
  • Vocational training pilot programs to:
    • Train school bus mechanics, bus drivers, and office staff about the maintenance and operation of zero emission fleets
    • Prepare high school students for jobs created by transitioning diesel/fossil-fueled fleets to zero emission fleet

More information about this funding program